Releases / 3 / NASA-UAP-D015

Astronaut Scientific Debriefings, 1962-1963

File

NASA-UAP-D015

Type

Document, 216 pages

Agency

NASA

Date

1962-1963

Released

Release 3, June 12, 2026

Open the original on war.gov

The government's description

This file contains memoranda, correspondence, reports, and other materials relating to contemporary scientific interest in investigating the nature of luminous phenomena reported by astronauts John Glenn and Walter Schirra during spaceflight. This collection includes transcripts from NASA interviews and debriefings with both astronauts regarding those observations. It also contains details relating to scientific observations of atmospheric phenomena, including brief descriptions of luminous particles, experiences while aboard spacecraft, and circa 1955 theoretical analysis of meteoric particles entering the atmosphere. Pages 34-35, 55-56, 57-63, 64-113, and 122-127 feature content relevant to the PURSUE initiative.

sessevs & Little bit, my skin waswt and it didn't stick the way it had stuck
when we tried it out in the trainer and in the capsule on the pad and I finally
gave up on it and just kept one eye shut. ‘This is marginally satisfactory, I
| guess, but I was not well nighted after coming up to the first night. There's
| @ wedundancy here but you eure do have the right information or cases co's
|
|
few of these will be repeats. Now lets start out with the conditions of
|
L dark adaptation.
Well, most of these things that we had plenmed to look into if we could
on Seeeeny sae Sieg ae eae aOR 2 RN te Sho guid wt te
Cape that we didn't get mpx more(done that we had planned to do but es I
é.
think most of you are aware, at the end of the first orbit we start, having
some difficulty with control systen ofa {from then on it was pretty mch systens
monitoring with some locking around outside and that was it. So a lot of the
SOE Ee ER OHMS OD 6 Dae oe OE Maps X bat tegen 16 hotns
I was going to try to use it over one eye so that
I yes night efepted. I was sveating a little bit, my skin was vet, it didn't
Stick the way 1t had stuck when we tried it out in the trainer and in the
capsule on the pad, gid I finally gave up on it and just kept one eye shat.
This is marginally satisfactary I guess but I was not well night adapted
coming up to the first night. What it boils dowm to is that my dark adaptation
{
me
vas just a result of the sun going dow and emt normal dark adaptation fron
being on red light and dim light which takes some 10 to 15 minutes to get any

#

2 J

Gegree of adaptation out of. ee ee re

ste Xeli. gnnt tht puke nlliicds dill aid agi i sige sha
when I'€@ be well night adapted |at the end of the periog,, This is come Bi 37
mimites later vhen you're approaching sunrise so you'd have @ -- I suppose
Sanuk sales aed: Saouais ‘ia slide seiilideg “Ugins sicheceads dk see a half
hour, 33 minutes, something of that order.

DLs you have wn cgpoviadidtey te deunt the sbicet

Mo, this is one of those things that went down the drain. I thought
about this on a subsequent orbit but I didn't spend any time on it. I feel
thet my vieton, the numbers of stars I could see was not apprecishly increased.
How, I had expected to see a ict more stars. I hed thought they'd really =
dump out once you got above the atmosphere but I--like it was in debriefing -
x tent bk the enn, een tothe bined oc'cdelk Mai Rina wk ns
air is very clear and dry, sx@ You know what it is Like out around Reno and
sone of those places; how the sky really comes out si night end you can/sce

@ million stars. gai thats what it locked like. It @idn"t look like eny more

WO-RI-AN, CAS“1-0-FIA, and vhet wes the other one-<it was off a little
triangle area by SERIOUS off 0-RI-AN. We had those three areas lined up and
it was just--I was doing systems monitoring at that time rather than counting

3
sters. But a general impression of looking cut at these areas was that the
muibers of eters I could see vas not greatly increased.
You mention the tranamission through the glass be comparable ... to the
atmosphere. That's something you people can check.”
That's right.
¥ senate, teva Veni omniliad of Wee Xintes hak Sos teh we peeneiy
would not see too many more stars because the trenmiission of light through
the window is cut dow by 27 per cent or something like that. The figure
thet they came up with was almost identical to what people have computed the
atmospheric attenuation of light is. So they felt that when we got above the
atmosphere it would probably be about the same looking through the window as
it ie locking through the atwosphere here, and I think they were just about
right. It locked to be about the sane to me.
I think it might be wise for you to read the next 3 or 4 parsgraphe.
IL think a lot of these are going to be real quick enewers, so why don't u
you get to it.
‘Did you see Magellanic Clouds? No. Andromeda Nebula? No. low
aid the moonlight effect your ability to see faint eurfece areas?
WM Tremendously. We hed moon oltte«almost full moon. You can lock et this
6 tas weve, (0S 20 ean 6 tometinennd tmidmings te t6 8 2 treeentons
edventege. I prefer to think it was en advantage because 1t did provide a
visual capebtlity on the clouds--on the dark eide which wae sufficient that
no
I could use it for a EAR reference where it might have been questionable
whether I could do that otherwise.

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This didn't seen to be any problem. Looking up fairly close to the moon,
’ I would guess a--counting a mumber degrees probably, you could see right up
to the edge of the moon. The stars would be visible right up--very close, its
not Like it i¢ when-|you bru MG woe Sun Me relhe aera ]

Pahiy faint stars?

Yes, I think so, just like the other+-the whole field of stars you're
locking at, you came up end--the only way, when you swing the capsule around
and you'd be approsgching ZHAX area where the moon was, you could tell it
beeause there would be moonlight coming in the window and you would see the
light moving across on the capsule. TMM Thats the only way you would know
that you're really coming close to the moom. You didn't know 4t by the sky
getting & real light ea you come to the moon like you do here. There was 4

a
little area sround it where this was true. It wasn't just/comlete cutoff,

but 1t was nothing like the buildup we have here where you are looking through
the etuosphere and get ell this) .

Any Comets?

No. Ho comets. I used the first sunset. I hed this little polorcid
filter out were were going to use so that we could lock directly at the sun.
This, while I think of it, this was another thing that was rather surprising
to me. The sun is not as blinding as I thought it would be. I told the people
in debriefing down there after experimenting very carefully with this a
Little bit, I looked directly at the sun with the naked eye just as you would
ao here. You've locked up and squinted so that you have really shielded your
sven sok Reith anseatagy ith ale Mittin Mibide od Sank tinea. And

6

this was very similar. You do the some thing there and I had no~-there was
no problem with the eyes. The light though, it was very noticable. The
light was a very brilliant clear, white light and what 1t looked like coming
in the window and the vay it looked on the suit~<-the best thing I could
relate it to were the are lights, the brilliant search light are lights thet
they have down at the Cape that are out on thebad at might. Its that type
brilliant white light coming in-<very bright. And it was warm enough that
i remember commenting, I put it on the tape I believe at one time that riding
along the sun was coming in end it was over on my right am and I commented
about my right arm getting appreciably warmer then the left when the sun was
on it. It was e very intense light tut as it came in the window and was
on your er here thats just what it looked Like. It looked like being on the
pad at night with these real bright search lights on. Same type light, it
wasn't eny of the ormnge~ish yellowish light.

ovse(Tuemdidhe)..e.-se0+. in sige from the UV?

Oh, yes.

This is the difference.

Any unanticipated alestial features?

The conets I--to get back to comehs here a minute--I guess we didn’t

completely cover that one. See any comets? No. Not at all. When the am

goes down its @--well this wee a very brilliant brillient thing and the light
was spread out much more in a such broafer band out toward the horizons than
i bed anticipated. I hed thought~-I don't know why, mo one had ever briefed
me on this particularly--I thought the eum dow. It would be a little bit of
light right on the ..+.s..... and bang, thats it. Tuere are nothing but stars

T
from there on. ‘hate whet I was prepared to see, I guess, but this wasn't the
wey it wag at all. ‘The gum goes dow end ite o brillient displey. ‘Theres ali
the spectswa lined up here almost. Just as the aun goes down~-well before the
gun goes down you have a broad band ......... down in the etmosphere that we
show on the pictures that I tock too end I'm sorry we don't have those fhere
to brief you with those but you'll see those leter where starting with the sun
down on the horizon there « great band that runs way out here maybe I think
I estimated sane 45 to 60 degrees on each side of the sun, way out. And it
gradually guk gocs down to @ point out here like that. Starting from a
very bright white bend close to the earth and going out te e point out here
end the other bands of light going from, oh, yellowish and orange color
on up into the blues as you get off townrd the bleck of aqpece. Just as the
gan sets that Lest little sliver of light where I was looking for the green
flesh thet everyone has been locking for, that I hed been briefed on, just
as I'm watching for that, jowt as the gun geisdow: om the horiwon, why it

joins this long sliver. So you don't actually see that last little sliver of

sun. It goes dow, you can tell when it goes down but ite not a clear ball
just going below the horizon like that. Its out in this broad sliver that
goes out toward the horizon.

This tend is priserily a horizon phenomena. It doesn’t run
SUSSMAN perpendicular wise?

tio. ite in the etuosphere. Very definitely.

Ite shows it quite well on that photograph there.

a eenet a ea eatieeateiaea eh ioee tad

The zodiacal light I locked for and I never was night adapted enough to see it.
Solar Corona?

8
Soler Corona. No. This--once again I think te obsefve these things
properly we are going to have to be night adapted before we get there ond
thats whet we lost by having other complications on the second
To get back to the unanticipated celestial features.
Well, unanticipated celestial features--the little light spots, lusinous
spote that I saw--I don't think these are celestial features. I don't know

what they are. Can we get beck to thet later?

Ub huh.

dacs wieelhbidaanatteieeds) ‘wiéilins dk ibis with ences is thik he
sunset lasted--the lightness much longer than I hed anticipated. This went
on for some 4 oy 5 minutes that you could still see bright bends and they then
they would gradually go to « more dim condition but this oceurred--this was
over some quite SHEWER lengthy period of time-<gbout 5 minutes. I had expected
the light to juet go down very shortly after sunset. But it didn't, it was
quite brillient, quite bright for a long period of time.

Would you concentrate on » Ft would be « concentration
ever the horizon but were there many

No. Another unanticipated celestial thing at fight though was thie cloud
that I deseribed, the haze layer or whatever it is. I notice this at firet
because as the stars were coming down toward the horizon they move rather
rapidly down toward the horizon et first. I was watehing one particular star
end it got rather dim and I thought well ite going behind the horizon and then it
got brighter egain as it came Gown closer to the horizon and then went out of
sight. Weil. whines ven X RechhG Wavy carefully X suite eea/tbaeen 0 tent Wah

wes some--I think we estimated about 6 to 5 degrees above the horizon and wes

9
probably a degree and a half to two degrees wide and it was quite visible
onee you start looking for it. It MGRYAMOMX seemed to go out and teper out.
Ho, it didn't taper as much as the light at the horizon aid during sunset.
It was more of a solid type Im band. It locked Like the color of it would be
sort of a buff--look like a buff Light eclor--I don't know, something Like
this rather than a pure white, be sort of an off color, just not a pure white.
(Question by Dr. Roman inaudible)
Ho. All these things you see are things that we bed plemed to use at
first orbit, mmx mainly just hold position, get all the redar Gata, ali
the tracking, monitor systems closely and thats what we were doing and then
we flew the first orbit then we were going to broaden this out a little bit
on the second and third orbit end thats mm where we got trapped because the
second and third orbit kept right on doing what we were doing on the first orbit.
We over time in Astronomy. Lets try to finish up real fast end come back
Any Bizast planets?
Yes. Venus, I believe it was--I identified it on the tape, on the chart.
Wasn't it Vemus that went down just above the thet particular day.
the
Vemus was very visible imnediately after/Z@i sunset. The sun would go down.
Just as quick as the last light was gone I could see that very clearly. In
fact I believe on the tape I identified that before the sunset. I could see
up that close to it.
(Statement by Dr. Roman, inaudible)
That will come up on the star chart that day. Yes, and we hed them all
plotted where they should be. You may be right. I'LL have to check the
chart on that. Venus and Mercury bad been right--closer. We had then

16

identified by the previous shot. I think maybe this one Mercury. Lee hah
check the chart on it.

See any stars ?

2o@iecal light. Wo. Solar Corona. Mo. I was not well enough adapted

patterns along that line.
Shedow of earth of sky?
Ho.

To photograph the Orion region, it looked about the same as it does from

the ground. This area in the center of the Orion that I was trying to use
as @& terget area, the center ster in the belt--we got several pictures of
thet. These were taken with different drift rates on the capsule. We tried
to press the capsule on manual control and get it right on very accurately
and im then use the camera but there was still some drift in the capsule et
that tine and I had to keep for it. This is not  steble a
platiora as you would like for this type photography. Made exposures of about
15 to 15 seconds. I was counting off the seconds nysclf without explosion.
Thete about it. I been imterested though to see whether those came out.
I did see some prints and I don't know enough shout evaluating those prints
te know whet we got.

(Question inaudible)

Well, we discussed this during debriefing some, I think we must have had
baie daeded Cesiaiaias thas alanis cutting off absolutely clean, that would
add just a bair of thrust in one axis or another at a time because I would

have the rates sero-ed completely and be sitting right on the spot -—rieth

in
rate
of magno control inputs and you'd shart a little drift Summ very slow.

Probably the rift rates went out over a quarter of a degree per second
during the time that I wae trying to make the pictures. But thate enough
if you aritt off and you have to correct back the line you drift off a line
correct back lime, you do this for 15 or 20 seconds, its rather e crude way
to take pictures.

{Question inaugibie)

Yes. Hand held and hed it up against the visor to steadiness and turn
it very glowly. We had the loose site on the top¢ of it. A loose site with
@ cross hair end so that I could keep that right on the--lined wp on the stars.
It will be interesting to see if we came cut with anything on that.

Make any other comments about our

No. Zt looks about like it does on the desert on @ bright summer{ night.

H Twilight. Did the twilight bother you at ell? Can you tell us anything
about that.

You mean the light I described ax after sunset?

(Statement by Dr. Roman, inaudible)

The only time twilight bothered either way was when you
because sunrise is the--the early pickup sunrise coming up is in the scope
facing backwards, of course, to the direction of motion and you see the sun
come up and this would--thisQiiRiieiaam@ twilight, you watch it incresing in the
scope, meanwhile we're holding mmumal control most of the time and this was very
Gifficult. For some reasons, this was more difficult to held accurate control
on the periscope at sumrise that it was to look back out the window and hold

12
it visually or on inetrument. And since we were having automatic control
trouble presentation on the attitude, I was trying to maintain control
looking back out the window and to check back and forth between the very
brilliant end bright light coming in at mmrise through the scope and
Look back out into the dark again, I finally just put filter over the scope
and go back to locking out et the stare and whet I w could see on the clouds--
moonlight coming off of them die and that seemed to be easier to hold the
position.

The moon look any different to you?

No. Not appreciably. It was brighter--s lot brighter. Just very clear.
Once agein, clearer than 1% is around here, brighter then it is around here.
SHS Once again, out om the desert on a real clear night, its very similar.

Lets push on to the earth qgiestions on your next page, Jom. You said

Ho.

Gay, haze and airglow band at night?

Yes, I Gi@ try the aizglow band at night end I could see nothing. This
may have been the leck of night adaptation--I don't know. I wasn't too
concerned about the night edapting so perfectly to that. I trieé the airglow
particularly on the storm areas over the Indien Ocean. There was a very
iexge storm there to the North, of course, and a sualler one to the South
of eourse, over about the first third of the Indian Ocean. We had wondered if

we could gee lightening from above an@ lightening from above is very, very

visible. Theres no problem at all on that. You can see the fleshes-~you don't

see individual flashes like you see a lightening bolt hit the ground here

13

but you see ea whole thunderhead Light up and
and another one would igiioumpmam light up over here and there would be some
Light go back an@ forth from here like this very borizontelly. And then you
would see another one light up and there wes @ 32% lot of thomderstorm
activity paerticulerly in the storm that was to the north, of course. A little
legs to the one south but the Lightening was vary visible.
Pretty mach the same thing you see frem ae high flying jet, isn't 1+?
Yes. You're a little farther away, of course. Ite similer to that

If you've been up above the-- or 50,000 feet Zum at night and there is some

little low thunderheads where you have the--maybe some of the flashing
@ little bit down at low altitudes, it would be a similar type thing. You're
just farther away from it but there's to problem ot stexmkipeem: all seeing
fleshes. It was on that area to the North, of course, in particular that
I tried to use this airglow filter for e period of time but I didn't get any
pattern out of it at all. This may bave been my lack of night adaptation.
At twilight did you see the shadow of the earth on the atmosphere?
Ho.
Last of these. Can you describe how the atmosphere changed during the
twilight process? You've already gone over this, if there's nothing you can
add-~

Well, I think thet about describes it. One thing I was surprésed at
were the
during the twilight period that might be of some interest wtthk little
they were
discontinuities in it but I think memctite just weather build-ups and high
I

clouds off om the horizon. & though the horizon would be extremely even and

14
that the weather would be so that you wouldn't
see any of this but you could see little tumps along in the twilight glow
after the sunset end this shows up in some of our pictures. © You can see
these little bumps along. Do you have copies of those up here?
Not up here. I saw some that were first rum yesterday dowm st the Cape.
We had a first look at these out at Grand Turk. I think the copies wo
got were not the best in the West. They seem to be a little rough. They
had @ lot of specs on them and I'm looking forward to getting beck down
there and going over them again. But you could see some of these. You
could see a little bump out here, there would be a little discontinuity.
crsecsesee angle or altitude..........+.(question, partially inandible)...?
Bo. They were in the lower part of the light bend so I assume that they
were weether build-ups.

Wheat 4id you estimate the height of the atmosphere to be under daytime

conditions? In fact, this angle of the horizon business?

Well, estimates on the angle, saying that this was some 6 to 8 dearees
wide, up te this layer for instance was about 6 to 5 degrees wide and 1t was
maybe @ degree and « wakg half or two degrees think. This sort of an estimate
of the size of the over here. We're about 30 degrees in the window
our angle we ean 2k lock out and a little less am than = quarter, maybe a fifth
of this business of--say if you estimate ebout 6 degrees. When I say &@ 6 to
8 degrees this is not an accurate protractor type measurement.

Could you use e spacecraft as a protractor?

Well I used the window, just the window area

-» (Question, .partially.iuaudible).... from the top of the window from the
horizon up to the top of the atmosphere? sheesetereserereceeess Doma It off
fron the autopilot?

15

You might be able to try this. I @idn’t try it that way. You might

be able to, holding your head@ima fix you might be able to do soumthing like
that. ‘This would be fetrly accurate. ‘This would put it down, I think, where
you could pick it off within a--our gradations on that attitude control systen
are fairly fine--about, I guess, three sixteenths of an inch is 10 degrees
bat you g could pick it off to within a degree and a half or 2 degrees vith

pretty fair accuracy. VA
ZI metice in some of the pictures there is a f image of the sun

@bout 10 Gegrees fron the primary image apparently due to the 2 thicknesses

of glass.

Yes. I think thate what it was from. I don't recall seeing any of those
et all. iI notice them in the sane pictures and there was encther phenomena
in the pictures you may have noticed. bs tein th ete! a3 deh
noticed it first before I haé--up above the horizon some 15 or 20 degrees
there appeared to be a green dDand go across that perellel the earth's surface.
Did you notice that in thepictures? Andé this wes in quite a mmber of then.
and I never saw any band like that at ali. I don't know whether it was
actually there and just showed up on the fills and I just didm't aee it or
couldn't gee it or whether it wes alwaye when the sun was eat « particular
eres out here and it was just a certain reflection off the window or reflection
off the lens of the camera but I think we should probably take those pictures
and try to analyse what angle the sun wes to them as well as we possible can.

I think John is doing that right now.

Is he? Because this green band is « new one on me. I never saw that

until we got the pietures and I imagine ite just a reflection on the XX lens.

16
through the window like 2 suns or satellite......?

Did. you.gee.any miltiple inages./... (question partially inaudible.........X%
No, no.
Could I @ question here on the surface?
Go ahead.
I notice on the picture here and aleo the comet the description of the
en the horizon in the daytime.
erouna thehorizon near the sun.. Was this a uniform thing

No. 1% comes out even in broad daylight. It seems to go out to a little
more Of a pointed area out--way out the horizon if you leaned over and Look
out the wimisevindow way out toward the North, for iustance. This would not
be o@ broad a band as it appeared to be when we're » looking back directly
on the flight path, for instance. |

It does appear to exist 350 degrees?

Oh yes.

Were there any apprecieble irregularities in it or was it completely smooth!

Smooth. These are very-~~there are fuzzy edges. You Gon’t run up like you
see On the spectrum to this color and to that color. They ell fade into each
other like a rainbow but its a--there are no situstum discontinuities wheres a
yellow band was more thick than a blue band here or something like that. They

ell just ran out even.
Ave you referring now te the sunset phenomena?
That true then toc. I was speaking primerily just during broad daylight.
Do you get different colors in broed daylight other than the blues?

dust the Blues end whites during broad daylight. Yes.

17
You notice any--very maryclouds or any peculiar cloud fomatioau?
Yes. We got quite & mumber of cloud piek pictures and you cam pick
out the relative types of clouds. We did wonder whether you could teil
vertical clouds from SER-06 clouds. You can tell what clouds are vertical
development and you get a three dimensional effect. looking eat them you
ean tell that some are higher than others.
with
Comparing what you said mult whet the picture showed, is there anything
particular noteworthy that you might have seen that the pictures might not
show?
I don't think so other than the things we have mentioned here.
(Question, inaudible)
Is what Now?
Does your window produce any pam polorization?
We have a real limited degree of polorization in the window.
low many do you have in # form?
I will make a note on that one and check the exact polorization of it.
We had-~~thie was checked at the time that we ran some star studies in
i. heuel aak 4 sain tae shila Cea
The reason I asked
The exact figure on that I can't give you.
Did you pass over any snow propagations, mountains ?
Yo. I could see out in the West looking way up North from the area right
over--well the South of San Diego at the end of the second orbit. ‘There was
80 much cloud cover up to the Berth that I couldn't be veal pomiiikix positive.

18
It ren up and locked like it ren off the edge of a « Then there
were some white areas way up to the North and I imagine these were probably
snow fields. I thought at the time they probably were but I couldn't be
sure. I didn't specifically go over any erea where I could look right dom
at this cloud end that snow. I was surprised at my--and another thing, as
fax as the weather goes, end that is whet e tremendous area of the earth

was
xe covered by clouds that Gay. I don't know whether we're going to find

PPPRERIG Bisap pics not. But I was surprised. I had very littie view

aoe at gO ONE

Yee. The intertropical + We bad been briefed on that
and, of course, thet tock care of things all the way across the Pacific.
There was cloud cover all the way atross there. There was cloud cover over
all Eastern Africa. I never saw the Leke Chad area that I was looking for.
it was covered. ‘The only part of Africa we really got @ good lock at was
Western Africa in the desert regions. You could see the big = dust mek storms
blowing and these were very visible. I commented on it end Kenya came back
ané said yes that they had been heaving these dust storms for about a week.
Tremendous blowing clouds of dust that obscured large--very large areas of
the ground. Coming across the states end, this whole area scross WI-HAS
and Northern Mexico, Southern California and that eres, had very large cloud

: end high GER-O6 clouds cbscurea ukstim fron chove. There were
some breaks in it and you could see through momentarily.

What color were the dust clouds?

They just looked like dust. Brownish. MMMM Just looked like « dust storm

you've seen out on the a desert. Geme color. The colors from above locked--

19
I could see no difference in flying in an sirplane at 50,000 feet and lodking
down end seeing colors on the ground thm there is from the capsule.
Lets
MGRBiswitch the subject again. Did you have en opportunity to try
cloging your eyes and seeing the Sorentoff Radiation fleshes?
Seeing whet?
Radiation fleshes from energetic particles fastened to your eyeballs.
Is thet another - Wirst time I heerd of it.
What do you call this again now?
Sorenkoff Rediation by = good Russien frie&d of that name
Golly, tha missed that one on briefing.
(statement, = insudible)
When a comic ray passes through a material in which the--tts velocity
exceeds the velocity of light in the mediwa you have this radiation given out-
Sorenkeff Radiation and John Winckler of Minnesota thought that you might be
able to observe this if you shut your eyes when the heavies came through.
(statement, inaudibie)......
Awe these suppose to be very visible, very bright or just--
No ope knows because they never get down to the earth's surface. They
would have been in the g blue light.
We éidn’t vide around for any peried of time vith the eyes closed. There
was mh enough going on that--titis eye patch, we had that. ‘That was intentionally
done, not to two eyes, just to one go that you'd still monitor everything that
was goin on. So I 4a not wide erount vith the eyes [72 Lue pyicrd of tyne
Alright. Lets get to the lusinous particles. Back to page 1.

Thats a good ome. That sure is.
Were they all traveling in the same direction and the same velocity?

Yes. They all just appeared to be uz sitting out here floating and
they particular didn't have any interaction with each other. Thay were~-

some went running this way end some that way. They all appeared just to be
stetie in their field. Sis ples to ee. The only ones that appeared
to move were the ones thet seemed to have a little flow

Yi icticciguue BO the ote of te capes and {8 wut Gift off like thie
sit Gh wih deoh sdin'ed tte atten Wi dase 2k oc A te
ae. poate Gn: hats heite: Gee, SNES RF Srey Sey 24 ee
tave been--I don't know what I would have on one like that.

observed observe
I sat there and whem this thing just as carefully as I could whew it for
some 3 to 5 minutes at three different periods. The lights were not very
dim little Lights as though reflections from something. They vere every bit
cis eh had: hie easiest MAEMO GAA na rales Wants one ahah,
And you've seen fireflies out in the meagow or when they just stand out
like very, very bright stars. They were as least as bright as the brightest
fireflies you've ever seen in a situation like that and the light was very
steaiy and they were about the seme color as fireflies. This vas ea luminous
yellow-green or green~yellow color. I'd say it was almost an identical to
e firefly ana they were just as far at that particularities time. I would
look out the window this 2 way and there just seemed to be no end to them
out here, no end back this way, no end on this side, up or Gow in particular .
(Question, inaudible)......

Yes.

20
The density looking perpendicular to your path is about equal to that

I had 2 things came in mind. One was, I thought we founds the lost
35% Air Force needles, thet wut was the first thing. But they weren't--
wasn't like that et all. ‘The other thing, I thought perhaps we were getting
freezing of the water coming cut of the capsule and we were having snow,
something like thet. In fact, later on they called me from the ground and
atked if I thought that that is what it was. But it wasn't thet type thing
et all. It didn’t appear to be eminating from the capsule. The particles
were not closer together~--closer to the capsule than they appeared to be
further away. The average distance of the particles apart was probebiy--
i estimated I think some 6 to 10 feet, in that neighborhood. Cecasionally
one would be right in the shadow of the capsule and would drift up pass the
Window end it looked rather white Like a wee tiny little piece of cotton
or @ little--it looked like a little enow flake. Gome little piece of thing
like that. These white suk ones that I saw come up by like that I assume
were the same things as the others out here because I never saw anything else
outside of the window.

Did you ever see the sae one go into the shadow and come back out?

Well, I was asked that before and I--ny initial answer to it was yes
end then I couldn't recall any real specific instance where I watched one go

from lumiuousity to white and back to luminous again. Go I can't say

posivively I did on that. I think they did but I don't want to make «
positive mimtentex statement.

21
(Question, partially insudible)............. in the shadow of the capsule
they were simply white like snow?
Thats right, thate right. They were very Liminous. When the first rays
of the sun would come--when the first rays of the sun came by the capsule is

I won't sey it wasn't.

T don't know how you ¢ould have much depth perception but do you have eny
idea about how fer away the fartherest ones were?

Ro. fT couldn't estimate how far away they were but you had a very definite
feeling of depth perception through them, mainly, I think by looking out to the
side out here. 4nd if you hed « lot or particles hanging out here and you move
through them see = the ones move as you move them them and the near ones move
right within. Ones fer out move very slowly so this gives you a sense of depth.
4nd I think that the way I perceived most of that.

=e" You say they're all moving in the seme direction?

Thats right. eA

Did any move faster than others?

They didn't appear to. They all appear to be hanging mxpe except for the
ones that seemed to come up around the capsule in this flow condition.

(Question, partially ineudible) Did that flow look anything Like

Yes. Thats what we talked about. It aid. The few particles that came by
Was just like a almost.

2la
Sux (Statement, partially inaudible)
eavencing @ new theory that this might very well be some full
luminescence of areas around the capsule
we talked about this A night and day
change » Whether theres enything of this kind
recombination back in the shadow
of the capsule « Five miles an hour
motions ; area of
capsule speed and so on. I+ certainly seem-~it seem to be mumm connection
with the capsule in some way and not with something coming from outer space.

Did you see them before the sun rose?
No.

Did you look for them before that?

Yes. ‘The second time around I was watching for these things.

But you did see them as soom as the sun rose?

The very first light of the sun--the very first rays of the sun than

up, you could see the first ones appear just Like that when the sun came up.
(Question, ineudible.....?

Yes.

Do you have an impression of the shape, the structure of the indlvédual
particles.

22
lio. ‘These one that would come fairly clost to the capsule I could see.
Thats where I estimated they were just a very tiny size up to maybe 3/8 of
en inch or half an inch.
Would you characterize them as sort of irregular like cornflakes, like
crystal, like snowflakes?
They didn't appear to have any oblong pattern to them or any particular
circular pattern. No real semetry at all.
Were they flat like snow flakes?
These little white things which I = think were the seme items were right
up close to the window in the shade looked o lot like little snow flakes.
Would you say they were speherical or ?
I think more like sort of a sphere.
they were luminous and the sun was on them and there was no shugamim shepe to--
just like looking at a firefly light. That's the nearest thing I can come--t
keep coming back to because that’s just what they looked like.
(Question, Inaudible).....7
So. Ho. There was no on and off again type thing at all. ‘This was encther
thing thet going back to the stars it was noticable too as we had expected
there wans't any of the--I didn't notice any particular amount of twinkling of
the stars, not like they do down here.
ab yes au buli-ot Aiin, dai do ?
No. Its just like you have a big static field like you have gone out
here with strings end placed them in this room and if you cane back and
through that deor and back to way across the room that just what they looked
like going by. It just wasn't--

23

They al) went by in the direction of

That's right. Wow, I turned around once so I could see if they

were coming toward me. I got around facing toward the mumghighg sunlight.
As I come around and the sunlight was off to my right I could see far
fewer of them at that time than I could see when I was & facing backwards.
This would be on the side aay from the sum is & where I could see most
of them. But they-~the ones out here were still coming towards me. Now
this ie--I want to check and see if these were eminating from the capsule.
They were not. They were still coming toward me frou out there so they
eouldn't heve been eminagting from the capsule.

From the @ireetion toward mgt which you were moving.

That's right.

How close

Six to ten feet apart.

(Question, partiallyinandible) .......you said you sav it 3 times. Did yout
This was approximately the Samtds.cssscccccnssecccessest

Well, this was right at each sunrise. Now this wasmother thing we talked
about. Bill Douglass, I think, fex felt that there might be some possibility
if the earth does have its own band around the equator, juct as some of the
Planets do, that perhaps were were at the edge of a little band like that

that wes appearing each time we came up past the equator on the dark side
eat that
ané it just happened to coincide with the gunrise murk time. We entered at

sunrise each time. We don't have the data--I haven't checked beck here to
get the data on that yet as to whether this was always right at the equatorial
region that we ran into.

(Question, inaudible)....7

Right at the first light of sumrise there was a--no other time. I
epecifically looked for them at sunset. As the last light of the sun went
away I thought we might see them there. I didn't. ‘This was always at sunrise.
Now, this difference may be that I was more night adapted
at gumrise. Maybe they were there all the way eroud.

(Question, Ineu@ible).....?

Gh, I can't answer that as to the length of time I specifially wetched

one particular perticle but they wore not blinking on end off or anything
like that.

i)
Did you have the inpression they would be there if you 7
they were about 6 to 7 feet apart. The window is only a
certain size_- .
(Statement, inaudible)
Well, I had the impression I could have sat~-I could have been sitting
there and watch one particle for some distence as it went on back maybe for
@ mimute or so.
When they were in the shadows of the spacecraft, dia they appear to vary
eny in brightness 7?
Ho. ‘They weren't lustinous when they were im the shadows. I can't
Specifically sey. I watehed 5 particles from a luminous condition to
in the shadows non-luminous end back to mm a luminous condition.
(WE Question, ineudibie)...?
Oh, yes. ; I could have seen it farther
very bright firefly from a considerable distance and this was a--
When you saw this the second and third time around 4ia you have the feeling
thet there were any more of less than there was the first time?
Ro. We talkeé ebout that too and I think it was the seme type. I don't
think the density of it was any different. Completely snowed. ‘The first
time I saw these I looked down injo the--I checked sone system@--had been
looking outeide the the cockpit and made a check a check ac
I was doing ali the time and had had my head in the cockpit for some Littie
period of tine and glanced back up at the window. I had been doing this just

26

as I could start to begin to see some faint light down below and I glanced
back up ut the window and ay first impression vas, mazk well we've gotten

way out of ettitude and probably come to the because here
it was just Like looking“owt on a complete ster field, there was no other
reference at all end looking beckvard tovard this dark avea what bad happened,
instead of the even horigon back here that|I had haf with the stars up sbove
and the darker area dow below. Mow in this dark area down below too were
@ll these other lights pinpointed in. They just locked, at first glance,
like e continuation of the whole star field down inte that area. I thought
we had drifted up and here I em locking at nothing but eo sterfield and how
aid I ever get into this crazy attitude. I checked iustruments egein and
checked the periscope agath end I hain't drifted. I was still in the sane
attitude I was in except this.big darker area here that had been the earth
back behind it that I had been locking et was now filled up with el) these
Gots as the first light of the sum surfaced.

How long after the sunrise did you observe same of these in the shadows
of the spacecraft? Was it almost immediately or towards the end of tim this

period?

Oh, I don't think there any difference on that as fer as when they
would Grift up inte thet. This could well have been occurring just as well
when I first come into thes as they could at the end of the time. I didn't
have ony iapression that there was more mebiek drift by the capsule at one
time then another or more flow around the capsule that pulled them in past the
Wingow at one time or enother.

mi 27

You can’t see them on the film?

No. The ones we had out there at Grand Turk I couldn't very--we hed
to many seretches end spote on those pictures that I couldn't really
pinpoint then. But when we get hold of the original pictures and can
project those, I hope that we can see more, I gamit don't know. Those
reproductions we had out there were not very satisfactory. I hope the
originals are better then thet. Did you see the originals? Ave they clear?

I say printe which I think Starteé to develop. They seen
fatriy clear.

Did you see any of these spots on thes? Did you have the film? Did
you look at the flin?

i 41d not look at the film directly. Bat 1% mot the sort of picture

you bad in Grand Turk. You hed a really gum clear
print thet @eme day. |
Thats right. And the way they looked they were pretty ‘
They weren't the best job IT ever caw. I'm afraid I don’t know waht
to tell you except that. i wish I could be more helpful. All I can say is
we observed it ané it was very clear and distinct. tt wasn't a reflection
from anything. It was very positive. We observed it & long period of time

on three different orbits at exnetly the seme spot. Beyond thet, I have not
the aiggiemh ides what it is.

We they all the came color?

Yes. % Very even colored except that some of then vould look ao little

larger than others, a little brighter than others. The color was iientivet
identical.

