NASA UAP D015 Astronaut Scientific Debriefings 1962 1963

....... a ittle ra r ··- to at • Vu W.. t.Mrtid. or =--~--===L-...::::actnaU 7 .Dll":l.,IID1~ • Oil ➔ ----. I' ~ t o itlllN tMt 11U a ..tataala . ~ •tat-it ~ e tan I rtson, &'tall. tll&t tbe t I 11.gbt. ,, C COIie C 1 bo • • at boti. ,tbeil l ltlQ'ecl 1n tbe ~ ont.bento • Dee' j( • • • ) t hit • 4 •••••• ••••••••••••• 5 0 :t 9 • _______......,___. • • • /8 0 • ' a re. t . . " . ' . ~--...........--......................,..__. t ) 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. ftespite the fact that he was _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. ftespite the fact that he was ~ it~ e v e1 , 'n ~ 1 properly Q~"- o. a number of his observations remain of \ ~·t"· l.., ~ interest aad ~ further explorationJ"1further~re, ~.~ JV? it is evident that the astronaut can perform various scien- tific experiments , ~has the aeiil~y capability of doing ~ so despite the many limitations imposed.by the. Mercury capsule. com act Some commezits* on f£ 01. Glenn's observations are presented below ~• •~ •-, - \) u LL ... IA .~ t N.,c~~- clc--+'""""'""! "\ r· kun.inous ~ rticles : In response to~ a series of questions, Col. Glenn described the velocity field of the luminous particles, their brightness 8'1./i. outside the ii.- QM~ shadow of the spacecvaft, the coloring aBa sunlight and in their shape. For the velocity field, the particles !all. moved at preeise)y the same speed and !!.ll,.moved a~ precisely in the same direction except for particles coming very close to the spacecraft. This occurred similarl:i, :i,Q, all three _,_ .... ~"'~•"<- f .-L orbits. From t !!.ll,.moved a~ precisely in the same direction except for particles coming very close to the spacecraft. This occurred similarl:i, :i,Q, all three _,_ .... ~"'~•"<- f .-L orbits. From t.l¼e ~ -eie Vconsiderations alone, it may , . ..~d'f¥t.....~ 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. -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, ,,_ - , \wM. ~ \: has i;c;r,r9~9d the life support system which ~ ~ ....~ ~ ~ \'""~\~) wat9z: i;a:t;e apaee) Col. Glenn iJjf described the ~ .,., particlei and the luminosity. The fact that the coloring was a yellow-green and the eiiee~ive observational pi,e- a,~aPen~ ~~~,~ 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. The change of angles of the ~particles approaching - ;l- close th the~ spacecraft~ be attributed to the e.""' observed in the scattered light from the spacecraft and were probably illuminated only by visible ~- ~~f the spectrum. The change of angles of the ~particles approaching - ;l- close th the~ spacecraft~ be attributed to the e.""'1ft,- 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 ~ from the spacecraft during~ ! c~ .~ nd ~ tH ' l ,BS , ! while the spacheaft is in sunlight could be ~ by the .o-\,,..U\..c.l, ~ ~~~ ~ > 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 -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 9'f . 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 9'f t~e twill o{ '- band six to eight degrees 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 the multipa~wl:l:,ers of the 1'window cause the high observation = ~\:- 0~ angle~ the horizon ~ ~ ti&..,.a;l.la-~l'O"l~tm~te2:~~~, this ~ ~ likely because of the variatio~ a.ad angle of o~~~ \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 ~ _.,'4'4. observations 1'1:rurther- ~ more, he was able to infii.is8a:ec that the stars e»serve</t,hrough the haze layer became less intense while changi ng angle _,,,..,._ ~ the horizon . ~ USSR repo:i;l,s by Tito'V! also ind ., .