Pioneer D Press Kit

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NA TIO NA L AERONAUTICS AN D SPACE AD MINISTRA TION WO 2-4155WASHINGTON,D .C. 20546 TELS WO 3-6925

J

November 3, 1968

t PIONEER D(To be launched noear l i e r than Nov. 6)

nts

3/(CATGORY)=2 (NASA CR OR TMX OR AD NUMBER)Y


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NA TIO NA L AERONAUTICS A ND SPACE ADMINISTRATION WO 2-4155N E W S .. WASHINGTON,D .C. 20546 TEL S * WO 3-6925FOR RELEASE: SUNDAY

November 3, 1968RELEASE NO: 68-192

PIONEER D LAUNCH

The United States will launch Pioneer D, the fourth Inthe current series of Pioneer interplanetary spacecraft,from Cape Kennedy, Fla., no earlier than Nov. 6, 1968.

Pioneer Dls mission is to acquire additiocal data onsolar plasma and energetic particles and magnetic fieldspropagakedby the Sun towards the Earth. These data, com-bined with that from previously launched Pioneer spacecraftstill operating, will be used in the continuing study tounderstand solar processes, the interplanetary medium, andeffects of solar activity on the Earthas environment.

The launch window for Pioneer D is from 4:45 to 4:59 a,m.E$T, The window opens slightly earlier on the succeeding days,

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Pioneer I) w i l l join three other Pioneers spotted aroundthe Sun and w i l l become Pioneer IX when it achieves success-fu l orbit. Pioneers are th e only currently act ive U. S,interplanetary craft,

Launch dates and distances of ear l ier Pioneers are:Pioneer V I , launched Dec, 16, 1965, now 164 million m i l e sfrom Earth; Pioneer V I I , Aug. 17, 1966, now 108 mill ion milesaway; Pioneer V I I I , Dec. 13, 1967, 34 mil l ion m i l e s away.Through Novo 1, 1968, the three Pioneers had received 20,000commands and returned six b i l l i o n b i t s of data on 6,500 milesof data tape.

After launch, Pioneer I) w i l l sh u t t l e 23 mil l ion m i l e sI n and out from the Sun in I t s o r b i t a l pa th every five monthsas the sol ar cycle peaks i n 1969.Sun than earlier Pioneers -- to within 70 million miles of theSun -- it w i l l observe solar particle concentrations almost

Travelling closer to the

double those found near Earth.About 770 days af ter launch, Pioneer D w i l l pass d i r e c t l y

behind the Sun.During the following 100 days, the spacecraft may pass

behind the Sun two more times. These three separate passeswould allow the most extensive measurements of th e so l a rcorona y e t made -- by analysis of $he way passage through thecorona affects the three Pioneer radio signals.

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-3-T h i s t r i p l e occultat ion w i l l require a launch speed

which can vary only a few miles-per-hour i n some 24,000mph.known u n t i l precise launch speed i s determined af te rlaunch,

Whether t r i p l e occultat ion can occur w i l l not be

If it does occur, the spacecraft , on the other sideof th e Sun from t he Ear th , w i l l appear to an Ear th observert o pass behind th e Sun, then slow down and speed up again,passing behind the Sun twice more.

This can happen because Pioneer D on a smaller, ovalo rb i t t r a v e l s fas ter than the Ear th on most of i t s o rb i t ,but slows down below th e Earth's or bi ta l speed a t i t sfarthest point from the Sun.

The e i g h t s c i e n t i f i c experiments on Pioneer D includea new, improved magnetometer, and instruments to measureth e so la r wind, cosmic ray part ic les , elec tron density,e l e c t r i c f i e l d s and cosmic dust.

I n a new c e l e s t i a l mechanics experiment, tracking datafrom a l l of the Pioneers w i l l be used to Pefine measurementsof the Earth-Moon mass ratio, Sun-Earth distance, planetor bi ts , and to check th e theory of general r e l a t i v i t y .

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The Cosmic Ray Telescope on Pioneer D is similar tothat on Pioneer VI11 which made the first measurementsof fluorine among galactic cosmic ray particles. It hasmeasured nuclei of the 14 lightest elements in a variemof energy ranges, These include hydrogen nuclei travellingat g0 per cent of light speed.

The Electric Field experiment on Pioneer D is alsosimilar to that flown on Pioneer VIII, which found verylarge waves in the solar wind,

The million-mile-an-hour solar wind, which constantlyblows out from the Sun, is threaded with curving magneticfilaments rooted in the Sun, carrying massive streams ofhigh energy particles. At the Earth, they have an averagediameter of about two million miles, New ones constantlysweep past the Ea.rth in co-rotation with the Sun's 27-dayrotation.the Earth by a more direct path.