‘a wiaande
Were there eny changes/looking out the side cross your end back?
Bo. I don't recali amy. We talked about that too and I couldn't recall
that they Looked any different in one direction than they did in encther.
(Question, inaudible)....?
Ho.
(Statement, inaudible)...
It might well heave something to do with differences in electrostatic
potential. .
(Question, inaudible)... ?
The drift would be like--well if you were looking out--well if e snow
fleke cone drifting by the window is something goes 2 very rapidly, of
course. iis: sees teekclieg Wek tan tad: emis batten eta just
come just some up across the window and maybe
around end then drift away ané @s it got out there a d&t little
bit it just seemed te assume its position out here.
(Statement, inaudible)...
Gh, no. ie woe sei 1k Sahel shire Shes And Subs ‘Sine tien Wary
snooth trajectory and run off like this. It would @fift: up around here
like that and then it would Gift off on it om. It looked very mach~-it
blow Like
just Looked like snow. It Looked like mmx you ye would see in aii wind
tunnel only with a single particle.
Do you have any om your capsule?
I‘n gure there is. I don't know what it is but I'm sure there met be

29
Thexe would not only be am electric charge, there would be a differential
charge between the window and the outeide of the capsule which could
explain 2
(Statement, ineudiblie).....
(Question, inaudible)....7
Well, thats a pretty th tough ome. I dom"t know. That would be like--
I hate to be too positive because it might lead you astray but I keep coming
back to the fireflies agma again. Very, very similer to locking out at this--
a big firefly or little firefly. looking out on o real dark night in a pasture
this might be @ email firefly up close and a big firefly farther away. As
you @rift through these things they go by, they all lock reasonably wiifor.
The ones that are up close and some of the luminous ones were up mm very close.
Definitely, did that make sense?
As they would be up close and then drift away they didn't appear to
diminish their light very rapidly. Just like seeing a firefly again.
Weli. John you kept your dste with us promptly. I think we should let
you go promptly. )
I hate to break this up too because I want to find cut what these
things are. I don't know Wheat to tell you. Im afraid I'm about ary on
new information.
I won't ask you what aid they say John
I may have to go back and check them. I'm ready.
(Statement, inaudibie)....

3p
I'é like te get together again because this was the first real honest
te goodness business like this we've conducted aince I got back here end
this is whet I went to get back to next woek. I'm going back to the Cape
Monday uight. I'm going to be down there all next week om touring plan
get back to work and finigh
(Statement, inaudible)...
I don't think there's any great urgency from our point of view mainly
it was to get the first impression there is always debriefing.
Any time you would Like to get even with us
(Conversation, several people, inaudible)
Thank you Glen.
Themk you.

ROUGH DRAFI': l/13/62
CODE SCG: MD:dd
MEMORANDUM to Director, Office of Space Sciences
Subject:
Considerations and (tecommendations of'Mtwmed
0
'},pace~lorationYollowing the~tJ rview ( February 27)
~
with Lt. Col. John H. Glenn, q7coi{"i(i_erm presented a
~
detailed and factual description of his observations
during the MA' 6 flight.
He answered rather well the many
and varied questions presented to him during the limited
interview. ftespi te the fact that he was ~ 1 it~ e ve1 , 'n ~
\
~·t"· l..,
properly Q~"- o.
a number of his observations remain of
~.~
JV?
~ interest aad ~ further explorationJ"1further~re,
it is evident that the astronaut can perform various scien~
tific experiments , ~has the aeiil~y capability of doing
com act
so despite the many limitations imposed.by the. Mercury capsule.
Some commezits* on f£ 01. Glenn's
below \)~•u •~LL
•-, -. .
IA.~
r·
kun.inous ~ rticles :
observations are presented
t N.,c~~- clc--+'""""'""!
"\
In response t o ~ a series
of questions, Col. Glenn described the velocity field of
ii.- QM~
the luminous particles, their brightness 8'1./i. outside the
in
shadow of the spacecvaft, the coloring aBa sunlight and
field, the particles !all.
in
moved at preeise)y the same speed and !!.ll,.moved a~ precisely
their shape.
For the velocity
the same direction except for particles coming very close
_,_ ....
~"'~•"<- f .-L
to the spacecraft.
orbits.
This occurred similarl:i, :i,Q, all three
, . ..~d'f¥t.....~
From t.l¼e ~ -eie Vconsiderations alone, it may
be stated that the luminous Jparticles observed by Col. Glenn
were not extra~errestial particles but were particles asso­
ciated with the spacecraft or ~fte la~@Mftg e~ the booster.

-2The consistency in the observations on the three separate
orbits would require that the particles were associated
with the spacecraft itself
( I have heard that O'Keefe
~.... ~ ~~ ~
~
\wM. ~ \:
....
6\ANI&~~ -..,..laA,
,,_ - ,
has i;c;r,r9~9d the life support system which ~
~ ~ ~ \'""~\~)
wat9z: i;a:t;e apaee) Col. Glenn iJjf described the
~
.,.,
particlei and the luminosity. The fact that the coloring
a,~aPen~
~~~,~
was a yellow-green and the eiiee~ive observational pi,e-
became fluorescent in sunlight. ~e particles observed
in shadow were observed in the scattered light from the
spacecraft and were probably illuminated only by visible
~~~f the spectrum.
- ;l-
The change of angles of the ~particles approaching
e.""'1ft,-
close th the~ spacecraft~ be attributed to the
since
repJesive charge HD the polarities of the particles
and spacecraft were the same.
The ability of Col. Glenn
to observe the particles under improper dark adaptation
~ indicate'that an astronaut would be in a position
to carry through a series of experi'1nents to investigate
C.o~.L"
the physics of Q.QmROMS
in the solar environment.
P.1wpe1
ry
~ d ° \ h e various gases and dust particles ejected
~
while
from the spacecraft during~ !
c ~ . ~ n d ~tH'l,BS,!
.o-\,,..U\..c.l, ~ ~~~ ~ >
the spacheaft is in sunlight could be ~
by the
a.\~ ........ c\M,\t.~~'
astronaut- scientist ~ 1&.,"U!S...lt'emld!.r.sr--~~~09...~~~ed
~
Observati~ns of.~low ana:-/iaze:
Limited by poor
dark adaptation, Col. Glenn was not able to descibe any

-3significant observations of the sta/ ield or the moon.
In
the absenf e of atmospheric scattEring the sun appeared a
brillant white, but showed no signs of corona .
It is of
interest, however_, to consider Col . Glenn's observation
-.'t
o{ '- band six to eight degrees
9'f t~e twill
a- eix-~e -eiga~-aegPee-e&Ba
above the horizon, with a haze layer about two degrees
Although it has been speculated that
wide at the top. ~5'~~1!:irl~-.eilli-il~e
observation = ~\:the multipa~wl:l:,ers of the 1'window
cause the high
0~
angle~ the horizon ~ ~ ti&..,.a;l.la-~l'O"l~tm~te2:~~~, this
~
~
o~~~
likely because of the variatio~ a.ad angle of
\Jw&. ~ - - . > - " I
~Ill'\.
~ ~~w.-\ 0
:\.,:u .~ •
view a;i,10w :ee Sel '-l.lina.._o& P0'5ft'D1 Bi& the space craft,- ~.\ t.e'-M'" "~••:~
~ that he did not see any
double imag~ing
~
~
:La any of his ~
observations 1'1:rurther_.,'4'4.
more, he was able to infii.is8a:ec that the stars e»serve</t,hrough
~
the haze layer became less intense while changi ng angle
_,,,..,._
~ the horizon .
~ USSR repo:i;l,s
.,"C
by Tito'V! also ind ., .__
_,,<>I' :fJ
o\~t.. ... ~,..... ~'-u"~ .t.,.a4!d.,. ~ -sm rJ.-.uL,,:.,,. •.,.\. •
7
~ ~ l ~-.llt.,dicated a high angle haze layer . ,. n i'1 e,v:ia.ewe ~het . s f ~ ~ ~
-4-.,.
&.·\u.~ ~~\AM ~U\~c.~Ch4.,, ...p. 4~"-"-'1--f.a~-,,.
Au-6her investigations of the air glow and haze layerKiG£
should be carried out .
Meteorology:
~~
The strikinJ ~ of lightning dis-
charges as observed by Glenn point the way to consideration
of an
l~.,\
j ■ I · on
system for monitoring lightning storms over
the earth using the meteorological satellite . The mapping
~ ......~.l. ~
of the distribution of thunderheads i(Ji)oG. lightning during
the night appears to be relatively straightforward) while
the similar :mapping during daylight appears feasible because~
of the short time constanu of the lightning flashes .
-..3-
.A
Recommendati ons : 'l!bere &ve ,..,.~ - o t ! - number of

-4=
~~ kehwc..4Ack~
recommendations ~paeP te ~a eper en+, following the very
successful flight of the Mercury capsule.
fi.
The astqrnaut-scientist r.a,;rryi ng g,.i,;t "iB:e ob-
~.."'-<;\-,. C , ~ V \ · ~
bt
s-e,~:rt..lreD.~~:im...,a....~ac.~~~le should publish~der his
•
:\.a..
"
~1~~-'""
A...~
name {with an associat~)ai111s0Heral M~ie--lc in a widely
?'"', •!) • bre ♦ eMSars• Utt- ► , these first­
distributed scientific journal •. In this manner, '4;a.e obd
hand
servations would have wide distribution, be properly
~ ...C2.A.-._
cridited to the observer, and pePtioala¥ly be edited
for correctness .
. . Additional support to the astronaut in carrying
out scientific observations is warranted particularly
in consideration of Col. Glenn's attiftude and interest in
carrying out such observations.
Several instruments may
be added to the spacecraft, within engineering limitations~
eJ.,
to assist in obtaining further detail~data.
Q.,
Col. Glenn suggested that t.ae follo
would be to his interest.
-~""'-
discussioms
Such follow-on discussion is
strongely recommended for further questions and exchanges) ~
inform the astronaut
aihalysis
to ova~~ate-~eP-tao-astPeRa~t of the results of t h e ~
and study of his observations.
C . It is of se.e:~
a:t-importanli" that proper dark
adaptation methods be incorporated into the spacecraft system
so that the astronaut may optimize his visual observations.
c o"'tl'le\.s
Investigations of the physics of OQB!!fteft~s and the
feasibility of the ~ l " th-tificial ~omet "experiment
may be carried out directly by the astronaut in a relatively
strai-ghtforward way.
~
These experiments should be
'"t.- ~---\; .,;.. -o.\.u.~~ ~
~'(W\-~•
carried out ae eB Bi@eM ~~ the feasibility of this ~
.

