--- PAGE 1 --- --- PAGE 2 --- ....... a --- PAGE 3 --- ittle ra r --- PAGE 4 --- ··- to at • --- PAGE 5 --- Vu W.. t.Mrtid. or =--~--===L-...:::: actnaU 7 .Dll":l.,IID1~ • Oil bo ➔ ----. I' ~to • itlllN tMt 11U a ..tataala . • ~ •tat-it ~etanI at rtson, tbe &'tall. C boti. 11.gbt. ,tbeil l ltlQ'ecl 1n tll&t ,, C COIie 1 t I tbe j( ~ ont.bento • Dee' --- PAGE 6 --- • --- PAGE 7 --- --- PAGE 8 --- • --- PAGE 9 --- • --- PAGE 10 --- --- PAGE 11 --- --- PAGE 12 --- ) --- PAGE 13 --- t hit --- PAGE 14 --- • --- PAGE 15 --- 4 •••••• ••••••••••••• --- PAGE 16 --- 5 --- PAGE 17 --- --- PAGE 18 --- 0 :t --- PAGE 19 --- --- PAGE 20 --- 9 --- PAGE 21 --- • --- PAGE 22 --- _______......,___. --- PAGE 23 --- --- PAGE 24 --- • • --- PAGE 25 --- • /8 0 --- PAGE 26 --- • --- PAGE 27 --- ' a re. t --- PAGE 28 --- . . --- PAGE 29 --- " . --- PAGE 30 --- ' . --- PAGE 31 --- --- PAGE 32 --- ~-- -- ........... __. ......................,.. t --- PAGE 33 --- ) --- PAGE 34 --- 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 observations are presented below \)~•u •~LL •-, -. . IA.~ r· t N.,c~~- clc--+'""""'""! "\ kun.inous ~ rticles : 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 their shape. field, the particles !all. For the velocity in moved at preeise)y the same speed and !!.ll,.moved a~ precisely the same direction except for particles coming very close _,_ .... ~"'~•"<- f .-L to the spacecraft. This occurred similarl:i, :i,Q, all three , . ..~d'f¥t.....~ orbits. 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. --- PAGE 35 --- -2- The 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 ~.... ~ ~~ ~ 6\ANI&~~ -..,..laA, ,,_ - , has i;c;r,r9~9d the life support system which ~ ~ \wM. ~ \: .... ~ ~ ~ \'""~\~) 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 --- PAGE 36 --- -3- significant 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»serveI' :fJ o\~t.. ... ~,..... ~'-u"~ .t.,.a4!d.,. ~ -sm rJ.-.uL,,:.,,. •.,.\. • ~ ~ l ~-.llt.,dicated a high angle haze layer . ,. n i'1 e,v:ia.ewe ~het . s f ~ ~ ~ 7 -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 l~.,\ of an 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 --- PAGE 37 --- -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 discussioms would be to his interest. 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 ~ . --- PAGE 38 --- -5- 1 ~~ ~ ~~~ ~ ~&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&.. .,..__ ~, .....,,_.\..,. lo.\u. apparent ts" take advantage of ,tae im~eYement& ;L;e tac ~•~~. ~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., ~'YI. ~ - ~ t ~o ~ - a committee or sub-conmdttee QQ forwed oa.e.~ indluding such people as RGefte, ~Utt , Minnaert, Towsey, 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..,. ,>-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.-; .,.,_,_ --- PAGE 39 --- B 2 3 196 ? U.\h e, NllW Mll:XICO tO: Dr. Jocelyn Gill July 13, 1962 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. Maxinrum absorption occurs in the range 3500 < ). < 4500 A and drops to ~1/2 the peak value at 5000 A. They give no data for longer wavelengths. 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 . •. --- PAGE 48 --- 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 --- PAGE 49 --- 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 auch • ••• sequences already exif:>t). 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 1 • I 1 --- PAGE 50 --- . ' . .. LOS ALAMOS SCIENTIFIC LABORATORY UNIVERSITY OP' CALll"ORNIA l.09 ALAMO., NIEW MUICO TO: Dr. Jocelyn Gill -- 10 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. If your group recommends inclusion of such J observations on a future flight, we may be ·able to help on some points in data acquisition. I am sure the project would deserve review and .control by a panel --- .......... of men such as Bates and Nicolet. Respectfully submitted, ~y--~ BOB E. WATI' BEW:jo Assoc. J-Div. Ldr. Distribution: and Grp • .Ldr. J-16 .I l - Dr. Jocelyn Gill. ' --- PAGE 51 --- In ~ly refer to: SGC:Mt:llll. 21 Feb~ 1962 MQl)BANDt){ Subject: Poeaible 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.• • i'bit . In .a.dition, the ge.-.( ! 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 /4 is faf~8} 1/ _v}r/ ¢1/1• . #J.JJiJlliJJJlfl:!J°Y:!iJJJ,~v.~ir The f i lter observati on on the airglow was made at 17h 0~ 6s, UT. --- PAGE 59 --- 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. (Pesults of the Second U. S. Manned Subqrbita l Space Flight, 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. It does not appear possible that this layer can a ctually absorb starl:ight. 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. In fact, it is not definitely visible on the photographs of the day side. 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. The latter i ndi cates altitudes of 2° to 36 . 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. --- PAGE 60 --- 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 --- PAGE 61 --- 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 --- PAGE 62 --- 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. Note t hat at 02 52 47, Carpenter noted a particle moving faster than he. At 02 50 00 , he planned to observe sunrise and was facing forward. This particle was thereby probably seen east of him. Most of the particles are seen behind hi m and f alli ng --- PAGE 63 --- • • J ... 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. These photog.ra:phs plainly sh~w. the flatte~ed,, sa\.lsage- . .. ·kc.h""' ,, + ~\:~ Ct, fft.,;~c. ( n~'(':, thh \- v:,h .. 1" \\(. ';,(..\.v .,.,_,, \ , \(~ \-h •,,11 0,v I>' • ~"',\,( ei,., tr,-, , ,1 ·t )c ,., .., ,rr l " '"~ '> 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. As a conse~uence, the whole d Lsk appea rs flattened. 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 re- frac t i on is to make the sun appear as a red ring of light around the earth. --- PAGE 64 --- 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' h .· • • \ I • ' ~. A~ ~ ... .' . spacecraft. It was a good so~d thump when it 'took· oft. • ·' • • •• '. , '' ,r~·:/; ._, : ri-~ --- PAGE 65 --- 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 .I t was real definite. Something on the order of a half of e. gegree per ·secon 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, to pitch back down .afte~ ' I you deployed. You. went to cage - to retroattitude and the attitudes just and start back .over. It was real ·clear on the records where it went 1out .. / 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 awe;y. 