Very-high-energy solar storm particles reach

The Pioneers can measure this solar w i n d , particlesand fields far more precisely than past spacecraft. The145-pound craft are "spinners,"full circle in the plane of the Earth's orbit.

They contlnuously scan a

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-5 -The.Environmenta1 Sciences Serv ice Admin istration (ESSA)

uses Pioneer Space Weather Reports d a i l y i n i t s analyses ofsolar weather a t i t s Space Disturbance Laborato i n Boulder,

Pioneer D w i l l carry f o r the f i r s t time an improved datasystem wi t h the addition of a "convolutional coder," whichi s expected to double the data returned during most of themission through a new wag of processing the data s ignal onthe spac ecra ft, The system eliminates lmost a l l t rans-mission errors, and can apply to most d i g i t a l data communi-cat ions i n space or on E a r t h ,

I n addit ion t o Pioneer D, the Delta launch vehicle w i l lcarry a 40-pound Test and a in ing Sa te l l i t e , TETR-2, i n toa s ep ar at e e l l i p t i c a l 200 by 500 m l e o rb i t , incl ined 32 to35 degrees to the E ~ u ~ t o r ~ piggy-bac~mounted i n the rear of the second stage and i s ejec ted in toa 98-minute o r b i t a t 21 minutes into th e mission

TETR-2 w i l l provide cklng and DataAcquisition with an orb ing out equip-ment and training personnel of i t s w e d Space F l i g h t Net-work, MSFN, under condit ons similar t o those provided by anor bi tin g Apollo spacecr aft,

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-6-TETR-1, launched along w i t h Pioneer V I I I , carr ied

out a similar mission w i t h complete success,TETR-1 w a s launched December 13, 1.967, and reentered

t he Ear th ' s atmosphere over th e Pacific Ocean Apr i l 28 a f t e rbeing successful ly u t i l iz ed i n te s t and t ra in i ng exerc isesof t h e MSFN p r i o r t o the network's successful support rolei n t h e Apollo 5 and 6 f l i g h t s ,

The Pioneer program i s direc ted by NASA's Office ofSpace Science and Applications.NASA ' s A m e s Research Center, Mountain View , Cal i f , TheDelta launch vehicle i s managed by Goddard Space FlightCenter, Greenbelt, Md., and i s launched by Kennedy SpaceCenter, Fla.

Project management i s by

Communications and tracking w i l l be by NASA's DeepSpace Network (DSN), operated by th e J e t Propulsion Labora-tory, Pasadena, Cal i f .

The Pioneer spacecraft are b u i l t by TRW Systems Group,Redondo Beach, C a l i f . The Delta rocket i s b u i l t byMcDonnell Douglas Corp. a t Santa Monica, Cal i f ,

(END OF GENERAL ReLEASE; BACKGROUND INFORMATION FOLLOWS)

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PIONEER D SPACECRAFTOverall Configuration

The Pioneers are designed as rugged, high-performancespacecraft , ab le t o r e t u r n large amounts of data on f l i g h t sof several years over distances of many millions of miles.All spacecraft systems have been chosen f o r s i m p l i c i t yand r e l i a b i l i t y . Maneuvering, f o r example, i s handled by asingle cold-gas j e t .Pioneer D weighs 148 pounds and carries 39.5 pounds ofsc ie nt if ic experiments . A t t i t u d e of t h e Pioneers i s

extremely stable .has been about one degree.Average d r i f t f a r each s i x months i n spaceThe spacecraft i s a dmm-shaped container, 35 incheshigh and 37 inches i n diameter. I ts sides are covered w i t hso la r ce ll s, and divided by 8 narrow c i r c u l a r band con tain ingaper ture s f o r f our experiments and fo ur o rien tati on Sunsensors. A f i f t h Sun sensor provides t h e experiments w i t ha direc t ional reference to t h e Sun's position.A t 120-degree in t e rv a l s around the s ides of t h e space-c ra f t are three five-foot four-inch booms, deployed horizon-t a l l y i n f l i g h t by t h e spin of t h e spacecraft .Within t h e spacecraft , a ci rc ula r p la tform carr ies mostof t h e equipment. Below &he platform i s a pressure spherew i t h gas f o r th e or ien tat ion system.The spacecraft s tructure, made pr inc ipa l ly of aluminum,is l ightweight and i t s cy l indr ica l shape is inherently strong.There are more than 56,000 par ts i n Pioneer, including i t ssc ie nt i f ic ins truments.