-51

~~ ~

~~~ ~

~&Ao..~

~~

-,14-. ~ 0 - tlM Q..

..

ForVai:r ~low aea. optieal etttd:ies, .the photo.,,.... A..~ ,:......
>MC,--. p .,..c,,h ...~ o...
multi lier :Be! "b
systeml ~ series of filters
r:4,-~J►"'-> --~c.~... ~-- . t . . ~ - - ~ ~ u.v. ~\_,..,, - ... ~
(including~a J;,Oii~e flaorceeent ~lain fi]:l;er to stuely

½

~t-..Av,.u.,,,-.o:..c.. )

tac ultra viole:!T) should be incorporated into the
spacecraft.
~iUJ£e -a :au.ml:lal' ef eeicntifie exper i:tJ.c:nto appear

reasanabl.e--f'o-l:leri~ncces£ of :ehe Me1cwy or'eito~,
: ] I'

~J1~h~~ consideration of the preseno/~lanned
manned-space-flight-program, some reeommendatiGns are
~,c:r-\N·~ '"'Q ,_.f"•'ltC..~ ,..,Q.U.. .oc.~41•,u&..
apparent ts" take advantage of ,tae im~eYement& ;L;e tac ~•~~.

.,..__ ~, .....,,_.\..,. lo.\u.

~gj ent 1 f1 c

expJ oration af tbe saJ ar £ystem and in
~'-h;;:t_~ ~ In. ~ ¼..~; ~\ S(, a'.., ,'
astJ?efl:Ofl\Y • At headquarters, ;U; i.r. recomme:ee,e,4 that
•
_ ~ ~~\
£)• A . \t,rogram (ahief and supporting staff i;e ~ae
~ r e p o r t i n g to the G.irector of ~pace
~ciences for scientific exploration ei in the !Manned
~pace°Tliiht ~ rogram as:111.,
a committee or sub-conmdttee QQ forwed
oa.e.~
indluding such people as RGefte, ~Utt , Minnaert, Towsey,

~o ~ ~'YI. ~ - ~ t

tn.

Sekera, asg £0 forta- to
• ')/
•

~ the scientific community

aB.e. i;a.e ~ Y and,
c
..,.....
rl. .:that a branch or dividion at one of the centers
-::,-, "',_""~o..,. <Y,l
~ '-'
-r7
1 #tDf\~ 8 \. ,Q.suc el .&»4(.WEOK4A~ as a scientific team fo¥ aireefllsupport of the
.>,>-UV\.... ~
--t-A:,-~i.; _,£.,,.r~-..,...,s.
astronaut-scientists "ao oei-e into sys-sola1Y spa~e.

V\A.. Y),,J.~
\~ u

L t),, ""

7

'2.-; .,.,_,_

In reply refer tor SGA(IRGsem1)

MEMORANDUM for the Files

Subjeet: Telephone conversation with Dr. John O'Keefe
from Capo Genaveral

The following information was gathered from « con
versation with Dr. O'isefe on Wedmesday, Fab. 21, 1962:

Astronaut Glenn reported having seen small
luminous particles during his flight, They appeared
to be moving at a speed of about three or four miles
per hour. They were apparently not more than 1°3
feet away from the enpsule, and were visible by
binceular vision, Their color wes golden like
fireflies, and they seemed to be more to the
rear of the capsule than ahead of it, though they
were visible for great distances all around, These
partieles were visible only at sunrise (not at
sunset), and the capsule seemed to be immersed in
then, They very definitely had nothing to do with
the eapsule or its movenent,

Glenn alse reperted that very clesr pictures
of the stars, including Orion, hed been taken with
the UV eamera, although the eaprule zotion had
caused a “wiggly” view,

Jocelyn R. Gill
Staff Scientist
Astronomy & Solar Physies

Sy vaton bo ue dou

.....-- --:-1---
,___ • - -
UN IVERS IT Y OF CA LI FOR N I A
LOS ALAMOS SCIENTIFIC LABOltATOllY
(CoNnACT W-740S•BNG-36)
P.O. Box 1663
LOS ALAMOS, NEW MEXICO
IN JU!PLY
a1P1a TO:
J -l6•8J.2
,,
I
..
JUL I 7 1962
Dr. Jocelyn Gill
Room 62033
Federal Office Bldg. No. 6
Headquarters, N.A.S.A.
Washington 25, D. C• .
I
I
.-.·.. riot,
¥..;
,
,.
l ,, # u,\ 1AA l1 0,i
Dear Dr. Gill:
-The June 29 issue of Science brought to my attention J. H. Glenn's comments
on "The High layer~'.
It seemed possible that the layer he described could be
.
accounted for as a region of relatively large nitrogen peroxide (N0
2)
concentration,
and the past two weeks have been spent in checking this hypothesis • Unfortunately
I am not familiar with either photochemistry or upper atmosphere physics so the
following analysis leaves much to be desired; the hypothesis seems tenable, however,
f
.
so I would like to bring it to your attention.
Effective path length and comparison with possible surface observations.
Referring to Figure 1, the height (H) of a point at a distance (L) from a point
on the surface of a sphere of radius (R) can be found from the formula
(1)
which has the solution
(2)

Vertical path (No. 1)

Horizontal pa
from surface

LOS ALAMOS SCIENTIFIC LABORATORY
UNIVl:R■ ITY
LO■
ro:
DATE:
Of' CAI.IP'ORNIA
AI.AM0e, Nl:W MUICO
Ju}¥ 13, 1962
Fox- th, followins I will assume that the concentr.a tion ot absorbins mo1ecu1es
in the region of interest can be described adequate}¥ by an exponential decrease
w1 th altitude above the bottom, of the layer, hence, can be represented by
where Y is the scale height in the layer and H must lie in the .ia.yer • . Then the
.number of molecules per cm2 is found to be
(4a)
(4b)
• RPo
J
e
~ [-1 + V1 + y2 + ·2y sin e ] dy
(4c)
' I
(5)
where the integral is over the range of y desired (usua.l.ly O ➔ ex,).
·For a vertical view (sin 8 • .l) path, the sollltion is simpJ.¥
(6)
where Po is the density at the base of the layer.
L

LOS ALAMOS SCIENTIFIC LABORATORY
UNIVll:llalTY 0,, CAL.1,,0IINIA
LOe ALAM0e, NIEW MUICO
• 1'0z
nr. Jocelyn Gill
DATBz
July 13, 1962
For a horizontal path (sin 8 • 0) te.nsent to the baae of a layer (path No. 3)
we ·note that y << l in the contributing region, hence, can get an approximate form
~
N • RPo
l
~r.
ex,
•e
Y2
(7)
ccy
O
which has the value
~
­
N•\J 2
(8)
Po
Here Po is the density at the base of the layer, as in eqµation (6).
'I
An astronaut's view thru a layer :from above would see twice the path computed
by equation (7), ·giving
N3 • Po ✓ 2nRY molecu.les/-cm2
(9)
f
•
Aline of sight tangent to the earth and passing thru a layer at base altitude
H (path No . 2) will have
.
.1!J.,
N- ~y [pl e y
J
(10)
..fu.
and we note that [P1. e ~] is the density at H1 , the base of the layer, which we
set eqµal to Po as in equations (6) and (9),
RY
• ~
N,a • Po -L • Po -
2H1.
r-
(11)
I

LOS ALAMOS SCIENTIFIC LABORATORY
UNIVEllelTY Of' CAl.lf'OIINIA
LOe AI.AM09, NllW MIIXICO
tO: Dr. Jocelyn Gill
DATE:
July l.3, l.962
Aaeuming that 'Y • 7 km 1n ~ abaorbing layer, ve note that a. surface obaerver
vieving a layer at an altitude near l.00 km vill have availabl.e the ratio
(12)
An astronaut · vieving along path No. 3 woul.d have a mu.ch greater thickness, as
2,rR ;
y
75
. (l.3)
Viewing thru the layer to a point ne.ar the surface and out again the enhancement
would be mu.ch less,
(14)
Light received by an observer :from a "point source" in space is attenuated by
-uN
•
a factor e
where CT 1s the absorption plus scattering cross section, giving
I
-• e
-aN
Io
(15a)
and
I •.
1n .!_ • -CTN
Io
(15b)

LOS ALAMOS SCIENTIFIC LABORATORY
UNIVl:RatTY 01" CALll"ORNIA
L.09 ALAM09, NIIW MUICO
TO: Dr. Jocelyn Gill
-5-
DATI:
July 13, 1962
From the repcrt 1n Science, I infer that for the layer reported,
(16)
or
(17)
giving
aNi • o.o4 ± 0.027
(18)
0.22 ± 0.15
(19)
and
0N2 •
Any such absorbing layer present during the day would result in rapid heating, and
•I
reradiation in the infra-red range from whatever bands may be present.
However,
the absorbers postulated below would be destroyed by photodissociation and/or
heating during the day.
Hence, it is not surprising that solar spectra have not
shown such an absorbing layer.
StellarJplanetary or lunar spectra might show the existence of such a layer,
if the absorption spectrum has sufficient structure.
Setting
(20a)
we find the effective path length Xi.
(20b)
~ • 3.9 x 106 cm (starting absorption at
.100 km altitude)
'
(20c)

LOB ALAMOS SCIENTIFIC LABORATORY
UNIVltRelTV 01" CAL.ll"ORNIA
LOe AL.AM09, NltW MUICO
DATB a
Dr. Jocelyn Gill
July 13, 1962
(20d)
X4 •
7 .8·x 106 cm
(20e)
Absorbers Present in the Upper Atmosphere
'lliree constituents of the atmosphere near 100 km altitude absorb light through
most or •all of ,the visible range, as would be re_q uired to get a noticeable d1mm1ng
of starlight.
They are:
l) N~ (nitrogen peroxide)
v
2) 0 -
(negative atomic oxygen ion)
3)
(negative molecular oxygen ion)
02
Of these, I found no cross section data for o;.· For 0-, Massey (Negative Ions;
Cambridge U. Press) gives curves showing absorption cross sections starting at
•
•
5620 A and approaching~ 4 x 10
-l.8
•
.
•
cm2 /ion 1n the region A< 5000 A.
'lb.ere is
•
very little structure (only the onset at 5620 A).
From ecpation (17) we find that
~ 3 ± 2 _18 • (7.5 ± 5) X 10l.7
N3(0-) •
4 X 10
could explain the observed attenuation.
For an effective path length of 5.4 x 107 cm, we have Po• (1.4 ± 1) x 1010
negative ions/crn.3 •
Since the daytime free electron concentration in the E layer is 1.5 x 105 and
the night vallle is~ 104 it seems- hard to believe such a high nighttime concentration
•
of negative atomic ions.

LOS ALAMOS SCIENTIFIC LABORATORY
UNIVll:R■ ITY
01" CALll"ORNIA
L.09 ALAMC>e, NllW Mll:XICO
tO:
July 13, 1962
Dr. Jocelyn Gill
NitroGen peroxide haa been extensive~ studied and two papers were fou.nd
'
'
which gave absorption coefficients in the visible region of the spectrum. Wiley
and Foord (Proceedings of the Royal Society Al35, 174 (1932) give a coefficient
which I convert to
er
~l - 3 x 10-l.9 cm2/molecule
depending on the wavelengths selected by their filters (the lower value was for
the range 4900 < ). < 525·0 A) •
Hall and Blacet (J. Chem. Phys. 20, 1745 (1952) give a curve obtained with
.
'
a Cary spectrophotometer having ~ 5 A resolution.
the range 3500 < ). < 4500 A and drops to
give no data for longer wavelengths.
Maxinrum absorption occurs in
~1/2 the peak value at 5000 A. They
I convert their absorption coefficients to
~ 6 x 10-ia cm2 /molecu.le at 4000 A, and~ 3 x 10-ia cm2 /molecule at 5000 A.
Structure produces changes in cross section of~ 2 x 10-ia cm2 /molecule at wave­
lengths separated by a· few angstroms.
Ta.king an 'a verage value of 4
x 10-ia cm /molecule ·we find
2
1
• and using X3 • 5. 4 x 107 cm
Po• (1.4 ± 1) x 1011 molecules/cm3
.
•.

LOS ALAMOS SCIENTIFIC LABORATORY
UNIVIEll81TY OP' CALIP'OIINIA
LOIi ALAM09, NIEW MUICO

TO:

Dr. Jocelyn Gill

DATE:

July 13, 1962

Readily detectable structure would produce ve.r1e.t1ons of o-N1 and aNa ot
about half the attenuation figure given in equations (18) and (19) which is
near the threshold of detectability.
I have not yet found an author who estimates the concentration of Ne or
N02 'in the atmosphere; Bates and Nicolet discuss the reactions which lead to it
in the book "'lhe Earth as a Planet", edited by G. P. Kuiper (Volume II of
The Solar System).
Nicolet calculates the photodissociation time as 200 seconds during daytime,
and shows the concentration must be so low that no effect on solar observations
would be found.
As a general conclusion, it seems to me more likely that N02 would be
responsible for an absorbing layer, generated perhaps with the aid of downward
diffusion of NO to higher pressure regions favoring oxidation to N~.

'lhe

color suggested by Glenn fits very well', as may be quickly verified by looking
thru. the vapor space above concentrated nitric acid.

Experimental Proposal.
Ideally, one could ask for the absorption coefficient as a function of wave­
length (over a very wide spectral range) and time after sunset on the air volume
investigated.
I t seems possible to get very useful data with a relatively simple experiment
perhaps possible of inclusion in one of the manned orbital flights.
Using a slow-speed movie camera, photograph the star field and such planets
(including the moon) as opportunity permits, with approximately a 10° field of
view and enough exposure to pennit photometric measurements as the light sources

LOS ALAMOS SCIENTIFIC LABORATORY
.. . ..
UNIVERSITY OP' CALIP'ORNIA
L.09 ALAM09, Nl:W MUICO
'
1'0: Dr. Jocelyn Gill
DATE:
July 13, 1962
"pasa through" the atmoaphere, especially the abaorbill6 layer (perhap
• •••
sequences already exif:>t).
auch
At the expected orbital height, I estimate a 7 km
thick layer w~ld subtend,.., 1/2 degree and a given light source would "pass
through" it in eight seconds. Attempts to derive a density distribution would
requ.ire a fair number of points in the 111-1/2 or 2 degrees" (divide by 3 ?)
so a frame interval near one per second _seems desirable.
If operated continuously
thru the ni.ght passage approximately 100 feet of 16 mm film would be required
per passage •
As a crude attempt at spectroscopy, color filters could be used on some of
✓
the sequences, without too serious light loss.
For example, a Corning No. 5030
or No. 5543 filter would limit exposure to the wavelength range of maximum
absorption by N02 (light loss may be considerable) ·and a Corning No. 3480 filter
would limit exposure to the wavelength range where 0- absorption is negligible.
Relatively broad band interference filters would be useable on the brighter
stars and planets.
Direct visual observation through such filters would also be
useful, especially if photography is impractical and the astronaut tries to
reproduce any attenuation noted by neutral density filters in combination with
the same filters and stars used in space.
Photometric observations of some of the "intense" airglows mentioned by
various authors would also be very instructive • The increased intensity due to
J
external tangential viewing woul~ help a great deal, and precise height de­
.
terminations could be made •
It may be useful to ask Glenn and Carpenter to reproduce the dimming (as well
'
/
as memory allows) by narrow strips of neutral density filters against the star
•
I
1
1

.
'
.
..
LOS ALAMOS SCIENTIFIC LABORATORY
UNIVERSITY OP' CALll"ORNIA
l.09 ALAMO., NIEW MUICO
-10
TO: Dr. Jocelyn Gill
DATI:
July 13, 1962
field they saw, or to compare the intensity and color changes noted with that
thru an absorbing cell containing N02 • • 'Ihe required thickness is readily availabl.e.
Acknowledgments
The author has benefited greatly from discussions with several associates,
especially as regards references to sources of upper atmospheric .and photochemical
data.
Dr. Robert Sherman has assisted in location of data on the absorption cross
section of N02 •
Dr. Arthur Cox suggested a number of references and confirmed the
author's belief that reasonably accurate photometric observations could be made on
photographs of a star field.
Dr. Ieston Miller has emphasized the importance of
even crude control of the wavelengths responsible for exposure.
All of the men
mentioned ·above are members of the Los Alamos Scientific Iaboratory.
Dr. J. A. 0' Keefe of the Theoretical Division of the Goddard Space Flight Center
generously discussed the observations of J. Glenn and S. Carpenter, and my hypo­
thesis regarding N02 absorption.
He has referred me to the excellent articl.es in
"'Ille F.a.rth as a Planet" and encouraged my submission of this letter.
Future Work
I would, of course, be interested in your opinion, and that of other experts in
the field, of the above hypothesis.
J
observations on a future flight, we may be ·able to help on some points in data
acquisition.
--- ..........
If your group recommends inclusion of such
I am sure the project would deserve review and .control by a panel
of men such as Bates and Nicolet.
Respectfully submitted,
~y--~
BEW:jo
Distribution:
l - Dr. Jocelyn Gill.
'
BOB E. WATI'
Assoc. J-Div. Ldr.
and Grp • .Ldr. J-16
.I

In ~ly refer to:

SGC:Mt:llll.

21 Feb~ 1962
MQl)BANDt){

Poeaible

Subject:

1eritit1c Viaual IIitoruat1on

Obtained 1>f J. H. Gl.enn

1.
Two (2) 1ntentl'ting obaervationa r e ~ in the Pree ,
as ddcribed by Colonel GJ.enn ~ the NA-6 flight. It 11 ot
Vit4U. 1ntereat to obtain a more 4ataUttd deacl'iption at tbfte ob e ~

t1ona in order that the &ccur&cy Md the detail• ot 'What,.. obseried

may~ Pl'Ol*.rly Neoi"decl for ,oientitic eriJ.:uat1on.

The two obaer­

vatioDB wre:

( ) T h e ~ ot the ~ t m.Jl!lbW or lUIJliriowl particles
ap~tl.y travelling Vith t
1Pt,Cecratt at 1'r1endlhip-7 euifri1t ;

and
(b) Th altitudel or angular view o~ the -upper limb

ot the tmo•ph&re.
2.
The thouunda ot 1Ulll1n0ul parttcl.• •
<!ascribed u
travelling with tM apaoeoratt. It la in;IOrtant that Glenn describe
1n a.eta:11 preci~ th• obaervationil characteristic ■ under 'Which he
aaw the piirt,1,.cl.. 1n or4ir to obtain an ..timate of the b~tne•e
ot th•e ~ l c l • . 'fhe quat1cma that
ww.d like anawerad

What-. the bMi1 ot 01mn'• 4eterminat1on wt that the particles

vere
tuall.y t:s'Yell.1.ng ¥1th tho •pacecn:'aft and. vh4tther thia condi•
t1on peraiated on aubuquent c>i'bit . In .a.dition, the ge<JDetey- or
the obaMrrYatiana ehow.d be turther deacribed in order to ~rive th

geanetric 41itrtbut10n at the parbicles relative to the e&pacecratt•a
v:l.iuknr. ( ~ preoue obeervat1onal tw and th4I poe1t1on of sun1.ight lum1noa1ty can NllkJ:U:y be a.t4tj,ni;ned trom the orbit of the
pacecratt itaelt). 'l'hee• particl• ~ be pocentr1c 1n origin
and may' be ••pended in the - ~ - '1'bera ~ .t leUt tw
hypot
1• tor a;pla1n1ng pantclAa tr&vellbJg v1th the apacecn,tt.
'l'he intensity c ~ to atarl~t aboul.4 lMt 4-termlned 8.1.ao
tbia 1.nformat1on ia ot ~ • 1n 4 - ~ turther ~ormation
about the a olute JIUlabex- and cros1•aectiona ot the 1)$'t1cl•
may
rel.ate to tbe dujt content or zodiaciil 11~ u WU u the gegen­
echein.

«tt»
In & similar mamer, the observations of the horizon and the

HAND-CARBX
NATIONAL AERONAUTICS AND
SPACE ADMINISTRATION
WASlijNGTON . O.C.

SPECIAL

GPO

16-76611- 1

NASA HEADQUARTERS ROUTING" SLIP
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1 Rec'd
IR·~ / C .
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4.
,,,_
II
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'/ I
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,
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~
INFORMATION
INVESTIGATE AND ADVISE
NOTE AND FORWARD
II
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11h-l .-"" ""
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REMARKS:
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FROM:
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NAME,
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NASA form 26 (Rev. July 19~9)
Dubin
l~?h/62
• U. S. GOVERNMENT PRINTING OFFICE : 1959 Ol'-51302.1

In reply refer to:

SGC:ML:ml

21 February 1962

MEMORANDUM
Subject:

Possible Scientific Visual Information
Obtained by J. H. Glenn

1.
Two (2) interesting observations were reported in the Press,
as described by Colonel Glenn during the MA-6 flight. It is of
vital interest to obtain a more detailed description of these observa­
tions in order that the accuracy and the details of what was observed
may be properly recorded for scientific evaluation. The two obser­
vations were:
(a) The report of the great number of luminous particles
apparently travelling with the spacecraft at Friendship-7 sunrise;
and
(b) The altitudes or angular view of the upper limb
of the atmosphere.
2.
The thousands of luminous particles were described as
travelling with the spacecraft. It is important that Glenn describe
in detail precisely the observational characteristics under 'Which he
saw the particles in order to obtain an estimate of the brightness
of these particles. The questions that we would like answered are
what was the basis of Glenn's determination~ that the particles
were actua.lly travelling with the spacecraft and 'Whether this condi­
tion persisted on subsequent orbits. In addition, the geometry of
the observations should be further described in order to derive the
geometric distribution of the particles relative to the spacecraft's
window. (The precise observational time and the position of sun­
light luminosity can readily be determined from the orbit of the
spacecraft itself). These particles may be geocentric in origin
and may be suspended in the atmosphere. There are at least two
hypothesis for explaining particles travelling with the spacecraft.
The intensity compared to starlight should be determined also as
this information is of importance in determining further information
about the absolute number and cross-sections of the particles and may
relate to the dust content of zodiacal light as well as the gegen­
schein.

,

- 2 In a similar manner, the observations of the horizon and the
extent of the atmosphere are of great interest in determining the
distribution of various atmospheric characteristics. The precise
lighting conditions regarding the position of the sun and the
intensity of the outer edge of the horizon as observed by Colonel
Glenn may be used in the consideration of what Glenn actually saw.
For example, he may have seen the limit of the atmosphere (based
on the 8 degree limb described in the press, the atmosphere
apparently extended to over l50 Km) by Rayleigh scattering; he
may have seen the airglow; or he may have seen the MIE scattering
from dust in the atmosphere. The true limiting angle of his
observations and a graph of the itltensity drop-off with angle from
the earth should be obtained in addition to the lighting conditions.
It is recommended that this information be obtained from
Colonel Glenn as soon as possible.

Maurice Dubin
Head, Aeronomy Program
Geophysics & Astronomy Programs
Office of Space Sciences

F______
L

SG_........fl___
Fellows

DRAFT OF NOTE ON THE SCIENTIFIC OBSERVATIONS
Towa rd the end of the flight, between 16 hr and 47 min (UT) and 17 hr
and 03 min (UT), 24 May 1962, Lt. Cdr . Carpenter made a series of observat i ons
on a l uminous band vi sible a round the hori zon.
The most de ci s i ve observat i on
wa s made wi th an ai r glow f i lter suppli ed by Mr. Iawrence Dunkelma n of Goddard
Space Fli ght Center.
The f i lter transmits a narrow ba nd of wavelengths,
approx i.mately 11 Angstroms wi de at the ha lf power poi nt
and centered at t he
wa, ve length of the strongest radi ation of the ni ght a i rglow, namely 5577 Angstroms
The f i lter cut out a ll other Ught, but passed the light of the , luminous ba nd,
which i s thus i denti f i ed a s the 5577 l a ye r .
Lt. Cdr. Carpenter noted tha t the layer was very bri ght.
He f ound
t hat Phecda:Ursae Majori s, magn i tude 2.5 was lost to s i ght a t the brighte s t
pa rt of the layer.
Assuming that the i mage of Phecda occupi es about 1 SY.Uare
-8
mi nute of' arc on the retina, or 8.18 x 10
magni tude o.8 yi elds 10-
o_,)J-
steradi ans,
O.ssuming that a s tar of
6 lux (1umensJm2 ) we f i nd that the brightness of t he
l aye r i s about 3 lumen1m2 )(steradian) or 3 x 10- 4 st i lbs.
Thi s i s e ~ui va l ent
~t
(S"-~)
t o about 4 x 104 erg;,m2 )(sterad:i.anh_, taking the le a st mechani cal e y_ui va le nt
of light as 1. 6-1 x 10- 3 watts per lumen f or 556o A as per the AIP ha ndbook .
It
is about 50 t i mes as bright as a white surface i lluminated by moonlight.
The a ngular he i ght of the layer was found i n 5 d i fferent ways :
t he twilight layer.
1.
By dire ct esti mate - 8° to 10°.
2.
By noti ng that it is approximately twice the height of
Lt. Cdr. Carpenter estimated the he i ght of the twi light
l a yer a,s 5 sun diameters , whi ch means 2-1/2 degrees, hence the he i ght of the
5577 layer would be 5°.
3.
By observation of the star Phecda (ju Ma) a s it pa ssed
t he middle of the luminous band.

4.
By noting the time when Phecda was halfway f rom the
lumi nous oand to the horizon.
5.
By noting the fact that when the cross of the reti cle
r.~
,th(.. 'A 1,( ·1 i) ~ /).\ \>.-.(
!
i s set diagonally,~ just covers the distance from the band to the hori zon.
By method 3, we make use of the time of passage through the middle
J
of the layer.
This point is marked by a re f erence to a mark on the telemeteri ng.
enl:y: ee found on ~he gr ottae. etatiea ta:r;,e s,
.:i. ~
'-"'' .;i.--,c.:h •" .,.;.~1
).."f' cn\:!r . L\ t r f e ,, 4e r
v a:'.. efl 1:,Pe Mt yet svail:a:til.e, ~ l,y careful timing of the capsule t ape'/\ it
,,.
appear s to have been very close to a 4h "1,m j.9s, capsule elapse d time, i.e.,
16h5cPl/5s.
UT.
For this instant the capsule coordinates as i nterpola ted from
the Woomera tra cking data, were - longi tude - 127° 40:0
latitude
= -18° 49:8
he i ght
= 226 kilometers
At thi s moment, the l i ne of sight to ( Ursae Majoris was t angent to
t he l ayer of maxi mum thi ckness of 5577.
The angular zen i th distance oft U Ma
a t t hi s time was found to be 101°42 1 •
A line of this zeni th dista nce i s t a ngent
t o a spherical shell of the proper radius whi ch i s 137 ki lometers below the
capsule or 89 ki lometers above sea level.
Ac cordingly, thi s observa t i on should
be i nterpreted a s i ndicating that the densest part of the 5577 l aye r i s at a
he ight of 89 ki lometers, which is in good a greement with rocket mea sures.
The lower limit of the visible light appeared to be near 78 ki lometers ;
r t / ht 5/ derrmtat1f . i3/no. t
p nie1d aysif1fi,/ bt, j~i n1 a 1/1111io/u~ / hell
/1 s /ex-p/c~ to/dim/nisVgragla11r d~wara
i, /a6arentlbri ~~e9i , e4en} r
.
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.
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The f i lter observati on on the airglow was made at 17h 0~ 6s, UT.

Sunrlse was observed at about 1m later, while the observation was going on.
It follows that the airglow is visible even when the twilight band is very
strong.
An attempt to observe i t in the day is certainly indicated.
In this
connection, it should be noted that Capt. V. I. Grissom reported a grayish band
at the top of the blue sky layer.
Space Flight,
(Pesults of the Second U. S. Manned Subqrbita l
NASA, GPO (1961). le remembers this layer as narrow and grayish
i n color, representing an actual i ncrease in intensity.
He po i nted out the
approximate position of the layer on one of Lt. Cdr. Carpenter's photographs
at the height of 1.7 degrees above the horizon.
Grissom may have observed the
da ytime airglow.
Carpenter did not note any structures, either vertical or horizontal,
in this layer.
He did not observe it completely around the horizon but believes ·1 l
to be continuous all the way.
a ctually absorb starl:ight.
It does not appear possible that this layer can
Any layer at this level capable of absorbing a
noticeable fraction of the light (25i or more) would also scatter light strongly;
i t would therefore be a very prominent object on the daylight side.
is not definitely visible on the photographs of the day side.
In fact, it
Thl s i s entirely
i. n agreement with Lt. Cdr. Carpenter's impression, namely that the decreased
visibility of stars passing through the layer was a contrast effect.
A remarkable feature of this observatton is the discrepancy between
the eye estimates of 8',.10° for the alt i tudes above the hori zon, on the one
hand, and the results of timed observations on the other.
altitudes of 2° to 36 .
The latter i ndi cates
The latter are clearly correct; f or example, Carpenter
noted tha t when one ann of his reti cle was at an angle of 45°, it covered the
space between the horizon and the bright band.
The crossann is 1.21 centi meters
i n length and it is a distance of 26.2 centimeters from the astronaut's eye.
At an angle of 45°, i t subtends a vertical angle of about 2°.6.

It thus appears that there i s a strong i llusion whi ch exaggera tes
angl es near the horizon, and whi ch was evi dently also present i n MA-6 , s i nce
Lt . Col. Glenn a lso reports 7° to 8° as the height of the luminous ba nd.
The
i llusion is perhaps comparable to the well-known illusion which makes the moon
seem larger near the hori zon.
Carpenter also noti ced and photographed the Glenn e f fect.
He reports
white objects resembling snowflakes, seen at sunri.se on all three orbits. '
However, he also saw these objects 7 minutes after the f i rst sunrise and aga i n
43 minutes after sunrise; and zll, llm, 23m, 26ffl, 3(1!! and 45m after the second
sunri se.
It i s thus quite clear that they are not related to sunri se, except
pe rhaps i n the sense of being most easily visible then.
Carpenter managed to photograph a few of these particles.
Some of them
we re very considerably brighter than the moon, which was then very near the f i rst
quarter.
At this t i me, the moon i s about -10; the particles may have been be­
t ween -12,5 magni tude (10 x bri ghter than the moon) and -15 magni tude (100 x
bri ghte r than the moon).
The second i s -considered more l i kely, in vi ew of the
appearance of the full moon (-12,5) as shown on MA-6 photographs.
At -15 , the
parti cle brightness i s consistent with centi meter size snowflakes.
The
partic les were verbally described by Carpenter as between l mm and 1 cm i n size ,
and having a strong visual resemblance to snowflakes.
Shortly before reentry, just at sunri se, Carpenter performed the de­
ci s i ve experi ment of hitting the capsule walls with hi s hand.
The blows promptly
resulted i n the liberation of large numbers of particles. It i s thus clear that
17
at least those parti cles observed in the MA-6 flight emanated from the capsule .
The possibility that the particles might be dye marker or shark re­
pe l lant , both of which are green and both of which a re exposed to the va cuum,
was considered by Mr. Frank M. Crichton, NASA capsule inspector.
Crichton had
te st s made which demonstrated that ne i ther materi al tended to escape f rom the

package i n a vacuum.
The possibility that it might represent small partic les
from the fiberglass i nsulator was also considered; in view of the smallness of
the fi bers, it appears l :lkely that they would have been blown away at once,
l Lke the Mylar confetti.
The dynamic pressure of 1 dyne m2 is sufficient to
L\I'" \\, ••''\
remove at once~weighing less than about 10 to 100 milligrams cm2 ; which
corresponds to a thickness of the order of 0. 3 to 1 mi llimeter for most
ordinary substances.
As menti oned in the MA-6 report, there are two plausible sources
withi n the capsule for these parti cles.
(1)
Snow formed by condensation of steam
from the life-support system.
(2)
Small particles of dust, waste, bits
of i nsulation and other sweepings.
The latter are very consp i cuous in a zero g environment, when there
l s nothing to keep them down; it is found to be extraordinarily difficult to
free the i nterior of the capsule of such material.
Undoubtedly, the exteri or
parts of the capsule which are exposed to the environment will contain these
things, and they undoubtedly play a part i n the Glenn effect.
In pa rticular ,
a corkscrew shaped piece observed by Carpenter was probably a t urning or
perhaps a raveled piece of insulation.
On the other hand, there is considerable evidence which points to
snow as the source of the majority of the material.
In the first place, water
is dumped out of the capsule i n far larger quantities t han any other substance.
In the second place, the material looked like snowflakes both t o Glenn and to
Carpenter.
In the third place, the fre ~uency with whi ch the Glenn e ffe ct i s
reported by Carpenter appears to be correlated with the tempera ture of the
exterior of the capsule as recorded by thermocouples in the shi ngles.
The
temperature was always lowest at night, falling to temperatures of -35°C just

be f ore sunrise, a nd rising to plus 10°c just a fter sunr"i se.
DJ.ri ng the se cond
da y , the tempera tures were lower, rea ch i ng about -25°c during portions of the da y .
From about 3h 3dn, CET, on the second period of sunli ght,
the temperatures were
h i. gher, ·,. nd, bnly one part l cle is ment i oned .
I f' the effect i.s indeed due to condensation of moisture, t he n t he
broad end oi' t he capsule is a more likely source than the na rrow end , be cause
t he temperatures were 200c or more higher at the n;:i.rrow end.
The condensation probably took place ·Lnside the capsu le, r a ther tha n
outside, because even at the lowest recorded sh i.ngle ·i..<::l.ilJ;)r.::-:.l·ture , a round -50°c,
the vapor pressure o ver ice amounts to about 0.039 milliba rs.
Although this
pressure is very low, i. t greatly exceeds the ambtent pressure at the lowest
capsule altitudes.
Accordingly, it is not possible that snowf lakes should f orm
under these circumstances, even though it is true that the capsule mu st be
surrounded by an expanding atmosphere of wa ter vapor.
If the water-vapor expands freely, ;_ t is clear tha t the pressure at a
dis t ance of 1 meter f rom a hole 1 cm in di ameter wi.11 be of the orde r o i'
1/10 ,000 of the press ure at the hole.
Hence i t i. s f airly cle ar t hat t he pressure
i nside the capsule will be far higher than the outside pressure, i n sp i. te of the
presence of 18 one-centimeter apertures.
Hence condensation within the capsule
l s more likely than condensation outside.
It is noteworthy tha t no f ormati on
of rime was noti ced either on the window or on the balloon stri ng .
It i s con­
s i dered most likely that tne particles of the Glenn effect are snowflakes f ormed
-L n the capsule, between the cabin bulkhead and the heat shi eld by the steam
e xhaust from the li.fe-support system.
It is suggested that they es cape i nto
spa ce through the porte, being driven outward. by the expanding vapor.
t hat at 02 52 47, Carpenter noted a particle moving faster than he.
he planned to observe sunrise and was facing forward.
probably seen east of him.
Note
At 02 50 00 ,
This particle was thereby
Most of the particles are seen behind hi m and f alli ng

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back.
This supports the idea that the partlcles probably are pushed outward by
t he expanding steam from the capsule, before they begin to stream backward.
It
l s probable that many of the particles lodge on the outside of the capsule,
since Carpenter i s quite sure, from the direction of streami ng a cross the
wi ndow, that the particles came from a point near where the knocking was done.
Carpenter obtained two excellent photographs of the sun when just
abov~ the horizon.
Ct, fft.,;~c. ( n~'(':,
These photog.ra:phs plainly sh~w. the flatte~ed,, sa\.lsage- . .. ·kc.h""' ,, + ~\:~
thh \- v:,h .. 1" \\(. ';,(..\.v .,.,_,, \ , \(~ \-h<v ~h-'- y--r,'> •,,11 0,v I>' • ~"',\,( ei,., tr,-, , ,1
·t )c ,., .., ,rr
shaped f onn photographed earlier by Glenn.,'\ Calculations of this theoretical
shape are being made at this ,time for compar.i son with the astronaut observations .
The flattened shape is due to the fact that the lower port i on of the sun's d i sk
is seen through layers whtch refract the l.ight much more strongly than those
through which the upper part is seen.
flattened.
As a conse~uence, the whole d Lsk appea rs
A s i milar, but much smaller flatten i ng has long been known to be
observable f rom the ground.
A part of the i nterest of tht s phenomenon comes
from the fact that at great distances, as at the moon, the e ffect of this refrac t i on is to make the sun appear as a red ring of light around the earth.
l " '"~ '>

r
SCIEN'.rinc DEBRIEFING
... .
•'
Ji.me
,
1, 1963
(First Experiment • Flashing Light)
John McKee:
One of the first questions that I have regards some estimates
you made of the beacon distance.
Were those based ·entirely on the knowle
of how bright it was tram p~vious aircraft training ·or do ·you feel there
was some other distance cue somehow involved in the ·test.
J
Cooper:
No.
If I had no prev;ous experience on the light·, I don Vt believe
I would have had any possibility of telling how far it was except· that on
that second night pass after ejecting the light.
Apparent'.cy the sun was
shining on it as I saw this steady glow, up to about · my level on the orbital
path.
At that time I bad a little bit more depth perception on it ·a nd could
') .
seem tp note the proper drift on it.
That was the first time that I •saw it.
and t o the experiments we _q;f,d on :the aircraft When we had radar measurement
•
I
you notice the pitch rate.? -- or what was the sensation?
. Cooper: · No, I ~idn't notice any 'rate as such.
I cou1d really feel
the spacecraft and to me it felt Jµst like there were doors banging ·open
down there,.,as it departed and Just a li~tle bit .of a Jolt: through _~he : t'
•
•
spacecraft.
It was a good so~d thump when it 'took· oft.
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h
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A~
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ri-~

Scientific Debriefing
Bill .Armstrong:
Act~ Gordo, it turned out, it gave you about a half of •
a degree per second in the opposite direction.
This was very apparent on th
postfiight record.
You can see your ·thruster ·acti~ when you start to pitch
'
'
up El.lld then as you come right to the bottom of the curve you can see this
little blip on your rate; and then the attitude started back' the other we;yo
Something on the order of a half of e. gegree per ·secon
.I t was real definite.
or e. little moreo
It was real definite where it occurred.
Well what it does
is start your pitch back the other ·~•
·'
a:riy thruster action to go ,back 1n the other _
direction,
'
you deployed.
to pitch back down .afte~
I
You. went to cage - to retroattitude and the attitudes just
It was real ·clear on the records where it went 1out ..
and start back .over.
/
Shepard:
Say, in regard to the first question, do you think because you
.
'
had th~ earth as background you could Judge d~stan~e, . because you ha~ e ,
as background'l
Cooper:
I think possibly so~
Of course it's like an airplane when it·•s
a considerable distance out.
It is almost impossible to judge the distan
'
You can talk yourself into believing it -is almost any distance fro
I
.
.
you, ,. And when it gets on 1n closer you really have a bit m?re perspective
awe;y.
I did feel that I had almost Judged the distance on that first t
on ito
In fact I didn't even "!:>elieve that was it when .I first saw ito
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t cou1tln't
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, . ." think of anything ·else that it could be but it was just solid lighto
~d
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,[!, '"'
it turns -' out looking ' back now 6n it, · I -am..sure this.... was
because_the s~.'. :~- ::· -~~ .~,,
.
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Sci~ntific Debriefing
-3-
had not completely set; !')11-sure 1'113' ·retro pack .area was in the eunligh~•-,. , .
'
I'm sure that is what I saw
the sun reflecting ·off of it.
. glowing,--was
'
. AJ.though I had, not seen it tram· previous viewing OD tbe day side or the
night _si~eo
McKee:
When you didn't see it OD the first night side, did ~ou have any
personal feeling that the light' wasn't ~hing?
1;
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Did you correct your
F,.. ~ ...,,
.· attitude when you didn't see .it or· did you have any feeling what the problem .··:.
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Cooper:. I Just don't have any idea.
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I kept doubting Jey"Sel~~ • This was
.
the first time of course that I .had ever tried
aligning to small end forward, . •
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a 180° yaw -as weJ.call it and of course aligning , on the night sideo
' to doubt that I was aligned properly,
,
·,.'.,
I begaxi
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I went to the star charts and rechecked
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l't J ')
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night I was aligned exactly ·on and in using the horizon .line J~t about 1n : ,,:
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r and found 1n fact that I was not quite aligned correctly at· first . . ·But then ..• :•..:,
,,
I did double check ' and found that I was --- I'm sure several times thru the ' .·,· >.'.--~ i
!'
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~.
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.the middle of the window even moving up and down almost.. invariably•
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don't have any idea why I didn't see it.
,.
Bill .Armstrong:
You .did change your ·attitudes? ·That was one of·the th
.
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I wanted to Knowo• I?o you remember at the beginning of t~e night phase,
. you first start looking : low and then toward th~.'·eni·
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ust sort /of scan the area or vb&:
••
~ o/ -did·.
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f •"''"
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-4-
Scientific Debriefing
Coo:per:
Well first I started trying to get Tfl¥. 180° yaw point.
This is
not the easiest thing in the world to get on the night side, and particular~ . . , ,_
when you have to go
......
into your ■tar charts
norn:ia.;uy been used to using them.
-me the proper orientation.
50 ~ute1 ahead ot Where :,ou had •
ir:.finally did find star patterns that gave
'
,I was wiing, around 15 to 120 degrees pitched downi
\
I .was just keeping the horizon ~ th~ sort of bottom
'
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I got_around. ·this area, I then tried varying ·the· attitude ~P and down tolook for the light~
. ..
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You mentioned ' in your repOrt that,--you talked about approx
She:pard:
25 minutes a:f'ter you caged your gyros, that you saw' a ·lot of li'ghtning
par'tfcularly in that area.
.: • '.o:.
Cooper: · Well, · this is .,one possibility· that there was a slight compromise
to the . light. 1 Particularly on the first night side there was co~iderabl
large lightning down ther_e .
I found concentrations of large thundersto
•right up .in there and saw quite a lot iof -light flashing through fairly
I
large areas.
I still don't believe that even on the other night
spite.• of these I still could\
see :the light even with -:this as a·- ba.ckgroun
.. ... . .
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It is r~ally not an excuse for ·not seeing it ,and I really honest]¥ _
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say why I didn •t. . I had 'b~gun ~o doUbt th~t ,1~ was re
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p~ of the Window ~d~•:-1·!_·, :./·:~'l~·~ ;{
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,.
·,.'.,, ,·.
----···
.. flash
- ••
C
••
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t .., ,f-
'· • ,•• ·,

-5-
Scientific Debriefing
The moon was probably 14-al.
Cooper:
It was down to about a third moon.
It was a ver:, distinctive moon vb~ you ·could see it but it' wasn.'t causing
the great amount of light tbat a . twU moon would have caused. , , I could see
I
the glow on the ground, on. the· clouds :~d on the land, from the moono ., It
'.
up just at t1:ie .last part c,f the ~n1Jtrt. ·It- was never ·close to th~ moo:Q.
1
deylighto
. Bill ,Armstrong:
'i. in-the retro pack area; they ·ran •.cooler, this flight.
Bill Carmines said th$t they- b-4: ~;ualJ~· flashed the light at thi~ lo~r '
temperatures without .any probla.
Re talked to Langley people and he says
'
. that i~ the light had fail~ 1;0. work the first time it would have never
: , ·warmed enough later in the n:1~t to start flashing.
.
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it no~ having been ·working t-he f:Lrst time Bll;d then ·worked the second t:1.me.,,.·,
