Radiation Belt Satellite Press Kit

8/8/2019 Radiation Belt Satellite Press Kit

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NEWS R E L E A S ENATIONAL AERONAUTICS AND SPACE ADMINISTRATION1 5 2 0 H S T R E E T , N O R T H W E S T W A S H I N G T O N 2 5 D CT E LE P HO N E S D U D LE Y 2 - 6 3 2 5 E X EC U T I V E 3 - 3 2 6 0

FOR RELEASE: Wednesday

Release No. 60-148March 23; I960NOT" FOR RELEASE uN"r%LLAUNCH

C,ITITAT1ON.This r a d i a t i o n b e l t s a t e l l i t e i s designed t o make t h e

broades t s tudy ye t attempted of the ene rg ie s p re sen t %n t h e VanA l l e n r a d i a t i o n b e l t s , It c a r r i e s f i v e radiation d e t e c t o r s andits o r b i t w i l l expose them t o t h e e n t i r e w i d t h of the Van ABPenbelts and beyond,

The project 1s u n d e r d f ~ e c t i o w f the NatSomal Aeronauticsand Space Admlnfstratfon, The Amy B a l l i s t i c Missile Agency oft h e Amy O~dnance issile @omanddesigned t h e s a t e l l i t e anddeveloped and built the Juno 11 launch vehfcPe, The NASA JetPropulsfon LabsratosJy is respons ib le f o r the three upper stages,The radia%fon. experiments were devised and b u i l t by t h e Bhys%a~uDepartment of t h e S t a t e Unive~sfty f Iowa.,

A l aunch fn@%fnat ion f 2 8O from the, equa tor will give thes a t e l l i t e 8 highly e%lb$pi%calr b i t , It fs des i red to abtafn.a n orbft ofapogee w i t h

Just over 200 m3.la pe r iod of about

.es pe r igee, 17 hours ,

iF:'J

Just over 200 m3.les perigee and about 33,000 milesa pe r iod of about 17 hours ,

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The major objective of the s a t e l U t e i s to provide anana lys i s of the energ ies of t h e electrons and pr o tons p res en t i nth e Van Allenb e l t s over an extended pesbfod of time, The VanAllen b e l t s , discovered in I958 by Dr, James A, Van Allen o fthe State University of zoms extend from 50s m f P e s t o manythousanas of miles abcve the eaIdthf8 surface and c o n s i s t ofcharged particles which are t rapped and guided b y m g n a t i c linesof fcwce,

M @ ~ ~ u ~ ~ ~ ~ ~ ~ ~f $he extent of t h e b e l t s and general level oft h e energy of 5he p a r t i c l e s I r a these belts have been mde byp rev i o u s satellites. T h e i r data. have shown, however9 t ha t thebelts are contLnuaPly changing and f l u c t u a t i n g ,

A widely accepted theory sS;ates t ha t the charged particlestrapped % n the outer portion of the b e l t s are emitted by thesun and travel. toward the earth at some l9O0O miles per secondarr iving i n one or two days, Nearb the eaerth, they are t rapped byth e e a r t h * $magneJ-,%c ield and modify the r a d i a t i o n belts,produce mgrraetfc stoms a n d d l s m p t r a d i o a n d c~awnepfi@%tions*

The %merbelts are believed $8 be %%Pled by particles ariseng

atmosphereo ~ i e afthe oreigln and natwe of t h e b e l t s have

been p~oposed nd t h e data ~e$uBt$n.grom the detai led studiesto be conducted w i t h this saLelPite will be valuab le i n selectingt h e most applicable theory,

_.. I . ... -. . . . ..-. .- . . . - - - . . . - .. . - .. ._--..- . . . . . . . . .__I.... I - .-I . .. -


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-3-In a d d i t o n g the unders tand ing o f f lu c tu a t i ons i n t h e

r a d i a t i o n e n e r g i e s i n the Van Allen zones will l e a d t o a greatunders tanding of bas ic re la t ionships between t h e earth and thesun

The space probe, Pio neer I V , was launched i n March, 1959,a f t e r a p er i o d of u n us u al l y i n t e n s e s o l a r and a u r o r a l a c t i v i t y ,It d e t ec t ed t en t imes as many e n e r g e t i c p a r t i c l e s in t h e b e l t sas d i d Pioneer I11 which was launched during a p er i o d of r e l a t i v es o l a r i n a c t i v i t y th e p r ev io us D e c e ~ 5 c ~ , n October, 1959,Explorer V I encou nt ered p a r t i c l e r a t e s 5,000 times lower t h a nthos e of P ioneer IV but a f t e r some solar a c t i v i t y s e v e r a l weeksl a t e r , i t s detector showed a r e t u r n of p a r t i c l e p o pu l at i on n e a r lyt o t h e P io ne er I V l e v e l .