Communication SystemThe 35-pound P ioneer communications, t i m i n g , and datahandling system has performed w e l l aboard Pioneers V I , V I I ,and V I I I . It has returned 6 b i l l i o n data b i t s t o Ear th of3,400 measurements. Pioneers V I , V I I , and V I 1 1 have received20,000 commands from the ground.It maintains two-way S-band communication a t about2,300 meg&ert;z.

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INSU

-7a-PIONEER8 SPA

HIGH GA I N ANTENNA LOW G A I N ANTEN NA

\OP COVER (INSULATION)

M A GNETOMETEREXPERIMENTANTENNASOLAR ARRAY FRAMES / STRUTS

SUN S E N S O R B

WOBBLE DAMPER

SUN S E N S O R E FA SUN S E N S O R A

EQUIPMENT PLATFORM, !@THERMAL LOUVERS

PLATFORM STRUTS

INTERSTAGE STRUCTURE

S

ZZL

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-8-Commands are se nt t o Pioneer from DSN antennas i nb inary ( 1 ,O ) code. These commands are received by space-c r a f t antennas and routed t o one of two radio receivers.They then go t o one of two command decoders.cornrrrands are routed by the comand dis t r ibut ion uni t to aspacecraft system o r experiment f o r execution.

Once decoded,

To send information back t o Earth, the spacecrafttransmitter driver puts coded data on the basic S-bandca rr ie r and routes i t t o one of' the two spacecraft travel-l i n g wave tubes , which amplifltes th e si gn al t o about e igh twatts.The Pioneers have the gre ate st data-return capacity ofany interplaneta ry spacecraft because t hey match the most

e f f i c i e n t ra te of data re tu rn w i t h the dis tance from theEarth.seoond. They re tu rn data a t 512, 256,64, and 8 b i t s perThe new convolutional coding system should double th edata rate, almost doubling the amount of data returned. Ifthe new system fails t o operate properly, con tro l ler s canswitch back t o t h e standard system.With th e new coding system, an encoder uses the s igna l sfurnished t o each on-board sensor t o provide proper syn-chronization w i t h the spacecraft d i g i t a l telemetry uni t .Data from t h i s u n i t i s processed by an on-board data system

i n t o a coded data b i t stream f o r transmission t o th e ground.The ground station computers are programmed t o processt h e coded d a t a , b i t stream by essen t ia l ly reversing th e space-c ra f t coding system process. The f i n a l data output has sucha l o w e r ro r ra t e that the total information rate i s aboutdouble that of th e ear l i e r system.The spacecraft memory can store samples of data f o rup t o 19 hours.

At tit ud e Cone r o lThe Pioneers use t h e gyroscopic effec ts of t he i r60-rpm ro ta t io n t o mainta in a stable a t t i t u d e .Changes i n a t t i t u de are achieved by turning th espacecraft about a se lec ted axis through many br ief t h ru s t sfrom the nitrogen gas j e t a t the end of one boom. Force fromt h i s gas j e t must be a p p l i e d perpendicular t o the desireddi rec t ion of motion because the spinning cra f t precesses l i k ea gyroscope.

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Thrusts a p p l i e d a t one point on the c i r c l e of space-c r a f t r o t a t i o n are timed by a sensor which sees th e Sunonce each Spacecraft revolution.The many t h rus t s a t one point produce wobbling rota.tion.Wobble is eliminated by f l e x i b i l i t y of a l l three booms andby a damper co ns ist in g of two small b a l l s i n two cylinder sa t the end of one boom.Pioneer D must have i t s spin axi s perpendicular t oboth Sun-spacecraft l i n e and Earth-spacecraft li ne , so t h a tso la r c e l l s a r e i llumina ted e f f i c ien t ly , and t h e narrow beamantenna focuses on the Earth.Sun orientation is automatic. One Sun-sensor sees theSun f o r 80 degrees above the plane of spacecraf t ro ta t ion;

a second sees t h e Sun f o r 80 degrees below t h i s plane.Proper orientation is achieved when the spacecra f t tu rns un t i lboth see the Sun.For Ea r th orientation, ground commands rotate thespacec raft around the spacecraft-Sun l in e, u n t i l i t s high-gain antenna acquires the Earth.