Do ·you think your _att,itude. ,..~~ •-eauld you tell any difference •in your
attitude, the second night vl,Am -~
·:
st •do you think 70\1. . •
. ·,
(
$.alf the ·llgbt.
: ••
.
It is hard to visuali~T .. ~: ; . '
In yaw as C?JDPared
~ed d~ ~b~ter the
,1
~ tip'.
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• •
;.

I'
Scientific Debriefing
Cooper:
.'
-6-
Well, not realq.
well estimate 18o0 yaw.
As I went into both night sides I cc;>u.ld pretty
The first' night side I was not complete:cy around,
,
,·~
I started :,awing around &114 ni,gbt wu audde~ upon me and I wasn°t quite in ' '
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the :t'ull 180 positi~, so I did have to hunt ,for 'the 180 posi~ion a little' •
'
bit• . On the second n:i..ght -side af'ter -I ejected the -light, I was alre&q¥ in_'
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· m:, 180~ position before ·g oing -into the night side.
..... ~+~•
Merce;:
H6w ·liigb above or ·below horizon line or -~dow did you look ·for light! ./; :; , • •
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In other words how .f ar down "or :how; high did you go with your ·pitch .attitude?
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On the first night s.i de I .allowed it to drift very, very slow:cy and •·~ • _• .. , : ,
. •
Cooper:
.,.
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...
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"'J.
\t. , .. , .. t
:,
' changed them as I needed to, 'very very· slight:cy to keep m:, yaw on 180° and· /./. '.., Y·
\
But X went '&1.1 tlle ~ down to
it varied back and forth very ·sl.igbt:cy.
'
)
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t,
. •' ;~ ~;~ ·, ,,,.~
t\ '• '
,
where the horizon ·1would fill the ·whole window and up to where. I Just ba.re:cy , ..,- ¼·.J., ·;
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~.. , __ i .1,.·.t- \,. r
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h¢ the horizon in sight.
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Bill ,.Armstrong: · Did you see it cane right a'WIQ" ·when · you·:iooked .on
I
nigb.t'l
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/ In oth
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· ·- :rd8 °you :picked it up.
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-1-
Scientific Debriefing
Cooper:
.Almost.
Just like that.
Almost as it began to get dark.
Zam it gets dark~
Of course it gets dark
I had Just,--it was dark earth background
and as I say 'lI13 first teeling on at,eing it was definitely coming :f'rom below_
j
very very slowly.
As I watched it was getting higher in 'lI13 line of sight to the
I
·earth.
In other words as I ·was holding -the earth on .a fixed place1ton the
window this was coming u~.
finally ·up to 'lI13 level.
It was · coming up in relation to me, and was
And ·. as I saw it coming up it was solid light.
My
first though. on it was -that it looked Just like th·e missiles that I have seen .
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It didn't have the same glow but it· was
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a ·high·•
launched at night :f'rom Cape C~veral; when rou 're t:cying at night at
altitude. and see them launched.
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very· very bright, and solid and <seemed to becoming up.
,, •'
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Bill Armstrong:_ That is something else we checked into• . It would have be~--;~
impossible for this light to have been steady_for -you.
It is neceSS_!ll'Y to
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fully charge the condenser and then get a quick discharge.
Cooper:
•,· •
That's why I think .it mat have been the suns~ine on it
Because of t~e altitude we were both at, the sun ·would be shining on it at
that point.
I had Just gone •into :the night side.~ Even though i~ was dark
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if I had yawed around to zero _yaw it ·would have been in ·. the bright sun.,
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Scientific Debriefing
-8-
of t he window when I first picked it up.
•
By the time it got up to where
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was may'be 15 degrees higher ( 1n relation_to me and m:, l.ine •of sight) 1
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suddeacy saw it flashing.
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Bill Armstrong:
~at' a ,.1ust where it would have been.
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just coming to the horizon.
If woul.d have·
John Boynton: ·Was this predominantly ~bove the horizon?
Bill Armstrong:
In the first orbit, no.
On the first orbit it is' very-1low~
That is why' he •might not have seen it the initial part of the orbito
I
about 20 or 30 minutes thru the1night s~de, it passes through the horizon
and then it goes about 25 or 30 degrees high.
It goes· through a fai,rly
large angle change. at first, and the further out it gets of course the
smal.ler the angle .change is. 'l'he second night a:f'tier depl.oyment •Just ·a bout ., ,_
.
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at sunset 1t start·s up through the .horizon and 't hen all the time .during the '
• '
second night phase it is ..above th~ horizon. · Then the third C)ne is · above the
1
hor.:Lzon all of the·'time.

,.
-9-
Scientific Debriefing
Bill Armstrong:
You get a 30 degree angle view througb'._the window.
the top of the window to the bottom,
variation of ·. 30 degrees.
John:
'·'
How far ·would he have to pitcp down'l
Bill Armstrong:
He would probably have to be below retroattitudeG
to almost have all earth · in the window.
Cooper:
Probably about 30 degrees G
I had a ~-:few comments that I made · on the onboard tape about the
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"I am at . 4st daylight going ixlto
·looking ,for that flashing ·
. dark" I had been
.
·beacon.
"This light in sight is below me.
~
It is quite a brownish
In other words I was
b;rown and considerable ~titude above the ground."
convinced it was not a light down on_the ground but _it had ·movemento
I
t
mentioned several other items here such as this light being ·visibl_e _among
the starso
"The ligJ;it is f.1lashing, now.
I
bright and quite discernible.
It is· the lighto
It is quite
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It appears to be about -10 to l2 miles awayo
I'm keeping it exactli in the windpw.
About the order ·of a second magnitude .. • '
\.
star now." and that time was 05:ll:34.
".The light is sM.µ in sight in .the ··. •
• -·
. . ;' ~ .;
'
' center of the window. 11 •
l
Bill Armstrong:
•
Did you,--acc?rding to -the voice tape it.
xruq, have yawed away a _little bit then ·. and then c;:ame .-back..
Did you yaw away and -t?hen •come right back to ~t'l ,

Scientific Debriefing
Cooper:
Just once.
Bill Armstrong: Did you do it twice or Just once?
.1,
Cooper:
·'
No, , I kept it 1n s,ight for quite awhile ·ap.d then yawed away from ·it
and then came right back.
Cooper:
At 05:13:40 I made some coments on the Mi1q Way and varioW;J
things and at 05:16:35 the light was still in sight.
Thunderstorms were
in under it at the moment but it was still quite distinctive..
And this
at 05:18:05.
Bill Armstrong:
What brightness do you think you need if you ·. are . going to
try to acquire some target in space.
Cooper:
It was very distinctive both t1I!1-es.
At this brightness where i~
was on the second .night side af'ter the ejection, both times it was very
'
distinctive more than ·the brightness of course, it was the flashingo , On
the third night side it was extreme~ faint but the ·flashing allowed me,to
pick it up.·' I wouldn't have been .able to see it .t he third night but
fl.ashing.
Bill .Armstrong:
Do you think that either at the initial acquisition -of the
.
>
.t hing ·or ·e,v en toward. the end of the second night phase the 1?rightnessl would "_
.
. . .. :
b~ sufficient if you wOUld be •t7:Ying to l~cate a re~de~vous target'l :·

,.
• I
Scientific Debriefing
Cooper:
I think so.
• -llI think with that brightness~ if you know approximately
'.
where to look for the thing and with _it flashing, you certa~
ought to be
(
able to find it pretty· readily.
Day: , Do you think similar experiments should be carried on ·or is this
sµfficient'l
Cooper:
I think this prob~bly shows us 'What we:- really want to seeo
ther e is going to be problem like there is in .aircraft a
I think
As YO:U move
to it you are going to have to have something that gives a little bit more
capability to obtain distance f'rom it at the time; su~ as perhapa,-two lights ,
that you cou.l~ raµge on; like naVigation lights on aircra:t'to
I
QuestiQn:
Were internal lights .on in the night observations?
,.. .
Cooper:
'
On most night aides I had all the lights down complet.ely and used
'
I
I
just the glove lights to read , critical items.
Bill Armstrong:
On ·t;he third night phase you say you had to do a good bit ,,
of' searching. ; Were you searching the entire third night, and when did you
fir-st see it'l
· ,1
I
·c ooper:
Slightly past the middle of the night.
I think that on the third
~ight side the· brightness was such that it was sheer accident that I found
\.
If _)rou Just happen to pass it' in t~e scan pattern you might _s ee it flashing,
,
I
(
:tt would, however,·
be very easy to Imiss. .. •
,/

·,scientific Debriefing
Bill Armstrong:
• l2-
You feel brightness suitable f'or a rende~vous
be something on the order. of second or third magnitude.
I
•
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•
.'
•
.
~ l
•• .
•.
•
-
'
Cooper:
'
Yeso
That 1 s one of t he main things we wanted to ·r ind out..
Bill:
of the secon~ night l ook about right?
Does
Was the third night too d:l.m'l
. '
Cooper:
Bill:
Yes, the third one is .getting ·a little too d:l.mo
.,
I •
Do you think you have got to have good sighting
information
.to
pick . ,.
•
I
•
these up ev:en 'W'ith bright light7
J'
C~o:per:
Well, it is a pretty big sky at night .up there and there are a lot
of bright starso
I
I t hink ·y ou're going to have to have some -sight~g,..date.
to get within a ~easonable ~one area to hunt . for ito
McKee:
What about the flash ·:rrequency r ate'l
• Cooper:
I
I think the f lash rate could be cut downo
I think you could maybe
haJ.ye the flash rateo • I woul.d rather .- see it twice as bright and see it fl.ash
·\
,
.
.,
half as of'teno , A
distinctive. ·:
. flash , rate, even -one every two seconds is. stii;t
,.
.
.
I
May1>e not quite as distinctive as ·the one per second, but it •Still wbuld
.
'
attract your ~ttention.
_Bill: • How about the· deploy marks?

-13-
Scientific Debriefing
Cooper:
Those deploy marks worked real well.
in 1·etroattitude also.
They were excellent for getting
They -position your head ·to a real positive position,
'
,
I
"
I
Bill:
We have read the attitude ·records pretty carefull:yo
20 a.nd 22 degrees, so you were right in .there.
You were between '
Do you think the window
I
smudges, the discoloration of the window, might have had significant effect?
Do you think it produced enough attenuation to cause any trouble?
,
.
Act~ I tried and tried to note how much attenuation you get at
,.night.
.
It's just a few seconds until the time you get dark-adapted; I thought
you became dark .adapted very rapidly, and I didn't see or note any real attenuationo •
• I am sure there was some as there was definitezy smudge layers there ... .- But·,,.
it didn't seem to be....
The bright stars sure seemed bright.
.
'
.
,,,.
(,
Bill Armstrong:. • J)id you a c t ~ see the light against the ground'l • , •
\
Cooper:
Yes.
I made this comment ·here that I even saw it against the
thunderstorm.
I
John Boynton:
· o
Go:;t.;do, you talked about the flash rate.
The flash rate in
, your debriefing ·might have been ·. slightzy below a flash per ·second.
, Cooper:
I did it on the tape • . I counted off here on the. tape so. you could
get it of~ the t~pe.
I counted 1,2,3,4,5,6,7;
slightzy s+ower ·than ·one flash .per. second..
It seemed to me that

.
I
Scientific Debriefing
Question: . What did it check out'l
i
-ii'
•1~
.j Carmines: ·.62 (flashes per minute).
l
\
Bill:
Did you make attempts to see it· on the day side'l
Cooper:
I sure did.
I never saw it then•
. Armstrong:
It should ·have been closer on the dey side than in the night
portiono
,
It came 1in c;l.oser, arid started out away some time during ·the f:t,rst .
day. pass )
Before you picked it up it had started out again.
It should
have been in to about two miles sometime during the first day sideo
Cooper:
At first I was on 180 degrees .yaw, and allowed it to dri:f't offo ·,
' _back' ,' •
didn't find it, but e·e'fore I got to the next night side,- I brought yaw
.
•
to 180 degreeso· There was a possib_ility I .m issed •it thereo .
,,
~
McKee:
Did the flash seem very consistant'l
Cooper:
Yes, it seemed to be very consistant .
. Carmines:
Cooper:
Carmines:
Did you see it tumble'l
~
,,,.,)II'~
•
•
••;

Scientific Debriefing
Bill:
-15-
The spread of light isn't too great.
J
',
Coope~:
It is pretty hard to Judge the; light
Mercer:
Did .you see the ·stars during this• ~'l
,
Cooper:
I
Not this particular ··orbit.
I
No I didn't.
I
(Second Experiment • Balloon J?.ra,g)
Dey:
Mr. Carmines will you give. us a quick run-down on ·.the -balloon ·expe
failure?
Carmines:
I tal.ked with Instrumentation people and everyone agreed that
we really don't know what happened.
We had one relay actuateo
There are ·
several possibil.ities • . To me the most l.ikely place of trouble is the final •
plug.
The pins are on the pigtail and in putting this together you can bend
'
\
I
W~ checked the plug :and.in this case the
these pins and get a misalignment.
'
:pin is near ·the case ~d if it ~ent it could ground..
I
Bill:
.
•
The squibs were in parallel and a number ·of ·tests showed' eithe:x: •one '.- ·•
..
of the squib would fire the latch.
I
I
'
The most probable cause , is in ·the circ,uitry.,
'I
'
(Discussionoon ·G~ound Light _Observation)
,
Bill Armstrong:
How hard wa.s it to pick up the light when .you .first
Did you have -t rouble picking ·up this ground light at all?
,
I
, ,
•
- ' ,'
-·
l,
'·. .
. .. -. ,
. ---: -, :, •
, •
• •. . '
I ,

',,
'
-16- .
Scientific Debriefing •.
;
>fl' '
'· ' ,.
Cooper: No. It was just a bit :further to the l.e:f't than I thought
be.
More toward'. the · center of' the window?
Bill:
Cooper:
Noo
More slight]¥ to the le:f't of' the window.
yawed ·off a l.ittl.e.
I coul.d have been
I thought the pattern of the l.ittl.e town, . it was by
was rea.l.ly more distinctive than the l.ight. , If' I hadn't "imown _the light was
there I 'WOul.dn_'t have sel.ected it in preference to· l.ots of other lights I saw'
on t he ground,--•if' it hadh't been for the l.ittl.e horseshoe-shape towno
,Bill Armstrong:
What brightness did you see at thi's attitude?
.
.
I woul.d sq it , was about between third and fourth magnitude
•
I
BaW it.
'7· .
AB you continued to obse;rve it · did Y9U notice ~t dimming?,,
Bill:
Cooper:
Noo
I coul.d see it f'or se:veral. s_econds-.
One f'alicy of the ground
lights is ·that you are moying on the ground pretty rapidlyo_ You don't have
mariy
seconds to ·observe any ·:f'ixed points op. the groundo
It's moving right
on past you and gone fair]¥. rapid]¥. . ·of' course as it gets on .out it gets dimmer
·t
,, ,.
~
and dimmer •
•,Question:· / Havet yOU .&J;IY idea how~_lo~· you ·~
able -to ob,serve it?
:
;
'
\

Scientific Debriefing
-17-
Cooper:
I doubt if it was that long,
I
Maybe as long as a minute.
I
30 or 40 seconds.
I lost it because it got too weak.
It was a long~
:f'rom being. straight out on the
,, horizon but as it got . on up towards that
direction it faded outJ
'
,' I
Bill:
In checking the plot, it ·1ooks like it varies from a little over
second magnitude when you forst saw it to about a sixth magnitude when the
light was turned off.
'
•
'
I
/
McKee :
Do you know what angle you pitched down to'l
Cooper: . I believe it was to -40.
I was then at ~he angle we were
to pitch to. . I apparently had eased off in ya~.
well right up the window.
i
"
However ·it tracked pretty
So the yaw was fairly ~ell: ·on.
But the., · •
-
light was off a li~tle further to the lef'to
·,
.
Bill:· Did you· ever look away from the light and then .look . back?
able to do this and ·pick it up again? ,
Cooper: .I took ray eyes off of it and had them on the photometer and looked
•• through the hole in it and extincted it.
Turned the dial the wrong way in
/
',.,1
• the ,d ark,,' and I- did extin.c t ·a ll right.· I thought I'd ge1; a good reading on ·, • • .:
•
, , it.
,,,
I
I
I gave that device ·up.
It did extinct.
Bill: ;• Did you ever notice any change
,I
' ll~
,
~
'
•
'
I
:
~...
I
'
•

,.
1' '
Scientific Debriefing
-J.8-
Cooper:
Yes, it got dimmer.
Mercer:
Cou1d you see _lights of cities through J.a¥ers of cl~dst
Cooper: 'I saw a lot . of cities underneath the clouds.
yaw ~ignments was over Shangpai. •
..,
i
Mercer:
Were light patterns more •distinctive than individual bright lights?
Cooper:
Yes.
I was , over the ·e ast coast of. Australia. · . I saw t~e very:
distinct city l.ight patterns there around the Melbourne area.
Paul:
.
,
'
.
When the light dim:Ded .out did ·you lose the-l.ight
Cooper:
I l.ost both in ·much the same period of ·time. :
·Jones:
Did the ground-li~ _appear sharp as a point .source or· was it
diff'u.sed?
' I
·Cooper:
:Ct was more' diff'u.sed.
Not a sharp point.
single light but it -was not like the stars.
Smith:
You think a: flashing light would be preferable?
,
/ ,
.
'.

-19-
Scientific Debriefing
Cooper:
~finite~:
The ideal would be a series of lights.
A better
combination would be a series ot flashing ·lights arranged in .some pattern. ,
~ e like a running rabbit strobe pattern.
I am sure it wouldn't have to
be synchronized.
Bill: 'You mentioned how fast :fast you were moving.
Do you think you had
enough time to make use of some sighting ·device such as -a sextant? .
Cooper:
You aren·!t going to be able to take very long. readingso
Youvre
going to ~ave ✓ to be set up and ready to go, and you 're going to have to have
some devices .that are •r e ~ usable.
You figure that when you get from the
west coast of the United states to the east coast of the United States, the ,
. '
ground is moving under you fair~ rapi~ in ten minutes. The ground is
.
moving t .oo fast. You need to have some devices that are r e ~ usable and
you need to be se~ up and ready t(? go.
' .
seconds for a reading._
Bill Armstrong:
'
I guess you have about 20 to 30
One · of the•·,·phas·e s· of the Apollo mission .requires a position ··.
'
fix ~ile still in a holding orbit.
Before going into ·the translunar ·phase ··
I
•
sightings of earth fixed targets for navigation would be ab~ut the same
yqu experienced in the ·ground light.
Would this .b e practicable2
J
,,

I
i
I
'
Scientific Debriefing
Cooper:
-20-
You 're going to have to be right on in .attitudes.
to have to know exact~ what time it's going to occur.
You 're g~ing
I'd guess you have
I
about 20 to 30 seconds to do your ·actual sighting and you have to have a_good
'
angle off to do it.
• I
Bill:
•
How about the brightness Gordo?
How do you .feel about this part and
leaving .the flas~ part ' out of it? · Was it bright enough light to be seen
eaai:cy?
Cooper:
Tl;l.ere were a iot brighter ·lights on the groundo
Bill:
I'm sure of that but do you think this is sufficient?
Cooper:
You can see it.
you're J.ucky.
.spot it.
If you look for it and know it is there and if
Knowing where to look for it and no cl.ouds there, Y9U can
(And awe::, :f'rom other ·background lights.) · I still think a pattern.
woul.d be better than going ·to a brighter •light.
I !l,on •t think the cha.nge •
in the brightness of the light would be as effective as making .some kind .
I
•
•
./
of a patterno
~
l
Did the ground lights twinkle?
Cooper:
Yes;
Just like the stars do looking at them :f'rom the ~01:1-lld,
as the' stars don't1t ~ e there.
McKee:
,
I would like to ask. 1 You seemed to have seen our ·-lights as we
expE:cted • . You .saw some objects on -the ground better than we expectedo

t Sc i ent ific Debriefing
,,I
-21-
/'
1,
, i (McKe e continued) you say why you saw such small items?
ii,
,\ •
!~
l
'' Coo;pcr:
I was coming :f'rom Houston the other day in a 102 and I not ed I
,.. coulcln 't see nearly as clear around ·40,000 feet, particularly in one area
. that I was in.
There was · a lot of haze and it .was quite humid and I couldn ' t
I
disti nguish things on the ground very well but yet when I got into the west
coast of Florida and got into an area that was somewhat clearer, at t h e same
altitude I could see many things.
I think again, that it depends on how much
humidity _you have and how much haze is in an area.
I passed right over the
vicinity of Los Angeles and San Diego and never saw them at all.
very surprised.
I waoo 't ,
I could see where they were but I couldn't see them.
I
passed right over Miami and Miami Beach and I could see that there was a
t 'own there . . Ther~ was a lot of build up and civilization.
the streets but the buildings were not very distinct.
I could see
But yet over areas
of El Centro:·and the Salton Sea and ·the dry lake areas I could see tremendously
greater detail, 8J1.IJ. individual roads.
Over the Himalayas, up in Tibet, of
course there you'r~ above a good portion a certain amount of the atmosphere
J•
i
I suppose, I was really surprised: what I could see.
,
I found some real
detai ls and little , villages with maybe 20 or 30 houses I suppose, stood out
i
very distinctly.
'
•
•
You .could estimate the number of houses and if a house was
out individually away f'rom ahythirig else I guess against the right color
background, the yard, I could discern individual buildings.
of t h em with smoke 1 coming out of the chimney.
very sandy blowy, dusty; Tibetan are.a .
f'roz en over and some f'rozen solid.
I saw a number
There was snow on this upper
I could see a lot of lakes some partial.ly.y
The visibility was tremendous.
see vehicles that ,:;t assumed were trucks.
I could
I could see them kicking up ' dust.
...
:.

.
.
Scientific Debriefing
-22-
(MIT Horizon)
The purpose of these pictures is that we are teying to
Dr. Peterson:
find definite informa.tion."about the earth for Apollo guidance.
This is
of a group of four pictures taken in four_different yaw directions, one
the sun.
Is this maneuver an expensive and troublesome· thing to do'l
Cooper:
It takes control power; ·it takes control fuel, , it takes time.
However, it is not real expensive as far as fuel.
up.
You have to stay power
We debated back and forth about 't he most accurate wa;y of making sure we· .
get these 90° points.
We were a little concerned about accuracy and decided
to stay powered up and utilized .the gyros ~o locate the 90° · positions. • But
it does take that period of time of power ·to dr;Lve the automatic system;
does take that fuel to move around•
.,,
Dr. Peterson:
I noted you mention 25 hours 20 minutes.
there is a hole in the transcript.
· Co0per:
A1; that ~ t
25 hours and 26 minutes.
,
'
I got those at 25 hours and some odd minutes when the moon was set
in the west.
It was right where ·we had plann~d to get it the first time.
We rescheduled them later in the flight if we didn't get them at the original· 1
time.
But I took them as planned initial.:cy,.
Dr. Peterson:
On two of those ~twas possible to locate. the moon.
I
I
~
Did those come out all right'l
I
not all of them.
Bill .Armstrong:
Yes, . these
I•
·• ' '
are all of them.
(Looking ·at p~ctures)

Scientific Debriefing
-23-
Dr. Peterson: · There is a smudge in the middle of the window.
have been accidently concealed.
It could
Since these negatives are on1¥ suitable
microdensit9JI)etry there doesn't need· to be e:a,y discussion Qt the details ot • •
their significance•
. (Inf'ra.red Weather Photographic Experiment)
I
• Mr. D~:
I would like to move on to m Weather photography.
\
1
'
Soules:
This experiment went very well ~d we got the. information we ·
wanted.
'
Thank you very JIDlch. 'Did you· have aeytrouble with ·the
filter holder?
'
'
None at all.
-
It . worked •very well.
'
•
And the lens opening of 5.6?
Cooper: ·It was exactly-on ·what ·was marked on the 'magazineo
Soules: · There are si; pictures at the end of the series and I can Vt
- them. • Do you· have aey- idea ' where they could have been taken:'l
(There was a lot of table discussion of pictures here) ·
This was a:f'ter,:the. Florida series.

Scientific Debriefing
Soules:
You ma.de the remark that you were coming over A:t'rica.
aey more information?
~
Cooper:
-24-
There was none in the tra.ns9ript.
What base was this oni
\
/
I
Bill:
Wasn't one of them over the coastline?
Cooper:
Yes, I did one right on the . coast of A:t'rica.
~ight over the coastline.
I got one coming
Another ·one I got almost over ·the other coast;
:toward Johannesburg; it was· ·an inland picture, almost the northern areao
. ,'
Soules:
The last four are a ~stery. •
Bill Armstrong:
It, looks like you had about a quarter inch motion .on
I'm sure. I didn't. · 1I ' was ·holding the camera just
1
Soules :
, -Soules:
We might , check the camera.
What was the d o ~ t color of the ·earth over Baja California?
I
Cooper:
I :found that the green showed up very little.
• djstinct green that 'I
The only really
saw which showed up much was in the high Tibetan area.
It. was a \right emerald green, by ·some o:f those lakes.
,copper sulphate mining area.
It looked like a
The browns ·of the. .Arabian Desert Sand show,e d :
up quite distinct. • Th~. Sahara was :not quite so brown although i~ .did' have
I

-25-
Scientific Debri efing
( Cooper continued) ·a brown look,
cast .
Everything predominantly had a. bluish
.All. the :wat er, all the sea water, looked very very bright blue.
And areas -we ,know 'were heavy toreat •
'.
The areas that a.re definitely brown you can
Even the Salton Sea looked very blue.
areas looked kind of blue-green.
tell they a.re brown~
'
I
Soules:
I have a. question on the thunderstorms.
Cooper:
I could hear. it day or night and on both HF and UHF..
instantaneous .
Cooper:
UHF.
It was . almost
.
As I woul~-- see the lightning and the clouds light up , I
would get the static.
• ·: Soules:
Could you hear ·sta.tic'l
:
•
~
What i s the frequency band on HF'l
HF i s 15 megacycles.
The. static was louder in :the HF the.µ ·in tbe
You could j ust hear ·it, it wasn lt high magnit ude.
r
Soules:
• .
Was there a difference in loudness between day and night'l
Cooper:
I think night side w.as considerably louder.
thUDdersto~
'
were louder
,on ' night side.
Of course I noted
There were large _m asses of
thunderstorms out to the east of Australia.
"
SoV,les:
1
'
0
Did the flash come tram below the (?a.psule or •could you look off
~t ~ -. angle 'l
/
..

Scientific Debriefing
Cooper:
I could not see distinct lightning patterns.
.
It ju,st all lit ~•
I
The whole cumulus mass of clouds would light up.
Soules:
Did.you notice thunderstorms between Hawaii and Ce.liforniao
Cooper: -Yes, several off the west coast of the United Stateso
remember just how far.
I don•t
There were several cumul.us buildups.
Soules:
Did they look like the usual thunderstorms?
Qooper:
They went on down·to a stra'j;us deck on into coast on .down about
Los Angeles.
They stood further -off the coast than up north..
\
• Soules:
-
the tropical' areas'l
Cooper:
•
Did you see any long white bands of clouds along the east coast in
Yes.
,,
' ,,.
One was over the Arabiap. desert that was quite distinct ..
took a color photograph of that.
Soules:
was· it a very sharp line of clouds with bµ.ild-up in it'l
Cooper:
Yes.
Soules:
Over the oceans did you notewwide bands with perhaps clear ·area
over it'l
Number 10 picture is over the Arabian desert area..
,
.
r/

-27-
Scientific Debriefing
Cooper:
No.
I noticed several large cyclonics.
I did not notice any very
I
disti nct sharp bands.
However I ~id notice tropical thunder~torms.
•
Near
I
-the Solomon Island Areas there were a lot of low streets and ridges ot
smaller cumulus clouds.
There were little rows of them.
'
.
;
/.
I
.I

f'~.
\ . fcient~.f'ic Debriefing
-28'·i
SoU::.es : Was the horizon always ·a sharp line?
Cooper:
Yes, day and 'night the hqrizon was sharp.
In the day you have this bright
I I
blue 'bund around it.
Soules:
Some photos show the horizon seemed fuzzy.
Cooper:
In the Himalayas on a couple of occasions where the horizon was rough
due to the mountains, the horizon was ·still very distinct.
Squles:
Did you se-e the moon at the time of occultation?
Cooper:
Yes, several times.
'•
I was sorry I d.i;d not get picture·s.
...
Soules.: ' Did you see a halo around the moon?
Cooper:
I saw no sign of a halo.
It was quite sharp.
Soules:
Did you ever see a slight flash?
I
Did the moon's color chang~ at all as it
went through the atmosphere?
1
Cooper:
No.
I was looking for this too.
I was disappointed in the moon scenes ..
·r didn't see anything di'stinctive at all.
Soules:
I made a sketch of haze layer.
Would you take a look· at 'i t and tell me
what you think?
Voas:
Gordo, would .you draw it on the board?
(Period demonstrating on blackboard of horizon, haze, etc.)
Cooper:
This is the earth with a sharp horizon on the earth.
level was always under me separated from the horizon.
line.
The lower haze
This was not a real distinct
It was a little more distinct and it appeared to be the same color as if it
were a cloud and as the stars would pass down through it y:ou could track a fairly
• high order of magnitude of star and you could track it ,down thro~gh haze and _it
';
would appear real bright as it came down through it.
Soules:
:About what magnitur could you see?
,,.'
II
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1cienti fi c Debriefing
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ooper:
-29I\
The stars in the Big Dipper could just be seen.
1'!1th the bo.ttom star sinking
i~
.,
I noted the Big Dipper
·~
I
l~
down into it.
If,
1;
11
,.
t1
The top of the layer would be bow ;:nany degrees above the horizon?
Soules:
i .
•
'
,,
)
Ooo:per:
I figured it was about six or seven degrees.
rl
l
(Long period of sketching.)
Peterson:
. I
Would you estimate any appraisal in terms of stellar magnitude?
You
explai:c.ed that the fifth magnitudes could be seen, did the weaker =- stars go out
• I
in that area?
'
(Still illustrating.)
Note:
During this period when ,900:per wa..s talking and sketching on the board,
the recorded comments are meaningless.
Cooper:
Dr. Voa.s:
I can't recall a single ti.me at night but what I saw the haze leyer.
I described the earth as. being d.a.I:k.
Which is darker, the earth
or the 11ttl.e band of sky?
Cooper:
When there was no moon the earth was darker.
light from the sky.
,· shinier black.
Dr. Voa.s:
Cooper:
It is a difference in two different blacks.
The horizon is very wel~ defined?
It is actually a different black.
There is a · distinct line of horizon
This is in complete night.
When the moon comes up the earth becomes lighter as the moon shines on it?
Cooper:
It shows up distinctly,' especially when there are c;:1.ouds.
Soules:
Here is a picture that Wally took.
Soules:
. .
Does that look like a haze band on the •. •
.
horizon?
O'Keefe:
The sky · is a
The earth is a du.11 black.
and the earth is darker.
Dr. Voa.s:
In general. there was more
When was that picture taken?
.
Is that too high?
-

-30Scienti f ic Debriefing
I ('
'i f oules: You saw something over South America?
,! l
I
fooper: Yes, there is this other higher level I saw over South America.
l
~---------
ptanley Soules: Did you see different cloud layers at night?
'
~ooper: Only i:t there was moonlight and if there were towns or cities below
them.
On several occasions I could see reflected light particularly through
stratus type clouds.
Soules:
You could distinguish clouds.
Does the earth appear as blue to your eye , ,
as it does in the photos?
Cooper:
Yes.
Soules:
What is the color of the· twilight zone?
Cooper:
It is a baby blue~
Soules:
Did you see any meteor trails?
Cooper:
No~
Soules:
Did you see ·a lot of sun?
C<:> Oper :
I Sure did • I T.TCIIY'
"....... l't to tell you I did'.
Soules:
Was there any evidence of a corona?
Cooper:
No.
The overall color is pretty blue.
It is a pure~ pure blue, very, very_ bright.
.,
Cooper:
'
In fact, the sun appeared to be like the moon 'does i'rom the earth.
But up there
It doesn't look the same
It is a very arc-like color, bluish white.
!
I
,,
it is just a glob and it is very very whitish bri_gb.t.
Question:
I
,
Very bri ght. You know down here there are all those rays around it.
color.
I
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What about the looks of the ds.y slcy?
The ds.y slcy just is not as dark as the nie,:it slcy.
It is black and dark
but not as dark as the night sky. You can see the brighter .stars on the day side
when you are away from the sun and neither it nor the earth shine are coming in the
window.
Give yourself a few seconds to get dark adapted and you can see the brighter·
'
stars. They };lave to be fairly ~right to see them.
On·the order of '3rd magnitl.lde.
I

-31-
;-, pcientj f ie Debriefing
1~ l
.pr.
Voe.s :
,,
The day sides get a lot lighter, at night they are about the same
i
fia.rknes s as the inside of the spacecra.f't.
The night sky and the day sky is about the same as the difference between
Cooper:
I
.
~ jet black and a dark gray . . (It is about the same difference b_e tween the night
\
,
sky and the day sky.)
..
'
It is a sorter kind of dark during the day.
Not nearly as
dark as the night sky.
Dr. Voe.a :
Is it a smooth overall gray on the window?
Do you see any chance at a.l.l
that the grayness you noted could be minute amounts of scattered light from fog onthe window?
Cooper:
I don't believe . so, Bob, because immediately when ·you got a faint amount
of obli que llght on the window it immediately looked like it was iced- over.
All
you had to do was get just a faint amount on it and it appeared to be just likeI a
canopy frozen over.
O'Keefe :
Was this scattered light 1n the window or not?
I hoped you could see,,
some ki nd of a pattern.
Cooper:
That• s what I •m saying.
When you have any kind of scattered light on the
window, when the window was in any kind of an attitude (demonstrated) say this is
.
• the window
and out here
is . the sun, any time the window was moved around where
.
•
there was any kind' of light shining on the window - just a faint amount of it
. would completely obliterate the vision through the window.
IFR.
There was just no looking through the window.
I just went completely
Of course, the earth gives off
an awful lot of light, and you can't see anything as long as the earth i s shining
in the window.
Any time the sun was back here fmd I was faced away from the earth,
regardless of attitude, the sky appeared to be a smooth gray.
O'Keef e :
You could see the griton\ the window?
• Cooper :
You could see the light actually impinging on 'the Wind.ow.
• the scum all over the inside of"the outside ~e.
You could see
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fcienti f ic Debriefing
'
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~'Keefe :
Somevlhat of a pattern?
•i¢,ooper:
That's right. A pattern over the outside of th~ window as well as the
I
•
scum on the inside;
l
(·
()'Keefe:
It this had 'been scattered light you would have had this pattern?
•.
Cooper:
That's right • .
(Dim Light _photograpbs.) .
Presentation of Dim Light Phenomena.:
Day:
1
Roach:
Roach, 0'Keefe, Huell.
You had above this haze layer another layer. •Would you sketch that'l
(Illustration.) •
Cooper:
This one time I did have it.
I am almost certain this was .about
24 hours
I
and 30 minutes over South America. , I was facing to the east and was on dri:f't, I
think.
I was_looking to the east, northeast area.
0'Keefe:
Reference was on page 26.
Cooper:
That was the luminous activity on page 37.
I was in ful1 dri:f't.
"Righi? now I can .make ou1;
a lot of luminous activities in an easterly direction."
on a 05 13 40.
The Milky Way was quite distinct.
America) I couldn't make out on this layer.
/
'
'
This was at 05 11 34 and
This particular time (over South
'
I wouldn't say it was mu~ like a. layer.
•
It wasn't distinct and it didn't last long; but it was higher than I was.
It wasn't
/
in the vicinity of the horizon and was not well defined.
Roach:
More like a patch?
Cooper:
Smoother.
Roach:
You didn't feel this bad' a discrete shape?
Cooper:
It was very indistinct 1n· shape.
It was a good sized area. •
It was a faint glow with
a reddish brown
;
. cast.
· Roa.ch:
Because of your altitude or what'l .
:
I
.
, - - - . -~--~ - - ~ - ~ - - - _ _ _ ; · . . . . . . . 1 - 1 . - -

-33-
Scientifi c Debriefing
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. l' Cooper:
It wasn't so distinctive as to move back on to it.
1, 'l
•
'4,nd definitely lighter than the sky.
It was very faint
It was picking up some light of.•some type,
'""
-'j t was light in contrast to the sky •
•
'ick Day :
C\'poper:
Could you see this better out ot the corner of your eye?
Yes.
Sort of that type of thing.
I'm almost certain· that this was
over South America, just coming up on ·to the northeastern part of South America.
It was around 50 degrees West and about zero degrees of latitude.
Roach:
This reminds me of what Mr. Schirra saw off Madagascar.
Cooper:
He saw .it off North Africa.
defined.
I-twas rather diffused but not covering the whole earth.
Roach:
It seemed to be ·quite extensive but not .well
Could you tell us what happens when you pass from day into night, around
twilight? . We are interested in horizon effect after sunset •
.
' \
Cooper:
(Cooper draws some more pict~es.)
You never tire of looking at the sunsets.
As the sunI begins to get down
towards the horizon it is very well defined and not diffused as it is 'when looking
through the atmosphere, and it is quite difficult to look at.
It is quite white
and as i t gets on down to where the sun begins to impinge on the horizon line it
does give ·a spreading effect.
The sky is getting quite dark here and you get the
1
impression of blackness up here.
I
(Illustrating.)
.
The layer is bright orange ·
color and light spreading out in this direption •••
As the sun begins to go down it is replaced by this' bright gold orange.
It extends
out ·for some way.
The sun
It defines the horizon line fairly well at this ·time.
'
does begin to get this flattened effect.
Roach:
What was it'·s maximum flattening?
Cooper:
I never got too much.
.
\
It appears to get down part way below the horizon
/' n

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. Scientific Debriefing
!
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;._ ~d _spread.
j _.
-34-
It doesn't take long.
As it goes on down you still have this orange
I•
•
•
fight on the horizon and this area is all considerably ligliter althou~ black is
.,,
goming on down.
You do · ge~· glow up off it.
You could actu~ sWing away and tell
l
light
w ere tlle sun ll&d set a number of seconds after.
:,?
It is not ray-like.
It
/,
is hard to describe. ~e sky area: is lighter but there are not any rays. ,
\
Note: At this time there was a general discussion of the night sky ,i mmediately
af'ter sunset.
The transcript is too incomplete in this region to give a recorded •
account of this discussion.
It appears that after describing the sunset and the
airglow layer someone Ast. Cooper an additional glow extending vertical above the
i
position on the horizon 'Where sunset occurred.
Obviously reference was being
I
made to observation of the Zodiacal light.
Cooper:
That' s right.
After this effect disappears ( glow of sunset) and you •
think you're on complete darkness, I would guess on the order a minute after
I
sunset, you get this other.
very far along.
I gue.ss two different times I saw faint glow but not
.,
It lfS.S more on the order of 3 to 4 degrees farther on
-------•and a fainter order . .,
Roach :
Did you 'notice this was cone shaped?
Cooper:
A little bit cone shaped.
Roach :
Did you happen to sweep across it that way?
Cooper:
It was a minute or so prior to sunrise and I moved back across and about
J
'
'
the time I got back the sun was there.
Roach:
Did it seem to be confined in your Window'l
Cooper :
Yes.
Roach:
Was this jus~ before sunrise?
Cooper:
The sun is . getting ready to come up and at' this particular time I got
0
The bright blue -band grew wider as you moved away.
this glow prior to getting a blue band and in a few seconds the blue widens and '
I
. widens. ,
...
'.

. -35-
§~ientif ic Debriefing
Rpach:
Is 'this :phenomenon very close to the sun'?
Cpoper:
I had the feeling that this was just a glow off the su.µ._ It was not
•
1: '
·'i
7,1.',
~P bri©J.t
~
:1
as the Millcy Way.
:
Mercer:
Was it tipped to the right or le:f't of sunriseZ
C~oper:
I was sitting tipped myself and don't rememb~r vb.ich way it was.
l
I have
the imp.ression it was not vertical.
Dr. Voas :
It appears the red and gold you• described at sunset does not occur
at dawn .
. I
Cooper :
Sunset is more of a golden orange.
Dr. Voas :
Did you notice any of the flattening as the sun rose?
Cooper:
Not as much) but you do get a little bit.
Roach :
Going back to the time just preceding retro, were you constantly on stellar
observat ion before the dawn?
Cooper:
Yes.
,(
Were you able to follow any stars'?
. ...
With the sun to my back, the first thing I got -was the moon glow..
and through the cloud below I got Shanghai.
The first •indication· you get of the
sun going up behind you is the lightening of the clouds underneath and you note
the clouds getting iighter and lighter and you can still see the stars.
As you
\
reach a certain point., your window gets enough light - your window appears 'c ompletely
frosted over.
Roach :
What star were you using? ,
Cooper:
I was using Betelgeuse and tracking on.~ up from that to Sirius and Procyo~
and then I had a bS-l7ren area.
the last .
clouds..
.
Then I believe Castor and Pollux and Corvus was
I couldn't pick up Antares.
By this time I
-was getting good light on
The stars don't give ·you much yaw determination.
You can si
there for
a long t ime' and if 'you hold rates . very close. to zero you can get a fairly good
indicati on, but it is a lengthy process when you are determining yaw by seeing the
'
·-- ·movement ' of stars.
·-~...,.. --- - . - .·--- ' - -~ - ~
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.S~ientific Debriefing
-36l\ ;
.
~iach: ' From that standpoint, is it better to retro in the da.yl~ft?
~
cqpper: . You could probably do .it at night, but it is preferabl~;- to do it in the day.
,
Njte:
'
~'he next few comments are not interpretable, but 1t appe,-.rs eom one raised
~
.
a ~question about the blue horizon band visible during daylight,
This is ·predominantly blue· and if you have land masses or things that .
'
you know are not blue - - - but this is about a two degrees thick band. It isn't