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 on ito I did feel that I had almost Judged the distance on that first t In fact I didn't even "!:>elieve that was it when .I first saw ito t cou1tln't • I I• , . ." think of anything ·else that it could be but it was just solid lighto ~d -~ {_ 1 -, ' . . • ·,. • . . ., i . • . ;r. ~ t ..._.., ··~~ ,[!, '"' it turns -' out looking ' back now 6n it, · I -am..sure this.... was ~ . because_the s~.'. :~- ::· -~~ .~,, --- PAGE 66 --- 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 . glowing,--was ' the sun reflecting ·off of it. . 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? Did you correct your 1; 1 .· attitude when you didn't see .it or· did you have any feeling what the problem .··:. F,.. ~ ...,, ., , - • I • l •, • 'I- - • •~ -, • ' . - , was? ,. • -,-~ ;' _·•: ... ,~ ' . .. - Cooper:. I Just don't have any idea. I kept doubting Jey"Sel~~ • This was the first time of course that I .had ever tried . aligning to small end forward, . • . ·,.'., a 180° yaw -as weJ.call it and of course aligning , on the night sideo I begaxi I . . / ' to doubt that I was aligned properly, I went to the star charts and rechecked , • • ., " r 1 !' 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 ~ ..: • - • " • t • , l't J ') • f •"''" night I was aligned exactly ·on and in using the horizon .line J~t about 1n : ,,: • •, ,1• ~. •. I , . . .the middle of the window even moving up and down almost.. invariably• ,. - -- • don't have any idea why I didn't see it. Bill .Armstrong: You .did change your ·attitudes? ·That was one of·the th . . 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· •• ~ o/ -did·. • ' ' . ust sort /of scan the area or vb&: --- PAGE 67 --- Scientific Debriefing -4- 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 50 ~ute1 ahead ot Where :,ou had • norn:ia.;uy been used to using them. ir:.finally did find star patterns that gave ' -me the proper orientation. \ ,I was wiing, around 15 to 120 degrees pitched downi ·,.'.,, ,·. ' ,. :• I .was just keeping the horizon ~ th~ sort of bottom p~ of the Window ~d~•:-1·!_·, :./·:~'l~·~ ;{ \ ')" \ •' I • t .., ,f- I got_around. ·this area, I then tried varying ·the· attitude ~P and down to- '· • ,•• ·, look for the light~ . .. I 1 She:pard: You mentioned ' in your repOrt that,--you talked about approx 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 , ~ ·•· . It is r~ally not an excuse for ·not seeing it ,and I really honest]¥ _ C •• I ', . . ~-- ; .- ~ ...... - ----··· - •• say why I didn •t. . I had 'b~gun ~o doUbt th~t ,1~ was re .. flash ~ .., ~ • • • I • I • --- PAGE 68 --- Scientific Debriefing -5- Cooper: The moon was probably 14-al. 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. It is hard to visuali~T .. ~: ; . ' - , .'· •• ,1 ~ tip'. • • ;. 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 -~ $.alf the ·llgbt. In yaw as C?JDPared ·: st •do you think 70\1. . • : •• ~ed d~ ~b~ter the . ·,( --- PAGE 69 --- I' .' Scientific Debriefing -6- Cooper: Well, not realq. As I went into both night sides I cc;>u.ld pretty well estimate 18o0 yaw. 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 ' ' • / I 0 0 ' 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_' I • I · 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! ./; :; , • • • I • I , . I , . ' , In other words how .f ar down "or :how; high did you go with your ·pitch .attitude? / ¾:,' • I ')} .. . • ::.;, Cooper: On the first night s.i de I .allowed it to drift very, very slow:cy and •·~ • _• .. , : , .,. . ... ' "'J. :, , \t. , .. , .. t ' changed them as I needed to, 'very very· slight:cy to keep m:, yaw on 180° and· /./. '.., Y· \ t, it varied back and forth very ·sl.igbt:cy. But X went '&1.1 tlle ~ down to . •' ;~ ~;~ ·, ,,,.~ ) ' I t\ '• ' , where the horizon ·1would fill the ·whole window and up to where. I Just ba.re:cy , ..,- ¼·.J., ·; \ • •, · • . •. . • ., • ~.. , __ i .1,.·.t- \,. r ~ •r • ~ \,. • • • ' • • ;"' ,' "..' •' :'i # h¢ the horizon in sight. / "7 ' . ,· . . ' Bill ,.Armstrong: · Did you see it cane right a'WIQ" ·when · you·:iooked .on I nigb.t'l 'I ,,. / ; ' / In oth • · ·- :rd8 °you :picked it up. • J --- PAGE 70 --- Scientific Debriefing -1- Cooper: .Almost. Almost as it began to get dark. Of course it gets dark Just like that. Zam 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~. It was · coming up in relation to me, and was finally ·up to 'lI13 level. 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 . I , ' • • • • I • ' ~ launched at night :f'rom Cape C~veral; when rou 're t:cying at night at a ·high·• altitude. and see them launched. It didn't have the same glow but it· was ....., • ' • • ' .. ' • ' ':,I •• • • ·1 I' - very· very bright, and solid and .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 :· --- PAGE 74 --- ,. • I Scientific Debriefing • -ll- Cooper: I think so. I 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 I think ther e is going to be problem like there is in .aircraft a 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. .. • --- PAGE 75 --- ·,scientific Debriefing • l2- Bill Armstrong: You feel brightness suitable f'or a rende~vous be something on the order. of second or third magnitude. I • l • .' • . ~ l •• . •. • - ' ' Cooper: Yeso Bill: That 1 s one of t he main things we wanted to ·r ind out.. Does of the secon~ night l ook about right? Was the third night too d:l.m'l . ' ., Cooper: Yes, the third one is .getting ·a little too d:l.mo I • Bill: Do you think you have got to have good sighting • information I .to • pick . ,. these up ev:en 'W'ith bright light7 J' I C~o:per: Well, it is a pretty big sky at night .up there and there are a lot of bright starso 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 think the f lash rate could be cut downo I think you could maybe I haJ.ye the flash rateo • I woul.d rather .- see it twice as bright and see it fl.ash ·\ . , ., half as of'teno , A . flash , rate, even -one every two seconds is. stii;t ,. distinctive. ·: . . 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? --- PAGE 76 --- Scientific Debriefing -13- Cooper: Those deploy marks worked real well. They were excellent for getting in 1·etroattitude also. They -position your head ·to a real positive position, ' , I " I Bill: We have read the attitude ·records pretty carefull:yo You were between ' 20 a.nd 22 degrees, so you were right in .there. 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 · o John Boynton: 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; It seemed to me that slightzy s+ower ·than ·one flash .per. second.. --- PAGE 77 --- . 