Power SystemsPioneer D ' s 10,368 s i l ico n cry s ta l , n-on-p so la r ce l l s

provide the spacecraft i t s 60-watt power needs.Auxiliary power during launch, before s ol a r ce l l s begint o funct ion , is provided by it rechargeable silver-zinc batteryw i t h a capacity of about two hours.

Temperature ControlTemperature i s con.trolled by managing heat producedby spacecraft equipment and by heat-re f lect iv e coatings onthe spacecraft ex te ri or . Twenty louv ers under the spacecraftequipment platform, actuated by bi-metallic springs, openand close automatical ly t o re lease heat.

Magnetic F i e l dThe ma n e t i c f i e l d of the Pioneers is extremely low,1/10 gamma fl/!jOO,OOO the Earth 's f i e l d ). Engineers achievedthis low magnetism by using non-.magneticmaterials, newfa br ic at io n and in spection techniques, and design innovations.

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-10-SCIENTIFIC INVESTIGATIONS

Interpl anetary space i s hundreds of times less densethan the most extreme vacuums on Earth. Nevertheless, solarand galactic events propagate through it, They cause t h eauroras, feed t h e Van Allen radiation belts, and providet h e Earth'i ts basic energy source.

Known phenomena i n i nt er pl an et ar y space include:P a r t i c l e s -- Elect rons and hydrogen, helium and ot he r,nuclei carrying an electric charge whichmake up the "sola r wind"; cosmic rays fromSun o r ga lax which are extremely energetic(fast-movingT charged nuclei of many ele-ments; cosmic dust and meteoroids.Radiation -- The e n t i r e electromagnetic spectrum suchas l i g h t , radio and X-rays.Fi e l d s -- Magnetic, e le ct ri c and gr av it at io na l.S ci en ti st s now believe, based t o a subs tan t ia l degreeon Pioneer discoveries that , these ingredients go togetheras follows:

Description of Solar SpaceThe so la r wind or ig in at es when th e solar surfaceheated by the thermonuclear re ac tio n i n the Sun's center,throws off an ionized gas into space,negative electrons are ejec ted i n t o space from the Sun's2,000,000 degree F. corona, perhaps heated by local shockwaves. The par t ic les reach a speed of around one millionmiles-per-hour as solar gravity weakens,

Poli t ive nuclei and

The magnetic f i e l d on the Sun's surface i s th e t o t a lr e s u l t of 8 mass of small bi-polar f ie lds , This complextw i s t ed f i e l d i s car r ied by the so la r wind f a r beyond theEarth 's o r b i t , The f i e l d is fur ther bent as nuinem8 solarwind "beams" (masses of gas on separate paths) co ll id e andchange di rec t ion ,major radia l sec to rs (commonly from two t o seven), each w i t ha single f i e l d di rec t ion th e reverse of i t s neighbor,are believed t o be created by surface regions which send outhigh-speed streams of so la r wind f o r months,dies , i t s sec to r disappears, and new regions produce newsectors .

I n t h e Sun's corona, the magnetic f i e l d dLvideg Into

These large sectors, extending f a r beyond the Earth,When a region

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s on the Sun t h r dense masssolar wind par t ic les and of high energy pa rt ic le s (s ol ar cosmicra ys ) , b r i n g storms, magnetic f i e l d s t rength r is e s from100 t o 1,000 times t h e n o m 1 of 100,000 gama, ( F a r t h l ssurface f i e l d i s 50,000 gamma; in terp lanetary f i e l d , f i v egama ),

Lower energy solar cosmic ray par t ic les cover th e 93 mill ionmiles t o the Earth i n one t o two hours,p a r t i cl e s a r r i v e i n as l i t t l e a s 20 minutes.of the twisted in terp lanetary f i e l d but follow i t s generald i rec t ion , They t r a v e l i n long curves arr iving a t t h e Earth-Sun line a t an a le of about 45 degrees,