Co'pper:
,
'
quite as thick as the band underneath - - - the last layer at night is thicker
I
1
.
'
l
.
than this blue band and it is a brilliant blue.
Roach:
Then, is there some structure above the blue layer?
Cooper:
I never could see pattern structure above that.
This is any time you have earth shine.
It is really not black.
This is not a real sharply defined - - -
There is a little blue gray going thru this area here.
The overall band is real'
bright pale bluw and just faintly diffuse on this side.
(Explanation is made using
a sketch at the blackboard.)
Question:
Cooper:
Is it diffuse on the upper side?
It is not just a real sharp line or two different distinct colors.
It does
diffuse very slightly,.
Question: .How wide is that band in angle?
It is about 11iwo degrees.
,, Cooper:
Huch:
I understand it gave a little problem in roll and yaw.
.,.
You said just as the
sun was s inking. _
Cooper:. That's right •. Tb.is is where I could tell where the sun had been.
I moved
back to t hat and I put the gyros to free and went into the automatic mode. , (Again
using sketch.)
Huch: , Wi th reference .to the sunset, do you estimate the time when the Zodiacal light '
sequence was started?
-:----....,.. ••
p
' ..-:-T"'7-
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-37-
Scienti f ic Debriefing
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."i
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·,qooper:
I would guess it was on the order of 20 to 30 second.s 1af'ter sunset, that is
,
/
jµst a guess.
And this is all the counting I was doing to give ·you the timing and
:I
•. ~
~ere ~a s interference from the ground stations.
I
.~
,-llch:
i1,
1
Did you observe capsule sta.bility - did you :f'eel it ~s holding sufficient'.cy
·f_
~till for time exposures?
cboper:
Of course, we knew it would be moving.
Did better than I thought i t would.
Huch:
For the most part they came out quite clear.
You get pitch up at the rate of 4° per minute.
Bill Armstrong:
Cooper:
Actual:cy, you had more than that.
Shepard:
During the Zodiacal light sequence, you had over . 5 degrees :per minute.
Question:
What are your attitude tolerances •in ASCS?
I would say within about 5 l/2 degrees.
Cooper:
Question:
How fast is this per minute?
John Ve:n Beckel:
Shepard:
The period is 2 to 3 minutes per oscillation.
It is about .05 degrees per second.
,,
The limits could be as much as 11 degrees.
John Van Beckel:
Cooper:
This will be a very slow variance.
It is pretty close to plus or minus 10 degrees.
Did you ge~ anything :from·,.the latter portion of the picture?
The airg.l.ow
pictures?
Mercer:
Yes.
Cooper:
I worried that the angle of the camera was down too much.
Huch:
was there anything unusual that happened through the night?
Cooper:
Huch:
Coop-er:
There was a lot of lightning.
Was there an accumulatio·n of moisture on the window?
No.
To me it didn't seem to cut down too much.
You reported a lot of lightning.
Cooper: Right when I was taking dim light pictures there were several thunder-
Huch:
\
. storms and a lot of lightning.
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~cientific Debriefing •
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~epard:
Did you get any readout on attitudes?
~ercer:
We got good attitudes.
On the pictures, ce.n you relate the airg,low band to what you drew on the board? '!.,,
~id you take e:ny exposures into the sunlit sky?
(
Cpoper:
No, I didn't.
I was going to try and snap one of this planet but couldn't
get the camera out in time.
After I once got it out of the equipment locker, the
planet was gone.
Huch:
was the camera easy to use'l
Cooper:
Huch:
Yes, after I once got it out of the locker it was easy to use.
Would it be possible to take a picture of the Milky Way?
I
Cooper:
Yes.
The last picture that I made was this haze layer when it was so
bright.
It should be somewhere right near.
It was near the vertical coming through
the window.
Huch:
The range of light intensity was very extreme.
Cooper:
The last exposure I made was of this glow and I think I used a 20 or
a 15 second exposure time.
Note:
A general discussion was carried on at this point concerning the number
of exposures and general observations.
It is not possible to decipher these
comments into usable form.
(Radiation Experiments.)
Warren:
We have some preliminary results I will give to you later.
Did you take
the chamber out of the dit.ty bag and fasten it on the hatch?
Cooper:
I took it out of the storage container and fastened it to the hatch on
the first orbit.
Warren:
Could you give me a time estimate?
Cooper:
I would say within an hour •~fter liftoff •
..., _ _ .. _ _ - - - - - i - -
---
.
...
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-39-
;,scientif ic Debriefing
,. f
: }bu,ren:
Did you take it off prior to retro?
I,,
I►
'
Qooper:
Yes.
~rren:
Did you take a reading of it at any time?
I stowed it :lfl the glove compartment ~
I took it off just prior to retro.
(
I•
I
I
~
'I·
I
croper:
No, I didn t.
W~rren:
Di"d you place it vertically?
Cooper:
I placed it vertically.
Warren.
We got from that .and also from film badger you carried on under
Where did you place it?
I
clothing - - - We got an estimate of 15-20 milliroentgens.
more in an X-ray than you had here.
Warren:
I think you would get
It was. about what expected.
Is there any particular reason that the 7th and 9th orbits were left out •
or were you just too busy?
Cooper:
'
I don't remember which orbit I missed.
I believe one of them I was q~te
busy trying to get this condensate water situation straightened out and debated
.
turning it on later, but decid,ed I had better not.
Warren:
It wouldn't have served much use later.
Cooper:
That was the 5th orbit.
Warren:
The 6th and 7th were the ones missed.
Cooper:
The 6th one was where I was having the condensate difficulty.
I
r
I don't
know why I missed the other one on the 9th orbit . . We weren't schedule to run one
on the 9tht
Bill:
He had one at 9 hours and 4o minutes OX} the 7th orbit; then he had another
one on t he 8th, 11:15 to ·ll:25. ' And then you go into rest period after that.
Warren:
Bill:
Warren:
We got that.
~e went into rest period a:f'ter that.
Late in the night, you turned the tape on continuous and it steyed on
'
the rest of
the flight.
Was there any particular reason you could not have le:f't
·the switch on?
I
Cooper:
You mean the radiation?
'
We hadn't planned to do this because of power
~

'-
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, $cientj_fic Debriefing
I
·-40-
I •j '
!!
;,d
• I·
·,! d~ fonserva.tion. It does ta.ke a certain amount of power.
,I
!{
I.
I
~cKann : That decision was ·ma.de not to turn that on continuous: pecause it bad
s
I
I•
.
·r ever been checked out for continuous operation because of somp difficul.ties that
piight arise because of this.
\
~heps.rd:
?
That seems to be a reasonable decision.
l
I
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/
I
Warren : That is all I had. '
I
Cooper :
Did you get anything at all?
Warren :
Particul.a.rly on the 7th orbit we got some date, that gave us quite a
good b:Lt of background.
1
Thank you.
)
/
/
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-41-
;Scienti fic Debriefing
(General Observations)
,Pr• O'Keefe:
I u.:c.dersta.nd the hissing noise was completely -negative.
Can you
i e sure it was not then'l
<
I
Ooo:per:
I didn't ever hear it at all.
Dr. O'Keefe:
Cooper:
I had good fit~ing ear caps.
Were you listening for it at the time'l
Yes, except I had my visor closed and with ~he visor closed you can't
hear too much.
I
Dr. 0 'Keefe:
At one p~_int a rumor circulated· in the public mess that you had
......
seen a meteor.
Cooper:
This was a false rumor.
Dr. 0 'Keefe:
At one point you said you saw frost on the window. •
I
Cooper:
This is _the mat_e rial that turned out to be oil.
Paul Lewan:
Have you seen the terrain photos'?
coast of Africa'?
Cooper :
Have yo:u seen number 8, east
Does it look this blue'l
Not quite"' The film has fairly true'reproduction but in several cases it
might be a little more blue in film, than it actually is.
Paul Lewan:
Cooper:
How ·apout the shots over Himalayas'?
They look fai~~y true to color.
Paul Lewan: Where you're goo.ng over the ocean, could _you distinguish different
shades of b1ue'l
Cooper:
Yes, over GBI, E1euthera and Buba and right down the whole island chain, •·
you could very definitely tell the shallower water areas~
and green water in some of the lagoons.
You could see reefs
Not real distinctive green as you might think,
\
and you could se~ sand at about its normal color.
If you are looking straight down
on things the color is more true than if you're looking at an angle.
at an angle, there is more of a bluish tint.
If you're looking
...
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Scienttfic Debriefing
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l?aul Lowman:
I
;1
When you were over the daep ocean could you see FY evidence of currents'
o.t the coast of Africa or the coast of South America.
i4
Did you/ see different colors?
j
gooper:
~
;;
'
There was some slight difference in color.
I couldn't determine a pattern
(.
/I
~d couldn't determine what it was.· I thought it might be'wave patterns.
'\
Paul Lowman:
Were there different colors going over fores~ areas, over Africa?
Were t here different shades of green?
Cooper:
Not too many.
They looked to be a blue-green instead of a pure green.
Greens didn't come through too well.
They were somewhat diffused with this blue
color.
Paul Lowman:
Over the Himalayas, shot number 12, was the green true?
Cooper:
Yes, fairly true.
Shepard :
I think w~ should get weather records and corrilate the color with the
moisture content .
/
Cooper:
Did you get the list where I identified the pictures?
Paul Lowman:
Comparing with these rocket photographs over in El·•,Paso · area, do
you recall looking there or to we~t over Arizona?
Cooper:
I didn't.
I noted I was over this area.
It looked familar.
feeling in looking out I was right over the Mexican Border.
I had the
I don't recall just
what gave me this f~eling.
Soules:
There is quite a bit of detail in IR photos.
Cooper:
Just beforeI that I noted the town of El Centro and the air base.
noted one little dry lake area east of there.
I kept trying· to see Muroc Dry Lake
and Rosemond up north but neve:c :did see those, but saq several dry lakes.
one very clear.
It was not a large one.
I
I saw
It was about due east of Salton Sea
area.
~. -. Paul Lowman:
Cooper:
Could you:,see Biggs Air Force Base.
I didn't notice Biggs at all, in fact, I couldn't see the main part of
...
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1
fcient ific Debriefing
-43-
h~
'\i
~f he city: of El Pase,.
'..,
I could see some little isolated civilized areas.
I
pever
did see the main part of city.
,
tfi:
;Paul Lowman:
Did you see any distinct shadows from the terrai!n?
Cooper: •Yes.
You could see shadows of the m_o untains quite clearly.
l
t
\
Mountains?
.
Even more
/,
blearly than the mountains in the twilight were the shadows from clouds on ground.
Paul Lowman:
How did the camera o_perate while taking pictures?
Do you recall
shaking the camera at any time?
Cooper:
No:
Paul Lowman:
I don't recall shaking the camera at all:
They all look pretty good; I just wanted to make sure.
Is there
any vibration in the capsule when you are taking pictures?
Cooper:
No.
Paul Lowman:
Very little.
It is pretty smooth.
Do yqu think if you had a cha.nee to sit down with those photographs,
you could give us an idea of the inclination to the vertical or horizontal?
You
said over the West you couldn't see Los Angeles or San Diego, do you remember
how far north you could see'l
Cooper:
along the coast'l
I could see three or four hundred miles on up north.
of cloud cover-a lot of stratus.
There was a lot
You could see patterns where the ground caused
difference in cloud formation.
Paul Lowman:
Cooper :
How about on the east coast?
I
Could you identify anything there'l
I could see the Cape clearly on one pass e.nd ;the St. Johns river and
could see where it ,ca.me in the inlet at Jacksonville.
Right to a.bout Savannah,
Georgia and clouds became broken and I could see banks of clouds lined on up
to what I believe was the bulge of the Hatteras area and prehaps 150 _miles on
• further.
But clouds wer~ obscuring.
I felt I could see quite clearly on up north
to Hatteras and perhaps on up to the Washington area.
I made my turnaround.
It looked just like a map.
My sight of this was when
It was a great wide expanse of
...
I

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-44-
, ,cientific Debriefing
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:!- ~
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Ir
't
\
''.:, J
j he Ear,t coast.
l
But there was a quite a bit of clouds up north, broken clouds.
\
"'·t:
':\-,
faul Low.man: Were there any up.usu.al terrain features?
ti'
-gooper:
- - - -
~
I
-~
·t
k. O'Keefe: .Did you see anything that looked like a crater?
!
I
Cooper:
No.
Paul Lowman:
I sure didn't.
I was looking for it too.
You· went over one in Ghana, but I don't know if it ·was good or
not.
Cooper:
Over Africa there was unasua.l rocky terrain up in the Atlas mountains.
I didn' t see any craters.
Do you--could you see clouds and shore lines at night with no moon?
Dr. Voas :
Cooper:
Fairly well.
If there was no moon you could see them faintly.
Any other terrain features that you could see?
Dr. Voas :
Cooper: •No .
Not much.
Dr. O'Keefe:
You mentioned these small particles.
At night with no ~oon?
You could see the moonlight on the water.
Do I understand correctly
I
that they seemed to , be pushed outward from the capsule?
Cooper:
If you consider this west and this east 8.lad the spacecraft is going east,
regardless of spacecraft attitude,
if any time I fired one of the thrusters at
night, I could see glow from almost every one of the thrusters.
The pitch-down
thruste r I could see and the yaw I could see sh(?rtly after they got out of the
nozzle.
You get tremendous streams of luminous particles of fireflies, and
regardless of what attitude you were in, ther appeared to come out from the
spacecraft.
A grea1; many could be seen for some period imd they seemed to go
back along flight path.
•Dr. Vo~s :
Did they, actually appear to flow around?
Would you say now that they were
parallel ~ ~s they go back, they will appear ·optically to come together.
But did
they act ually curve around as if there was a flow field.
Cooper:
I felt they were actually moving around.
Their relative movement was
...

~
$cienti f ic Debriefing
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~
~
ti
i
i
1
\'Ot real rast·.
I could see them move right on out.
In a matter of 4 or 5 seconds
i
they would be as far away as the other end of the room.
Some you
t,
~t>uld see for maybe as long a.s 30 or 40 seconds.
,;'
~estion:
1
C~oper:
Do you mean back from you or back along the :t'light path7
I mean back the actual flight path.
I
Dr. Voas : Were these paths actually curved? You're of course familiar with the
fact that .as things go backward they appear to converge .
Did they actually seem
to curve in?
Cooper:
If I would be sitting facing this way, the ones out of the left yaw
thruster would move right out and move directly back along the flight path;
the ones out of the .right one would go out in front of me and would turn back.
John Boynton:
Cooper:
Did you note any difficulty in identifying lunar features?
I couldn't :9-istinguish anything on the moon.
brighter.
And seeme.d to have more light.
'
'
I couldn't really distinguish anything.
Roach:
Would it be practicl.e to have binoculars aboard?
Cooper:
I think it would.
Huch:
It seemed considerably
The moon was much clearer than on the ground.
Could you see the earth shine on the moon7
Cooper:
The moon w~s f'uller when it was settil:lg than at other times during the
night.
I never realized that before just now.
But
it seemed to be almost full
when it was setting.,• But on the night side there was only a thir~ of the moon.
How about that now. , The moon was almost f'ully round when it was setting.
I think
the :pict ures will show it.
Roach:
That could be earth shine.
Cooper:
That's right.
Dr. Voas :
Cooper:
It is a pale color, of course, in daylight.
Did it appear to you normal in brightness on the day side7
Yes, it was just a lightish blue color.
--------------.---••
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fcient:lfic Debriefing
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• f• I (
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~
, ·.;.
•Aiuestion:
l
-46-
·~
Could you determine wind direction and velocity by SillOke?
~
,.,,,.
I'
f
Cooper:
,iI,
I could tell direction - over the Tibet·area the wind 1was from the south.
,I!
'"
'!J.,.
·~uestion:
l,_
~coper :
I•
Did you see industrial smoke?
'i
I
1;,
I
I remember one fairly large area there was considerable haze and factory
1
~ype smoke winding up, but don't remember where it was.
It seemed to be;1 like an
\
inversi on.
Hanel:
You did not see the motion of the clouds?
Cooper:
No I could not determine the motion ~f the clouds. Oh, you mean velocity
by the way the smoke was moving.
Hanel:
I mean the clouds were moving .
.;:l
heparcl:
Your first question was could he tellwind velocity and direction from
the smoke?
I don't know whether I could judge velocity or not.
Cooper :
I could tell the wind
was bl~ving fairly strongly, because the smoke appeared to c9me out
stacks flatly, it didn't drift up.
of the smoke
But looking at the clouds, I could not tell
which direction the wind was blowing.
Hanel:
Did you have difficulty in seeing Cirrus clouds?
Hanel:
Another question.
in polar regions.
No.
Cooper:
an airplane.
We may have some trouble distinguishing snow from clouds
You had no difficulty in distinguishing snow from clouds?
I thought the snow was very very distinct.
It is just like flying
Sometimes when the snow is very smooth and even, it is difficult
to tellclouds from snow.
You can determine the cloud height if you have a good
perspective of the cloud height.
You can tell vhether the clouds are low or medium
·clouds or very high clouds.
Hanel:
You never took two pictures of the same a~ea?
pictures?
Cooper:
That is, two overlapping
'·.
Yes, I think I ~id over the Himalayas.
I have two pictures of almost
-
the same area of .the Tibetan High Lake area.
----.---
.
.· . .
. ~r
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"
tcientific Debriefing
-47-
Yes, th~y do overlap. - They are pretty badly tilted/but
they do
;. I
. '
; /'
'
Janel:
" you estimate how
Co~d
Did you have difficulty in seeing Cirrus clouds?
,
~\
wuch of the surface was covered with Cirrus?
~
qooper:
Surprising little of surface was covered with Cirrus clouds.
I would
I
guess nbout half.
There were some areas where clouds were fairly extensive.
Cirrus were biggest portion, about 75% of all -clouds were Cirrus.
Question: · Did you see any dust storms?
Cooper:
At no time· did I note a dust storm. ' I looked fpr them over Africa.
One
place I thought I might ·find them was over Arabia, but I saw no dust at all.
John Boynton:
the wiI1dow.
You .mentioned that particles of dust or water were attracted to ,t
Was this rapid or gradual?
Cooper:
Very gradual.
Numberous little dust particles, a little water and little
crumbs.
The larger objects didn't seem to be attracted.
about.
There was less motion after we powered down cabin fan. •Various pieces of
i
They just moved slowly •
dust or crumbs off of sandwiches I had eaten.
John Boynton: · Did you note they might have been attracted .to other areas?
Cooper:
I didn't note any particular pattern.
I did note the sun was very very hot
through the .window. . The particular pattern of the sun would be hot on my suit.
I
would feel heat through m.y glove when I touched the window.
...
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srientif
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··Pf. Voao: • You seemed to have the general impression that you w~re stationary
.~
8:fld everything else is moving.
~
Cpoper:
That's right.
t
You sort of become the center of everytijing, and you think
hpw you can move the earth around, 'When you want it, rather than move yourself.
I
Dr. Voao:
Now, as you sat there with this moving picture in front of you, did you
\
have the general feeling you were sitting upright or flying on your back?
I did very distinctly feel I was sitting upright.
Cooper:
A couple of times
on account of the way you fee_l in the straps like hanging upside down.
ti.me I dropped something, I grabbed at it below.
pencil.
Every
I never had trouble handling
I never had any trouble putting it where I wanted or getting it.
One
ti.me I made a wild grab for the · camera as I thought it was going to fall, but of
course it didn't.
Dr. Voas:
On periods af'ter you awakened, did you__ have· ·reeling you had gone to
sleep sitting upright?
Cooper:
Yes.
Dr. Voao:
Definitely.
You mentioned sometimes you had the feeling of being upside down.
this correlated with the spacecraf't being inverted?
Was
Visually, I mean.
I
Cooper:
No.
I think this was purely a feeling of the straps.
You're floating
in the straps rather than being firm; like inverted flight in an aircraf't.
Voas:
Did you have ~, general feeling of being stationary?
This general feeling
of being stationary was not changed by any control action?
Cooper:
I tried to give them some pretty good rates, but bad no feel for rates at all.
Cooper:
Vision-wise, you would see things changing ou then pretty fast, but it
wasn't bothersome at all.
Dr. Voas:
Cooper:
When you say "pretty good rates," this is 2 to 3 degrees per second?
Three, four or five degrees.
'
'
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. . . ..

Scienti fic Debriefing
-49-
i
(
hr . Voi~s:
At retro fire, did you note feelings of lateral motion?
11 r
, pooper:
On the third one, it gave me pretty good little boot in yaw.
IF
' il)r.
Vons:
t
This is distinguished from what you could see lookiig out?
As I .,
I
:understand it, you felt the retro rockets but they didn't change your imprilssion
that you were sitting stationary?
Cooper : All I did was feel them and I still had the feeling I was moving right along.
Dr.
Vons:
Did you feel you were moving backwards?
Cooper : I ~ moving backWards in retro attitude, then you get quite a motion as
I stated over the earth.
Question:
Did you have any sensations of change in attitude _between perigee and
apogee, perhaps as a result of the amount of curvature you could see in the earth's
surface?
Cooper:
No, I couldn't see any noticeable change in that.
What was more distinct
was whether you had haze or were in a clear area.
Lou Fir.her:
Cooper:
We identified one of your pictures taken vertical off Calcutta.
Did you note the one before that over the Rangoon area, with the little
things out over the river; they look like warehouses or something?
Fisher:
Did you see , Calcutta?
Cooper:
No.
Fisher :
Did you see any airports?
Cooper : Ye~, I saw numerous airports.
I
The runway patterns show up very distinctly .
....
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I ··i~ scient i fic Debriefing
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,Boynton : Did you find that later in the flight audio inputs became more startling
'
ior more distinct'Z Did they seem to be more profound'Z
•/
..
,~
:. ,;
:Cooper :
Later in flight, I began to' notice the relay panel wiping .back and forth
.
/whereas I hadn't noticed it before.
The music sounded pretty good.
If I'd had
\a radio on board, I could have used it.
John Boynton:
Did you find you might look forward to hearing collllllunications, say
more s o than in the· first of the fligbt'Z
Cooper :
No.
John B.:
Could you hear better?
Cooper :
No.
Dr. voas:
Not that I noted.
\
Did you at any time hear an unusual noise?
I
Cooper:
No.
Roach:
Was there any change of radio static in electrical storms'Z
In connection
'
with t he · problem of radio static, there is a phenomenon of static going to and
fro between the hemis:pheres, wen it returns it comes back as a ,wistle •
D~d you
ever hear a wistle'Z
Cooper :
Note:
No, I didn't.
Some questio~s were then raised concerning the appearance of the horizon
•
at sunrise and sunset.
I
Cooper stated that the horizon near the sun was a golden .
color at sunset, spreading away from the sun.
He stated:
"The real dom_inant thing ,
is that it is gold as it •is setting and it is real blue as it 1 s~arts to come up. 11
He stated again tha~ he saw the Zodiacal light both night and morning.
It was· a .
very low order magn,itude light, about the s~e at sunrise and at sunset.
He '
estimated its elongation to be ~bout 15 degrees.
,
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....

SCIENTIFIC DEBRIEFING OF LT. CMDR.
WALTER SCHIRRA

HELD AT NASA HEADQUARTERS, TUESDAY
MARCH 12, 1963

FOR OFFICIAL USE ONLY

15 November 1963

In Reply Refer to:
SM(JRG:neml_
1EMORANDUM FOR:

All Participants

FROM :

J. R. Gill

SUBJECT:

Scientific Debriefing of Lt. Cmdr.
Walter Schirra, held at NASA ,
Headquarters, 1arch 12, 1963

This document is a literal transcription of the
subject de-briefing made from the tape recording.
It is issued to participants only for their
comments · and/or re~ommended deletbn.
Deadline
for receipt of this is December 20, 1963. After
that time an edited version may be prepared for
wider distribution.

~ Q:~
gocel~n R. Gi ll
Enclosure

FOR OFFICIAL USE ONLY

p 1 &2
Dro Eugene M. Shoemaker, Chairman~ · Manned· Space Science
Working Group served as Chairman, substituting for Dr. John Clark,
Chief Scientisto

The following people were present:

Mro Carl Abraham, NASA Headquarters
Mr~ Richard Daniels, NASA Headquarters
Oro Winifred Cameron, Goddard . Space Flight Center
Mr. Maurice Dubin, NASA Headquarters
Mr. Larry Dunkelman, Goddard Space Flight Center
Dr. Jocelyn Ro Gill, NASA Headquarters
Oro Dale Jenkins, NASA Headquarters·
Dr. Urner Liddel, NASA H~adquarters
Mr. Oran Nicks, NASA Headquarters
Oro John Nordberg, Goddard Space Flight Center
Oro John O'Keefe, Goddard Space Flight Center
Cmdr. Walter Schirra, Manned Spacecraft Center
Mr. George Tennyson, Goddard Space Flight Center
Oro Eugene M, Shoemaker, NASA Headquarters
Dr. Shoemaker - I have a series of written questions to start
things off.

These have been submitted by some of the _people here

today and we may then ask for some supplementary questions from
the rest of the people this morning.
the question on airglowo

We might start off with

Will you give us · an account of

Mercury's passage through the airglow layers?
the planet Mercury?

Did it seem to have color?

How did you identify
Were there any

stars nearby?
Cmdr. Schirra - I think Larry Dunkelman and I discussed this at

3
great length and I don't know whether we could be any more
expansive on that subject than we have already.
The only
thing that I can think of that we didn't talk about is an
e f fective color of the planet 1ercury.
me as any other · star.
It was as white to
It was not blue, red or some other color.
It was definitely "star-appearing" to me.
It would have a
definite atmosphere where it would change colors and where it
di dn't have · any · atmosphere, it didn't change colors.
I would
say that from that it had no different appearance than if I could
see it from the earth as a star.
1ercury itself was plotted on my
star chart; which is · a very valuable tool for these flights.
There
is just no doubt where Mercury has to be and we checked on it and,
of course; it was Mercury.
I think Larry · called me one day and we
all were · surprised that I saw Mercury longer than I shouid have seen
it and I guess this was explained by its being · seen · through the
refraction · of the · atmosphere.
Is this ~orrect?
Dr. O' Keefe · - Yes, that's the answer.
made the contribution.
Mrs. Cameron is the one who
This is her theory.
Schirra - This · was a tremendous yardstick - as far as I was concerned .
It was so obvious to · me that I just had to take the time · to desc r ib e
its passage through the various layers of light and the way I
descr i bed · it · in the handouts "Results of - Third U. S.
fanned
Orbital · Space ' Flight; October - 3, 1962" that you have is about
as accurate · as I can · describe it now .
Dr . Gill - Could you · make a little drawing on · the blackboard for us ?

•
4
Schirra - Again, Larry, do you have that?
(Referring to drawing
prepared by W. Cameron and L. Dunkelman)
Mr . · Dun-ke Iman - We have.
Schirra - We sat down for about an hour and traced this very
carefully.
Mr . Dunkelman - It happens that the movement of Mercury behind
our atmosphere is really not phenomenally related to airglow as
such .
Mercury is simply a pointer - an index finger.
It gave us
a chance to see what parts of the upper atmosphere you were looking
at and this has more to do with ozone and atmospheric constituents
than it has to do with airglow.
We think the answer here lies in
the fact that the ozone is absorbing the orange, yellow, and green
light and leaves this interesting blue which is an ozone blue
rather than a Rayleigh blue and we think the reason why Astronaut
Schirra saw the several shades of blue is he may have been looking
edge - on at the ozone layer.
So it is really not so much related to
airglow as it is to the way of looking at what produces the color.
I think we are interested in finding out what causes the phenomenon,
rather than to attempting to learn anything new about the atmos­
phere .
•
Schirra - I think one of the reasons that · I was so enthused about
tracking Mercury through these colors is that I am a fan of blue
colors .
I grew up with a Maxfield Parish painting; if anybody
knows his colors of blues - they are fantastic.
electric blues .
Gold blues,
As a result, these caught my attention.
I am

•

5
not that much of an artist or poet, but I was trapped with this
set of blues and I did expand on it at greath length, I thought.
These electric blues O' Ke efe - (Interrupting) Subtraction is what it sounds like.
Schirra - So it connotes ozone in that sense - electric blue is exactly what it looked like,

A very, very satisfying color.

Dr . Roman - Coming back to the color of Mercury, do I gather from
your comment that you feel it was distinctly yellow, yellowish
f or example, or was it that you didn't pay a great deal of
attention to?
Schirra - No, Nancy, I would say it is very much like any other
star that · I would see, rather than having a color.

I didn't

detect a color.
Dr. Roman - Astronomers think of stars as having color,
Schirra - I have seen different-colored stars from earth-bound
environment and anticipated or, in fact,I was looking for different
colored stars or planets and did not detect any colors.
Roman - This means that your background was just a little too
bright to see colors.
Schirra - That, and the window itself just isn't an optimum plate series of plates - to look thro~gh.

I insisted that what I really

felt had happeried is that I was seeing no more than about 5th or 6th
magni t ude stars · that the clouding of the · windows, as a result of
the escaped rocket, reduced my visibility of the stars about one
magnitude.
dow .

In other words there wasn't gross clouding of the win ­

That is what I was trying to make clear by using magnitude of

stars as the yardstick in this case.

I'll stick with that.

This

•
6
is about the best way I can describe it.
I could see more stars,
as Scott Carpenter described it, when back on th~ surface of the
e art h and many, many more stars in an airplane cockpit than in
or b it al flight.
Roman - You could see more in an airplane?
Sch i rra - Yes.
So in the debriefing of the flight I stated that
this is not a problem for pursuit of Mercury flights.
It is a
p r ob lem for pursuit of space observation and with the Gemini
ve hic le, we have so1v~d th i s by having the windows properly
covered and also we hope so - well, Gemini doesn't have an escape
r ocket for one, which helps us,
Now on Apollo, we are plus or
minus on whether we can afford the weight of having window
cove r s, but if we do, it does have an escape rocket.
covers, then these windows should be protected.
If we have
And better, be­
caus e we will need the stars on this particular mission.
But to go
back and try to cover the Mercury window at this late date would
be p r ohibitive hardware-wise and schedule - wise.
O' Ke e fe
=
What would you cover it with?
Schi r ra - First of all
no tower · rocket .
for Gemini, we have no problem.
There is
With Apollo they had window shutters the last
time I saw the mock - up which is not at all static.
dynamic even though it hasn't flown.
It is quite
How this will be done I
don ' t know, but I think this is a requirement.
I don ' t even think
it; I know it is a requirement for Apollo.
O'Keefe - You don ' t think there is a possibility of putting a thin say, some transparent grease over the window - which would come

•
7
off in the vacuum?
Schirra · - This might be a way of doing it.
Having it sublime
away or something of this order.
O'Keefe -
That could be done.
If that were done ...
Schirra - I definitely feel that th~s should not be a neglected
problem; if we, for example, do remove the window cover from the
Apollo command module.
It definitely should have some type of
protection when the star rocket goes.
This is going to be a
by-product of its own combustion, it won't leave marks on the
window.
I saw marks on mine as weli as a clouded effect and I
feel so strongly about this~- When I had the sun at oblique
angles shallow to the window I could see this film much as you
describe it.
Smokers in the gr~up will appreciate this.
On the
inside of an · automobile window, you can see the smoke condensa­
tion on there which you very rarely get washed off until you wash
the car yourself .
You see this when you have light at very
oblique angles across this window.
This is about the same type of
intensity - it is not enough to restrict your vision although it
does affect it at night.
This is exactly why I make the point.
I think · that is about the easiest analogy I can make for you.
Dr. Nordberg - You say this was on the Mercury window after the
exhaust.
Schirra - Yes sir, this is the result of this exhaust gas bathing
this window as the rocket lit and left almost instantaneously, but
the gas does form over it.

8
Nordberg - Could you, were you able to observe, during the orbital
flight any decrease in the film on the window.
It may have evaporated
away , or did it just stay?
Schirra - I was hoping to see that and I did not observe a decrease o
This surprised me too.
lime awayo
I would anticipate that that gas would sub -
I suspect that the vehicle itself • ,.we are getting
into the fireflies again - but the vehicle itself is surrounded by
an environmento
We have the same problem when we try to run a
capsule or · spacecraft in an altitude chamber.
It is outgassing
the water cooler systems and other components even in a man­
created vacuum .and as a result we can't maintain this vacuum
because it is creating an environment all the time.
I think this
is what we have done in the Mercury spacecraft with the byproduct hydrbgen peroxide gas and the water coolers antl this is
where I feel our firefly, frost particles come from.
Oid you
notice ~b~the ·~ay- getting into that, - that the particles were
observed almost immediately after I w·as •in orbit? - I said, "I
see frost flakes."
Mr. Dubin -~ You were in sunlight at that time too • . ..
Schirra - That's correct.
This is my only definition of the
difference in the way the sunlight itself gets to where I waso
Meaning that at sunrise it goes through a lot of atmosphere,
and as I get into sun above my horizon, I have no atmosphere;
so then its white again.
Nordberg - This deposit is of great interest to us .
That is

9

why I asked the question because we observed this on Tiros tooo
One of the two cameras was just completely clouded for a few
hundred · orbits and then gradually after a few hundred orbits it
improved a little bit o
Schirra - I need a little more flight time:

I ' m all for ito

Nordberg - We eliminated this by putting a sheet over it in
third stage and since then we have never had any troubleo
Schirra - Sure p that's ito
can't let rest o

I am sure this is something we

We've got to cover these windows to protect

them from clouding during the transition to where we are now
to space itselL
Dubin - Do you ever detect any gas around the vehicle?

In sun­

light due to shadowing of the vehicleo

.

Schirra - No, I looked for thato The only vestige of something
around me were these• particles as we have described them.
O'Keefe - Well, it is very helpful to know that they were seen
throughout the dayo
Schirra - Yes, I think really what it depended on was how much
sunlight I had coming through the window.

If it was really

bright within the vehicle, I didn't see them as wello

If I got

an off - angle where the sun was fairly shallow in relation to my
windowp I could then see these particles; of course, up until my
loca l noonp I did not see them anyway.
-O'~Keef·e - About this problem of condensation and the local environ ­
ment you are speaking of, I think that someone investigated that at
the Manned Spacecraft Center .

It is quite true that with an outflow

10
of gas like that the ambient pressure - the general ambient
pressure - is quite different from the pressure right around
your vehicle o

I still wonder whether you can get the pressure

up around the vehicle for the level where condensation takes
place"

I have been trying to persuade some people that the

condensation takes place before it leaves these ports of course
as it spreads out in space "

The pressure is certainly much higher

around the bottom of the heat shield, but I do not know whether
that is right or not"
Shoemaker - Do we have any more questions on the airglow?
They are very usefulo
Dr o Liddel - We have two problems here o

One is the pressure and the

other is the rate of evaporation "
O'Keefe - That's trueo Once formed, they may not sublime out.
Question is how were they formed.
Schirra - I think there is one thing that we might bring into this
before we leave it unless there is a separate question on it o
The green - yellow~ almost a chartreuse, coloring of these particles,
I feel, did not permit you to see the edges of the particles as
well as they appeared when they were in the white band in the
sense of looking like frost particles o

So they looked more like

blobs and · this is typical of fireflies themselves "

You can ' t def i ne

the size of the blob you see as green - yellow ~ but if you see a snow ­
flake, which is white, you can very e asily see its edges in a sense .
Not that you focus on them bu t you can visualize that they have
edges .

This is a point that I don't think I have made in the past,

., '

\':

. ·, ,

11
but · I think this is basically why we refer to the white particles
as · frost because it does remind us of this.

This is what probably

tempts · me • to say that it has to be watero
Cameron - Do you think the chartreuse ones were maybe the ones that
Glenn · thought actually glowed, didnvt he?

They were lighted

wrong.
Schirra· - I think - well this gets back · to my opinion and I
saw myself on film yesterday at the press conference talking
about it and said that I guess we need some more opinions but we
ha~three opinions now and basically I put two together and made
my · own, but the green I feel is strictly the case of the sunlight
going through this tremendou~ amount of atmosphere at sunriseo
What is left · as a light spectrum is this green - yellow on these
particles.

You can all explain this better than · I can, I am sure ,

but what gets through all this atmosphere would probab1y be this
green - yellow.

I think that in a sense they are not self-illumi ­

nated · but they reflect as if they were self-illuminated.
O'Keefe - Well, if you pass sunlight through a 1:hick layer of
atmosphere then, of course, what you will get will be a red - a
deep red - however, that doesn't necessarily. prove that you are
wrong in what you are saying because the things would be illuminated
in two ways .

They would be illuminated not only by the direct

sunlight~ but also by the scattered· light around the horizon
which · you have photographed at sunrise and the combination of these
two colors might give you a chartreuse as you have said because it
is a double · illumination.

However, there is another possible

12
explanation.
If it is really true that this chartreuse color
only turns up only at suprise, we may be with the explanation
that · Herzfeldllput forward for it.
Schirra - This is the nitrogen effect?
O'Keefe - Yes.
Schirra - I would like to stamp that one out.
have · nitrogen outgas in the vehicle.
We ~an't afford to
(Laughter) The only nitrogen
which we have stored aboard is that which pressurizes the hydrogen
peroxide system.
If we lose any of that, this is almost fatal.
O'Keefe - Well, there is plenty of nitrogen in the atmosphere at
that level~ · Still Schirra · - You mean in the external atmosphere?
O'Keefe - Yes.
Ambient atmosphere.
Schirra - Fair enoug~.
Well then, that paper - I was left with
the impression · that the nitrogen came from the vehicle itself.
O'Keefe· - I am sure that it didn't cross Herzfeld's mind.
Dubin - There's also nitrogen . . .
Schirra - Well, it read that way to me.
I should say that I am
very conscious of what nitrogen does for me within the vehicle!
(Laughter)
This is basically my control field.
Dubin - I was going to say there is also nitrogen absorbed in met als ..
Schirra - The gaseous content of the vehicle is very carefully
measured prior to sealing up the vehicle for lift off.
It is
purged and we go up to about 97 or 98 percent oxygen.
Obviously,
there is not much left in the cabin, you can't get it all out becaus e
!/ Abstract published in Voll 136, #3522, p. 1121, July 29, 1962 of
Science by Charles Herzfe d.

13

you just can't purge particles in the interior in that these are
angles and trap volume~, but I would suspect that we had a very
low order of nitrogen gas within the vehicle that could come out.
Now it can come out if the vehicle's leak rate - in the vehicle is
excessive - and in this one it was somewhat less than 600 cc.
I think it was about 500 Dunkelman - 588.
Roman - I think your suggestion, Larry, was that it would be on
the outside of the vehicle.
Schirra - That I hadn't had a feeling for and I suspect this is
the only way you could get it in contrast to getting it from
within.

So I won't argue this point.

I am well aw~re of the

fact that it could be adsorbed and then passed off in this
environment.
Roman - John, (to Dr. O'Keefe) is it obvious that sunlight coming
through , in the upper atmosphere would be red if you are above
the dust layer?
QJ Keefe - Well, when you look at the sun in th~ photographs