__ to infii.is8a:ec that the stars e»serve</t,hrough the haze layer became less intense while changi ng angle _,,,..,._ ~ the horizon . ~ USSR repo:i;l,s by Tito'V! also ind ., .__ 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 7 . s f &.·\u.~ ~~\AM ~U\~c.~Ch4.,, ...p. 4~"-"-'1--f.a~-,,. -4-.,. Au-6her investigations of the air glow and haze layerKiG£ ~~~ .,"C _,,<>I' :fJ should be carried out . Meteorology: The strikinJ~ of lightning dis- ~~ charges as observed by Glenn point the way to consideration of an l~ . , \ j ■ I · on system for monitoring lightning storms over the earth using the meteorological satellite . The mapping of the distribution of thunderheads i(Ji)oG. lightning during ~......~.l. ~ 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- Recommendati ons : 'l!bere &ve ,..,.~ -o t ! - number of .A -4= recommendations ~paeP te ~a eper en+, following because~ of the short time constanu of the lightning flashes . -..3- Recommendati ons : 'l!bere &ve ,..,.~ -o t ! - number of .A -4= recommendations ~paeP te ~a eper en+, following the very ~~ kehwc..4Ack~ 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 ~1~~-'"" A . . .~ • :\.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 cridited to the observer, and pePtioala¥ly be edited ~ ...C2.A.-._ 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~ to assist in obtaining further detail~data. eJ., Col. Glenn suggested that t.ae follo Q., -~""'- discussioms would be to his interest. Such follow-on discussion is strongely recommended spacecraft, within engineering limitations~ to assist in obtaining further detail~data. eJ., Col. Glenn suggested that t.ae follo Q., -~""'- 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 th 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. Investigations of the physics of OQB!!fteft~s and the c o"'tl'le\.s 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 carried out ae eB Bi@eM ~~ the feasibility of this ~ . '"t.- ~---\; .,;.. -o.\.u.~~ ~ ~'(W\-~• -5- 1 ~~ ~ ~~~ ~ ~&A o . .~ ~ ~ -,14-.~0 - tlM Q.. . . ForVai:r ~low aea. optieal etttd:ies, .the photo- multi lier :Be! .,,.... A..~,:...... "b >MC,--. p .,..c,,h ...~ o... systeml ~ series of filters 4,-~J►"'-> --~c.~... ~-- . t . .~ - -~ ~ u.v. photo- multi lier :Be! .,,.... A..~,:...... "b >MC,--. p .,..c,,h ...~ o... systeml ~ series of filters 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 r:- ...~ 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 .,..__ ~, .....,,_.\..,. lo.\u. ~,c:r-\N·~ apparent ts" take advantage of ,tae im~eYement& ;L;e tac ~•~~. '"'Q ,_.f"•'ltC..~ ,..,Q.U.. .oc.~41•,u&.. ~gj ent 1 f1 c expJ oration af tbe saJ ar £ystem and in astJ?efl:Ofl\Y • At headquarters, ;U; i.r. recomme:ee,e,4 that • ~'-h;;:t_~ ~ In. ~ ¼..~;~\ S(, a'.., ,' _ ~ ~~\ £)• A . \t,rogram (ahief and supporting staff i;e ~ae ~ i.r. recomme:ee,e,4 that • ~'-h;;:t_~ ~ In. ~ ¼..~;~\ S(, a'.., ,' _ ~ ~~\ £)• A . \t,rogram (ahief and supporting staff i;e ~ae ~ r e po r t ing to the G.irector of ~pace ~ciences for scientific exploration ei in the !Manned ~pace°Tliiht ~ rogram as:111., ~o ~ -~ 'Y I . ~ -~ t a committee or sub-conmdttee QQ forwed tn. oa.e.~ indluding such people as RGefte, ~Utt , Minnaert, Towsey, Sekera, asg £0 forta- to ~ the scientific community aB.e. i;a.e ~Y and, ..,..... c rl. -::,-, "',_""~o..,. <Y,l .:that a branch or dividion at one of the centers ~ '-' 1 #tDf\~ 8 \. ,Q.suc el .&»4(.WEOK4A- -r7 • ')/ • ~ as a scientific team fo¥ aireefllsupport of the .>,>-UV\....~ --t-A:,-~i.; _,£.,,.r~-..,...,s. astronaut-scientists "ao oei-e into sys-sola1Y spa~e. V\A.. Y),,J.