H i g h e r energyThey break out

The flow of lower energy cosmic rays of ten las tsmany hours, The Sun appears t o "store" them near i t s surface,The par t i c les f requen t ly are inJected onto a number ofdi ff er en t magnetic filaments, and pa rt ic le s from the samesolar storm may reach th e F a r t h i n t i r e l y separate, tw is tedstreams.The solar wind s p i r a l i n g out from high speed regionson the Sun collides w i t h slower solar wind masses, crea t ingrelatively dense shock areas. These radia l shock frontsbehave l i k e vanes of a ce nt ri fu ga l pump, pushing g a l a c t iccosmic rags out of the Inner so l a r system.V e r y in tense waves, much l i k e sound waves, form duringso la r s torms, esp eci al ly a t boundaries between f a s t and slow-moving segments of the solar wind, These waves accelerateand a l t e r solar wind flow.The solar wind now i s believed t o blow out t o between900 mill i on and nine bi l l io n miles. Whese it stops i s theend of the in terp lanetary f i e l d and the boundary betweenin te rp laneta ry and i n t e r s t e l l a r space. S l i g h t var ia t ions ind i r e c t i o n of ga la ct ic cosmic ray p a r t i c l e s may be due t o passagethrough t h i s boundary.The North-South magnetic f i e l d of t h e Sun i s t h e sum of

many local f i e l d s .each 11-year solar cycle and then reappear w i t h North andSouth poles reversed.It seems t o disappear a t th e peak of *

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Instrument*

PIONEER DSCIENTIFIC INSTRUMENTS AND

(E.)Three-4x1s Magnetometer 6.66

Cosmic-Ray Telescope 7.89Radio Propagation Detector 5.05

E le c t r i c F i e l d Detector

Quadrispherical P l a sm aAnalyzer

Cosmic-Ray AnisotzopyDetectar

Cosmic Dust DetectorCelestial Mechanics

0.80

5.91

5e56

4.26--

Power5.2

(watts)

2.741.35

0.43

3.10

1.78

0.43.--

Invest g a tor8C,P. Sonnett*D.S. GolburnAmes R e s . Cent.W.R, Webber*Univ. of Minn.V.R. Eshleman*A.M. PetersonR.L. LeadabrandH,T. HowardR. Long

Stanford UnLv.Stan. R e s . Ins t .

F.L. Scarf*G.M. CookI. GreenTRW SystemsJ .H, Wolfe*D.D. McKibbinAmes R e s . Cent.K.G. McCraken*Univ. of Adelaide,Austral iaW.C, Bart leyNat. Acad. of Sci.R.T. WlkataS.W. Cent. of Adv,S tu d i e sU.R. RaoR e s . Lab., IndiaO.E. Berg*GSFCJ .D. Anderson+JPL

* Principal Inves t iga tors-more-


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A summa S C t s s s e n t i a lcharac e i st e w t e n ters i sgiven i n th eThree-Axis Magnetometer

r ap id ly-varyinggne t ic f i e l d

t o +200 gammans three mutually

Quadrisphericalqua^

o s i t i v e i o nssure 50,000 t owith accuraciescen t i n ve loci ty.

Radio Propagation Detectorbetween Pioneer and the Ear th . The l5O-foot d i s h antennaat Stanford University sends radio sig na ls t o a s pec ialreceiv er on the spacecraft.r iment de tem lnes t o t a l e le c t ron content


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The receiver can hear the Stanford s igna l from 280mill ion miles. T h i s will allow solar corona studies whenPioneer D moves behind the Sun i n about two years. Experi-menters send low and high frequency signals t o the space-craf t . The greater slowing of the low frequencies byelec t rons in spaee allows measurements of electron densi ty.Electr ic Field Detector

T h i s instrument measures the electric components of lowfrequency radio waves and waves created by dens i ty var ia t ionsi n the s o l a r wind. Unequal concentra tions of po si tiv e ionsand negative electrons have electric f i e l d s between them.The instrument uses an al te rn at in g current electrometer t omeasure the f i e l d s as shown by small volt age changes i n theStanford antenna on the spacecraft.Cosmic Ray Anisotropy Detecto renergy (speed) of s ol ar and ga la c ti c cosmic ray par t ic les .This instrument finds a r r iva l direc t ion , mss, and

I t consists of a crystal scint i l la tor which producesflashes of l i g h t of varying intensity, depending on the energy,direct ion and type of cosmic ray pa rt ic le which strikes i t sc r y s t a l l a t t i c e . The instrument detects part icles arr ivingfrom eight direct i ons i n the plane of the Earth ' s orbit , andfrom below and above the spacecraft , The energy range ma-sumd i s from t h r ee mil l ion to 360 mill ion electron volts .Cosmic Ray Telescope

This instrument measures numbers, energy, direction,charge, and d is tr ib u ti on through space of nuclei of atomsfrom one nnillion t o one bi l l i o n el ectr on volt s.two solid-s tate, surface -barrier detectors, three sol id-s t a t e l i thium-drif t detectors , one detecto r w i t h a syntheticsapphire window t o a photomultiplier tube, and one with ap l a s t i c guard cup rnonitomd by photomultipliers.Select ion of one of five detector combinations to bemonitored i s by ground comuand.any such instnunent to date. By finding the r e l a t i v eabundance of elements i n cosmic pays, sc i e n t i s t s candevelop a theory of their origin.