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 ·, didn't find it, but e·e'fore I got to the next night side,- I brought yaw ' _back' ,' • . • ~ ,,,.,)II'~ • • ••; 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: Did you see it tumble'l Cooper: Carmines: --- PAGE 78 --- Scientific Debriefing -15- Bill: 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 , I Cooper: Not this particular ··orbit. No I didn't. I 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 ' these pins and get a misalignment. W~ checked the plug :and.in this case the :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 '.- ·• .. I ' of the squib would fire the latch. 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 , , • - ' ,' '·. . . .. -. , . ---: -, :, • , • • •. . ' I , -· l, --- PAGE 79 --- ',, ' ; Scientific Debriefing •. -16- . >fl' ' '· ' ,. Cooper: No. It was just a bit :further to the l.e:f't than I thought be. Bill: More toward'. the · center of' the window? Cooper: Noo More slight]¥ to the le:f't of' the window. I coul.d have been yawed ·off a l.ittl.e. 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 . . I woul.d sq it , was about between third and fourth magnitude BaW it. '7· . Bill: AB you continued to obse;rve it · did Y9U notice ~t dimming?,, 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? --- PAGE 80 --- Scientific Debriefing -17- I Cooper: Maybe as long as a minute. I doubt if it was that long, 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~. However ·it tracked pretty well right up the window. So the yaw was fairly ~ell: ·on. But the., · • - i 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 ·, • • .: ' • ,,, I I ,I ' ll~ , ~ ' • ' I : ~... I • , , it. I gave that device ·up. It did extinct. Bill: ;• Did you ever notice any change --- PAGE 81 --- ,. 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? , . / , '. --- PAGE 82 --- Scientific Debriefing -19- 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. I guess you have about 20 to 30 ' . seconds for a reading._ Bill Armstrong: One · of the•·,·phas·e s· of the Apollo mission .requires a position ··. ' ' fix ~ile still in a holding orbit. I Before going into ·the translunar ·phase ·· • J ,, sightings of earth fixed targets for navigation would be ab~ut the same yqu experienced in the ·ground light. Would this .b e practicable2 --- PAGE 83 --- I i ' I Scientific Debriefing -20- Cooper: You 're going to have to be right on in .attitudes. You 're g~ing to have to know exact~ what time it's going to occur. 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. If you look for it and know it is there and if you're J.ucky. Knowing where to look for it and no cl.ouds there, Y9U can , .spot it. (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 --- PAGE 84 --- t Sc i ent ific Debriefing -21- /' ,,I 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. I waoo 't , very surprised. 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. I could see the streets but the buildings were not very distinct. 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. I saw a number of t h em with smoke 1 coming out of the chimney. There was snow on this upper very sandy blowy, dusty; Tibetan are.a . I could see a lot of lakes some partial.ly.y f'roz en over and some f'rozen solid. The visibility was tremendous. I could see vehicles that ,:;t assumed were trucks. I could see them kicking up ' dust. ... :. --- PAGE 85 --- . . Scientific Debriefing -22- (MIT Horizon) Dr. Peterson: The purpose of these pictures is that we are teying to 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. You have to stay power up. 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. A1; that ~ t there is a hole in the transcript. 25 hours and 26 minutes. , ' · Co0per: 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,. Did those come out all right'l Dr. Peterson: On two of those ~twas possible to locate. the moon. I I I ~ not all of them. Bill .Armstrong: Yes, . these are all of them. (Looking ·at p~ctures) I• ·• ' ' --- PAGE 86 --- Scientific Debriefing -23- Dr. Peterson: · There is a smudge in the middle of the window. It could have been accidently concealed. 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. \ ' Soules: This experiment went very well ~d we got the. information we · 1 ' wanted. Thank you very JIDlch. 'Did you· have aey- trouble 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. --- PAGE 87 --- Scientific Debriefing -24- Soules: You ma.de the remark that you were coming over A:t'rica. aey more information? There was none in the tra.ns9ript. ~ Cooper: 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. I got one coming ~ight over the coastline. 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 : We might , check the camera. , -Soules: What was the d o ~ t color of the ·earth over Baja California? I Cooper: I :found that the green showed up very little. The only really • djstinct green that 'I saw which showed up much was in the high Tibetan area. It. was a \right emerald green, by ·some o:f those lakes. It looked like a ,copper sulphate mining area. 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 --- PAGE 88 --- Scientific Debri efing -25- ( Cooper continued) ·a brown look, Everything predominantly had a. bluish cast . .All. the :wat er, all the sea water, looked very very bright blue. Even the Salton Sea looked very blue. And areas -we ,know 'were heavy toreat • '. areas looked kind of blue-green. The areas that a.re definitely brown you can tell they a.re brown~ ' I Soules: I have a. question on the thunderstorms. Could you hear ·sta.tic'l Cooper: I could hear. it day or night and on both HF and UHF.. It was . almost . instantaneous . As I woul~-- see the lightning and the clouds light up , I : 1 • .. would get the static. ~ • ·: Soules: What i s the frequency band on HF'l Cooper: HF i s 15 megacycles. The. static was louder in :the HF the.µ ·in tbe UHF. 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. Of course I noted ' thUDdersto~ were louder ,on ' night side. There were large _m asses of thunderstorms out to the east of Australia. " 0 ' SoV,les: Did the flash come tram below the (?a.psule or •could you look off / ~t ~ -. angle 'l --- PAGE 89 --- 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 I don•t remember just how far. 