The r e s u l t s of t h e e a r l i e r samplings of t h e ev e r - s h i f t i n ge n er g ie s i n t h e V an Allen b e l t s have conv inced sc ien t i s t s of t h eimportance of measuring t h e numbers of e n e r ge t i c p a r t i c l e s o v erl ong per iods o f time and t o t e ns of thousands of miles i n t ospace

T h i s r a d i a t i o n b e l t s a t e l l f t e will attempt a more de ta f l eds tudy of th e energies of t h e b e l t s than any y e t attempted, I t sf i v e d e t e c t o rs are more complex than those flown before andare capable of separating t h e p a r t i c l e s by type and by energy,

P a r t i c u l a r l y of i n t e r e s t will be t h e f i r s t measurement ofvery low enepgy pa r t i c le s , I t is bel ieved tha t there aretremendous numbers of these p a r t i c l e s and that they may have amajor ro le in producing geophys ica l e f fec t s ,

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I n a d di t io n , s c i e n t i s t s hope f o r new data on the emissionof t h e ch ar ge d p a r t i c l e s from t h e s un t o t h e v i c i n i t y of theearth.

!Pwo h ig h e ne rg y p a r t i c l e d e t e c t o r s are conta lned i n t h ePioneer V payload , launche d March 11, 1960, and now t ravel-fngthrough space between t h e o r b i t s of earth and Venus, Shouldthese d e t e c t o r s note t h e passage of a cloud of ene rge t i c chargedp a r t i c l e s which would be expected t o be emittea f rom the suna t the time of a so la r d i stupbance , i t would be sf great interestt o note whether t he ins t rument s i n t h e radia t ion . b e l t s a t e l l i t ed e t e c t the a r r i v a l of such p a r t i c l e s in the v f c f n i t y of ther a d i a t i o n b e l t s .

PAYLOADT h i s payload resembles t he cy l indr i ca l shape o f ~~~~~~~~ T- IV s a t e l l f t e s , I t i s modified by a box-like s t r u c t u r e

surrounding i t t o s up po rt th e solar c e l l array.The c y l i n d e r i s about 21 inches long and seven in ch es indiameter. I t f% t s aah a rec t angu la r box 12 inches squaroe andnine inches hfgh.

In . o r b i t , t h e casing of the f o u r t h stage rocke t of the hfghspeed upper stage c l u s t e r will remain a t tached t o th e s a t e l l i t eand w i l l help serve a8 t h e a n t e m a f o r t r a n s m i tt i n g data %oear th,


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-5-I n addi t ion, because of the compara t ivC l ight weight

of t h e p ay lo ad , t h e t h i r d s t a ge w i l l go i n t o o r b i t , The threeburned-out scaled-down Sergeants i n clu~ter P l l o r b i t w i t h anapogee of about 1400 miles and a pei5gee of more than 200 miles,

Weights of t h e payload:Instrument pack assembly 12 .2 poundsSola r c e l l box assembly 7*l oundsInstrument housing assembly 2 e 5 poundsSmaller components 1.0 pounds

Instrumented s a t e l l i t e 22.8 poundsFourth stage cas ing 12,5 pounds

_ _T o t a l weight i n o r b i t 35.3 pounds

____IADIATION EXPERIMENTS -- The Ph ys ic s Department of th e Sta teUnive rs i ty of Iowa has provided a package of f i v e r a d i a t io nexperiments weighing a t o t a l of 6 , 3 pounds. The package isn ine inches High and 5s i nc he s I n dfarne9;er and s l i p s i n s i d e thecy l ind r i c a l payload ca s ing , I t i s a "plug-in" package, i n thati t can be s l i p p e d i n t o % he cy l inde r , screwed down, and pluggedi n t o t h e power supply and t ransmitter i n l ess than 20 minutes ,

The f i v e d e t e c t o rs are as fol lows:De tec to r A: With i t s companion Detector B, th is device

i s designed t o count very low e n e r g y p a r t i c l e s -- t h e f i r s t inany s a t e l l i t e which can d et ec t e le ct ro ns below 20,000 e l e c t r o nv o l t s .