It employs

Resolution i s bet t e r than

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Cosmic Dust DetectorThe instrument measures the momentum, energy, andd is t r ib u t ion i n in te rp lane ta ry space of minute meteoroids ,It determines the velocity, mass, and flux of part icles from5O mill ionths t o less than a t r i l l i o n t h gram a t speeds up t ogO0,OOO mph.Two sets of thin-film panels front a piezoe lec t r i ccrystal microphone mounted on an impact p l a t e ,measure particles of l i g h t time between front and rear f i lms,determine d ire ct io n by comparing fr on t and rear penetrat ionpoints, and measure impact on th e plate.

These elements

Celestial Mechanics ExperimentThe purpose of t h i s experiment i s t o b e t t e r determine:the Earth-Moon mass ra ti o, the Astronomical U n i t (Earth-Sundis tance) , shape and or ien ta tio n of the planet o rb it s, andt o t e s t general r e la t iv i ty .because of: i t s long durat ion; so lar orb i ts ; spin s t a b i l i -zat ion with negligible non-gravity ef fec t s ; and differentorbits for each Pioneer.

Pioneer data i s usefu l fo r t h i s

The experiment will use the DSN t racking data and largedigital computers,


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-16-THFtUST-AUGMFXI!ED IMPROVED DELTA LAUNCH VEHICLE

The launch vehicle for Pioneer D i s the outstandinglysuccessful workhorse Delta. This w i l l be the 60th Deltaf l i g h t , If successful, Pioneer I) w i l l be th e 56th spacecraftsucc essf ully launched by the, Delta vehicle,It has a marx-irnum diameter of eight feet without strap-on so li d rockets.Its l i f t o f f ' weighs is about 75 tons, and l i f t o f f th rus t is

Engines for the kerosene-liquid oxygen f'ueled f i r s t stageare b u i l t by the Rocketdyne Division, North American RockwellCor p . The three so li d rockets which st ra p on the firs% tageare by Thiokol Chemlcal Corp. The ZILMW-IRFNA fueled l iquidengines of the second stage are by Aerojet-General Corp. MajorautopZlot contractors for Honeywell, Inc, are Texas Instruments,Inc,, and Electro-Solids Corp, Guidance contractor i s WesternE le c t r i c Coo Delta's t h i r d stage solid engine i s by U n i t e dTechnology Center,

Delta i s 92 fee t high (including shroud),333,550 pounds 0

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The Delta payload w i l l include a small, 40-pound Testand Training Satel l i te (TETR-2), which houses a transpondert o transmit and receive the S-band.data signal simulating t h eApollo spacecraft, TETR-2 w i l l be used i n t he S-band systemcheckout and training exercises with the Manned Space Fl igh tN e twork.TETR-2 i s a follow-on to TETR-1 which was highly success-f u l i n carry ing out i t s mission of testing the Apollo commupi-cations network.TETR-2 w i l l b e piggy-back launched from the Delta vehicle,It is mounted i n t h e rear of t h e second stage, with a timer s e tt o e j ec t TETR-2 rearward a t th re e f e e t per second, approximatelyone minute after the t h i r d stage of the Delta has ignited. Theplanned orbit for TETR-2 i s e l l i p t i c a l a t an inc l ina t ion of 32t o 35 degrees with perigee o f 200 miles and apogee of 500 miles,The spacecraft i s octahedron-shaped (bottom-to-bottompyramids), 11 inches on each s ide ,The top apex supports an S-band antenna with mast. A t twoopposite apexes i n the cen ter plane a r e mounted the VHF t rans-

mi t t er antenna sect ions.ing and ejecting t h e spacecraft from i t s launch canister, TheVHF camand telemetry antenna sect ion i s located near the bot-tom apex.A f i t t i n g i s a t t h e bottom f o r mount-

The el ec t r ic a l power i s generated through solar cellsmounted on each of t h e e igh t surface panels of the spacecraft.T h i s power w i l l be used t o re-charge t h e batteries which fur-nish power requirements when TEXR-2 i s operating.hours of continuous S-band transponder operat ions, After maxi-mum operating time, a period of about 20 hours i s required torecharge the b a t t e r i e s ,