which were taken, it looks red.
Roman - · I see.
Schirra - The sunset is red.

Same old sun that we see here.

O'Keefe - Yes, but what you 1 d see on either side of it - flanking
it - is Maxfield Parish cloud, at least in the color photographs.
I think this is what Maxfield Parish went in for particularly.
He went in for very powerful colors - subtraction colors.

Turquo i s e -

rather than the pastels, rather than colors of the spectrum.

14
Shoemaker - Any other items on airglow we should take up?
Schirra - We will bring up this other thing I $aw - I guess?
Shoemaker - The cloud (bright area) you saw over Madagascar?
Schirra - Yes.
Dubin - I was wondering on these various effects on the horizon.
.
.
You ' make some statements about the blue horizon~-the different
colors.
Schirra - What time is this?
Dubin - This is at 06 44 GMT (See blue book, p. 104).
(Now
Report · of, Third U. S, Manned Orbital Flight.)
Schirra ~ This was the beiinning to what Mrs. Cameron has a sketch
of, I believe.
..,
Cameron - Actually you give two · descriptions here.
they conflict ,
I believe
I assume that one is an expansion of a part of
the other.
Schirra - It is, and as you can see_, it's a time span here where
it obviously is changing as the sun is setting as well.
Not
much in time, but my time was pretty fast in relation to sun ­
sets, I guess.
Dubin - Question is what the heck did you really see?
Schirra - Maybe if I just read it back myself, I can expand
on i t.
I'll read it out loud.
How's that?
I guess we can
pick up right at 0604 33 and I say there is a nice interesting
hor i zon, which rne~nt that I was captured by it.
The sun was
off to the left and I would say about 40 degrees.
This just

15
meant that it was off to the left of my yaw angle - I was in
flight path in yaw at this instant of time - which means you
could determine where the vehicle was oriented and then also
get the sun-line in relation to the window.
Cameron - Incidentally, the sun must have been very close to
setting at that time, wasn't it?
Schirra - It was setting, in fact.
This is where I went on.
There is a dark line at the surface of the earth, orange at
the clouds.
Now there was a cloud horizon, as well, that I
could see.
Then a light yellow, a light white, and then a
blue band.
This was coming from the surface of the earth
going up.
A very light blue and then I got all excited and
said that I had the planet Mercury in sight at this point.
Mercury obviously was in the black.
into the Mercury set.
of sunset, Mercury set.
It had not come down
If you want to describe it in the sense
I think it deserves the term of having
the opportunity to set as well.
I was coming up from the surface
of the earth towards the darkness of space and then I detected
Mercury where it belonged, trailing the sun.
Dubin - Well!
The sun was off to your left about 40 degrees.
Schirra - As well as Mercury,
Dubin - In the same direction?
Schirra - It was trailing almost a~cive the sun in this sense.
Which is where I had it plotted on the star chart.
Then I
wanted to describe the blue band and I said that there is a

16
relatively dark blue band right at the surface of the earth.
Of course, the orange and light yellow was changing at this
point and I then came into seeing this dark blue bando
In
other words, I had lost the orange cloud effect just above the
surface of the clouds.
This was the same kind of red-orange
we typically see through the atmosphere on the surface of the
earth which is, of course, the atmosphere.
I realize this cuts
out most everything but reds and yellow~orange.
But the light
yellow wasn't at all unusual either; I had seen this in many
sunsets.
The sun had set.
I wanted to describe this blue band.
I realized I had gone through some 34 seconds.
When I say
describing the blue band, it is some 30 seconds later.
say, 4 seconds to say that.
Took me,
Relatively dark blue banq right at
the surface of the earth and a light blue band meaning a next
band above it; another dark blue band, a large white band which
is the airglow o
This is the way I felt it should be.
I have
not made a careful study prior to the time of the various layers
on the earth or above the eartho
Then a deep black one and it
sort of goes from a grayish blue · to a dense black, almost looks
like the underneath surfac~ of a summer cumulo-nimbus effect,
where you have a nice bright earth and then you go into this
black cloud and then there is this roll cloud that precedes a
thunder storm and it's a very, very choppy underneath surface.
It looks very turbulent, to you.
This surprised me.
expected to see another sharp line and I did not.
I
This is what

17
I was referring to here as the transition from the last blue
band I could see to the total darkness of spaceo
is the only way I can describe thato
I gaess this
This was a surprise to me
to see thisp really o
0 °Keefe
=
Well, it is astonishing, isn't it?
Schirra - Yes, it iso
I expected to see a nice, sharply delin ­
eated arcp and this was not the case by any means.
O' Keefe - Whatever it was, it was turbulence?
Schirra = Yes, this is the way I would describe it.
It has
to be or the light in a sense made it look turbulent.
I
think you have all seen the base of a thunderstorm as it comes
towards you and the light starts diminishing rapidly as you get
a thunderstorm o
Just because it is so thick and almost opaque
in contrast to sunlight that can get througho
Then we see this
vortex effect underneath it and this is very much the way I
would describe it myselfo
to no light o
This was the transition from visible
No sharp lineo
I think you probably have it
fairly well sketched right thereo
Dubin = Have you seen the sketches?
(Mrso Cameron's sketches
of colored bands around the horizono)
Sch i rra - No, I haven'to
O' Keefe = Why don ut you take them around there, Mrs. Cameron
so we can get additions and corrections (to the drawings).
(Schirra and Cameron looking at the drawings)
Cameron = This is your first description (drawing shown to
Schirra) oo o
This is the second descriptiono ooo
0
0
0

18
Schirra - Yeso
Now as we progressed in time to the second
drawing, the sun has now really set and the reds and yellows
(in the drawing)
are fine ooo now just getting the afterlight
ooo that 9 s the ragged effect I saw o ooo
Schirra - This isn 1 t as thick as that grey to black band
as I saw it o
We are stuck with a small circle (radius of
curvature used in the drawing) and I had a big circle.
Dub i n - Okayp could you re - draw it on the board the way you
saw it?
Schirra - Al l it is is a straight line with a slight curvature
to it o
I had a broad angle of view, but the whole thing is
flattened out o
I don 9 t see that much curvature at allo
O' Keefe - (to Mrso Cameron)
Put in that remark about this
band is too narrow?
Schirra - This is too wideo (indicating drawing)
It would be
the grey to black (band)o
Shoemaker - It faded out more rapidly in proportion to the
white band?
Schirra - It was definitely not something you would like to
make with a compass o
Cameron - Narrower and wider ooo I tried to indicate that, but
as to scalep I didn ' t ooo I was just trying
0
0
0
0 8 Keefe - We made a first try at it ooo
Schirra - (Reading in the Blue Book) "I will bring up the
fingertip light o"
Th is will clue you o
This will make it

19
clear to you that the internal lighting was off inside the
vehicle.
I don't know why I didn't bring that point out.
This reminds me that it was dark and it was 0605 52.
to see what time it wasa
I had
We had this counter clock as you
know, and to see the numerals I had to bring my fingertip
lights up to see them.
It was quite dark within the vehicle
and this is quite an advantage to this observation.
Then I
say that Mercury is on the horizon and this meant that it was
just coming down through what I described going up, if you can
follow my directions here.
This is where Mercury was as the
pointer or index as it passed through these layers.
Now· again,
we proceeded through time so that light patterns will change
and that's why these descriptions do conflict as we progress
on in time.
I think this might explain why.
As I come back
through with Mercury now setting these same light bands are
not the identical ones that I described previously and I used
the word "airglow" and even the way it came out in the tape
I said see the Mercury going through the - and I was searching
for a term and so I just said "airglow" just so I wouldn't
have to get into a big discussion about what I was going to
report on.
Actually, I could have said through the -- I was
searching for a term -- but this "airglow" I was using simply
as a term to describe what I was looking at.
I could have said
through the lighted horizon.
O'Keefe - Twilight layer is probably a better way to say it.

20
Schirra - Very good, a better way of saying it.
O'Keefe - "Airglow" is a very complicated term.

We don't know

what it is all about.

...

That's what we are after.

Schirra - In fact, on occasion I have used airglow through
here just out of ignorance.

I think what we all are trying

to do right here is to try and clear up some of this ignorance;
so we need more data, of course.

Then,I say (reading from the

Blue Book again) "We'll see if she holds up," meaning, can I
track Mercury through all this?

That was interesting in

itself, that I could, I thought.
O'Keefe - This was quite important.

This was one of the

questions raised by Glenn on his flight whether some layers
are opaque or not.
Schirra - I could track Mercury through all of these points
or layers.
Nicks - Does it change its apparent size like the sun when it
sets?
Schirra ~ I don't recall having observed this.
Roman - Did you see any additional stars ... the fact that it
has a finite disk (Mercury)?
Schirra - No, again the window cuts out the fun of that, I
think.
O'Keefe - No, you wouldn't see a disk . . . .
Schirra - It would have been great to have had some magnifying
device at this point to make this observation.

No, it just looked

21
like a star.
O'Kcefe - I think when Nicks asked if the sun changed in
size, he really - the sun qoesn't change in size as it setso
He meant change in brightnesso
Schirra ~ Apparent size - not the size, but the illusion at
least .
I've got to break off a second here.
seeing many moon sets on earth~
I don't recall
Have any of you ever seen a
good moon set?
Roman - Yes.
Sch i rra - You have to be on the West Coast to do it; but, of
course, I saw a moon set on this flight and that is why I
brought it up.
I had seen
q
To me, it was the first real good moon set
(Laughter)
O' Keefe - There is a good solid reason for that.
t hat a full moon will set at sunrise.
That is
Not many people are
up at that time.
Schirra - I hope you have had a· chance to see the photographs
I took of this moon set.
Gill - . No .
Schirra - There are two black and white sets of these.
original prints were very good.
of halat i on around this .
I understand there is a lot
I definitely think you all should
get these out and examine them.
were not very good.
The
Now the subsequent prints
They were too fuzzy .
Gill - Who would have them?

22
Schirra - Paul Backer could trace them down at least.
He was the film-handler.
He could chase them down.
O'Keefe - Minnaert has suggested that after moonset, that
there might be a lunar zodiacal light.
(Minnaert, Light
and Color in the Open Air, p. 295.)
Schirra - Oh.
O'Keefe - It's a dim hope.
Schirra - Getting back to this light magnitude in relation
to stars is about 12 to 15 magnitude.
this .
I wouldn't even see
I suspect Gordon won't unless he just happens to look
out at the right time and has enough lighting.
Now with
instrumentation we could detect it, but visibly with the
naked eye you can't detect because you can't see through the
window.
You can't detect this low illumination level.
I might
add that I saw something subsequent to the flight that · really
flipped me.
I was on route to the West Coast on a night flight
(commercial).
I was sitting way in the back in the tourist
section in middle of a three-seater, and thought I was
anonymous, when the stewardess came roaring back and said
~mdr. Schirra, would you come up front;'' and out of my
obscurity I was drawn to the cockpit and I said to myself that
we ' ve either lost a pilot or co - pilot.
(Laughter) So I went
roaring up front and the passengers were looking with a
degree of apprehension, at least.
I went up to the cockpit
and looked out and we were heading West just after sunset and a

23
blue scout had been launched from Vandenberg (AF$).

It had

the most fantastic lighting I have ever seen anywhere~

It

had the exhaust trail and above the horizon it had this
fantastic glow - ionization glow (like a vapor · cloud) I
would describe it as - which would best pin down - resemble­
the zodiacal light if you ever wanted to do it ~

It had a

band across the horizon about 60 to 70 degrees · and it · went
right up the ecliptic and picked up the moon · and the · planets.
It was just amazing.
Shoemaker - How far could you trace it?
Schirra - I could see it right up to the zenith as much as I
could see out the cockpit.

We were all oohing and ahing.

I think you have seen this same glow from a booster · flight at
night, particularly if you can pick up a sunset or · sunrise
when you get above the earth's shadow and get into the lighted
area where the booster is.

There is a tremendous · expansion wave

that's behind the vehicle and this is basically what it looks
like.
Dubin - These pictures of Glenn's Atlas flight show the same
thing .

o o o

Schirra - I think it was mine you saw ...
O'Keefe - What you saw from the cockpit - was it from the blue
streak or was it the zodiacal light?
Schirra - I think the two just drew it together and that it was
definitely stimulated by this blue streak as it went up almost
up the ecliptic in relation to the arc field of view.

24
O'Keefe - It is not a difficult thing to see the zodiacal light
under reasonably favor~ble conditions.
Schirra - No, I have seen it frequently, but not ' as brilliantl y.
Gill - Have you seen it in Houston by any chance?
Schiira - I have seen it just flying at night~
I haven't seen it
from Houston recently, no.
Gill - Well, this is the season to see it.
You should see it . . .
about three-quarters of an hour after sunset.
Schirra - From an airplane, you can see it better than yoµ can
from a Mercury spacecraft.
You don't have this dimming of ligh t
through your canopy as you do from the spacecraft~
a spectacular sight.
This is rea lly
Of course, the pilots were so concerned
because they didn't know what it was.
This was hundreds and
hundreds of miles away, and yet they felt they were in danger .
(Laughter)
They wanted answers right away.
Gill - They got them, didn't they?
Schirra - Of course, you've heard that the whole West Coast was
enthralled by this sight.
It was in the newspapers.
Roman - Speaking of the brightness of the zodiacal light,
Dr. Mulders, NSF, was in Chile at a high altitude last fall,
and he commented to me, that the zodiacal light was so bright
that he was able to see it from horizon to horizon without
difficulty.
Schirra - Amazing--horizon to horizon- ~! am not sure what we a r e
going to see at thousands of miles from earth c
I suspect that

25
we are going to see a batch of clouds if it's lighted. (the
earth)
That's really what I saw a lot of.
I was just amazed.
Obviously, when I flew over Africa, it was loud and · clear and
you would see this if you were looking at Africa from some
vantage point many, many miles away.
I suspect that if you
looked at earth from a long distance away that there is so much
cloud cover that it might have an appearance much like Venus in
this sense.
Shoemaker - While we are on Africa, would you like to go on
and talk about the ... (interruption)
Schirra - You can't match my blues.
Maybe Parish · could help ..•
Nordberg - Does anyone have anything on the altitude, parti cular­
ly on that top that sort of turbulent thing?
Schirra - That's another one you should check into.
Through
the trajectory tables, you should find my altitude.
Now at
this point, I was just passed Indian Ocean ship as I recall.
O'Keefe - We've done all that.
If you say when Mercury went
through that we will tell you what the height was.
Cameron)
(To
You have it?
Cameron - I have it.
It's about 280 kilometers ~
the layers is about 66 kilometers.
Height of
I only know the height
of his observation, not knowing the width of it,
O'Keefe - (to Schirra) But you made a mark when you went
through it,
The first "time hack" was when you weTe going
through this turbulent area, right?

26
Schirra - Correct, that's when I came into it.
O'Keefe - What was the height of the layers at this time 66 kilometers, is that right?
Schirra - Right, that's what I was saying.
I hope we can
hold Mercury meaning that I'd like to see it · go through this
and I did not know that I could, but obviously I proved that
I could; I did.
This was quite a surprise.
Didn~t you say,
Jocelyn, that there aren't many people that have seen Mercury
sets?
Gill - Very true .
Mercury, (the planet) · period .
Very f ew
people know that it exists.
O'Keefe - Can I point out that you used the word · airglow just
in general terms, a faint, glowing light seen · from the · atmosphere
without your - What you called the airglow is not what is
technically know as the airglow.
Schirra - Yes, any time we use airglow I don't use it as we
professionally talk about airglow.
I was using it merely as
an escape clause.
Dunkelman - There is one other point there.
One isn't sure
just in what plane these phenomena took place .
They may have
been ahead or behind this plane (of the spacecraft).
We have
to think of this ... The 66 kilometers might indeed be reflec ted
as something that had been before this point, you see.
Nordberg - (Comment inaudible).
Schirra ~ My local vertical would be this hand as I show it
and, of course, 40 degrees to the left where the sun and

27
Mercury were traversing was in a plane something · like · thiso
This is your point I think, Larry, Isn't it?
Dunkelman - That's one • • •
Schirra - So they come down this way which mathematically isn't
hard to solve, but you should consider this.
Dubin - This plane may vary a certain amount and it is very
difficult to know which way.
Schirra - The spacecraft at this point was under attitude
control and was fairly tight in a sense.
Roman - I think Larry's point is that though we · don•t · real l y
know if we are ... if we are actually taking a traverse st r a igh t
through the atmosphere, it may be something in front, a tangen t

.

line, or behind it.
Dunkelman - The first thought _is to put a line right · through
there, and at this point this may be on the plane but · it may
not be that.

Some may be ahead or behind, or both . . . .

Schirra - In other words, these layers in this sense could
be all staggered out and this one stacked like a bunch of
steps in a sense.
Dubin - And they could be higher in altitude than a simple r i ght
angle projection.
O'Keefe - It's quite safe.
Schirra - I was looking at two dimensions in a sense.
Cameron - The right angles of proj~ction and this · is the
twilight zone of the spectrum.

28
Schirra - If there is another one of those coffees~ I'll
trad~ this one in.
Break
I don't mind it cool.
(General conversation)

29
Schirra - And the rare occasions that I've had the timing for this.
O'Keefe - There is a nice Delta Flight from Washington down to
Houston.
The thing goes exactly toward the sun - you can't miss it,
Cameron - You'll have to go to the cockpit.
Schirra - Hmm - You have to make the Delta Flight, in this par t i cu ­
lar c ase, from Dallas to Los Angeles.
I passed Albuquerque.
Shoemaker - This peculiar thing you saw over Afri c a - maybe you c ould
tell us about it.
Sch i rra - That , as I have said, was my biggest surprise.
I
talked to most of you at great length about things we woul d hope
to see or expect to see.
This I had no prior knowledge of and I
bas i cally can say that I was "sucked" in and originally called thi s
airglow, if you recall.
again .
I guess it is best to refer back to the record
This was S hours and 20 minutes.
Cameron - That's the time I got from you.
The only thing I
notice from the script was that you said Glenn was asking you when
you were passing over California if you had seen what the airglow
was .
Then you said something about you were surprised at how high
it was .
Schirra - This was the same phenomena.
I think, isn't that correct?
I had come back from th ere,
Let's see .
Dubin - The Indian Ocean.
O' Keefe - David Stern at Goddard predicted that you would see
something very unusual in this flight before you went up .
Schirra - Really?
•
0
•

30

O' Keefe - _Yes, he gave me a note.

I was supposed to pass that

note down to the Manned Spacecraft Center; I don't think I did.
I think it's my fault.

(Ed. copies were forwarded to MSC~)

Roman - What is this you are referring to?
O'Keefe - There is a very strong magnetic anomaly in this region,
and this is where ...
Dunkelman - I think the fact that Schirra had not heard of this makes
the observation even better scientifically.
Schirra - Hmm.
O'Keefe

Quite exciting about this thing, but exactly ·what region

is Cdr . Schirra talking about? ... He's talking about the South · Atl anti c
- and the South Atlantic was in sunlight.

This is probably as clos e

to it as we could get to be in darkness.
Schirra - I think what happened is I looked out as I was drifting
and this happened to be in the right attitude to see this, which
probably meant that I was looking toward the North although I can ' t
confirm this .
Cameron - You said something about you would judge that the width
was about a fourth of your window.
Schirra - Yes.
Cameron - Can you say how far - anything about how high it was
from the horizon?
Schirra - I was surprised when I saw what I thought were city ligh ts
and they turned out to be stars below this thing.

As a result, I

was confused in the sense that I wasn't then looking for yardsticks.

31
Cameron - Was this a patch, or do you think there was a layer
there?
Schirra - It was a layer across my whole visible horizon.

It

wasn 9 t just a blob in other words .
Cameron = And is that the only time you saw it?
Sch i rra - That is the only time that I recall ever ha~ing seen it .
At one particular point - Was it at 5 hours 20 minu tes (in the
record)?

I don 9 t seem to refer to it too well in here.

Dunkelrnan - We had to find it.
Schirra = You had to dig it out?
Dunkelman = We had to dig it out from your self-debriefing later .
Roman = Was there any color apparent in this case?
Schirra - I would like to refer to it, Nancy, as a little smog
color , having a little brown in it.
it was n ' t black or white.

Sort of Brownish gray - rathe r

It was definitely toward the brown smog t hing.

I 9 m sure you have had the unfortunate privilege of letting down in
Los An geles and seeing what smog brown is.
Roman = Right .
Sch i r r a - This isn 9 t what you would see from the surface of Lo s
Angeles, but above it when you look into this.
color i n a sense .

Sort of a dust y

If you'd like to use that term .

I don't like t o

use that term because if you have seen a dust cloud you've seen
more s olidity to it in your mind at least.
you that picture.
particles .

I don't want · to give

Definitely a fog effect rather than seeing

I think of it that way.

32
Dunkelman - We are here to hear yours and I think we should· figure out
s ome mo r e of this .
I don't want to inject my thought into this, but
I was trying to quote you in saying that it is brownish smog layers
and wasn 9 t sure how to define it.
Sch i rra - Yes.
This is dirty brown, not a pleasant brown, not one
you would like to see.
Sort of like a tattle tale b rown instead of a
t attle tale gray.
Cameron - Venus was just off the edge of it.
I have th e report · of i t~
Schir r a - Let ' s see , where are we there?
Cameron - J don't think you are saying anything about that.
I was
wonde r ing if you noticed Venus at that time?
Sch i r r a = There was some point in here where I miscalled Venus or
Mercury, I forget which, but this is wrong.
it an d they never did .
I told them to correc t
But anyway this is what I did say.
I think
you could disprove me very easily, because it just couldn't be t he r e .
I for got which one it was I referred to.
Venus and the moon · were
always together is the whole point» and they were t o me in a hori zont al
l ine which gave me a good reference.
0 °Keefe - Cdr. Schirra, there are some important points here.
Firs t
of all, of course, both Glenn and Carpenter saw stars underneat h th e
ordinary airglow layer.
Schirra - Yes, I remember.
O' Keefe - So it clearly can ' t be seen and one would expect th a t an yw ay.
Schirra - I would say that this is substantiated by my report of
seeing Mercury as it passed through these layers as Mercury set which

33

would prove that the stars well could be seen going through the
sam ,, traverse.
"Ii '

This thing I saw - let's just call it the smog · belt -

on this southern pass, to go back and recap the sensation that
brought this to mind which is not brought out here other than the
· "'
fact that I can identify what I saw. I was coming over a land area.
(I think I better take a second and break out my orbital map which
I have here.)
O'Keefe - If you have the tape, we might replay that.
Schirra

This would be better because some of the nine hours

there, I have not identified carefully enough, .and I should- have,
by going back over the tape and these areas of interest - I thin k we
should listen to the original tape again.

Let's get down to · where

we were.
Cameron - Larry (Dunkelrnan) has listened to it at the Cape, I think.
Dunkelman - Did you see wh~t I call normal airglow at night?
That is the soft white band.
Schirra - Yes, I did.
Dunkelman - All right, yes, that's important because I think ' late r it
will help.
Cameron - Was that the thing you saw?
Schirra - This is distinctly different and this, I think, we ident ified
in our earlier discussion (speaking of the use of the term airglow).
Dunkelman - Fine.
Schirra - I had moonlight as well, but I could definitely see this fa int
white effect.

34

Dubin - W.as there any color whatever in it?
Schirra - In the .airglow that I saw?

No, other than during sunset

times where you would have sunlight itself.
Dubin - No color whatever?
Schirra - I think of white as being all colors and you can see
I've been trapped with painting~ few times.
as you came into the middle of this belt.

This patch was denser

It definitely had tb · have

a light stimulus to it or I wouldn't have seen it.
aware of this and thought this as I saw it.

I was well

The initial impression

that brought to my attention is, first off, and this is the liabil ity
we have; we're wanting to see something that needs to be seen · with
the naked eye when the inside of the vehicle is dark.
Cameron - In the patch did you notice any variation in color eithe r
horizontal or vertical? - Or was it all one?

.

Schirra - The airglow now we are ~iscussing?
Cameron - The patth over (Madagascar).
Schirra - Oh~ this patch, it seemed ... You can't keep t~ack of whethe r
you a-re over. land or water continually and time is progressing fai rly
rapidly; for example, on this particular period where we are talking
in terms of 5 hours and 20 minutes, going back just a few minutes , I
am over Africa because I had left the southeast coast of Africa, in
other words, Durban and this is the place I had one time in my mind
wanted to see a flare and I did see cities and I know I saw Capetown
which was in the clear.

I talked to the Ambassador from that · section

of Africa when we were at Goddard for the 5th year celebration of
satellites, and he saiq, "Oh, I wish we had known that, because

35
everybody thinks that all you see is Perth!
we see a lot of other places as well."
(laughter) Well,
To go back, I was · trying
to re - establish this phenomenon in my mind so I had passed over
Africa and I was darkened within the vehicle.
I was drifting.
As I was drifting - we like to say that we can see a city because
the people of the city get quite excited about it as we know Perth
did - and I was proceeding across the Indian Ocean drifting, so my
attitudes cannot be defined, I wanted to say to myself, oh ·, · I see
some more cities below me.
Now I wasn't convinced in my mind that
I was over the Indian Ocean, yet with the attitudes · not carefully
defined, I might well have seen cities ,
are quite constellation setups.
These I said, ah, those ci t ies
They looked like constellations.
Then I said, my gosh! they are constellations.
They are stars
and this was below what I then, in my mind at least, had planted
as airglowo
Again, a lump term, meaning a lighted horizon, and I
looked above this brown smog effect and saw more stars again.
Then
I could see through this brown effect, stars, but they were · dimmed
considerably by it.
Now, I did not have the opportunity in that
the attitudes were dynamic to trace an individual star or planet
through this particular areao
I wasn't at this point too intereste d
in knowing what constellations I was looking at.
In drifting fli ght,
you don't really have a requirement to navigate, that is, to know
where you are in relation to a star field or surface.
Roman - So you don't know what you were looking at?
Schirra - So any particular star or constellation, I could not
ident i fy at this timeo
If I needed to, I would then have to destroy

36
my dark adaptation and light up my star chart and then identify
these things.
This is the problem we have.
O'Keefe - One of the classic problems in astronomy - one of the
solutions for it is to illuminate with a red light, because you
don't destroy the dark adaptation so quickly.
Schirra - This is why we went to these fingerti.P lights which are red .
I started out, and this might interest you, I went to the planetarium
in Chapel Hill and took both gloves with me.
and one had the red lights.
One had white lights
This was my test of these lights.
used them while working in the planetarium.
We lit up the white
lights and the whole dome was just brilliant white.
little peanut bulbs, really minute.
those white lights.
of this .
We
These are tiny
This was the last time I used
That very day - they were painted red as a result
You need very, very low orders of light to -
Dunkelman - I had the impression the first time we talked about this
that you had not seen any stars through the patch, this brownish
patch, but you feel that you had seen Schirra - Yes sir, this is what I am trying to do; recreate the scene .
That is why I went back to coming off Africa.
Having looked for the
lights, and having seen Capetown, I then felt that I was seeing more
city lights and then I was so surprised to realize that these were
stars.
Now this only means that I was not pitched down enough to
really see the earth itself.
So this means that it was quite high.
Roman - Do you feel that you were looking at the airglow laye r s a t
sunset or might you have been looking down at this sort of tangentially
as you are at some angle?

37

Schirra - I feel that I was looking up at it now in relation to my
local horizon.
Roman - You were actually looking up at it?

Have you any idea how high

it was above the apparent horizon at that time?
Schirra - That is where I am in trouble, Nancy, because there · is no
direct repeated knowledge of what this attitude is.
Roman - Well, the other question is ...
Sch irra - But I saw a good batch of stars below it which meant that my
axis had to be fairly well above the horizon.
Roman - Any _structure either turbulent or wave-like?
Schirra - No, this was a very soft - we best describe this in clouds
as being a cirrus layer rather than a cumulus layer; a stratus would be
a better term, I think.
Nordberg _- Sort of diffuse?
Roman - I am still not quite sure I have the answer to my question then .
I ' m not a meteorologist.
Schirra - If I were to do it, I'd take a chalk eraser and just ' make a
streak across the blackboard, it would be more intense in the cente r
of the eraser and then diffused as I got Roman - But no other structure?
Schirra = No other structure.
Roman - The reason I am asking this is that it sounds as if it might
be related to some other equatorial red airglow which has been · observe d
from the ground.

This has a distinct wave structure.

Schirra - I see.

No, I did not see the permanent wave effect or the

38

mackerel effect that you see in clouds.

This is very much a -

well, I would say if you · really wanted to do it - well, do · it in
water colors rather than chalk.
Nordberg - Did it cover your entire field of view?
Schirra - It covered my whole field of view, yes.

That's where I

"suckered - in" thinking that I was looking at "airglow - " what we
have used now - I think you understand how I have used airglow and
that there were cities below it and stars above it.

Then, these

cities were defined rapidly as stars and then I Dubin - You actually saw no horizon then?

And you saw none of th e

regular airglow?
Schirra - No, _I could not see any vestige of the surface of the earth,
meaning the true airglow in this sense.
Dubin - What you saw then were some of the bands with stars above an d
below - you remember how high up you were looking?
Schirra - No.

If I had not had the fetish of conserving fuel in this

drifting period - was most important - not only conserving fuel, but
to see what effects the vehicle would get while it drifted over a per iod
of time; in other words, what this minute atmosphere might do to the
vehicle, whether it would spin it up or slow it down or what have you.
I could have picked up my attitude just by pitching down and pick i ng
up the surface of the earth.

But then I would have destroyed the

period of time that we had been drifting to see if the vehicle
attitude had been affected by the orbital period.
Roman - For something like that, would it be desirable to carry a
small mirror, something like a woman's pocketbook mirror, which you

39
could look down at the different angles.
Schirra - We had a mirror on there.
look toward the heat shield.
This permitted me basically to
Something like a rear view mirror,
except it was a front view mirror in Mercury.
But in any case,
you almost need - we need something like a dental mirror to move
around .
I think again you get in trouble with a mirror; I con­
sidered this.
In fact, I had a mirror on my hand which was a flat
plate much like the woman's cosmetic mirror.
It was about the same
size, and when you use a mirror you lose so much just by the fact
that you change distances.
Your image has been ranged differently.
So I found that I didn't have any luck at all.
Tennyson - It was just your disorientation.
Schirra - That itself was another problem.
(Cameron showing Schirra
a drawing)
Cameron - I have a drawing here of what I think you saw out your
window at S hours 20 minutes.
Schirra - Oh, really, I'd like to see that, yes . . . .
Cameron - It's just the star chart.
I tried . . . . I think this is whe r e
you we~e, well, I made a tracing of the thing and slid it (the plast ic
slide which represents the capsule window) up (on the star chart)
here - here's the horizon and· I tried to guess where you might have
been, and I put the width about ... (showing Schirra) you· thought it
was Schirra - Very good.
But the thing is you see I could be tilted as
well in roll and it would move this field--see what I mean?

40

Cameron - I was wondering if you recognized this pattern here that
you saw below it?
Schirra - What really flipped · me -- this is where I got in trouble-I said somethin$ about the Pleiades and I know I could not see · those.
Cameron - You see according to this the Moon was up at the top (of
the window) and Venus was off to the left. Did you see them?
Schirra - I did not see them during this period, no.
O°Keefe

Where is Delphinus?

Delphinus is somewhere.

Roman - I was just thinking about that . . ..
Cameron - Well, he's in Ophiuchus and Hercules and
(General discussion which is inaudible)
Schirra - Delphinus does look something like the Pleiades in a sense ,
yes .
Roman - It's a little larger, but I'm sure that ...
Schirra - At one time I tried to trace this down and see what · I really
was looking at and I frankly have not done it.

This is typical of

everything we do, we always rushed into something else.
O°Keefe

=

(to Cameron) Can you find Delphinus?

It's right next to

the (Northern) Cross.
Cameron - I don't see it .

I don't think it's on here . . . .

Schirra - D~d I identify - when I said Aldebaran, I may well have been
talking about . . .
Cameron - There's a Norton (Star Atlas) in my bag - maybe I'm - if
you ' d hand it to me - maybe I've got the wrong page--I don't know I don ' t know why - he ' s got it there very clearly.
O' Keefe - You have Ophiuchus, Hercules?

41
(Conversation inaudible)
Schir~a - I used to carry my little star chart slide rule thing
around with me .
Roman - Alternatively, there are some (star) clusters - we l l, if
it ' s the Pleiades, it would be well enough defined and you wouldn't
confuse it - there are some clusters in a star field which · at · fir s t
glance give you the same haziness that you get from a cluster like
the Pl eiades .
Cameron - It ' s the wrong di rection, of course.
Roman - Well, but he is down in the Scorpio region if you think of it .
Schirra - One of those things I do recall very vividly was that I
.talke d about Aldebaran and it just couldn't have been there at t he
time I . . . .
Gill = O, well maybe you didn ' t have the Pleiades then.
Schirra - I know it wasn't . It wasn't the Pleiades .
Gill - Because you ' ve got Orion here.

Orion, the Pleiades and

Aldebaran go nicely together.
Schirra - They sure do, _but they shouldn't be there.

fill!. - But those were the wrong ones . (Laughter) They can't be there .
Dunkelman - I think Voas corrected that at that one time.

You see

Aldebaran wasn ' t there .
Schirra - Yes, this is the liability you get into if you don't really
know your attitude; with this star chart you can sweep out a whole
new segment of the sky .
O' Keefe

=

Why can't you have seen Aldebaran and these other things?

Were they above the horizon?

42
Schirra - I don't think they are in this area.
this star chart .
We have to expand
Now if I were yawed around 90 degrees, this star
chart is absolutely worthless because this only goes a plus or
minus 60 degrees .
O' Keefe = I know, I know .. .
Sch i rra = Maybe I could have
o °Keefe
=
0
0
0
But, your flight path did go over Aldebaran, Orion -
the plane of the orbit.
Schirra - As I recall , and my memory of course, is suffering
from the time span (which has elapsed since the flight on October ~ .5-,.
1962 . )
As I recall, Orion was on the daylight s i de, you see it's . ..
Roman = As I say, I was going to say that Orion was actually very
late =
just before dawn - if it were up at all.
Schirra = Physically it was impossible to see - here is the constella­
tion Orion way down here ~ in time, this is on my daylight side .
Roman = I would think that Aldebaran would be much the same problem.
Cameron = Just the same thing .
Schirra = It is right in this same family, of course.
Roman = What time of night was this?
Can you give me any idea
of the distance between sunlight and sunset?
Schirra = That vs why I am perfectly convinced that I could not
possibly see anything associated with the constellation Orion or
Aldebaran .
time margin .
With this star chart, Nancy, what we do is have a
(Looking at the chart .)
actually in my local daylight .
Now Orion down here is
It just was impossible for me to
see it at this point way back here .
It was occluded frank ly by the

43
surface of the earth; physically, I just couldn't see ito
Roman - That ' s what I meant when I said at best you - d see those · just
before sunrise -- if at all at this time of year.
Schirra - Right.
It was just impossible for _me to see it at thi~
point way back here, so it was occluded by the surface of the earth,
frankly, I just couldn ' t - physically I couldn't see it.
What
really would be fun, by gosh, would be to go back up and have Tony
Jenzano (Director, Morehead Planetarium) lay this out in the planetar i ·,
filJl = Yes, yes, you ought to be able to solve that.
Schirra = I would be able to tell exactly what I saw.
I'll do it -
That 0 s the way to solve this because then I can get the whole star
field, the complete celestial heaven at this time and space ·.
then we can make some points.
And
I think one of you should .go there
with me so we can have this pinned down.
I think we should lay
this out . He (Jenzano) can lay out the whole ~light plan.
Gill = To get it pinned down .
Roman - I would say here that Arcturus or Antares could have been con ­
fused for Aldebaran here.
Gill - Absolutely .
Those would be good candidates.
0 °Keefe - Let ' s not let this point go.
Who should go?
Shoemaker - I think we should plan to do this.
Schirra - I think this is the way to answer this rather than trying
to beat it to death .
I'll bet I'll be able to give you a whole bunch
of information in there (at the planetarium)o
0 °Keefe - Should it be you, or Jocelyn?
Gill - It depends on when it comes off - what time it comes off.

44

Shoemaker - --~hy don't we say we'll ~lan on this and then · we can · make
the arrangements -Schirra - I am afraid that I can't do it rapidly, but I'd say the
first part of April would be okay.
Shoemak er _~ Jocelyn, would you like to take this on to set it · up and
follow it through?
Gill - Certainly o
Sch i rra - I would like to nail this one downo

I~ has been · botheri ng

me f or a long time and I just don't seem to be getting any · ans wers
that I would like to have as well.
Gill - It is possible to have hindsight here.

I n other words, we can

recon s truct the crime and it is worth doing, I think.
Dunke l rn-an - I am glad you mentioned that you. could see some • stars
dimme d through this patch because-if you don't see -any,-1:he patch
turns out to be extremely bright .
Dunkelman - It's about 300 times higher than what the normal airglow
(seen) edge - on is .
Schirr-a - Well, it wasn't dim by any means.
Dunkelman - It wasn ' t dim - the answer I get _is that it is about
3 ergs/cm 2 /sec which is extremely bright and its structure is extremel y
high .

It is about three hundred times brighter than the normal ai r ­

glow o

I think we can "home - in" on this brightness rather nicely

because, if you saw color, you know it is a dirty brown, but if it
was color, that does require at least SO to 100 times more t han the
normal night airglow.
Schir~a - That's why you were asking me earlier was there a color