~ \~ u L t),, "" 7 '2.-; .,.,_,_ B 2 3 196 ? U.\h <!.°""""U)4.. '2'"3ol!I- '3oco 0 0 ~ -~ Vje0/2 w~Jo...:, caJ v-nf c~-4 ),, "" 7 '2.-; .,.,_,_ B 2 3 196 ? U.\h <!.°""""U)4.. '2'"3ol!I- '3oco 0 0 ~ -~ Vje0/2 w~Jo...:, caJ v-nf c~-4 .....-- --:-1--- ,___ • - - UN IVERS IT Y OF CA LI FOR N I A LOS ALAMOS SCIENTIFIC LABOltATOllY (CoNnACT W-740S•BNG-36) P.O. Box 1663 LOS ALAMOS, NEW MEXICO IN JU!PLY a1P1a TO: J -l6•8J.2 ,, I .. JUL I 7 1962 Dr. Jocelyn Gill Room 62033 Federal Office Bldg. No. 6 Headquarters, N.A.S.A. . Washington 25, D. C • Dear Dr. Gill: I .-.·.. riot, ¥ . . ; , I ,. l ,, # u,\ 1AA l1 0,i -The June 29 issue of Science brought to my attention J. H. Glenn's comments on "The High layer~'. It seemed possible that the layer he described could be . accounted for as a region of relatively large nitrogen peroxide (N02 ) concentration, and the past two weeks have been spent in checking this hypothesis • Unfortunately I am not familiar with either photochemistry or upper atmosphere physics so the following analysis leaves much to be desired; the hypothesis seems tenable, however, so I would like to bring it to your attention. f . Effective am not familiar with either photochemistry or upper atmosphere physics so the following analysis leaves much to be desired; the hypothesis seems tenable, however, so I would like to bring it to your attention. f . Effective path length and comparison with possible surface observations. Referring to Figure 1, the height (H) of a point at a distance (L) from a point on the surface of a sphere of radius (R) can be found from the formula which has the solution (1) (2) Figure 1 I Figure 2 Vertical path (No. 1) No. 3 No. 2 LOS ALAMOS SCIENTIFIC LABORATORY UNIVl:R■ ITY Of' CAI.IP'ORNIA LO■ AI.AM0e, Nl:W MUICO ro: DATE: Ju}¥ 13, 1962 Fox- th, followins I will assume that the concentr.ation ot absorbins mo1ecu1es in the region of interest can be described adequate}¥ by an exponential decrease w1th altitude above the bottom, of the layer, hence, can be represented by where Y is the scale height in the layer and H must lie in the .ia.yer • . Then the .number of molecules per cm2 is found to be (4a) (4b) (4c) ' I (5) (6) • RPo J ~ [-1 + V1 + y2 + ·2y sin e ] dy e where the integral per cm2 is found to be (4a) (4b) (4c) ' I (5) (6) • RPo J ~ [-1 + V1 + y2 + ·2y sin e ] dy e where the integral is over the range of y desired (usua.l.ly O ➔ ex,). ·For a vertical view (sin 8 • .l) path, the sollltion is simpJ.¥ where Po is the density at the base of the layer. L LOS ALAMOS SCIENTIFIC LABORATORY UNIVll:llalTY 0,, CAL.1,,0IINIA LOe ALAM0e, NIEW MUICO • 1'0z nr. Jocelyn Gill DATBz July 13, 1962 For a horizontal path (sin 8 • 0) te.nsent to the baae of a layer (path No. 3) we ·note that y << l in the contributing region, hence, can get an approximate form ~ N • RPo ~r. Y2 ex, l O •e which has the value ~ N•\J 2 Po ccy (7) (8) Here Po is the density at the base of the layer, as in eqµation (6). An astronaut's view thru a layer :from above would see twice the path computed 'I I by equation (7), ·giving N3 • Po ✓ 2nRY molecu.les/-cm2 (9) f • Aline of sight tangent to 's view thru a layer :from above would see twice the path computed 'I I by equation (7), ·giving N3 • Po ✓ 2nRY molecu.les/-cm2 (9) f • Aline of sight tangent to the earth and passing thru a layer at base altitude H (path No . 