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.. \ - • r/ • Soules: Did you see any long white bands of clouds along the east coast in the tropical' areas'l ,, ' ,,. Cooper: 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. Number 10 picture is over the Arabian desert area.. Soules: Over the oceans did you notewwide bands with perhaps clear ·area over it'l , . --- PAGE 90 --- Scientific Debriefing -27- 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 --- PAGE 91 --- 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. I Soules: Did you ever see a slight flash? 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. The lower haze level was always under me separated from the horizon. This was not a real distinct line. 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 I \ --- PAGE 92 --- I ~ [ 1cienti fi c Debriefing -29- I\ l ., ooper: The stars in the Big Dipper could just be seen. I noted the Big Dipper 1'!1th the bo.ttom star sinking i~ ·~ I If, down into it. l~ t1 Soules: The top of the layer would be bow ;:nany degrees above the horizon? 1; i . • ,. 11 ' Ooo:per: ) I figured it was about six or seven degrees. ,, rl l (Long period of sketching.) . I Peterson: 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: I can't recall a single ti.me at night but what I saw the haze leyer. Dr. Voa.s: 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. In general. there was more light from the sky. It is a difference in two different blacks. The sky · is a ,· shinier black. The earth is a du.11 black. Dr. Voa.s: The horizon is very wel~ defined? Cooper: It is actually a different black. There is a · distinct line of horizon and the earth is darker. This is in complete night. Dr. Voa.s: 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. Does that look like a haze band on the •. • horizon? . O'Keefe: When was that picture taken? . Soules: . . Is that too high? - --- PAGE 93 --- Scienti f ic Debriefing -30- l ~--------- 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. 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. The overall color is pretty blue. Soules: What is the color of the· twilight zone? Cooper: It is a baby blue~ It is a pure~ pure blue, very, very_ bright. I I Soules: Did you see any meteor trails? , I 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. In fact, the sun appeared to be like the moon 'does i'rom the earth. Very bri ght. You know down here there are all those rays around it. But up there it is just a glob and it is very very whitish bri_gb.t. It doesn't look the same color. It is a very arc-like color, bluish white. ' '' - Question: What about the looks of the ds.y slcy? ! Cooper: 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 --- PAGE 94 --- ;-, pcientj f ie Debriefing -31- 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. Cooper: The night sky and the day sky is about the same as the difference between 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 on- the 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. I just went completely IFR. There was just no looking through the window. 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. You could see I· • the scum all over the inside of"the outside ~e. --- PAGE 95 --- ( . fcienti f ic Debriefing -32- ' I I ~'Keefe : Somevlhat of a pattern? I • •i¢,ooper: That's right. A pattern over the outside of th~ window as well as the 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.) . Day: Presentation of Dim Light Phenomena.: 1 Roach, 0'Keefe, Huell. Roach: 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 I 24 hours 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. I was in ful1 dri:f't. 0'Keefe: Reference was on page 26. Cooper: That was the luminous activity on page 37. "Righi? now I can .make ou1; a lot of luminous activities in an easterly direction." This was at 05 11 34 and on a 05 13 40. The Milky Way was quite distinct. This particular time (over South ' America) I couldn't make out on this layer. 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. It was a good sized area. • Roach: You didn't feel this bad' a discrete shape? It was very indistinct 1n· shape. It was a faint glow with a reddish brown Cooper: ; . cast. · Roa.ch: Because of your altitude or what'l . : I . , - - - . -~--~ - - ~ - ~ - - - _ _ _ ; · . . . . . . . 1 - 1 . - - --- PAGE 96 --- Scientifi c Debriefing -33- l . l' Cooper: ' It wasn't so distinctive as to move back on to it. It was very faint 1, 'l • '4,nd definitely lighter than the sky. It was picking up some light of.•some type, '"" -'j t was light in contrast to the sky • • 'ick Day : Could you see this better out ot the corner of your eye? C\'poper: 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. It seemed to be ·quite extensive but not .well defined. I-twas rather diffused but not covering the whole earth. Roach: Could you tell us what happens when you pass from day into night, around twilight? . We are interested in horizon effect after sunset • . ' \ (Cooper draws some more pict~es.) Cooper: 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 I . impression of blackness up here. (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. It defines the horizon line fairly well at this ·time. The sun ' 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 --- PAGE 97 --- f j _. . Scientific Debriefing -34- ! I ;._ ~d _spread. 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. I gue.ss two different times I saw faint glow but not ., very far along. 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. J 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 the time I got back the sun was there. Roach: Did it seem to be confined in your Window'l 0 Cooper : Yes. The bright blue -band grew wider as you moved away. Roach: Was this jus~ before sunrise? Cooper: The sun is . getting ready to come up and at' this particular time I got this glow prior to getting a blue band and in a few seconds the blue widens and ' I . widens. , ... '. --- PAGE 98 --- §~ientif ic Debriefing . -35- 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.', :1 ~P bri©J.t as the Millcy Way. ~ : Mercer: l 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. I have f . 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? Were you able to follow any stars'? . ... Cooper: Yes. 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. Then I believe Castor and Pollux and Corvus was the last . I couldn't pick up Antares. By this time I -was getting good light on clouds.. 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. ·-~...,.. --- - . - .·--- ' - -~ - ~ --- PAGE 99 --- 1 '1 ~ i' I I .S~ientific Debriefing -36- l\ ; ~ . ~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, Co'pper: 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 quite as thick as the band underneath - - - the last layer at night is thicker ' l I . . 