The bat ter ies are designed t o provide approximately three

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-18-LAUNCH WI S

Launch windows during November f o r th e Pioneer Dmissionexis t from Nov. 6 t o 22,15 minutes duration,launch azimuth of 108 degrees,high and 10.6 m i l e s downrange a t a speed of 2,148 mph,stage burnout comes a t 2.5 minutes af te r launch, 55.9 nau t ica la l e s a l t i tu d e and 92.4 m i l e s downrange a t a velocity of 8,9150mph,

The once-each-day periods are of aboutDelta No, 60 w i l l be launched fram Complex 17, Pad 33 on aThe strap-on Delta rockets burn out a t 14.4 nautical m i l e sF i r s t

A t two minutes and 50 seconds a f t e r launch, the fa i r ingcovering th e spacecraft is jettisoned, and a t e i g h t minutes and55 seconds 1,100 m i l e s downrange and 203 m i l e s above t h e Earth,second stage engines burnout a t a speed of 16,600 mph.Third stage burnout occurs a t 20 minutes, 47 seconds af te rlaunch, 3,794 m i l e s downrange a t 250 m i l e s a l t i t u d e . The space-c r a f t i s then traveling a t 23,784 mph and i s on interplanetaryt ra jec to ry ,Pioneer Dts lanned perihel ion (clo sest dis tance t o the

Sun) i s 70 mil l ion m i l e s , and aphelion (farthest from Sun) i s93 mil l ion m i l e s .Delta w i l l place Pioneer D i n t o a smaller s o l a r o r b i t thant h e Ear th ' s c r b i t , and the spacecraft w i l l move steadily aheadof the Earth due t o i t s larger or b i ta l ve loc ity ,

w i l l deploy automatically, and t h e spacecraft w i l l automaticallyor ien t perpendicular t o t h e Sun for solar cel l operat ion. With-out so lar c e l l power, bat te r ies would f a i l a f t e r about two hours,Two seconds a f t e r third -stag e separation , spa cecr aft booms

The high-power amplifier f o r the spacecraft t ransmitterturns on immediately a f t e r third-stage sepa rati on, sending outa wide beam signal via the spacecraft's low-gain antenna,

About 30 minutes af te r l i f t o f f , the t r ack ing s ta t ion a tJohannesburg, South Africa, ac qu ir es the spacecraft , A keytask i s t o check so la r ce l l e lec t r i c power output,r ' i r s t s i x houre, the seven scientific experiments w i l l be turnedon, one a t 8 time,During the

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A t about 14hours af te r launch, experimenters w i l l sendradio signals from Stanford's l5O-foot d i s h antenna t o t h eStanford radi o r ecei ver aboard th e spacecraft. Data w i l l re-tu rn t o Goldstone, thence t o Stanford. This process continuesthroughout the mission.During t h e f i r s t two days a f t e r launch, controllers a tGoldstone w i l l command the spacecraft t o change position untili t s high-gain antenna points precisely a t th e Earth t o maintaina strong, two-way s igna l f o r the l i f e of t h e mission.With th e DSN's 85-foot antenna, con t ro l le r s w i l l reducebps) t ohe data transmission rate from 512 b i t s per second

96 days a f t e r launch; and from 64 bps t o 16 bps about 126 daysaf ter launch, The communications l l m i t w i t h t h e @-foot antennaw i l l be reached about 156 days af ter launch with Pioneer D about52 mil l ion miles fram Earth. Without the convolutional coder,the transmission l i m i t f o r each data ra te would be reached 16t o 20 days earl ier .antenna, tracking w i l l s h i f t t o the 210-foot antenna a t Goldstone,which w i l l allow a data ra te of 64 bps. Tracking by t h i s s ta t ion ,however, w i l l have t o be shared with other deep space missions.

256 bps about 79 days a f t e r launch; from 256 bps to L4 bps about

A f t e r reaching th e l l m i t of t h e 85-foot

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T SPA85-foot ant Space Network (loca t 120-degree Earth, w i l l t raPioneer D f o r t he firsM 8 s 2lO-foot antenna a t Go1 tone, Calif,, w i l l re-