45

in the airglow and I did not see it?
Dunkelman - We are trying not t~ ~ (influence your reply).
Schirra - ~laying one (response) against the other is indeed.. a good
way of doing it.
Dunkelman - Another think is that this was indeed brighter.
Schirra - Bu~,_ well below . . . .
Dunke l man - It is _possible that the normal ai rg low was the ire
but you didn't see it?
Schirra - It was well below my field of view though.
Dunkelman - But are we sure?

I assumed that it was well below, too,

but . . .

Schirra - Yes.

I saw what amounted to a clear starfield below this . . .

Dunkelman - About how many degrees worth though?
Schirra - I was just trying to think - Well, the window itself I'm just trying to think what I can see degrees-wise-this is Cameron - Thirty degrees .
Schirra - It was roughly thirty _degrees.
O' Keefe - But there is a trap here because that window shapes out
at such a steep angle - that if you attempt to· estimate height by
estimating portions of the window-Schirra - Oh, no, I wasn't doing that.

All I am trying to say is

that i n the window - included in the window - let~s forget this smog
band, it were stars only, it was below the window which would be the
earth .

There was no horizon and even if I could have been inverted,

we could just say that the window would be this · way.

There was still

no earth vision, nothing of earth I could see, including airglow or

46
anything else .

So I was strictly looking, if you could almost

say, I could even be looking straight up, which I know I wasn't.
The stars were equally bright and equally in number almost on
either side of this band.
Dubin - It was about through the middle of the window?
Schirra - That is correct .

I went even as far as to say that it

wasn ' t a third of the window and then I modified this down · to a
fourth, but ~twas more than a fourth and less than a third.

This

means, in any case, that it's approximately ten degrees thick and
this is a very rough estimate.
O'Keefe - It wasn't the Milky Way?
Schirra - No. No,

~

like to look at the Milky Way so I've seen

it enough to say ".no."
O'Keefe - Because you were facing according to your picture to - well no - Sculptor, Fornax - no Roman - The Milky Way in that part of the sky, should have a very
distinct rift down the middle, it wouldn't be brightest to the center
and shading off.
Schi rra - Yes, in fact, if I recall from the way we ran the planetarium,
the Milky Way was almost on my horizon.
~Dubin - How long can you see this by the way?
Schirra - We can do this too, John.
on this chart.

They have the Milky Way · projected

It is a very fine tool, I might add~ particularly when

you want to reconstruct the crime.
\

Gill - Might be very good practice afterwards for thq pilot to go

47
back to the planetarium (to reconstruct his flight path.) •..
Schirra - I sure wish I had thought of this a long time ago when I
was fresher on this.
Gill - It would fix things in your mind too - you'd be able to see them
again right away to pin them down.
Dubin - How long did you see this?
Schirra - I would not say seconds, I would say minutes,
Nordberg - Did this go away simply because of your progression in
orbit or because of your drifting?
Schirra - I think more because of the drifting, perhaps.
Dubjn - Did you see the stars through it?
Schirra - There again, I didn't have time to track stars through it.
When I say minutes, I don't mean a whole bunch of minutes, I mean
one or two or three minutes.
Dubin - Yes, but do you know whether you saw stars moving relative to
the band?
Schirra - No, they weren't .

It wasn't relative to the band.

That ' s a good question, now that you bring it up.
Dubin - In other words, the stars seemed to stand still.
Schirra - The band and the stars were planted together, much the sam e
way as you would see the Milky Way in a sense.

That's a very good

point.
O'Keefe - You saw a bunch of things there.

It might have been Aldeba r an

or it might have been Antares.
Schirra - I suspect that is what I did see at Antares or Alpheca,
and I think that is in that same spectrum there .

I think rather

48
than beat this any further, it's circumbent on us to go to the
planetarium and really nail this down.
All I have to do is just
take this window box we have and just move it around and - ah ha there it is.
• ·ounkeiman - Something we would li ke to know is the dimming ef f ect .
Schirra - Uh huh.
Dunkelman - You say that this patch was quite bright, that's on e t hi ng >
and then was it quite bright because it appeared bright or because
there are many, many fewer stars.
This is the question we have to
answer .
Schirra - Right.
You know what went through my mind when · I f in ally
realized what I was looking at?
had the periscope.
I was livid about the fact th at I
Absolutely livid, because · I would have shot up a
whole roll of film right on that (using uv spectrograph).
(Laught er)
I was fighting for that thing and that's why you can look · through and
I make perisocpe sound like a dirty word.
All through here the wo r d
periscope is shortened to four letters practically.
Shoemaker - Why don't we go on.
(Laughter)
Jocelyn, why don't you get together
with Cdr . Schirra and write a conclusion on this.
Schirra ~ We'll set up a rendezvous here.
Shoemaker - I think we have covered quite a few of the remainder · of the
questions partly in discussion.
I would like to go back to ' dark ­
adaptation here which is the next question.
You have talked about i t
and let's see whether there are any points that we havenJt • covered .
The
question is would you tell us when you think you were best dark-adapt ed?
Was there any time during flight when you employed only red light in the

49
capsule?
Schirra - We have answered that with the fingertips.
Shoe.maker - Did the light of the "time-correlation clock" shine in
your eyes throughout flight?
Schirra - The answer is no.
They put in a switch to turn that off and
I turned it once and it was never turned on again.
great annoyance.
This was a very
This was my prediction that I would turn i t of f
and never turn it on again.
Gill - You were responsible for having the switch put in, weren't
youT
Schirra - Yes, I went through some very careful studies on the da r kne ss
of this interior.
I ran a special test at the Cape and it is amazin g
how much light comes in there.
I told them this.
John and Scott were surprised when
Scott came back from his flight furious about this
time - correlation clock light .
So I put in a switch-in-series and
just clicked it off as soon as I got to the switch.
Gill - Good for you .
Schirra - It was the first time it was dark outside, frankly, and
that was the end of that light .
tube lights.
They leak like mad.
(Laughter)
The cabin lights are
Just terribly.
those off as well when I wanted darkness .
So I turned
Then I had pure darknes s .
The only light I could create then were the fingertip lights.
When I
blacked out that capsule, it was black dark other than when I ne eded
to see something with the fingertip lights.
This is · where our
crutches - as I described the map, the time and the star charts

.
(_
so
became a liability, because we had then to bring on light again
(I brought on the finger tip lights to do this).
strongly I feel about the star chart device.
But it required two tools and a slider.
sliders on each to use them.
Gordon knows how
This is a valuable tool.
Actually, two tools, with
I had to take one tool which gave me
a reference in the time that had elapsed to come back to the star char t
which had a reference for one time - I think it was an hour's worth.
So I had to come over here and compute.
For example, say I had S hou r J
and 20 minutes, so I'd run down 5 hours and 20 minutes and look acro ss
and this is equivalent to say 53 minutes.
So then I would say, Ah,
53 . minutes; so then I would race over here and set the little window
thing on the index of 53 minutes and this thing is floating around
and I would stamp it off and get it out of the way.
a chore.
It really is.
This is quite
So now we have included this on the flight
plan itself, what index of the star chart to use.
So we have
simplified this task quite a bit.
Cameron - As far as the star charts are concerned, fluorescence
Roman - Suppose you had an ultra violet lamp · in the capsule Schirra - If you kept it up?
Roman - That's what I was going to suggest - - (fluorescent paint on
charts)
Not depending on storing it up and letting it go down
afterwards.
Gill - You mean keep it on?
Roman - _Well, depending on which looks more desirable.
But
you could set that at a level where it would not blind you and

51
and you could see what you needed on the chart.
Schirra - Now this could be practiced in a planetarium.
O'Keefe - There are plenty of fluorescent inks.
Schirra - This star chart thing was a real problem even to get it
to the degree of refinement that I ~ad.
Gill - It has a white background now?
Schirra - We had to take the surface and sand it in a sens e to ge t it
non - reflecting, because that was a problem.
Dunkelmari - I want to caution you on that ultra violet light, though .
It has to be very carefully designed, because if just a wee bit
of

3615 leaks out of it; your eyeballs fluoresce.

It must be

carefully done.
Schirra - I've become very interested in this as a problem in that
on the Apollo mission, where you will need to find particular stars,
we should have some kind of star map that you can see without
blinding yourself.

Those fingertips to me were awfully bright.

Roman - You can ' t turn it down?
Schirra - No.
Gill - You must have been well dark - adapted?
Schirra - Yes, that's right .

I feel very strongly about this

dark - adaptation, by the way.

I have felt this way about this ever

since I have been involved with this.
was always a problem as you know.

As a night carrier-pilot, it

We would sit in the ready room

with red lights on and red goggles on and we · then would go roaring up
to flight deck and there would always be sbmebody there with a white
light to shine right in your face .

52
Dun ke i man - The Navy has done this very carefully.
Schirra - It can be destroyed very rapidly.
It turns out quite
frequently when you are in a cockpit and you're time - critical,
more so than when you are on a carrier deck fo r a night launch
than when you are on the pad .
Things are in a f r an tic tempo .
You make a very rapid checkout of the cockpit and you real l y don' t
care about light adaptation .
You just want to be sure that eve rythin g
is in its proper position.
So all of a sudde n - - bo om- -you are s hot off
into the black and surprisingly you are very well adapted .
I feel--
I know Scott has made a test on this -- ! think you come down to a very
rapid adaptation in seconds and then you pro gress get ting be tter
dark - adapted over many, many minutes.
I know this has been document ed.
It is not worth trying to adapt to this exponential curve that yo u are
trying to get hold of.
Gill - Five minutes certainly helps a great deal.
Schirra - I have said this in the past, for example, if it were
night outside right now, we could ~tep outside that door.
With t h i s
lighting you have in here, you can see outside this door (assuming
you are looking at the celestial night).
You can see more th an I
could see out of the window of the capsule with · perfect adapta tion.
I have done this.
I have been in a lighted room since the fligh t
and have stepped outside.
Now we have done this frequently at the
various control stations around the net.
I did this at Guaymas
which you well know is a tremendous place to look at stars.
I wa lked
out of a room just as lighted as this and got outside and boom, I saw
more than I could see in the capsule.

53
Cameron - I saw the zodiacal light once doing that in Chicagoo
I came out of a lighted building.
seen it.
It was the first time I had
It was in a part of the sky where I didn't expect to see it .
Schirra - I think that our test, frankly, that have been conducted
to determine dark adaptation are not done well enough.
I don't
think we can really justify how fast we adapt b:y the tests we hav e
run .
I have yet to see that quan~itative analysis made that shou ld
be made.
Intuitively, I feel that I ad apt faster than the tes t
has ever proven to me.
We had very comp l icated systems , such as th at
at Pensacola where you pick up the horizon and objects, trucks and
airplanes and ships, -- I'm sure you r e member this routine -- an d I
never was sympathetic to this study.
I think there is a bet t e r way
of defining it, however, by having you in an opaque room or rat he r
going from a lighted room into an opaque room seeing what can you s ee.
Have these measured light sources there and then identify them as
rapidly as you can .
Of course, you've got to keep identifying
because you are adapting all the time.
Tennyson - Is it correct then that this window of ours (Vicor
window) has .never really been nailed down as far as transmissivity
is concerned.
Schirra - It has been carefully nailed down, I understand.
Roman - Yes, but not under quite the · flight conditions.
Schirra - Well, I was carrying this photometer, and did make some
measured readings on some objects, but this comes back to the photo ­
meter check on Aldebaran.
This comes back ·to what I really made

54
it on.
I think they are trying to trace that through.
It wasn't
Aldebaran, that ' s for sure.
• Dubin - You say that you never saw your fluorescent numbers on
your watch?
Schirra - No, I did not.
This bothered me .
Dub in - Did you look at it?
Sch i rra - Yes .
Dunke l man - Is this some watch that requ ires e xposure to li ght f or
awhi l e?
Sch i rra - Correct.
There is another answer to th i s.
The ti me
function, meaning just running time, has th e fluorescent, but the
elapsed time that I used on this watch i s just black and whi te.
I wanted badly to get at least the hands coated and this i s a r eal
chore .
Very few people do this for you.
I would have liked very
much to have had this done, but couldn't ·get it.
DUnke J man - I would sure like to see the CIC lighting people
have a chance to put their two cents into this who l e thing ab out
the lights, for Apollo or something like that.
Schirra - I have gone on record saying that Gemini will -not f l y
until I personally run a lighting mockup on that vehicle a s we l l
as on Apollo .
There are many people who know how strongly I f e el
on t his subject.
Gill _- Very good .
Very good.
Sch i rra - What I ' m getting at is, if you can get the ligh t out
of the vehicle, you don't need to spend a lot of time adapting.
Gill - Right.

55
Nordberg - I am curious if you ha<l a chance to observe variations
of brightness around the horizon; around as far as possible
(during) both in day and nighto
Schirra - Again, the field of view isn't that big o
what you are asking faro

I know just

I didn ' t take the liberty of making

these, what would amount toi large yaw changes.
the opportunity to observe that transition.

I did no t have

The field of view I

had did not show these various changes .
O'Keefe - You see, this is like 30 degre es, that's half a radius. I don't
t hink

he could see much more than you could see overhe ad at ni ght.

Schirra - Yes.
ovKeefe - It means that if he doesn't see patterns in the airglow
from a single place at night, unless he has the freedom to yaw al l
around, he doesn't have the opportunity of tracing out the rather
large patterns which must be in the airglow.

They are of the orde r of

a thousand miles in diameter .
Nordberg - I was also curious about daytime, because of the
forward scattering and backscattering and 90° to the sun and
actually, in daytime if your turnaround maneuvers arep s ay , t hey
don 9 t go around in a plane tangential to the surface of the earth ?
They go around in a radial plane, don 9 t they?
Schirra - Well, this is the awful thing about our vehicle.

All

the thrusters are not aligned through the body axis, thereforep
you get two and three axes when you ask for one.

If you were

trying to track the horizon, using the yaw input, say the horizon
being like an arc here, you go like this.

Then you ' ve got to roll p

56
pitchJ like this, rollj pitch o
around o
In other words ~ you step your way
It is not a smooth maneuver as you would anticipate
in an airplane where you just roll and come around and cut a
swathe without changing attitudeo
Nordberg - In daytime, it should be really a striking thing,
the horizon looking toward the sun and, on either side of the
sun , and also looking straight away from the sun it co uld be
extremely bright ooo and at 90° 0
Schirra = You know where we are going to have the most fun?
It 0 s with the lunar module - the LEM or the Bug in earth orbito
By gosh, that's going to be great , because you pract ical ly have
an observatory on your hands o
A lot of open panel area that doesn't
have to be protected for re - entry or exito
That will give us our
first real opportunity to look in almost any direction at any timeo
You should see the fight we had 9 to keep a 5th window in the
Apollo command module o
16 lbso
They were about to rip it up and save
It was in the right seat where you spend 90% of the time
on a trans - lunar tripo (gasp) Negative o (Laughter) We said no
so we had a seancej that 0 s what we call ito
This is when we get · a
majority of the astro~auts together and we agree o
dissenters it is just too bad o
If they are in the minority~ wel l,
we come out with a united opinion.
Mercuryo
If there are any
This is how we got our window in
It was the result of a seance == it cost $500;000 and I think
you know its worth it o
attitudes o
It was for observation not only getting

57
Schirra - These things you canvt define by numbers.
In spite of
what my philosophy was for this flight you can't resist making
scientific observations .
Gill
=
That's taped?
I think it's legal.
That ' s what I. thought -- You wouldn't be human if you didn't .
Norqberg
=
I would like to get away from the horizon now for a
moment.
This is going to clouds .
There have bee n reports by
aJ:.1 .f:i ve of you on seeing cloud patterns and the like; is there
any good indication when you look down of on de p th cloud?
Schj.. r f~ - Very much so .
You can get Paul Back er (try Charles
Coler, MSC, better) to give you the Weat her Bureau photos I too~ .
It 's fantastic what you can see . It is the meteorolo gist's dream
,~t;,
to see this depth, cumulus effect , high cumulus, etc. As an
example, I
SqW
the Sierras, I could very definitely see the rising
terrain .
I was very much pleased.
I can best say this by s~ying,
if you ' ve flown at 30 thousand or 40 thousand feetp which you must
have , in a jet transport, you see this of course .
Now, if the
horizon itself is not visible to you when you are looking more
towards the surface of the earth, if the curvature of the earth is
not visible , you feel that you are at about 50 thousand feet .
Nordberg - And is this because of some sort of stereoscopic view
that you can still see shadows and brightness?
Schirra = I think you take every cue that you 've got and you
d~fferentiate colors by grays, blacks, whites, but there is
no doubt in your mind tha~ you see depth and there is one striking
picture, this Weather Bureau picture~ that shows ten different types
of cloud structure .
One is a big towering cumul us, almost a cumulus
·•·

58
nimbus that stands out like a ruler in relation to tpe vertical
plane.
I think it might be here (in the record).
Nordberg - I have seen some of the films.
were your flight or previous ones.
I don't know if they
I am just curious whether the
eye sees something better than what shows up on the color film .
Schirra - Yes, they do .
• ·o•Keefe
=
You use every cue availabl
1.
He doesn't have the stereoscopic effect i p the ordinary
I
sense, but you remember that he is in motion when He sees that th e
peak of the clous moves at a differen t rate so he gets a sort of
pseudo - stereoscopic effect like you get when you are dr i ving a lon g
in a car -- by the fact that they are moving relative to t he caps ule .
Schirra - Take page nine here, and put a sheet of paper on the top
of it to cut off the curvature of the earth and you've seen this
from an airplane.
Haven't you?
_Nordberg - Yes .
Schirra - That is why I've used it in this example that I am trying
to get across .
You can see cloud structures in this yellow band
here that are just terrific.
Nordberg - Well, how about at night?
Have you been able to see
any clouds in real darkness at all?
Schirra - Yes, I did and they were lighted by lightning.
In fa ct
I gave Woomera a report on the first orbit saying I would not
possibly see their flare because I was seeing lightning and they
hadn ' t stepped outside their room .
I said that you are about t o have
some real brutal thunder storms and the second orbit they agreed with
me~ because they were there then .
This was during the night side.

59

This was sort of interesting because I described the thunderstorm
flashes of discharges as blobs of lightning.

60
BEGINNING OF THIRD TAPE
Schirra - I could not pick up cloud structure because I was
looking down and at this pointp you don't have time, and I
don 't think your cues are good enough to separate elevations .
Nordberg ~ You don't recall seeing any clouds when there was
no lightning?
Schirra - No.
I don 9 t recall this.
I don't think I did reall y.
I was really frantically trying to see this typ hoo n, and we cal led
it a typhoon where Pacific Command Ship was.
it, and I could not see it.
It was down south of
It was still too dark, and I think
the other reason for it was that the periscope - here we go - was
annoying to me, that picked up the sunrise before I had my
sunrise, because it was looking in that direction, and it ruined
my adaptati on .
That was when I threw the filter over it, and that
was the end of the periscope forever.
I forgot to remove that
filter = not that I even intended to.
On descent on the parachute,
and in a way I would like to have had the prerogative of looking
at the periscope and seeing the recovery forces deployed around
there .
It took me a long time to realize why I couldn't see the
recovery forces .
(Laughter) .
And it finally came out that I
threw this filter over it just prior to retrofire .
And that was
the end of the periscope (laughter) which also showed that I
didn 1 t need it, obviously .
Nordberg - This question of frequency of lightning is a real
importan t one .
Would you say that you saw lightning through each
night time orbit?

61

Schirra - No, that was only during this area.

This could best

be described as the eastern half of Australia.
Dubin - Did you notice any lightning while looking down - you
couldn't see the flashes away from the capsule?
Schirra - No, oh no, no, I didn't get any light fed into the capsu le.
It was just my eyes that captured this light.
Dubin - In the daytime did you also see lightning the same way?

Di d

your ...
Schirra - I don't recall having seen lightning in the daytime.
a good question, though, and I don't recall it.

It 1s

I'm sure I woul d have

noted it if I had seen it.
Nordberg - One question, that I am sure you can't answer because of
the orbit of your vehicle, but it's of tremendous importance to th e
geological satellite people, and this is, the distinction of cloud s
and ice and snow.

I know, you probably never went over snow or ice.

Schirra - I looked up at the Sierras when I was on the second or
third orbit

- we can pin this down - and I was talking to John Gle nn

about somebody water skiiing on the Salton Sea, and at this time,
it was amazing how much I could see, because this area is practica l ly
crisp, clear air in . the desert, and I lived there for a number of
years, so I know that.

I could look all at the Sierras and I could

see snow - capped mountains up there.
Nordberg - But no clouds of course.
Schirra - Not, not - well - on the other side of the Sierras,
westward there was this terrible fog belt, and I do recall saying
sometime I may fly over the Pacific and see the Pacific.

I have

62

yet to do this - in aircraft - in all the times I've been out
there - see all of the Pacific.

I have never had that opportunity,

and I don't know that anybody ever will.
Tennyson - I think what he was getting at is when in the TIROS
satellite ~ the cottonpicker goes over and takes a picture perhaps
of stratus deck which to a continual extent runs right up against
the mountains that we know are snow-covered - wh e re one stops
and the other begins, the snow and the stratus.

It is difficu lt

or impossible to tell.
Schirra - No - well, my daytime was, of course, northern latitude,
and this was basically summer.

I was in the snow-capped Sier ras .

Nordberg - This question was really sort of just to make a po int,
that if ever an astronaut goes into a polar orbit.~.
Schirra - Yes.
Nordberg - ... or has the opportunity to fly over the ice caps
to look for this distinction, because this is something we find
we are going to live with.
Schirra - I have flown beyond a cloud deck in aircraft at 40,000
feet and had snow on the surface, and usually trees will come up out
of the snow and then make you realize that you are no longer looki ng
at a cloud surface.
Tennyson - Well, our definition of a TIROS Satellite - because of
the width of the TV raster - which is just not good enough to pick
up trees with the wide angle and the mediocre lenses we use.
Schirra - Well, yes.

When you are low enough, you get these terrai n

changes which helps you too, I think.

63

Nordberg - There are some thoughts that by polarization and so,
one can distinguish it over a uniform surface; of course, the
eye doesn't have this, but I'm just looking for a clue that the
eye might have which we hadn't thought of in an instrument such
as depth, because it's interesting when you say you can see all
this depth in the clouds themselves.
Schirra - Yes.
Nordbe.!.,& - ... whether one could see because of depth difference an d
shadows, or something, this distinction between clouds and snow.

On

the first TI ROS (satellite), TI ROS I , . ~
Schirra - This thing is stalled out (referring to tape recorder).
Is that o.k.

Is it finished?

1

- No, no that's going.)

Nordberg - The first TIROS was just sort of an observation when we
still were at this "Ge Whiz" stage on satellites.

Boy, we see

something
Schirra - Sure, now you want more?

(Laughter) - So do I.

Nordberg - People said look at those beautiful orgraphic clouds
over northern India, and there is this huge band, until somebody
saw valleys in these clouds and all there was - was snow~covered
areas and with the valleys being clear.
Schi rra - Very good. . ..
Tennyson - John O'Keefe has come up with a statement that I, at least ,
would like to think about some more and that is the relative motion
involved here.

TIROS and Nimbus, etc. are still picture - type items.

I think his (Schirra's) statement there that watching the tops and
bases and of the earth moving at different relative speeds may be,
at least, as important to height determination as anything we can

64

do with spare part items or items like that.
Nordberg - It's again the depth.
Schirra - Well, we are working a movie camera where TIROS is taking
stills, is what you are saying.
Tennyson - Exactly, and you imply a height which the eye in itself
in a still picture mode can't see, but as it goes you say, ah, ha
- this moves at a different speed, and therefore, it had to be
higher.
Schirra - I would accept that, except ~or the photograph I have
here which shows this depth.
not know.

Or is it reminding me of it?

I do

Do you see the depth I talk about in that photograph on

page 9?
Tennyson - To some degree (perhaps), b~t, no, not as directly.
I found that picture interesting, but as indecisive as a good many
of these prints are.
Schirra - Well now, do you have all of the~e Weather Bureau
photographs?
Nordberg - I have not seen all of them - well, we may not have the m I find that sometimes it is very peculiar that as a NASA outfit NASA Center - we often have less immediate access to some of these
• films than the Weather Bureau has - (Laughter).
Schirra - Well, let's -- I find this disturbs me very much in
that when I yielded to taking a camera·, I actually did want to take
one, but I wanted to make people fight to give me the best piece of
equipment they could get rather than fust take a camera.

I wanted

it very clear that those people who could use this data would get

65
the best print available, and I definitely have this group on
that list.

For one, I am disappointed that this occasion where

I pu~led this Weather Bureau filter out of the back to take
these two pictures of the moon, I have heard and I have yet
to have seen the graphic results of those two black and whites
on the moon, which are quite interesting to a lot of people.
I have heard this.

Now where they've gone, I don't know.

Although I know they can be obtained again, I thou ght this was
a shame.
Tennyson - I don't think that I have ever seen these pri n ts.
And, we are in the office that supposedly collects the requ i re­
ments for meteorological satellites and I have not seen the
direct prints of this.

The only thing I have seen come out

Schirra - Well, I have heard that if you take - and I haven't
had the prerogative either - if you take the motion and project
it on a very good s~reen, it is really something to see -- at least
of these two lunar pictures.

And that ' s why I took the Hasselblad .

To take this big piece of emulsion - the 70 mm film rather than
a 16 or 35 mm . - and this I do know about photography that the
larger the strip of film, the more you will get out of it.

That's

why we went first class with a Hasselblad (camera) and why I am
not at all in favor of taking a 16 mm.

c amera along which is wh at

we are using.
Nordberg - We had, in the early days, right after MA-6, we had
written to Kleinknecht and had gotten periscope film, which, you
know what the quality is, and we got always the answer that they

66

don't have the 70 mm. yet, but as soon as they become available,
they'd send them to us, but actually we haven't really received
anything from them since and the only time that I have seen
some of these photographs that you are talking about .•.
Schirra - Well, Kleinknecht doesn't have control of this, MSC
doesn't have control of these pictures I took, obviously, . or
actually I would have been able to se e them.
Gill - Who does?
Tennyson - The person involved with this (at least in th e past)
is Stanley Soules.
Schirra - Yes, when you think of the s mall number of p ictures I
did take, and the expense that was involved in taking these
pictures, it is just ama zin g that first class reproductions
haven't been disseminated widely.
Shoemaker - I think, Jocelyn, this is something that you and I
an d John O'Keefe should take up with our joint committee.
Gill - rv 11 look into it.
Schirra - They should be all over the place ... is really
what I am really getting at .
Shoemaker - This is something we can do something about.
Schirra - Sure .

I know Kleinknecht can't help you with this

because he has no control over this.
Shoemaker - I think we can straighten this out.
Cameron - Did you ever think you could see highways?
Schirra - I saw roads in areas such as Mexico where they disturb
the terrain by being in a straight line.

I never did have the

67

opportunity to see a highway, for example, and trace it,
because I wasn't over those populated areas such as the Southern
United States long enough or had the clear weather to just
sit there and observe them.

In contrast, I think what you

would do if you saw something and wanted to look at it, I
think what you would do is that you would pitch down more - to
look almost straight down and see it which Scott had the capability
of doing and he could really take a careful look at it.
O'Keefe - One curious fact that I haven't seen anybody take
advantage of is this.

It is quite common in triangulatio n -

that two stations which are a couple of hundred miles apart, or
a hundred miles apart, and that therefore as far apart as you a re
from the ground and along a light path which is much inferior it's nearly parallel to the earth.

In order for one of those

stations to see the other one - to measure on it - they provide
one of them with a 6-inch heliotrope, that's enough.

That means

that somebody on the ground with a six-inch heliotrope who knew
how to point could point a light that you could see even in the
daytime if they had a dark background; and conversely, if you had
a heliotrope, you could also be seen from the ground.
seen this possibility discussed.

I have never

Of course it also goes with the

fact that instead of these tremendous flares, if they knew how to
point, they could make a much stronger light where you are with a
search light.
Schirra - Sure . . ..
O' Keefe - The army 5- foot searchlight gives 800 million candles

68
on the axis which is easily the equivalent of 800 million candle
poweroo osingle flare on the ground ooo
Schirra - uh - huh -O'Keefe - Well, I think 2 or 3 million is the biggest thing they
ever tried to use o
So the directed beam has quite a big advantage
over the undirected beam, if people ' s orbital work is good enough .
Schirra - Agreedo
Our problem of course, is unless we have the win d0w ,
meaning, of course, attitude, fairly vertical in relation to the
surface of the earth, you can ' t take advantage of this.
This i s j ust
the confined attitude that we 0 ve been flying ino ••o
Shoemaker - I think this bears on another question that was
submitted.
I might read it and find out what else we can add to it.
The ph otographs of terrain were not successful.
Some of the trouble
was obviously due to cloud cover, and some of the film was over­
exposed .
Can you comment further on this, and do you have any
suggestions for successful terrain ph6tography on future flights?
Schirra - Yes, I do o
I used a BIWI automatic light meter which is
still ideal for the job 9 and again we were not briefed carefully
enough on the BIWI automatic, and if I' had this to do again, I
would get the manufacturer from BIWI to come down.
In fact, many
things I 've talked about for equipment, I would not ever -- I said
this years before this flight, but while on the programo.oif I needed
some information on the capsule, I would not feel adverse to callin g
Mr. McD onell (McDonnell Aircraft) down, as an exampleo
I f I had a
BIWI exposure meter, I would like to have Mr. BIWI or whoe ver is

69

the man to brief me on it, and I since have read up a little bit further
on this exposure meter and there is a little soft, white cap
that goes over the eye of the exposure meter which takes diffused
light o

It doesn ' t change the light meter reading, but it basically

~hen takes an average of all the ligh t it sees o

Now when I was

~

using it, I didn °t have this cap on there and I then got the
brightest light of some area and that ' s why we overexposed

the fil m

Nordberg ~ Yes, yes oo o it's very simple ooo
Schirra - It 0 s as basic as that , and that ' s why I over - exposed
these light values that I came back with and which were recorded
are really of no great value because of this, I think.

I t's a

small focus - the exposure meter is just about that size cubed
(demonstrating) it 0 s a beautiful little piece of equipment and
quite accurate o

We had a calibrator, but it should have been

(capped) ooo Gordon Cooper knows this and will have a cap on his ,
I might add o
Nordberg - Have all pictures been overexposed?
Schirra = No, I looked out on occasion where I would be looking at
an almost uniformly lighted area such as the surface of the earth o
When I had the horizon in the picture, we usually overexposed
because I had two different light levelso
Dunkelman - Well, the pity of it all is, since you do need an
exposure meter to get a good picture, and exposure meters give you
a number, it's too bad the numbers isn ' t available.
Schirra - I did record these .
Dunkelman - Sooner or later these numbers are going to give you a

70
lot of information about these flights.
Schirra = That was my intent in taking the exposure meter and the
Hasselblad because you took light values rather than F-stops
and shutter speeds and this means nothing ... those numbers.

The

light values connote exactly what you want to know.
Dunkelman - And a few of those and you've got it all made and
you know all the circumstances.
Schirra - Cooper will have this very same type of li ght meter.
Nordberg - You know why I asked this question, Larry, because
we are measuring visible radiation in one channel of the TIROS
satellite which is essentially the same thing as an incident
light meter measuring in one direction and when we compute the
reflected energy from the earth, it always comes out too little
which is the same thing as overexposed pictures .
Schirra = Sure, Sure.

It just depends on how much it sees.

I f it

sees the horizon, it's going to have some black in there relative
to the bright surface of the earth, so it averages it out.
Shoemaker = I ' d like to add some questions of my own to this.
You were over Africa during daylight on part of your flight,
were you not?
Schirra - Oh yes .
Shoemaker - And how about Australia?

Were you over there during

daytime at all?
Schirra - No, never having daylight over Australia.
Shoemaker - I am curious as to how much detail you could see on the

71
ground as to structure.
Could you infer anything about it?
Schirra - Amazingly enough I felt I saw every bit of what I see
here.
The terrain changes, the rivers - one of the best shots -
this is of course, South America, that's the one I'd like to use
in fact = when I came across South America, here we are, on the
sixth orbit, in this area it was all clouded, and I finally broke
into the clear - in this sense - just before I got to Rio de Janeir o ,
and I could see, I think it was the Corono River, I am not sure.
This is about where it started clear again.
river out very easily.
I could trace that
Just follow it all the way through there .
Roman - To the ocean?
Schirra - No, I could not do that.
I thought I could, but at t hi s
point, it's sort of a local sunrise, so you don't have good vertical
lighting on it at this point.
lighting almost.
Now in Africa, I had vertical
This was almost its local noon when I crossed i t .
I would like to have seen this large lake right here almost in the
center of the mass of Africa , and I don't recall seeing it.
0 9 Keefe - Chad, Chad .
Schirra - Yes, I think this is probably when I was conversing with
Conno and we had quite a bit of discourse about the suit circuit .
O'Keefe - Chad is a very tricky lake anyway.
Lots of the reeds in
it, and it is very shallow; I think sometimes it just isn't there,
sO
• • 0
Schirra - I think you just simply get a light reflection off it
possib ly .
It looked so pronounced here that I wanted to see this
as a check point and had it in mind, and I've forgotten ...

72
O'Keefe - I think this is swamp and it's very shallow.
Gill - You never would see it then.
Shoemaker - In photographs I've seen from previous flights, both
Glenn's and Carpenter's flfghts, I think we got some pictures on
Africa, and I was quite interested in these because they begin to
show up the structurep the bedding, etc.
Schirra ~ Yes, I was looking for this particularly over Africa and
South America because this was supposed to be real prime in transi ­
tion on the northwest part of South America which was really a
beauty when you visualize how you hit that with the 6th orbit, and
I didn't have that prerogative either.

Yes, when you come down to

it, this was all primed for geologic study, I thought ... Even
Cuba was hard to see. (Laughter)
Cameron - Did you see anything -on the order of craters?
Schirra - No, this is not the map I flew with by the way - sort of
blocked out for specific attention.
about the cloud cover.

I frankly was very disappointed

I think you've detected that anyway.

That doesn't go too far No rth and South you are in this tropical
zone which
is the cloudiest part of the earth.
>
Schirra - Yes.
O'Keefe - It is most systematically cloudy.

If you can go just a

little further north and south, the chance of get ting this weather
will be better, although this would probably always be true, just
as you've said, that most of the earth at any one time will be
cloudy.

This belt goes from about 35 degrees North to 35 degrees

south.

You didn't quite get an inclination of about 33 degrees.

73

Schirra - As an example, I was hoping that I could look up at
Japan after retrofire, and I couldn't see it at all.

It was

clouded in too.
Tennyson - Japan, this time of year, looks like it would be cloudy.
Nordberg - Particularly at this time of year - this was October, so
that was already in the Northern Hemisphere and should be out of
the tropical convergence zone.
Tennyson - But still Japan by nature is .... (cloudy)
Schirra - There was quite a bit of weather in the Pacific at that t i~~.
O'Keefe

Still, if he goes 28 degrees N to 28 degrees S, he was in

the tropical convergence zone most of the ti me.

So thin gs aren't

qu i te as bad as they would appear from this flight.
Shoemaker - The point is that this also is in the area which is
mostly extensive deserts; these are the precise areas where you
would see the geology best.
Schirra - Yes .
O'Keefe

This is 30 North and 30 South -- the deserts are 35

degrees.
Shoemak er - Well, actually the extensive deserts nearly all lie in
(interrup ted) ...
Schirra - Something I ' m curious about is, I would like to have some ­
body - well there are two ways of doing this - I bet I probably had
water underneath me about 90% of the time.
Cameron - About how much cloud coverage would you estim a te ?

Wo uld

you estimate the amount of the earth that was covered by clouds?
Schirra - I guess I could check this more carefu lly.

I would

74
estimate it to be about 80 to 90%.
When I went over - the United
States was clear east of the Sierra's, but it "sacked in"
(clouded over) again by the time I got to the Gulf of Mexico,
so I just had a small band when you look at this part of the
United States .
This is not very much percenta ge-wise.
South
America, I didn't get to until the 5th and 6th orbits, so I was
over water all the other time.
The northsic portion of the contin en t
was cloudy and finally I got into the clear on the 5th and 6 orb it s
by the time I'd just left South Americ a.
Aus t ralia, of course, was
ni ght, so it turned out that there wasn't much I could s ay about it .
· other than the fact that it was clouded over too .
I saw l ightn ing
as I got to the eastern half of Australia.