1 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. It is really not black. This is any time you have earth shine. 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: Is it diffuse on the upper side? Cooper: 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? ,, Cooper: It is about 11iwo degrees. .,. 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- ;- -- --- PAGE 100 --- Scienti f ic Debriefing -37- .J ."i ' ·,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. i1, I 1 .~ ,-llch: Did you observe capsule sta.bility - did you :f'eel it ~s holding sufficient'.cy I ·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. Bill Armstrong: You get pitch up at the rate of 4° per minute. 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? Cooper: I would say within about 5 l/2 degrees. This will be a very slow variance. Question: How fast is this per minute? The period is 2 to 3 minutes per oscillation. John Ve:n Beckel: It is about .05 degrees per second. ,, Shepard: The limits could be as much as 11 degrees. John Van Beckel: It is pretty close to plus or minus 10 degrees. Cooper: 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: There was a lot of lightning. Huch: Was there an accumulatio·n of moisture on the window? Coop-er: No. To me it didn't seem to cut down too much. Huch: You reported a lot of lightning. \ - Cooper: Right when I was taking dim light pictures there were several thunder- . storms and a lot of lightning. --- PAGE 101 --- ,.. 'I ~cientific Debriefing • . f \t Did you get any readout on attitudes? ~epard: ~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: Yes, after I once got it out of the locker it was easy to use. Huch: 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 - - --- . ... . ., ,. I .' --- PAGE 102 --- • ;,scientif ic Debriefing ,. f -39- : }bu,ren: Did you take it off prior to retro? I,, I► ' Qooper: Yes. I took it off just prior to retro. I stowed it :lfl the glove compartment ~ ~rren: Did you take a reading of it at any time? ( I• I I ~ croper: I No, I didn t. 'I· W~rren: Di"d you place it vertically? Where did you place it? Cooper: I placed it vertically. Warren. We got from that .and also from film badger you carried on under I clothing - - - We got an estimate of 15-20 milliroentgens. I think you would get more in an X-ray than you had here. It was. about what expected. Warren: 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. I Warren: It wouldn't have served much use later. r 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 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: We got that. Bill: ~e went into rest period a:f'ter that. Warren: 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 ' ~ --- PAGE 103 --- ' I '- , $cientj_fic Debriefing ·-40- I •j ' ;,d !! ·,! d~ fonserva.tion. It does ta.ke a certain amount of power. • I· !{ ,I I I. ~cKann : That decision was ·ma.de not to turn that on continuous: pecause it bad I• I s . ·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. ? I l I.- ' / I I Warren : That is all I had. ' I 1 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. Thank you. ) / / - I. • ' ' --- PAGE 104 --- ;Scienti fic Debriefing -41- (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. I had good fit~ing ear caps. Dr. O'Keefe: Were you listening for it at the time'l Cooper: 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'? Have yo:u seen number 8, east coast of Africa'? Does it look this blue'l Cooper : 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: How ·apout the shots over Himalayas'? Cooper: 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~ You could see reefs and green water in some of the lagoons. 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. If you're looking ... at an angle, there is more of a bluish tint. . ..• ~ . i,. ·;; ' --- PAGE 105 --- Scienttfic Debriefing -42- ~ 'I i! ;J I' ;1 l?aul Lowman: I 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. Did you/ see different colors? i4 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. I had the feeling in looking out I was right over the Mexican Border. 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. I 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. I saw one very clear. It was not a large one. It was about due east of Salton Sea area. ~. -. Paul Lowman: Could you:,see Biggs Air Force Base. Cooper: I didn't notice Biggs at all, in fact, I couldn't see the main part of ... ,. --- PAGE 106 --- 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? Mountains? l t Cooper: •Yes. You could see shadows of the m_o untains quite clearly. . Even more \ /, I 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: I don't recall shaking the camera at all: Paul Lowman: 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. Very little. It is pretty smooth. Paul Lowman: 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 along the coast'l Cooper: I could see three or four hundred miles on up north. There was a lot of cloud cover-a lot of stratus. You could see patterns where the ground caused difference in cloud formation. Paul Lowman: How about on the east coast? I Could you identify anything there'l Cooper : 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. My sight of this was when I made my turnaround. It looked just like a map. It was a great wide expanse of ... --- PAGE 107 --- ,. I I I :t , ,cientific Debriefing -44- Ir 1 ' 'l :!- ~ . 't \ ''.:, J j he Ear,t coast. But there was a quite a bit of clouds up north, broken clouds. l \ "'·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. I sure didn't. I was looking for it too. Paul Lowman: 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. Dr. Voas : Do you--could you see clouds and shore lines at night with no moon? Cooper: Fairly well. If there was no moon you could see them faintly. Dr. Voas : Any other terrain features that you could see? At night with no ~oon? Cooper: •No . Not much. You could see the moonlight on the water. I Dr. O'Keefe: You mentioned these small particles. Do I understand correctly 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 ... --- PAGE 108 --- ~ $cienti f ic Debriefing -45- ~ ~ ti i 1 i \'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: Do you mean back from you or back along the :t'light path7 1 C~oper: 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: Did you note any difficulty in identifying lunar features? Cooper: I couldn't :9-istinguish anything on the moon. It seemed considerably ' ' 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. The moon was much clearer than on the ground. Huch: 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. It is a pale color, of course, in daylight. Dr. Voas : Did it appear to you normal in brightness on the day side7 Cooper: Yes, it was just a lightish blue color. --------------.