e about 200 mil l ion miles).ceive data w e l l as V I , V I I , and VIII, a l l th ee s e n s i t i v i t y o i t s components i s one tenthof one t r i l l i o nt h of a l l i o n t h watt. This means th e l i f eof th e Pioneers is as 1 as t h e i r radio and other systemslas t .The I161 i s under technical di re ct io n of th e J e t PropulsionLaboratory, Pasadena, C a l i f .Four DSPi s t a t i o n s w i l l be used for Pioneer D, Echo andrs s t a t i o n s a t Goldstone; Canberra, Austral ia ; and Madrid,Spain. The s t a t i o n a t Johannesburg, South Mrica, w i l l trackduring t h e f i r s t f e w days of the mission.For Pioneer, the D 6M stations have been equipped withspec ia l c encoders and other equipment,The DSN t r acks the spaeecraft by means of two-way Doppler.A signal i s sent from th e antennas at a precisely known frequency,and a transponder aboard th e spacecraf t re turns It a t a frequencyincreased by an exact ra t io .Earth causes both frequen cies t o s h i f t s l i g h t l y downward. Thesefrequency s h i f t s can be used to ca lcu la te th e velocity within af e w f ee t per second (despi te dis tanc es of mil lio ns of miles) p lusexact orbit and distance from Earth,

Motion of the spacecraft away from

Quick-look informatdon is transmitted from E N t a t i o n sWithin a f e w days af te r launch, c m c t i v i t i e s w i l l

t o t h e DSA1 Space Flight Opemtions Facil i ty (SPQF) a t JPL,s h i f t to Ames Research Center,

The complete tape of recorded data received a t each DSNs t a t i o n i s mailed t o the SROF fo r checking and then sent toAmes, There it 3.8 processed into separate tapes and d is t r ibutedt o experimenters, con trac tors and pr oj ec t personnel.

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NASA HeadquartersDr. John Naugle, Associate Administ rator f o r Space ScienceDonafd P. Hearth, Director, Pla net ary ProgramsGlenn A. R e i f f , Pioneer Program ManagerClarence P. Wilson, Pioneer Program EngineerDr . Alber t G. Opp, Pioneer Program ScientistIsaac T. G i l l i a m , Delta Program Manager

and Applications

Ames Research CenterH. Ju li an Allen, DirectorJohn V. Foste r, Di rector of Development (Acting)Charles F. Hall, Pioneer Project ManagerDr . John H. Wolfe, Pioneer Pro Ject S c i e n t i s tRalph W. Holtzclaw, Pioneer Spac ecra ft Systems ManagerJoseph E. Lepetich, Pioneer Experiments Systems ManagerRobert R. Nunamaker, Pioneer F l i g h t Operations ManagerMy-les D. Erickson, Pioneer Data Handling ManagerRobert U. Ho fst ett er , Pioneer Launch Vehicle and Traje cto ryAnalysis Manager

Kennedy Space CenterDr. Kurt Debus, DirectorRobert H. Gray, Ass is ta nt Dir ec to r f o r Unmanned LaunchHugh A. Weston, Jr., Chief, Delta OperationsOperations

Goddard Space , F l i g h t CenterW i l l i a m B. Schindler, Delta Project Manager

J e t Propulsion LaboratoryDr. Nicholas A. Renze tti, Pioneer Tracking and DataAlfred J. Siegmeth, Pioneer DSM ManagerAcquisition Systems Manager

TRW Systems GroupBernard J. O:Brien, Pioneer P ro je c t Manager

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-22-SPACECRAFT.SUBCON?pRACTORS

ents , f ic .Dallas, Tex.

ntecCalabasas, Calif .es Aircraf t Co.eles, C a l i f .

Ele ct ro ni c Memories, Inc.wthorne, C a l i f .Vitro ElectronicsSi lv er Spring, Bid.Solid State Products, Inc.Salem, Mass.Western StmiconductorsSanta Ana, C a l i f .

BatteriesSolar CellsSolar Cell Cover Glasses4

Mplexer and BandpassF i l t e rTrave ling Wave TubesData Storage UnitTelemetry ReceiverPhoto Silicon ControlRec t i f i e r sPhoto Silicon ControlRectifiers

Sterer ineerirlg & Manufacturing Pres sure Regulator andLos Angeles, C a l i f . Relief ValveWeston Iigdraulicsvan mys, C a l i f .Quanti tronLOS eles, C a l i f .Philco-Ford Corp.Palo A l t o , Calif.Marshall LaboratoriesTorrance, Calif

Pneumatic Solenoid ValveCoaxial SwitchMagnetameterPlasma Probe, SCAS Cosmic RayInstrument, Cosmic DustDetector

Stanford Research I n s t i t u t eMenlo Park, C a l i f . Radio Propagation DetectorHoneywell Radiation CenterLexington, Mass. Univ. of Mime Cosmic RayInstrument

Documents

Pioneer D Press Kit