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-6-D e t e c t o r A c o n s i s t s of a flake of cadmiwn sulf ide i n s i d e a

l ea d sh ie ld which has a ho le i n one end . Ba f f l e s sh i e ld thef l a k e from l i g h t t o which it i s also s e n s i t i v e , b u t I t isunshie lded t o e n e r g et i c p a r t i c l e s .ho le p revents a l l e l e c t r o n s w i t h e ne r g ie s of l e s s than 200,000el ec tr on v o l t s from reaching t he cadmium sul f i de .counts a l l charged p a r t i c l e s excep t e le c t ro ns , p rimaro ily p ro tons ,

A magne t ic f ie ld across t h e

So i t

Detec tor B: This device works i n tandem w i t h Detec tor A.I t i s i d e n t i c a l t o Detec tor A except t h a t i t does not have amagne t ic f ie ld t o e l imina te t hose e l e c t r ons of less than 200,000e l e c t r o n vo l t s . Thus the d i f f e r e n c e between t h e s i g n a l s of t h etwo de t e c t o r s g ive s a count of those e le c t r on s w i t h e ne r g ie s ofl e s s t han 200,000 e l e c tr o n v o l t s and down t o 20,000 e l e c t r o n sV Q l t S .

Detec tor C: This device is a Geiger tube de tec tor similart o those f lown i n ea r l i e r Explorer and Pioneer pay loads . Thet ub e i n t h i s case i s enclosed by a l e a d s h i e l d which has asmall h o l e i n et t o persnit th e en t rance of s o f t r ad ia t ion ,shape of t he ho le a nd s t r e ng th of a magne tic f i e l d adrosa ita l l o w o n l y e l e c t r o n s ha vi ng e n e r gi e s i n t h e range of 40,000 t og0,OOO e le c t r o n vo l t s t o r e a c h the G eige r coun te r .

The

Detec tor D: Th i s d e t e c t o r u s e s a G e ige r t ube ide n t i c a l t o1tha t i n D et ec to r C, except that t h e s i s no hole i n t h e s h i e l d

so i t w i l l r e p o r t p e n e t r a t i o n of high e ne rgy pa r t i c l e a thr ought h e s h i e l d , , I t w i l l provide new data f o r th e a bso r p t ionspectrum o f the p a r t i c l e s and w i l l providedata for cornparisionw i t h t he c oun t ing r a t e of Detec tor C .


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-7-Detec to r E: T h i s d e t e ct o r a l s o i s a Geiger counte r but

i t i s o n l y l i g h t l y s h i e l d ed so that i t w i l l provide informat ionon modera te ly pene t ra t ing p a r t i c l e s . It w i l l r e v e a l the genera ls t r m c t w e of t h e b e l t s a nd t h e i r f l u c t u a t i on s so t h a t at temp%scan be made t o c o r r e l a t e the f i n d i n g s w i t h so la r and magnet;ir:a c t i v i t y . I n add i t i on , s ince t h i s d e t e c t o r i s similar t o t ho sef lo wn i n p r ev i o us s a t e l l i t e s (Explore rs I3 111, I V , and = I ) ,i t s data w i l l be compared w i t h that from the e a r l i e r experimentst o demons trat e t h a t i t i s func t ioning proper ly .

Three holes i n t he t op of the Z n s t , m e n t c o n t ai n er lead i n t othree d e t e c t o r assemblies -- Detec tors A , By and C. Detec to r Di s sh ie lded . Detec to r E -- which i s unshie lded -- extendsfrom th e t op of t he con ta ine r i n i t s o m housing.TEMPEX3ATURE EXPERIMENT -- T o cont in ue compil ing data on th etemperature of s a t e l l i t e s i n space, ABMA has provided temperaturesensors f o r t h i s p ay lo ad . Sensors are l o c a te d t o r e p o r t b o t hi n t e r n a l and external temperatures .TELEMETRY EQUIPMENT -- Data w i l l be rep ort ed t o ground s tat jhonsby a 300 mi l l iwa t t t r a n s m i t t e r o p er a ti n g a t 108.03 megacycles,I t i s capable of broadcas t ing f iv e channe l s of informationcont inuous ly ,

The t o t a l power requirement for t h e i n s t rumenta t ion i nehe package is about 1% watts. This is supplied from almostt w o pounds of nickel cadmium ba t t e r i e s which are recharged by

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-8 -1184 solar cells mounted on th e box-l ike s t ru c tu re surroundingt h e c y E in d r ic a l P n s t m e n 2 p ack ag e,covered w i t h glass s l i d e s .006 of' a n i n c h thick t o p r o t e c tthem from possible rad ia t ion . d m a g e ,