---- - •• : I --- PAGE 109 --- 1 fcient:lfic Debriefing \ -46- • f• I ( ~ . , ·.;. •Aiuestion: Could you determine wind direction and velocity by SillOke? l ·~ ~ ,.,,,. I' f Cooper: I could tell direction - over the Tibet·area the wind 1was from the south. ,iI, I ,I! 1;, '" '!J.,. I• ·~uestion: Did you see industrial smoke? I 'i l,_ ~coper : 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? Cooper : I don't know whether I could judge velocity or not. I could tell the wind was bl~ving fairly strongly, because the smoke appeared to c9me out of the smoke stacks flatly, it didn't drift up. 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. We may have some trouble distinguishing snow from clouds in polar regions. You had no difficulty in distinguishing snow from clouds? Cooper: No. I thought the snow was very very distinct. It is just like flying an airplane. 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? That is, two overlapping pictures? '·. Cooper: Yes, I think I ~id over the Himalayas. I have two pictures of almost the same area of .the Tibetan High Lake area. - . ~r .· . . . I ----.--- ···. •. --- PAGE 110 --- " tcientific Debriefing -47- Yes, th~y do overlap. - They are pretty badly tilted/but ;. I they do . ' ; /' ' Janel: Did you have difficulty in seeing Cirrus clouds? " you estimate how Co~d , ~\ 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: You .mentioned that particles of dust or water were attracted to ,t the wiI1dow. 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. i They just moved slowly • about. There was less motion after we powered down cabin fan. •Various pieces of 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. ... .- . ,. --- PAGE 111 --- J '• • ' srientif ic Debriefing -48- 1 1 ··Pf. Voao: • You seemed to have the general impression that you w~re stationary .~ 8:fld everything else is moving. ~ Cpoper: That's right. You sort of become the center of everytijing, and you think t 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? Cooper: I did very distinctly feel I was sitting upright. A couple of times on account of the way you fee_l in the straps like hanging upside down. Every ti.me I dropped something, I grabbed at it below. I never had trouble handling pencil. 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. Definitely. Dr. Voao: You mentioned sometimes you had the feeling of being upside down. Was this correlated with the spacecraf't being inverted? 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: When you say "pretty good rates," this is 2 to 3 degrees per second? Cooper: Three, four or five degrees. ' ' . . ·. ... . . . .. --- PAGE 112 --- Scienti fic Debriefing -49- i ( hr . Voi~s: 11 r At retro fire, did you note feelings of lateral motion? , pooper: On the third one, it gave me pretty good little boot in yaw. IF t ' il)r. Vons: 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: We identified one of your pictures taken vertical off Calcutta. Cooper: 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? I Fisher: Did you see , Calcutta? Cooper: No. Fisher : Did you see any airports? Cooper : Ye~, I saw numerous airports. The runway patterns show up very distinctly . .... ------~--...---------:..,.-- - - ~ -.''I, ' . ' . . .......,. - ',q --- PAGE 113 --- I ··i~ scient i fic Debriefing -50- i_i ,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. Not that I noted. John B.: Could you hear better? Cooper : No. \ Dr. voas: 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 : No, I didn't. Note: Some questio~s were then raised concerning the appearance of the horizon • I at sunrise and sunset. 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. , I .... -------. ___ __,__ . _ '• --- PAGE 114 --- SCIENTIFIC DEBRIEFING OF LT. CMDR. WALTER SCHIRRA HELD AT NASA HEADQUARTERS, TUESDAY MARCH 12, 1963 --- PAGE 115 --- - 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 --- PAGE 116 --- 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. We might start off with the question on airglowo Will you give us · an account of Mercury's passage through the airglow layers? How did you identify the planet Mercury? Did it seem to have color? Were there any stars nearby? Cmdr. Schirra - I think Larry Dunkelman and I discussed this at --- PAGE 117 --- 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. It was as white to me as any other · star. 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. Mrs. Cameron is the one who made the contribution. 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 ? --- PAGE 118 --- • 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. Gold blues, electric blues . As a result, these caught my attention. I am --- PAGE 119 --- • 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. In other words there wasn't gross clouding of the win ­ dow . 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 --- PAGE 120 --- • 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. If we have covers, then these windows should be protected. 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 for Gemini, we have no problem. There is no tower · rocket . With Apollo they had window shutters the last time I saw the mock - up which is not at all static. It is quite dynamic even though it hasn't flown. 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 --- PAGE 121 --- • 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. --- PAGE 122 --- 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. I would anticipate that that gas would sub - lime awayo 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 by- product 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 --- PAGE 123 --- 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 I am sure this is something we can't let rest o 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 --- PAGE 124 --- 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, --- PAGE 125 --- ., ' \': . ·, , 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 --- PAGE 126 --- 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. We ~an't afford to have · nitrogen outgas in the vehicle. (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. --- PAGE 127 --- 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. --- PAGE 128 --- 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. I believe they conflict , 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 --- PAGE 129 --- 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. It had not come down into the Mercury set. If you want to describe it in the sense of sunset, Mercury set. 