ill - You never saw any large view of water then?
In other wor ds,
you didn't see any part of an ocean?
Schirra - No, I expected to have some fun looking at shorelines .
This is what I really wanted to look at, to see if I could see
color contrast and even the Pacific Islands.
I had hoped to se e th e
Hawaiian Islands which would have been a real e asy one to pi ck up,
an d I think I had one little
li mpse; about as much as i f you 'd fly
9/10 cumulus structure and you pop one through there.
That's abou t
as much as I had and I couldn't even identify which Island I was
looking at.
O'Keefe
~
Probably Haleala or else ...
Schirra -
ight have even been Hawaii itself, I am not sure , wh ich
is probably the highest of the bunch, and it mi ght have p opped up
through it.

75
0 1 Keefe - There's a 10,000 foot peak (Haleaki) or Maui.
Dubin - How were you overall set for time?
You were up to the
sixth orbit and you had some trouble with your suit, so we found
out.
Did you have time to basically do more scientific work
than you had the privilege of doing?
Schirra - I think as we - and this is the trouble with Mercury
because this is just about phasing out - as you get your confiden ce
in the systems to where you don't need to monitor them as of te n, yo ,
could take time for observation.
But you continually, at this st age
of the game, cannot rely on the systems running themselves and so
you keep carefully monitoring these things.
This draws your
attention away from, say a five minute observation.
The only t ime
that you could make a lengthy observation would be when you are
under this automatic control when the capsule is maintaining its
attitude for you rather than you trying to maintain it.
very hard to do; to maintain a capsule attitude.
This is
In that it ' s a
three - axis motion everytime you make one motion because each one
is influenced by another axis thrusting.
So as a result, it gets
quite expensive fuel - wise to point your field of view at an obj ect.
You have to sit there and just steam around like mad to do th is.
Gill= Would you say that you ever had as much as five minutes at
a time to look out of the window?
Schirra - Oh, yes.
I think I took a fairly long amount of time
for example; observing this particular sunset that's repres ent ati ve
of about three or four minutes.
Even then, you keep checking thin gs
to see if what you see is really what you are seeing.
For example,

76
was that really Mercury?
Well, I knew it was Mercury just by having
had the opportunity to have Mercury projected on approximate launch
day, so I knew it had to trail the sun, and everytime we ran the
~lanetarium, we had Mercury projected tracking the sun, on the
s an. e p at h , of co u rs e .
Gill - So it is a great help to kn ow what things are there and where
they are before you take off.
Schirra - Yes .
You've got to have most of this stuff in your mind
rather than have to refer to something to remind you of it again.
This is why you can get confused as I was, when I was drifti ng, as
what star or constellations I was looking at.
Shoemaker - We have one more question.
trivial one.
I think this is rathe r a
I don't think we need to dwell on it.
Did the moon
interfere with your view at anytime, or did you make use of it in
anyway?
Schirra - I used it liberally, of course, for attitude reference.
On e
best example, on the third orbit, I was drifting and then restore d my
attitude during the night rather than during the daytime.
We were
trying to determine whether we could get the attitude back both
daylight and night.
Out of the unknown attitude, I first picked up
the horizon which was on the night side, very easily, which then
gave me roll and pitch and then I had no idea which way to go for
yaw.
We had no compass ... whether it would work or not is som eth ing
else.
I started looking around at this starfield which was not on my
flight path, by far, and finally, Cassiopeia became quite obvious

77
to me.
I said, "Well I, that means I must go left," and as
I came left, I started picking up other stars which became known
to me through the starfield that I had rehearsed.
Then the moon
and Venus showed up and that was here.
O'Keefe - It must be very difficult to pick up constellations when
you have a starfield to look at that is as small as through your
wind ow .
Gill - It isn't ....
Schirra - No, Orion, for example, was not included in t he windo w, so
you might see the belt and that's about i~, or maybe one or two others
in the constellation.
That's about all.
When you see something
like Aldebaran, and the "v" (Hyades in the Constellation Taurus) if you just saw that alone, you might very well get trapped,
thinking it was the Pleiades , particularly, if you don't have an
attitude.
You know how well, I know you got trapped (turning
to Dr. Gill) when we went into the Planetarium for the first t ime things were inverted for you?
Gill - Oh yes - yes, indeed.
Schirra - When you have an unknown attitude , the star p icture is bent
out of shape .
You can get into trouble fast.
Nordberg - I .had a heck of a time the first time I was in Austr alia;
it was difficult to recognize anything.
Schirra - Isn't it!
Yes and when we aren 't changing attitude and
even when we know the starfield, it's not chan ging once youv e
1
seen it on the first orbit.
So I was sitting there with the star

78
chart, bending it around. (Laughter)
Gill - It's very hard to get oriented.
Dubin - Did you or Glenn or Carpenter see any meteors?
Schirra - No, and we were naturally anxious to see them.
I
understand some little Japanese boy picked up one recently
(Comet Ikey~).
Isn't that right?
That was a comet and we were
looking for mbteors and comets and we never saw any.
Dubin - And so you never saw any?
Schirra - So I suspect that you have to see the meteors from t he
surface of the earth.
Dunkelman - No, again the field of view is too limited.
Schirra - Again the odds are pretty grim.
You take this lit tle
window and you project it through 180 degrees, and it's pretty
hard to see anything.
That's why I say this lab (lunar module)
is going to be fabulous.
It really will ... That's practically a
bird cage.
Nordberg - How about the brightness of the sky looking as stra ight
out as possible in the <laytime?
Schirra - I have asked Gordon to go ahead and do this again an d
concentrate on it.
I did not, but in my recollection, I did not
see anything in the heavens on the daylight side.
I think what
did this was the reflections off the window with this smoked over
effect which made it even less visible.
This film - back to the
windshield thing - where the smoke is condensed on there - under
the right lighting conditions you can barely see through one of
these things.
That's basically what happened there.

79
Nordberg - How about color?

Was it very dark blue?

Schirra - Oh it went from blue to black.

Not an appealing

blue by any means.
Dunkelman - Well, really to be fair to an astronaut, one ought to
take a replica of the window and go in the dark room and illuminate
it side-wise with a xenon arc or a solar simulator or somethi ng
that will come near it and then look out and see what you c an ' see,
and I am afraid that it is going to be pretty miserable.
Nordberg - It worked well in an experiment.
Dunkelman - I think it should be done ... it's the sort of thing yo u
should do.
Schirra - We continually do this in airplanes at 50,000 feet in
daylight and the sky is quite dark.

It's very dark to you.

It

turns out that all this incident light that's re f lecting around
this panel - just b~cause its plastic, it feeds light through it
much like a fibre optics system and becomes a glowing panel that
you are looking through here .
O'Keefe - The full moon which is as "black" as ... yet we all ·
know that the full moon just about blasts the sky.

That means

that if when you are lookin g out of that window, you see any
object which is illuminated by the sun, and which is as big as
one-inch ten feet away, you've got the equivalent of illumination
by the full moon in terms of you know, disturbing your adaptation.
Schirra - Oh yes.
O'Keefe - Even if it's painted black and of course, you are not
likely to be that lucky ... you are likely to have some nice, bright

80

gleaming thing.
Schirra - The only opportunities I had for looking vertically were
during boost and re-entry and a lucky chance while drifting.
O'Keefe - If you are going to observe during the daytime, the whole
window has to be turned so that the window doesn't look at the sun
and so that it doesn't look at anything that looks at the sun and
so that it doesn't look at anything that looks at something that loo kJ
at the sun.
Schirra - Right.
Tennyson - Otherwise, this would imply that to know with r e ason able
exactitude what is being photographed through the window in terms of
spectra or anything like that, you'd not only have to know the tr ans­
missivity of the window spectrum range by running it value by value
across it, but you would have to know what was on the window and
what the angle, the incident, sunlight and everything else were
because some of this is going to wind up inside on the camera.
Schirra - Right.
Gill - So, you didn't go through the periscope hole, you say?
Schirra - Basically, you were ...
Tennyson - I was talking about these weather bureau pictures .. .
Gill - Oh you were ... those weather bureau pictures, oh well . . .
Schirra - Where we are trapped really is that we can't duplicat e
what amounts to being in the bottom of a well.
Tennyson - Well, I understand.
Schirra - That's the whole thing.
Tennyson - This isn't a criticism ... it's just a comment really.

81
Schirra - That's our liability with the window being on an external
surface,

You are that close to the top of the well, so you get

incident light all over the place.
O' Keefe - We don't want to create artificial problems here.

That

smoke scum on the window would not re a lly distur b a s~el la s p ec trum be­
cause the absorption would be broad hand and would not be confuse d
with the stellar lines.
Dunkelman - That's right.
Tennyson - I was thinking about the I QSY ph ot ographs .
Schirra - Yes, yes.
Tennyson - We are going with the problem of, oh, the ultr a vi o le t
and what is going to fog our nimbus pictures so to spe ak thro ugh th ese
photographs, well, the same still unknown film on this thin (c ap s ule
window) being reflected in sunlight at an unknown altitude through
this window ... when you get through, what I'm saying is it would
be very hard for us to tell from these weather bureau pictures, et c.
(inaudible)
Nordberg - Well, of course, but it's really more an intensity
problem-just brightness rather .than spectral-I think spectr al i s no t
too much of a problem , but the fact that it just di ms thin gs un der
certain angles makes me ... things that much clearer.

But th is

experiment you suggested there is a real excellent one (ref e rrin g
to Dunkelman's.
Schirra - Oh yeah.
Dunkelman - Well, I mean it modifies it even more, makes it better
because you can do the same thing outside at night in clear air -

82
just look at the night sky and then again, having a low level
source coming up and even if the window is absolutely clean what
happens with these eight reflections .
Schirra = Sure .
Dunkelman - You see, the problem of not lett i ng any thing look at
the sun or letting that look at the sun look at t hi s i s ve ry important
even with automatic satellites .
Schirra - Well, I 9 d be very glad to see it (except capsul e window) .. .
Nordberg = Okay, can we get a window?
Schirra = I think we have got enough us e d capsul e s aroun d.
mine is on its way to South America though (laughter) .

I think

In fac t, its

to be there in three days .
Shoemaker = I wonder if we have one last question .
adjourn .

If not, we should

Any further questions you ' d like to pose to Commande r

Schirra?
Dubin = Yes, Commander Schirra, one question, what suggestions do
you have for improving the operation over and above what you have
already mentioned so far?

That's not a very nice question .

Schirra = No, you mean, as far as pursuing investigation sc ientifically
is concerned?
Dubin = Yes .
Schirra = I feel at this point, for example, in Cooper 0 s flight , what
we are really trying to do is to get at least man in space for one
day .

We don 9 t dare compromise that because we need to know how

man can hold up for this and we design the capability in the systems .

83
I admit this is my old pitch, but still he will have a lot of time
to do things.
So he has a number of experiments on his flight and
he definitely will perform these .
Now , in my case once I solved the
suit circuit problem, I really didn 9 t have many problems.
none to speak of.
Frankly,
But, again to conserve the energy to stay in
orbit meaning the control fuel and the electrical powerp I had to
throw away control attitudes.
Once you try to get a control attitud
back again, you 0 ve got to bring all electrical power back on the line.
You have to use a sizeable chunk of the control fuel.
dearly with this weight - limited system.
Thi s cost us
The way to get around
this, of course, is to have a larger field of view, since you don't
need to move the vehicle as much, and this is, I can already see,
the first salvation on this and this is the lunar module in earth
orbit .
The Gemini has even less field of view than Mer cury.
Apollo has possibly as much per man .
To get a large field of view
in space the first time, we can do it with the vehicle that
isn °t going to re - enter (lunar module) - basically that 0 s what it
amounts to .
ordberg
=
I think it 0 s really fantastic that you fellows have
seen what you have seen with such limitations.
I think it re ally
probably is one of the reasons that people like ourselves are used
t o just l ooking at one dial and we stand in the laboratory and
r ead one meter.
These fellows are really looking fo r everything.
Schirra - Wellp I think that this is part of what fell out of the
criteria that we were selected from, and that is the inquisitive mind.

....
84
We don't li ke to let things go on without knowing at what they are;
and you explore them pretty thoroughly, maybe with limited know­
ledge, but at least you try to get it down.
I have been fighting
like mad to get this continuous tape recording .
This was invaluable
to get answers just like Larry and I and 1rs . Cameron went back and
tr a ced out
some of this like the smog layer.
I would have
remembered this, but I probably couldn ' t have tol d you when I s aw
it without referring back to this continuous tape .
This is some ­
thing we are not getting .
O' Keefe - It es quite a fascinating thing to l i ste n to t he se tape
recordings; undergoing this is a tremendous experience .
You c an
hear what the person is - I think that is a debt to humanity
that it ought to be done.
Schirra - I ' ve been fighting for it all along .
At least, we ought
to be able tp store £or a period of ti me and then dump it in fast
time and then retape .
Dunkelman - And with your flight we actually see the be ginning of
an interesting turn of events .
In the past, people on the ground -
I think we had ...
S ch i r r a - Sure .
Dunkelman - Would tell the astronaut what to look for - now in y our
case, when you saw this brownish smog thing - here ' s a case where
you could have said to the ground, "now, you lo.ok" now, it seem~-d
bright enough, so if there were any people on the ground Schirra - Unfortunately, I ' d left my last point of contact which was

85

.the Indian Ocean Ship.
Dunkelman - Yes, but the point is this is the return, what I'm
trying to get at -- the moment you saw that which no one saw at the
time on the ground is the beginning of a new period which we have
to take advantage of on the next flight.
Schirra - Oh, of course .
Dunkelman - Here's the case where an astronaut can tell the ground,
"Now look" - "here now", you see.
Schirra - Interestingly enough - it was about that same t i me whe n
the Indian Ocean ship saw me .
Dunkelman - Oh, oh, now of course they are in the clouds and ...
Gill - Much more interested (in seeing you).
Schirra - I didn't know it at that point though.
Nordberg - That lightning case, though ...
Schirra - Yes, I gave them a weather report and they didn't believe
me either. (laughter) They said, "Oh, it's clear here."

Well, of

tourse, I had to look back on a very long slant line to see the
flare, and this was , then covered by clouds, well, then, if this
were Woomera, then the cloud structure would go up like this
we'll say, well, I was over here, so I really couldn ' t see Woomer a
at that time .

That 0 s how I satisfied myself I never would even

though they had a beautiful clear sky over their station for that
first period.
Tennyson - This is not only great for you, it's great for t he
scientific world .
Schirra = It is.

86
Tennyson - It's good to have somebody else who isn't constrained to
party lines.
Gill - It's a privilege to meet with you, really.
Tennyson - Something that shocks me is that the discussion from
Scott Carpenter and your discussion is the picking out of clues
from about, heaven knows, how many scientific disciplines from
your general experience etc., and integrate them all together and
be able to present them; frankly, I just find this very interesting
that anybody can do that.

The wide range of experience.

Schirra - I think it's the opportunities of so many exposures we've
had and we have taken advantage of them, and as an example, we can
have an audience with you people anytime we call, and if we have
questions and this is true throughout the whole pr ogram.
talk to Von Braun if I'd like to right now.

I can

I can talk to a technici an

that's working on a nut and bolt on Von Braun's booster right now.
We have this prerogative which is very great for us.

We are not

stuck with the disciplines of crossing party lines or anything like
this or going up to the ladder and back down again .

We go - we

just take a straight path to where we want to get information .

It

is a tremendous opportunity -for us, and we try not to abuse it, but
we use it liberally really.

I might add that anytime you have a

question, our phones are always available for this kind of thing.
r

Don ' t ever think we are incommunicado.
Shoemaker - Good - that's very good, Commander.
you very much.
Schirra - Sure, I was glad to come by.
TIIE END

I'd like to thank

President
he can observe and make plans
judgments that no instrument Apollo s
Glenn,
or animal can accomplish.
tried to
As an example, Douglas said terious " f'
that Glenn, on his own initia­ held 35-mi
tive, had turned his space· filled with
craft around 180 degrees on Force doct
tives showe
his s e c on d orbit to see ible but the
whether the mysterious "fire- larged for clo
flies" he had noticed on his perts.
first orbit might be paint or In reloading
other particles from his craft. Douglas said, G
The astronaut found that the grip on a film o
unknown o b j e ct s streamed floated in front
past his window in the same weightless flight.
direction as on his first sight- for H the tip of
ing, proving they were inde- it and it "sailed
pendent of the spacecraft.
never could get
_Scientists here b~lieve the again."
s~1ll unknown luminous par- The astronaut r
ticles, when fu~ther explored, he had no trouble
may lead to rmportant new ta b 1 e ts and a
knowledge of space ph~nom- s ueezed from a
ena. No unmanned satelhte or Dq 0 g 1 a
'd
observation from earth had deu
s sai
tected anything like this be- - - - - - - - - - - ,
fore .
Glenn reported they were 11ILK-Frou1,
small, but as he lacked any
checkpoint, it could be that
the particles were more distant
and larger than he th()lllght.
Similarly, scientists are much
interested in the luminous
1 haze belt Glenn saw about 7
\ to 8 degrees above the horizon I
over the dark pa_rt of the wards year•~ end an
earth Tuesday. Soviet cosmo.
.
naut Gherman Titov reported again next pring.
seeing about the same thing, If the estimated level
but there has been no expla- to be those actuall.ly
nation of it as yet.
d the will sti'll
These observations, say Mer- ence •
Y"
. .
cury officials, are an answer below the perm1ss1ble
to those who have opposed els set by Government
sending man into space when ciails.
in~ruments can make obser- N0 M k d Strontiu Ris
ar e
m
vations better and cheaper.
Astronaut Glenn himself
The PHS yesterday also
believes that the m~st signifi'. I ported that radioactive str
cant technical result of his tium meas urements from Se
flight was to prove the im- tember through NovemlJ
portance of man as a pilot in 1961, do not "differ materia
space travel.
from those found prior to
"We have piped man aboard ! sumption of Russian nucle
as_ th~ pilot ~f spacecraft," he weapons te~ts ." Milk sampl
said in nautical lingo. "Now from Washington, for exa
we can get rid of some of that ple, averaged seven micro
automatic equipment."
microcuries per liter during
Much of the weight of the September and 10 micromioro­
Friendship 7 capsule includes curies during October and No-I
duplicating systems put in be• vember.
cause it was not known These figures do not vary
whether man could function in Igreatly from those reported
a weightless state.
for other American cities,
The fact that man can be with the exception of Port
an active pilot and not largely land , Ore., which showed 3
a passenger on a spacecraft micromicrocuries per 1 i t
will have its impact on future during November. A P
Mercury flights and later spokesman said the Port

For An· t

CORRECTION
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in this newspaper yesterday. The Post regre
and publishes the complete listing below:

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BROILERS

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"Meteors" (A Symposium on Meteor Physics): Special Supplement (Vol. 2) toJ. Atmosph. T err. Phys. (1955)

Meteor Ionization in the E-region
MAURICE D UBIN
Air Force Cambridge Research Center, U.S.A.
ABSTRACT

The theories of meteoric interaction with the atmosphere h ave been reviewed to determine the total
contribution by m eteors to t he ionization content of the E-reg ion. From Herlofson's t heoretical
treatment of this interaction, and Watson's distribution of t he size and numbers of meteoric particles
entering the atmosphere per day, t h e number of electrons produced at various altitudes in the E-region
was computed. These computations indicated that most of the ionization at higher altitudes resulted
from meteors oflarge visual magnitude. Since, as Whipple has shown, the ablation process would probably
not occur in the case of micrometeorites because of heat loss by radiation, the collision processes for
ionization were r eviewed; it seems that the ion ization process is mainly a function of the relative energy
of the co11·
'ion, and therefore ablation prior to ionization would not be required for small particles.
Using the Jue (of GREENHOW and H AWKINS, 1952) for t he efficiency of t he ionization process and the
recently re ised value for the amount of meteoric material entering the atmospher e per day, the rate of
production f electrons was found to be 20 electrons/cc sec. From this value and the r ecombination
coefficients ·n the E-region, t he equilibrium electron den sity in t he E-region was found to b e between
2 x 10 4 and 7 x 10 4 electrons/cc. It is therefore proposed that the night-time value for the electron
density in the E -region results from meteoric bombardment, and that sporadic Eis caused by the same
process on the assumption t h at the distribution of meteoric particles in space is non-isotropic and
contains centres of high density. P erhaps, also, the interaction of charged micrometeorites with the
earth's magnetic field, may be considered as a mechanism for t he production of magnetic storms.

1. INTRODUCTION
METEORS, as commonly known, are extra-terrestrial part icles of only a few milli­
grams, which enter the earth's atmosphere at relatively high velocities. In their
interaction with the air, they are vaporized by the heat generated and ~re respon­
sible for the emission of light and. production of ions along the meteor trail. The
major portion of the kinetic energy of the meteoric particles is absorbed in the
altitude region between 80 and 120 km. It is attempted below to consider whether
the integrated effects of this meteoric interaction might contribute to the structure
of the E-region.
2. THEORY
HERLOFSON (1948) has constructed a model for the interaction of meteoric particles
with the atmosphere. It is assumed that in the region of meteoric flash , the mean
free path of the molecule is much greater than the radius of the meteor. Under
such conditions, the front surface of the meteor is bombarded by single air mole­
cules and the major portion of them is trapped in the metal surface. The kinetic
energy relative to the meteor which is given up to the meteor suffices to bring the
temperature to that of ev:aporation. The meteor atoms evaporate off the meteor
(ablation) with velocities appropriate to the temperature and the relative velocity
of the meteor with respect to the air.
From consideration of the physical interaction.of the meteor with the air mass,
using the differential form of the conservation of energy and momentum, HERLOFSON
determined the equation for the rate of evaporation at any point along th!;) trail.

n = ¾nmax(P/Pmax ) [l - ¼(P/Pmax)] 2
wher.e nmax = 7 X 10 23 r 00 3 = the maximum rate of evaporation.
p = the pressure at any point along the trail.
Pmax = 4 X 10- 2 r 00 = pressure along the trail where nmax occurs.
r 00 = the initial radius of the meteoric particle.
111

(1)

112

MAURICE DUBIN

Since the velocity distribution of meteors is over the range from 10 to 70
km/sec, for the purpose of computation an average velocity of 40 km/sec was used.
Pmax and nm.a.--.. were determined accordingly.
From equation (1) and WATSON'S (1941) estimate for the number and size
distribution of meteors entering the earth's atmosphere Table I was computed.
The computation has been made for three altitudes, 85 km, 100 km, and 115 km,
using the following rocket pressures:
Altitude (km)

I Pressure (mm.of Hg)

Number density of
air molecules (cm- •)

4 X l0- 3

85
100
115

1014
10l3
1012

4 X l0- •
4 X 10- 5

Thus equation (1) becomes
7 X 10 23
(
n = 4 X 4 X 10- 2 pr a} 1
9

1

p

3 4 X

10- 2

)2

r 00

2

n 115 = 1.6 x l0 21r 00 2 ( 1 -

l
) •
3 X 10 3r 00

The number of electrons per cm of path becomes, from HERLOFSO

(1948) ,

n X 10- s
n X 10- 2
n. cm-1 = - - - ­ v

4

From Table I it is evident that the number of electrons for a shell of 1 cm
thickness over the surface of the earth , resulting from meteors, is 10 20 electrons
per day at 85 km produced mainly from meteors of visual magnitudes 1 to 4,
about 1020 electrons per day at 100 km with the major contribution for visual
magnitudes 6 to 15, and again about 10 20 electrons per day at 115 km from mag.
7 to 20. The number of electrons produced per cm of path per cm 2 per sec at these
t hree altitudes is thus 10 20 / ( 4 . 4 x 10 23 ) = 2 x 10- 4 electrons per cm 3 per
second.
Now according to HERLOFSON, the kinetic energy of a typical meteor is divided
in the ratio 10 4 : 102 : 1 for the production of heat, light, and ionization, respec­
tively. These values were used in the computation of Table I. However, from

Table I. Calculation of the number of electrons produced per cm of path per meteor and per l!wenty-four lwwrn;ura function of visual magnitude.
(number in upper right is power of 10)
He ight = 85 km

I
Observed
No. of
meteors

Visual
magnitude

-3
~2
-1

0
1
2

3
4
5
6
7

8
9
10
15
20
25
30

I

I

2-8+•
7-l H
1-8+5
4.5+s
1·!+6
2-8+6
6-4+ 6
9-0+6
3-6+ 6

True
No.

Mass, g

2-8+4
7-l H
1-8+5
4.5+s
l·l +s
2·8 6
7· 1 6
l ·8 7
4·5'
l·l"
2·8 8
7· 1 8
1·8 9
4·5 9
4·5 11
4 .513
4.515
4·517

4
1·6
6·3 - 1
2-5- 1
1-0- 1
4-0- 2
l-6- 2
6-3- 3
2-5- 3
l·O- 3
4-o- •
1·6- •
6-3- 5
2-5- 5
2-5- 7
2-5- 9
2-5- 11
2-5- 13

Radius
CID

6-5- 1
4·83- 1
3.54- 1
2·60- 1
1-92- 1
1-41- 1
1·04-1
7-6- 2
5·6- 2
4-12- 2
3·03- 2
2·24- 2
l ·65- 2
1-21- 2
2·6- 3
6-o-•
1-21 - •
2-6- 5

No. of
atoms
evap.
cm- 1
6-0 22
3.022
l ·72 22
8·3 21
4.021
l ·86 21
8·0 20
2.920
8·019
9· 1718
l ·46 18

Height = 100 km

No. of
electrons

Total No. of
electrons

n 0 cm- 1

n e cm- 1

1·5 14

4-218
5·321 8
7.7318
9.518
l ·l1 9
l ·3O 19
l ·421 9
l ·3O19
9-018
2-718
1·0218

7.51a

4.31s
2· l13
1-013
4·6512
2-012
7 ·25 11
2·Oll
2-4310
3·65 9

.

:ro. of
atoms
cm- 1

n e cm- 1

6-721
3.721
2· 1 21
l •1 21
5-620
3.po
1-620
8 ·519
4.410
2·3 19
l •1519
5·75 18
2· 218
l ·2O18
(1·0816 )

l ·6813
9.2512
5.2512
2 ·75 12
1.412
7·75 11
4·0 11
2·13 11
l •111
5·75 10
2·8810
l ·441!'
7·19
3-o•
2 ·7 7

Total

n, cm-1

4 · 7 17
6·56 17
9·45 17
l ·2518
l ·5418
2·17 18
2·8418
3·8418
4·95 18
6·3218
·0518
1·02 19
l ·27 19
l ·35 19
1 ·21 19

Height

= 115 km

No. of
atoms
per cm

n , cm- 1

6-720
3.720
2 ·!20
l· !20
5-819
3·2 19
1·7 19
9.21s
5-018
2-718
1·4618
7·8 17
4·2 17
2· 1617
8-215
l · 1614

l ·6812
9·2 11
5·3 11
2·8 11
1·45 11
8·010
4.310
2.310
l ·3 10
6·8 9
3·7 9
1·96 9
1·06 9
5·4 8
2·05 7
2·9 5

Total

n, cm-1

4·7 16
6-616
9·5 16
l ·25 17
1·6017
2·2417
3·0 17
4·1 17
5·617
7·417
l ·O2 18
l ·39 18
1·91' 8
2-418
9-218
l ·3O 19

....
....

to>

Il4

MAURICE DUDIN

consideration oflong-duration meteor echoe it ha been suggested that the electron
density in the trail is greater than the critical density for the radio wavelengths
employed in probing meteors, and has led to a revision of the Herlofson ratios for
the production of heat, light, and ionization. GREENHOW and HAWKINS (1952)
thereby found that a mete.or of visual magnitude +6 would produce approxi­
mately 1012 electrons per centimetre of path. This is one hundred times greater
than HERLOFSON's estimates, and leads to a discrepancy of roughly five stellar
magnitudes between his theoretical estimate and the experimental determination
of electron-line density in meteor trail . GREENHOW and HAWKINS conclude that
meteors produce more· ionization than was originally estimated. Instead of the
kinetic energy of the meteor being divided between heat, light, and ionization in
the ratio 10 4 : 102 : 1, the ratios are probably 10 4 : 102 : 10 for bright meteors, and
10 4 : 10 : 10 for faint meteors. These revised estimates imply that the visual
magnitudes corresponding to ap echo of given characteristics is about five magni­
tudes fainter than given by HEBLOFSON. This means that the majority of echoes
of short duration must arise from meteors which are below the limits of naked-eye
visibility, and conversely, that all visible meteors must produce radio echoes of
long duration-a well-known ob ervational fact .
A further consideration in the model of HEBLOFSON is the fact that unmelted
meteorites hav been found on the smface of the earth. WHIPPLE (1950, 1951)
has shown that the micrometeorite, if below a certain size, can dissipate the
energy gained sufficiently rapidly to permit the ·e particles to be stopped by the
atmosphere without melting. Recalling that the Herlofson model required that
ablation of the meteorite was the initial step in the production of light and
ionization, thi point warrants some discussion. GREE HOW and HAWKINS
(1952) have indicated that for radio meteors the amount of light produced is
correspondingly reduced for small meteoric particles but the relative ionization is
not reduced, but rather is generally larger than indicated by HERLOFSON's treatment.
It seems worthwhile to review briefly the physical process involved in the
interaction of a micrometeorite with the atmosphere. Since it is not believed that
ablation results for these very small particle , one might question whether or not
the ionization efficiency would become correspondingly poorer. The physical
problem is one of considering a collision of the micrometeorite with a molecule or
atom of air, with the relative energy of collision in the range from 10 to 800 eV.
The mean free path of the air is much ·greater than the diameter of tho micro­
meteorite, and thus the problem may be treated by kinetic theory rather than
fluid dynamics.
•
There are everal proces es which might occur: (1) An elastic collision of a
molecule of air with the micrometeorite would yield a molecule with a velocity
capable of ionizing. (2) An inelastic collision of a molecule of air with the Inicro­
meteorites such that the air molecule enter the surface of the micrometeorite, and
thereby heats the Inicrometeorite and al o forms a "monolayer" on the surface;
such molecules if not chemically bonded to the surface might very ,easily evaporate
off the surface with the velocity high enough for ionization. (3) Secondary ioniza­
tion from collisions with a surface. (4) Attachment to oxygen by the collision and
the eventual addition of a free electron to the atmosphere; and (5) sputtering of

Meteor ionization in the E-region

115

the micrometeorite and the subsequent ionization by the freed particle_ Experi­
mental information on collisions of neutral particles and the resulting excitation
and ionization is very limited. Much of the available information is contained in
MASSEY and BURHOP (1952).
Although the ionization efficiency is much greater for electrons than for heavy
ions, as long as the ion energy is greater than the threshold value for ionization,
the possibility of ionization exists. For example. a recent technique for obtaining
velocities for neutral particles near the range of meteor velocities is the shock-tube
method of RESLER et al. (1952). It was found that the extent of ionization as a .
function of Mach number was rather large. In the case of argon at Mach 18,
argon at 1 cm of g pressu,re was 50 per cent ionized. Mach 18 corresponds to a
linear velocity of 18 X 0·350 = 6 km/sec, somewhat less than meteor velocities.
For this low velo ·ty there also was a highly luminous region associated with the
shock fronts in b h argon and air.
BERRY et al . (1942) investigated the ionization of gases by collisions of their
own accelerated olecules. They found that the onset energies observed for such
ionization were roughly only three times the ionization potentials of the atoms.
They also concluded that in the range of speeds for argon between 48 eV to 1,000 eV,
relatively little change had occurred in the kinetic energy delivered to the newly
formed argon ion, and therefore it seemed unlikely that the mechanism of ionization
was one involving a transfer of kinetic energy. Also at energies of about 2,000 eV
the cross-section for ionization of argon was greater than for N 2 by only a factor
of 2. In fact the arrangement of the cross-sections for ionization in decreasing
order was found to be A, N 2 , H 2 , and He.
An estimate of the order of magnitude may be determined (for a few of the
reactions) from MASSEY and BuRHOP. Although most experiments have been
made with positive ions, it seems that the cross-section for ionization in the case
of neutral atoms is at least the same order, but usually somewhat higher.
The secondary emission coefficient for surfaces, y, is the :q.umber of ejected
electrons per incident positive ion. Some ob ervers have found a higher value of
y for surfaces which oxidize readily, implying that higher values arise from the
oxide layer. PAE'.1.'0W and WALCHER {1938) reason tha.t since the electron emission
cannot depend much on the work function of the adsorbed atoms, in th case of ·a
monolayer of ox~gen on caesium, it would follow that the extra electron emission
came from the bsorbed layer itself. The value of y for the low-energy range in
the case of mi rometeorites and based on positive ion bombardment would
probably be in e range from 0·02 to 0·5. Allowing for an energy absorption of
10 eV for a secondary electron, these coefficients are in themselves sufficient to
give a ratio of kinetic energy absorbed in ionization for 200 eV of better than 10 3 : 1.
Negative ions have been found to result from the impact of positive ions on
surfaces. ARNOT and MILLIGAN (1936) have estimated that for incident Hg+ ions
of about 200 eV energy, about 10- 3 Hg- ions were formed per incident ion. For
neutral oxygen atoms and molecules which also form negative ions, this ratio
could very well be higher. Positive ions incident; on surfaces may be reflected
without neutralization, although it is generally felt that an ion on striking a wall
become, neutralized. For rare gas ions incident on nickel, the reflection coefficient

116

MAURICE DUBIN

found by HEALEA and HouTERMANS (1940) wa in the range from 0·2 to 0·05 for
ions of He, Ne, and A at about 400 eV.
The impact of ions on a solid surface re ults also in a process known as sputtering,
wherein atoms or clusters of atoms are ejected from the surface as a result of
impact. The threshold for sputtering is of the order of 40 eV, and most values
given {or rate of sputtering lie between 1 and 10 gm/amp hour. For incident ions
at 200 eV the sputtering rate would probably fall to one-third this range of values .
For a surface containing atoms of mass number 60, one gram per ampere hour is
equivalent to approximll,tely 0·5 sputtered atoms per incident ion. Thus the
sputtering rate for metallic meteorites might be of the order of one atom per
incident air particle and possibly higher for stony meteorites.
Basicall , for all these proces ·es the important parameter for ionization is the
relative vel city. The relative amount of energy absorbed by ionization should
not be diffe ent, whe~her or not ablation of the meteoric particle occurs. Because
of the long- ean-face path of air compared to the size of the meteoric particle, the
air particles must act independently of each other. Effectively the cross-section
for ionizatio might increase during evaporation, but this is equivalent to increas­
ing the air density to allow for a larger number of collisions. Indeed, one may, as
a gross estimate, expect that on the average a fixed percentage of the kinetic
energy absorbed by the air is transmitted into ionization with an efficiency given
by GREENHOW and HAWKINS' correction of HERLOFSON's treatment.
Recently WHIPPLE (1952) has investigated the amount of meteoric material
entering the earth's atmosphere. From experiments of BURNIGHT, and BOHN and
NADIG, using rockets; CROZIER and SEELY on air pollution; VAN DE HuLST and
ALLEN by observations of zodiacal light and eclip e , and PET'l'ERSSON and ROTS HI
from observation of deep-sea sediments containing nickel: WHIPPLE noted that
data from these methods generally agree as to order of magnitude of the amount
of material falling into the earth's atmosphere. From this, the frequency of small
meteoric bodies encountering the earth's atmosphere should exceed the older
estimates 'based on meteors and meteorites (WATSON'S) by a factor of possibly
10 4 . The result is perhaps 10 3 tons or more per day on the entire earth.
Earlier the value for the number of electrons formed per cc/sec was found to
be 2 X 10- 4 erctrons per cc/sec, based on WATSO ' 'S estimates and HERLOFSON'S
theory. Sine GREE ' HOW has indicated that HERLOFSON's value should be
increa ed by factor between 102 and 10, and the number of micrometeorites
should be inc ased by a factor of 10 4 to 10 3 , th rate of production of electrons
should be multiplied by a factor of about 10 5 , giving an average production rate
of electrons of twenty electrons per cc.
Having determined roughly the rate of production of electrons, the rate of
disappearance of electrons must be considered in order to calculate the equilibrium
electron density. The rate of loss of electrons along the meteor trail is given by

on = D \j 2n - ('J.,n 2 -

-

at

ynn 0

Where D is the diffusion coefficient, <J. the recombination coefficient, y is the
coefficient of attachment,. n 0 is the neutral atomic or molecular density, and n is

Meteor ionization in the E-region

117

now the electron density. For small particles, where the number of electrons
formed per centimetre of path is small, the diffusion term is predominant, and the
train quickly decreases to the equilibrium electron density, which is thus given by
°'n 2 = rate of production of electrons.

The effective recombination coefficient for the E-region is e<(O 2 ) '.::::'. 5. 10- s
cm 3 sec-1 , when 0 2 is present, and e<(O) '.::::'. 4 X 10- 9 cm 3 sec- 1 if oxygen has been
dissociated. Thus n is approximately equal to 7 . 10 4 and 2 . 10 4 in the upper and
lower E-region, respectively.
3. Co cLusrn s
The above is app ·cable to three effects in the E-layers. First, the diurnal variation
of the E-layer is found to agree fairly well with the (cos x)t law for the variation
of the simple Ch pman region (xis -t he zenith angle of the sun) . The variation is
found to be alm~st symmetrical with reference to the maximum at noon (MITRA,
1952). However, with the accepted value of the recombination coefficient, the
E-layer ionization at night should fall to a very low value. The residual ionization
density as observed is much greater than it hould be. It is therefore suggested
that this night-time value results from the bombardment of micrometeorites.
Secondly, measurements of effective electron density obtained by rockets
(LIEN et al. , 1953) indicated that a bifurcation, or two maxima, in electron density
were present in the B-region. It is suggested that one maximum results from solar
radiation, the other from micrometeoric bombardment.
And finally, it is proposed that the sporadic E-clouds of ionization result from
micrometeorites. Although some correlation with meteor showers is found, the
major portion of the ionization results from micrometeorites with a fine structure
undetectable by radio probing. The cloud-like structure of the E-layer very
possibly re ults from clouds of micrometeorites. The amount of micrometeorites,
the penetration depth, the ionization efficiency, and the distribution of the micro­
meteorites are all con. istent with the conditions required for such an explanation.
Granted the laboratory evidence for the ionization process is not adequate, but
the general physical reasoning based on ionization density measurements by radio
methods of lower visual magnitude meteorites leads to an order of magnitude that•
seems very promising.
In conclusion, it may be possible also to relate the meteoric bombardment of
the upper atmosphere to the high-latitude magnetic storms and aurorae. For this
process it is necessary that sufficient photoelectric effect from solar ultraviolet
radiation be ,Present to charge the micrometeorites and thereby allow some control
by the earth's magnetic field. This investigation will be described elsewhere.
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