The solar c e l l s are

The an"vnXX3 AS a d ipo l e S iE l i l aP tO t h Q S e U s e d l ?in ear lyExplorers , with t h e gap located between the instrument packageand t he f o w t h stage easing,

A b u i l t - i n t i m e r will autsmt ic89By cut off t h e t r a n s m i t t e ra f t e r one-year of operation,

LAUNCH lTEKICLEThe launc h ve hi cl e is a Juno 11, 1% conslsta of a

modif ied Jupi te r ERBM provided by DMA and a t h ree - s t ageh i g h speed @Itasterprovided by t h e NASA Jet P ~ ~ p u E s f ~ naboratory.

The J w o II s tands 76 feet h igh and we$ghs about 60 tonsincluding fue l . The f u e l i s high grade kerosene ; t he oxi d iz e ri s liquid oxygen. T h i s will be fits s,%xt,h i r ing:

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December 6 9 1958: P ~ Q ~ W X J11 space probe launchedt o 63,000 I Y L L ~~FLMarch 3 j 1959: Pioneer IT7 probe Pam@Ezed%n%oo r b i taround th e sun,J u l y 16, 3.959; Vehicl e was destroyed about fitireseconds af t e r launch when it t i l t e d shasp ly in anattempt t o launch heavy composite r a d i a t i o nsatel$fk;e,August 3.4, 1959: A %2-fsot i n f l a t ab l e sphe re pay loadf a i l e d t o achieve orbPt due t o psemture f u e ld e p l et i o n i n b o o s te r and ma%funct%on n a t t i t u d econt ro l sys tem f o r upper s tages ,October 13, 1959: Explorer VI16 heavy ~adii?.tic?ns a t e l l i t e launched Into orbito

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-9-The t h r ee upper st ag es , mounted i n a spin-tub assembly,

a r e v e ry similar t o t h e u pp er s t a g e s of t h e J u p i t e r 6 rocke t ,t h e v e h i c le that launched the f i r s t U, S . s a t e l l i t e , E x p l o r e r I.The second stage is a hollow, c i rcu la r g roup ing of' 11 scaled-down so l i d fu e l Sekgeant rocke t s . A t r i a n g l e of t h r e e s i d l a rr o c k e t s f i t t e d i n a i d e th e c y l i n d e r i s t h e t h i r d stage,f o u r t h stage is 8 single motor f i t t e d i n s i d e th e t h i r d s taget r i a n g l e .long and six i nches i n diameter.

The

A l l . of t he uppe r s t a ge rocke t s alae about 42.5 inches

The upper atages r o t a t e a t a r a t e of 600 rpn. Barring t h elaunch and f i r s t stage f l i g h t , th e upper s tage c lu s t e r , cappedby the payload, i s pro tec t ed by an aerodynamic shroud which i sre l ease d by explos ive b ol t s and pushed a s i de by a l a t e ra l rocke tp r i o r t o upper stage igntjitfon,

The guidance system employed i s t h e one used by Jup i t e r i ne s t a b l i s h i n g a h3gh record of accuracy during previous firings,A pla t form s t ab i l i z ed by gymscopes 18 o r i e n t e d on t h e pad i n Bd i r e c t i o n t o obtaihn the deslred orbi t . evia t iona from ap r e c a l c u l a t e d t r a j e c t o r y , s uch as r e s u l t i n g from wind, aremeasured by acc ele ra t io n devices , fe d into t h e guidance computer,and t r a j e c t o r y c o r r e c t i o n s are automatically made by Sheco nt ro l system. S te e r in g i s by the gimballed nozzle of t h ebooster engine and, a f t e r englme cut off, by va r i ab le t h rus ta i r nozz les ,

. . . . . . . . . . . .^_ - . - - .. . . . .- .. . . -_...__ . . ., .._I --.".., .... .. .


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-10-After boos te r engfne cutoff, agpraxfmately t h ree mfnutes

a f t e r liftoff, explos ive b o l t s separa te the boos te r which isslowed and s teered to one sZde by four small retro r o c k e t st o p re ve nt i n t e r f e r e n c e w i t h t h e upper stages,

Apprsximately 30 seconds a f t e r s epa ra tfon , t he nose coneof t h e aerodyvlamfc s b o u d is removed by ~xp 'koslve o l t s andpushed a si de by a small l a t e r a l r oc ke t. The upper s t ag es andt h e i n s t m e n t compartment of t h e Juno 11 system then coastfor about 4,g minutes,system, eons i s t fng of a n o n r o t a t f n g body w i t h the ro t a t fn gc l u s t e r a c t i n g l i k e a huge gyro arranged on f t s farward cnB,is or i en ted according t o a pre sc r ibed program by a i r nozzlesof t h e spa t i a l a t t i t u d e c o n t r o l system.