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 --- PAGE 130 --- 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. Took me, say, 4 seconds to say that. 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. I expected to see another sharp line and I did not. This is what --- PAGE 131 --- 17 I was referring to here as the transition from the last blue band I could see to the total darkness of spaceo I gaess this is the only way I can describe thato 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 This was the transition from visible to no light o 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 0 0 0 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 --- PAGE 132 --- 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 --- PAGE 133 --- 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. I had to see what time it wasa 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. --- PAGE 134 --- 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 --- PAGE 135 --- 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. I don't recall seeing many moon sets on earth~ 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. To me, it was the first real good moon set I had seen q (Laughter) O' Keefe - There is a good solid reason for that. That is t hat a full moon will set at sunrise. 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. The original prints were very good. I understand there is a lot of halat i on around this . I definitely think you all should get these out and examine them. Now the subsequent prints were not very good. They were too fuzzy . Gill - Who would have them? --- PAGE 136 --- 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. I wouldn't even see this . 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 --- PAGE 137 --- 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. --- PAGE 138 --- 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~ This is rea lly a spectacular sight. 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 --- PAGE 139 --- 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. (To Cameron) You have it? Cameron - I have it. It's about 280 kilometers ~ Height of the layers is about 66 kilometers. 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? --- PAGE 140 --- 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 --- PAGE 141 --- 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. --- PAGE 142 --- 28 Schirra - If there is another one of those coffees~ I'll trad~ this one in. I don't mind it cool. Break (General conversation) --- PAGE 143 --- 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. I guess it is best to refer back to the record again . 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 had come back from th ere, I think, isn't that correct? 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 . • 0 • Schirra - Really? --- PAGE 144 --- 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. --- PAGE 145 --- 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. Sort of Brownish gray - rathe r it was n ' t black or white. 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. Sort of a dust y color i n a sense . 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. I don't want · to give you that picture. Definitely a fog effect rather than seeing particles . I think of it that way. --- PAGE 146 --- 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. I told them to correc t it an d they never did . 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 --- PAGE 147 --- 33 would prove that the stars well could be seen going through the sam ,, traverse. This thing I saw - let's just call it the smog · belt - "Ii ' 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. --- PAGE 148 --- 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. This patch was denser as you came into the middle of this belt. It definitely had tb · have a light stimulus to it or I wouldn't have seen it. I was well aware of this and thought this as I saw it. 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 --- PAGE 149 --- 35 everybody thinks that all you see is Perth! (laughter) Well, we see a lot of other places as 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 , These I said, ah, those ci t ies are quite constellation setups. 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 --- PAGE 150 --- 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. One had white lights and one had the red lights. This was my test of these lights. We used them while working in the planetarium. We lit up the white lights and the whole dome was just brilliant white. These are tiny little peanut bulbs, really minute. This was the last time I used those white lights. That very day - they were painted red as a result of this . 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? --- PAGE 151 --- 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 --- PAGE 152 --- 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 --- PAGE 153 --- 39 could look down at the different angles. Schirra - We had a mirror on there. This permitted me basically to look toward the heat shield. 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? --- PAGE 154 --- 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? --- PAGE 155 --- 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? --- PAGE 156 --- 42 Schirra - I don't think they are in this area. We have to expand this star chart . 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 0 0 0 o °Keefe = 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 . With this star chart, Nancy, what we do is have a time margin . (Looking at the chart .) Now Orion down here is actually in my local daylight . It just was impossible for me to see it at this point way back here . It was occluded frank ly by the --- PAGE 157 --- 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 ·. And then we can make some points. 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. --- PAGE 158 --- 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 --- PAGE 159 --- 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 --- PAGE 160 --- 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. They have the Milky Way · projected on this chart. 