2) will have . .1!J., N- ~y [pl e y J ..fu. (10) and we note that [P1. e ~] is the density at H1 , the base of the layer, which we set eqµal to Po as in equations (6) and (9), N,a • Po -L • Po - RY • ~ 2H1. r- (11) ­ LOS ALAMOS SCIENTIFIC LABORATORY UNIVEllelTY Of' CAl.lf'OIINIA LOe AI.AM09, NllW MIIXICO tO: Dr. Jocelyn Gill DATE: July l.3, l.962 Aaeuming that 'Y • 7 km 1n ~ abaorbing layer, ve note that a. surface obaerver vieving a layer at an altitude near l.00 km vill have availabl.e the ratio (12) An astronaut · vieving along path No. 3 woul.d have a mu.ch greater thickness, as 2,rR ; 75 y . (l.3) Viewing thru the layer to a point ne.ar the surface and out again the enhancement would be mu.ch less, (14) Light have a mu.ch greater thickness, as 2,rR ; 75 y . (l.3) Viewing thru the layer to a point ne.ar the surface and out again the enhancement would be mu.ch less, (14) Light received by an observer :from a "point source" in space is attenuated by • where CT 1s the absorption plus scattering cross section, giving -uN a factor e and -aN I - • e Io 1n .!_ Io • -CTN (15a) I •. (15b) LOS ALAMOS SCIENTIFIC LABORATORY UNIVl:RatTY 01" CALll"ORNIA L.09 ALAM09, NIIW MUICO TO: Dr. Jocelyn Gill -5- DATI: July 13, 1962 From the repcrt 1n Science, I infer that for the layer reported, or giving and aNi • o.o4 ± 0.027 0N2 • 0.22 ± 0.15 (16) (17) (18) (19) Any such absorbing layer present during the day would result in rapid heating, and •I reradiation in the infra-red range from whatever bands may be present. However, the absorbers postulated below would be destroyed by photodissociation and/or heating during the day. Hence, it is not surprising that solar spectra have not shown such an absorbing layer. StellarJplanetary or lunar spectra might show the existence of such a layer, if the absorption odissociation and/or heating during the day. Hence, it is not surprising that solar spectra have not shown such an absorbing layer. StellarJplanetary or lunar spectra might show the existence of such a layer, if the absorption spectrum has sufficient structure. Setting we find the effective path length Xi. ~ • 3.9 x 106 cm (starting absorption at .100 km altitude) ' (20a) (20b) (20c) LOB ALAMOS SCIENTIFIC LABORATORY UNIVltRelTV 01" CAL.ll"ORNIA LOe AL.AM09, NltW MUICO Dr. Jocelyn Gill DATB a July 13, 1962 X4 • 7 .8·x 106 cm (20d) (20e) Absorbers Present in the Upper Atmosphere 'lliree constituents of the atmosphere near 100 km altitude absorb light through most or •all of ,the visible range, as would be re_quired to get a noticeable d1mm1ng of starlight. They are: l) N~ 2) -0 3) 02 (nitrogen peroxide) (negative atomic oxygen ion) (negative molecular oxygen ion) v Of these, I found no cross section data for o;.· For 0-, Massey (Negative Ions; Cambridge U. Press) gives curves showing absorption cross sections starting at • -l.8 • • • . cm2 /ion 1n the region A< 5000 A. 'lb.ere is 5620 A and approaching Ions; Cambridge U. Press) gives curves showing absorption cross sections starting at • -l.8 • • • . cm2 /ion 1n the region A< 5000 A. 'lb.ere is 5620 A and approaching~ 4 x 10 very little structure (only the onset at 5620 A). • From ecpation (17) we find that N3(0-) • ~3 ± 2 _ 18 • 4 X 10 (7.5 ± 5) X 10 l.7 could explain the observed attenuation. For an effective path length of 5.4 x 107 cm, we have Po• (1.4 ± 1) x 1010 negative ions/crn.3 • Since the daytime free electron concentration in the E layer is 1.5 x 105 and the night vallle is~ 104 it seems- hard to believe such a high nighttime concentration • of negative atomic ions. LOS ALAMOS SCIENTIFIC LABORATORY UNIVll:R■ ITY 01" CALll"ORNIA L.09 ALAMC>e, NllW Mll:XICO tO: 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 - .