During ascent t o the apexa t h i s coasting

The second s t a g e ignites pulling t h e upper stage andpayload assembly, spinning a t 600 rpm, c l e a r of the shroud,The second stage burns f o r SIXecondsg followed Bay a coastingpe r iod of two seconds,. The t h i r d stage then fgnl%k;es btir.;l;inyfor an effective t ime of EFX seconds9 fallowed by the fourths t a g e w h h h a l s o bums s ix seconds and injects the payload,

TRACKINGResons ib i l%ty f o r tracking the ~ a d i a t i s n elt sateelkite

and recording its s c i e n t i f i c f i m 3 a g s i s by NASA GuddardSpace Plight Center ' s Space 0 p c ~ a t i s n s an,b;roP Center,

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I n i t i a l t r a c k i n g of the satellite t o de te m~ fn e ngectfonand o r b l t a l elements w i l l be under superv i s ion of ABPIA.Microlock s t a t i o n s p a r t i c i p a t i n g under ABBN d i r e c t i o n 222.8Aberdeen Prs J ec t Ground, M d under Ba, l l i s t ;kc ResearchLabora to r ies ; Cape Can.avera1, P l a . , 2nd Huntsville, A l a ,operated by MA; A t l an t i c , N. C. ; Remuda; Port Nomouth,, MOJO;and Mayaquez, Puerto R i m , all operated by the Amy S i g n a l Co rps ,s ack i n g i n fo ma t i o n from these stations is fed to t h e ABMAEvalua t ion cen.ter,nf t h e NASA Space Operat ions Control C e n t e r . NASA d n l t r a c ts t a t i o n s p a r t i c i p a t i n g are Blossom P o i n t , Md.; Sann Diego, calif,;Sant iago, C h L l e ; Esselen Papk, South Africa; hbomekaa, Australia,Quitu, Ecuador; Lima, Peru; and hntafagasta, C h i l e

I n , a d d i t i o n , s t a t i o n s a t South Poin t , Hawaii, and Xngapsre,under d%,b3ectiono f t h e Space Technology Labora torfes wZ11

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-12-Miss i l e F i r ing Labora to ry .

Major subcon t rac to rs inc lude the Rocketdyne Division ofNorth American Aviation, wh:Lch fwnishee t h e J ~ p f t e r ~F j O , O O Opound t h r u s t l i q u l d e ng in e, alnd t h e Ford Instrument Company,which manufactux-es t h e a l l - i n e r t i a l guidance system employedby th e J u p i t e r .

The h i gh speed upper stage c l u s t e r was desiencd by t h eJet; Pn?op.rxlsiorz Laboratory. John SlnalB i s J P L proJec tengineer . The cPustcr was built by Cooper 3evz1,0pdnen5Co.ulporatBon of Nornovia, C a l i f o r n i a .PAYbBAD -- The r a d i a t i o n b e l t s a t e l l i t e w a s designed, aesembled,and t e s t e d by t h e Development Opera t ions D i v i s i o n of ABFdA(which w i l l become th e George C. M a x h a l l Space F l i g h t Cente rwhen i t I s formally t r a n s f e x e d t o NASA on July 1, 3.960).Dlirector of the Division i s Dr. Wemiher von Eraun, Leadingr o l e i n p re p ar at io n 02 t h e paylozd was by the Guidance andControl Laboratory .

The rad ia t ion b e l t experiments were designed and buLltby t h e Physics Department of' the State Unlvessi ty of Iowa,9 ~ .ames A. Van A l l e n , Chairman. George M. Ludwig,graduate stude:iS; in t h e Gepartment, supervised co n s t ru c t i o nof the pay load,

e t ec t o r s A and B were designed an d b u i l t by GraduateStuden t John Freeman. D et ec t o r s C and D were designed and' b u i l t by Graduate Student Curt Lzughlira, 3on Enemark', a s en i o rs tuden t , supervised assembly of t h e f l i g h t u n i t s and C a r l McIlwain,r e s ea rch ass is tan t i n p h y s i c s , a s s i s t e d i n dessign of the detec tors .

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Radiation Belt Satellite Press Kit