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 --- PAGE 161 --- 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 --- PAGE 162 --- 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? I was livid about the fact th at I had the periscope. 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. (Laughter) Shoemaker - Why don't we go on. 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 --- PAGE 163 --- 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. This was a very great annoyance. 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. John and Scott were surprised when I told them this. 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 . (Laughter) The cabin lights are tube lights. They leak like mad. Just terribly. So I turned those off as well when I wanted darkness . 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 --- PAGE 164 --- . (_ so became a liability, because we had then to bring on light again (I brought on the finger tip lights to do this). Gordon knows how strongly I feel about the star chart device. This is a valuable tool. But it required two tools and a slider. Actually, two tools, with sliders on each to use them. 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. This is quite a chore. It really is. 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 --- PAGE 165 --- 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. As a night carrier-pilot, it was always a problem as you know. 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 . --- PAGE 166 --- 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. --- PAGE 167 --- 53 Cameron - I saw the zodiacal light once doing that in Chicagoo I came out of a lighted building. It was the first time I had seen it. 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 --- PAGE 168 --- 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. --- PAGE 169 --- 55 Nordberg - I am curious if you ha 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. --- PAGE 187 --- 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 --- PAGE 188 --- 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. --- PAGE 189 --- 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. This is very hard to do; to maintain a capsule attitude. 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, --- PAGE 190 --- 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. I think this is rathe r a trivial one. 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 --- PAGE 191 --- 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 --- PAGE 192 --- 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 'I /-.J " (<~ ~ ~-/o,1.4~ ••• -'6&- - .c~-- .J..~ - ~ ~ c . - - ~ ~~- ~.,Y>1~~ J 1 ~ '.) C--..c.._ - -=- ~ ~~~~ ~ -··\"' ~ ~~ --- PAGE 204 --- •f/,,,,,.,,IJ'V _rlJJ" ~ ~·- ,,. c,,,..y..,."'" 1- . . i _,-wM 1A'1,,,,,- "''II""'..:/. ~ --·~C)--r ~ ~~ - ~ .,..,,,, .,,f_ ,,, - ., 'I' .,. -~,.,/~ - " .,,,.,,J - ~ ........,.,, 14(. - - ~-'Jf ~ .. ~~~ © ~..,.,.I ...v ~...,, !_YIY - .-•J"""'" 0 - - ?4)'71Uf ~ - ~ _., ~ , ">\II, - , 1 ~ J , > c-- ==- ~"""\"'9 - -~.......,-~w, t'~"\'f @ ro/..,.,. __,,_. r '!"'lf'·• ..-r .,~•"'1:1) r~ ,.;,- ,,.lo, f- ,,,,,,.,,.,. ..,,,.o•~ ~·-;;-~ ,,. .,. ,. .,J © ,. ~~'1'1""'\-~~ ~-,q\~t\ - • q,e,.? - ?, ..,,...,.c,r 5_.,.; 'tt © ~~ - ~"-~ '5- ."",, ... ,.,,,~, r'·".!!1-l'WA/"'O (!) ~ ,,....!/..'f }11,J- ~'1-.....,r() (i) ..\-- ~ '(> ,-..- ~ 'Y"'\a ..... - ~ f l I r~,,,./"1'7) --t ,.,,f.,,, ~ m 111 ~ MJ.9--., +<'1AI ~~ __,,_ ~ 0? - I ·-,/"I,...,..c 'Tl • I/ •-t '»I ""'J1' t.._...,," • ~ 1' -.w./#'fl" (/SAJ__,,,_,,. C .., l -: f,,,,, ~•f.:, ~~' f? -= ,,.,,. "i? .., ? ,.,.2 0 I '1) ..... ~. ~ _..,....,\ "'·,~ _.,..._... ~ ~.,: r s,.•~-..o (t,') ....~ \'\'._ ""-Cl f' Ms 1\'° ~ ·._v fr 1r,''> ~ "-'j -1 .. !"",.__~ .,. "&/, l. -vf ".._"'\" a - - ~:,, ~ ,-- 'T'-·,"';" " : .,. -~"'x:Ar c,tt..••t·r ..•:,, - --- PAGE 205 --- --- PAGE 206 --- - d"q,.c,.:)- ~4~ 0- ...:,u,,/oeQ =- '30-0 =- >--IA~ &4- t:i:o _...__ 1,-tl :>, - ., _,..-- _.::-::::= • ~ /"1.-,..,.l«A /) ,.e c&..<... ~· - cl~11 - ,-4,~ · ,,t.,.... 4 ,d----, ,,e._1.::._ - - - • .1 r-- ~ • - fo O - --- PAGE 209 --- "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 (1) 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 --- PAGE 210 --- 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- •) 85 4 X l0- 3 1014 100 4 X l0- • 10l3 115 4 X 10- 5 1012 Thus equation (1) becomes 7 X 10 23 9 ( 1 p )2 n = 4 X 4 X 10- 2 pr a} 1 3 4 X 10- 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- 2 n X 10- s 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 --- PAGE 211 --- 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 Height = 100 km Height = 115 km I No. of :ro. of Observed atoms No. of Total No. of No. of Visual True Radius Total Total No. of Mass, g electrons electrons atoms n e cm- 1 atoms n , cm- 1 magnitude meteors No. CID evap. n 0 cm- 1 n e cm- 1 cm- 1 n, cm-1 n, cm-1 cm- 1 per cm -3 2-8+• 2-8+4 4 6-5- 1 6-0 22 1·5 14 4-218 6-721 l ·6813 4 · 7 17 6-720 l ·6812 4·7 16 ~2 7-l H 7-l H 1·6 4·83- 1 3.022 7.51a 5·321 8 3.721 9.2512 6·56 17 3.720 9·2 11 6-616 -1 1-8+5 1-8+5 6·3 - 1 3.54- 1 l ·72 22 4.31s 7.7318 2· 1 21 5.2512 9·45 17 2 ·!20 5·3 11 9·5 16 0 4.5+s 4.5+s 2-5- 1 2·60- 1 8·3 21 2· l13 9.518 l •1 21 2 ·75 12 l ·2518 l· !20 2·8 11 l ·25 17 1 1·!+6 l·l +s 1-0- 1 1-92- 1 4.021 1-013 l ·l1 9 5-620 1.412 l ·5418 5-819 1·45 11 1·6017 2 2-8+6 2·8 6 4-0- 2 1-41- 1 l ·86 21 4·6512 l ·3O 19 3.po 7·75 11 2·17 18 3·2 19 8·010 2·2417 3 I 6-4+ 6 7· 1 6 l-6- 2 1·04-1 8·0 20 2-012 l ·421 9 1-620 4·0 11 2·8418 1·7 19 4.310 3·0 17 4 9-0+6 l ·8 7 6-3- 3 7-6- 2 2.920 7 ·25 11 l ·3O19 8 ·519 2·13 11 3·8418 9.21s 2.310 4·1 17 5 3-6+ 6 4·5' 2-5- 3 5·6- 2 8·019 2·Oll 9-018 4.410 l •111 4·95 18 5-018 l ·3 10 5·617 6 7 I l·l" 2·8 8 l·O- 3 4-o- • 4-12- 2 3·03- 2 9· 1718 l ·46 18 2-4310 3·65 9 2-718 1·0218 2·3 19 l •1519 5·75 10 2·8810 6·3218 ·0518 2-718 1·4618 6·8 9 3·7 9 7·417 l ·O2 18 8 7· 1 8 1·6- • 2·24- 2 5·75 18 l ·441!' 1·02 19 7·8 17 1·96 9 l ·39 18 9 1·8 9 6-3- 5 l ·65- 2 2· 218 7·19 l ·27 19 4·2 17 1·06 9 1·91' 8 10 4·5 9 2-5- 5 1-21- 2 l ·2O18 3-o• l ·35 19 2· 1617 5·4 8 2-418 15 4·5 11 2-5- 7 2·6- 3 (1·0816 ) 2 ·7 7 1 ·21 19 8-215 2·05 7 9-218 4 .513 2-5- 9 6-o-• l ·3O 19 20 25 30 4.515 4·517 2-5- 11 2-5- 13 1-21 - • 2-6- 5 . l · 1614 2·9 5 .... .... to> --- PAGE 212 --- 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 --- PAGE 213 --- 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 --- PAGE 214 --- 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 - ynn 0 at Where D is the diffusion coefficient,