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 2/ cm 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. ~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 I convert their absorption coefficients to lengths separated by a· few angstroms. Ta.king an 'average value of 4 x10-ia cm2 /molecule 1 ·we find • and using X3 • 5. 4 x 107 cm Po• (1.4 ± 1) x 1011 molecules/cm3 . •. LOS ALAMOS SCIENTIFIC LABORATORY UNIVIEll81TY OP' CALIP' ·we find • and using X3 • 5. 4 x 107 cm Po• (1.4 ± 1) x 1011 molecules/cm3 . •. LOS ALAMOS SCIENTIFIC LABORATORY UNIVIEll81TY OP' CALIP'OIINIA LOIi ALAM09, NIEW MUICO TO: Dr. Jocelyn Gill DATE: July 13, 1962 Readily detectable structure would produce ve.r1e.t1ons of o-N1 and aNa ot about half the attenuation figure given in equations (18) and (19) which is near the threshold of detectability. I have not yet found an author who estimates the concentration of Ne or N02 'in the atmosphere; Bates and Nicolet discuss the reactions which lead to it in the book "'lhe Earth as a Planet", edited by G. P. Kuiper (Volume II of The Solar System). Nicolet calculates the photodissociation time as 200 seconds during daytime, and shows the concentration must be so low that no effect on solar observations would be found. As a general conclusion, it seems to me more likely that N02 would be responsible for an absorbing layer, generated perhaps with the aid of downward diffusion of NO to higher pressure regions favoring oxidation to N~. 'lhe color suggested by Glenn fits very well', as may be quickly verified by looking thru. the vapor space above concentrated nitric acid. Experimental Proposal. diffusion of NO to higher pressure regions favoring oxidation to N~. 'lhe color suggested by Glenn fits very well', as may be quickly verified by looking thru. the vapor space above concentrated nitric acid. Experimental Proposal. Ideally, one could ask for the absorption coefficient as a function of wave­ length (over a very wide spectral range) and time after sunset on the air volume investigated. I t seems possible to get very useful data with a relatively simple experiment perhaps possible of inclusion in one of the manned orbital flights. Using a slow-speed movie camera, photograph the star field and such planets (including the moon) as opportunity permits, with approximately a 10° field of view and enough exposure to pennit photometric measurements as the light sources . . . ' . . LOS ALAMOS SCIENTIFIC LABORATORY UNIVERSITY OP' CALIP'ORNIA L.09 ALAM09, Nl:W MUICO 1'0: Dr. Jocelyn Gill DATE: July 13, 1962 "pasa through" the atmoaphere, especially the abaorbill6 layer (perhap 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/ 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 external tangential viewing woul~ help a great deal, 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 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 J . ' / • I 1 1 . ' .. . . TO: Dr. Jocelyn Gill LOS ALAMOS SCIENTIFIC LABORATORY UNIVERSITY OP' CALll"ORNIA l.09 ALAMO., NIEW MUICO -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 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 J the field, of the above hypothesis. If your group recommends inclusion of such 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. BEW:jo Distribution: l - Dr. Jocelyn Gill. ' Respectfully submitted, ~y--~ BOB E. WATI' Assoc. J-Div. Ldr. and Grp • .Ldr. J-16 .I In ~ly refer to: SGC:Mt:llll. 21 Feb~ 1962 MQl)BANDt){ Subject: Poeaible Obtained 1>f J. H. Gl J-Div. Ldr. and Grp • .Ldr. J-16 .I In ~ly refer to: SGC:Mt:llll. 21 Feb~ 1962 MQl)BANDt){ Subject: Poeaible Obtained 1>f J. H. Gl.enn 1eritit1c Viaual IIitoruat1on 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: ( )Th e~ ot the ~ t m.Jl!lbW or lUIJliriowl particles