ionosphere beacon satellite s-45 press kit 052161

8/8/2019 Ionosphere Beacon Satellite S-45 Press Kit 052161

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N E W S 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 IN G T O N 2 5 , D. C .T E L E PH O N E S: D U D LE Y 2 - 6 3 2 5 . E X EC U TI V E 3 - 3 2 6 0FOR RELEASE: Sunday AM'SMay 21, 1961

NASA WILL LAUNCH IONOSPHERE BEACON SATELLITEA second at tempt w i l l soon be made by NASA t o laun chfrom Cape Canaveral an ionosphere beacon s a t e l l i t e (S-45)on the l a s t of the J U N O I1 r o c k e t s e r i e s .

i n many par ts of th e world are p a r t i c ip a t i n g i n t h i sexperiment, intending t o f in d out more about t he shapeof the- ionosphere -- where t h e r e are concent ra t ions o fe l e c t r ons , where t he i onosphere' s p r o f i l e has peaks o rv a l l e y s i n i t s s t r u c t u r e .

Near ly fo r t y un iv er s i t i es and government l a bo ra tor ie s 5

So f a r , too l i t t l e i s known about t h e ionosphere,which i s t h e i on i zed po r t i o n of th e e a r th ' s upperatmosphere. The ionosphere extends from 30 t o manythousands of m i l e s about the ear th . Lack of t h i sknowledge i s c o s t l y i n p r a c t i c a l a p p l ic a t i o n s, suc h aslong-range communications, which depend upon r e l i a b l ybouncing s ignals o f f ionosphere l ayers .The new payload being prepared f o r o r b i t i s c a l l e d

th e Ipnosphere Beacon S a t e l l i t e S-45a. I t looks verymuch l i k e Explorer V I 1 and Explorer V I I I , two truncatedcones back t o back. The S-45a, however, has a 6-footloop antenna around i t s e q ua t or t o t r a n s m i t i t s lowerf requency s igna l s t o g round s t a t i o ns ,Unlike Explorer V I I I , t h i s 75-pound sa t e l l i t e w i l ln o t b e an experiment i n i t s e l f , Explorer V I 1 1 c a r r i e dins t rum enta t io n fo r d i r ec t measurements o f t h e p o s i t i v eion and e l ec t ro n concen tra t i ons i n i t s o r b i t a l p a t haround the ear th . The new s a t e l l i t e w i l l t ransmi t ons i x freque ncies (approximately 20 mc, 40 mc, 41 mc,108 me, 360 me and 960 mc). Ground s t a t i o n s re ce iv ing

t h e s e s i g n a l s w i l l analyze them by v a r i o u s methodssuch as change i n po la r iz a t io n and Doppler sh i f t t od e t e r n i n e c h a r a c t e r i s t i c s of t h e ionosphere. Thes a t e l l i t e i s expected t o o r b i t t h e ear th every ll5 minutesw i t h an apogee of ab out 1,600 miles and a per igee of about240 m i les ,


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The IonomhereUntil the beginning of space exploration, very littleindeed was known about the ionosphere. Until the adventof radio broadcasting, a generation ago, no one had,seriously investigated the ionosphere at all. Sincemeasurements were necessarily made from the ground,much ionospheric theory developed before the age ofrocketry has since proven to be erroneous.

amount of data about the ionosphere. Many miles ofmagnetic tape have been analyzed to date. This hasresulted in findings that have led to better methodsin ionospheric research. Yet the surface of space,so to speak, has scarcely been scratched. When theobject is to map the whole ionosphere, its contentfrom region to region about the earth, and its profilefor hundreds of miles into space, there must be agreat deal of research.

United States rocketry has produced a tremendous

Rocket measurements have revealed the cause ofradio blackouts in high latitudes and crude means ofpredicting them have been devised. These flightshave brought about an explanation for the inexactnessof previous methods for predicting maximum usablefrequencies for long-range communications circuits.Rocket-gathered data have revealed serious errorsmade in the past in the interpretation of data obtainedby ground stations. This has stimulated the developmentof more accurate analysis of these data by modernelectronic computers.Experiments must continue where unexplainablephenomena are revealed, A good example is a costly

NASA tracking station at Lima, Peru, which has beenopkating on a frequency of 108 megacycles.the signals fluctuate and this station cannot getaccurate tracking data. A t another station at EastGrand Forks, Minn., signals vary greatly wheneversatellites pass to the north after a severe disturbanceon the sun.

At times,

There is so far no completely satisfactoryexplanation for these phenomena. When there is one,it appears, it will be the result of cientificof the Ionospherd Beacon Satellite.investigations such as those conducte \with the help

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New Zealand ExperimentOne example of the benefits which may be expected fromgreater knowledge of the ionosphere relates to New Zealand.The two-island dominion is remote from Europe and America.Radio communications between these continents and NewZealand are vital, and unfortunately frequently besetwith costly radio signal interference.New Zealand's Seagrove Radio Research Station is oneof the participants in the S-45 experiment.of the Physics Department of the Unlversfty of Auckland.

s-45 Program ParticipantsIt is part

Others participating are: Pennsylvania State University,University Park, Pa.; University of Illinois, Urbana, Ill.;Central Radio Propagation Laboratory of the National Bureauof Standards, Bsulder, Colo.; and Stanford University,Stanford, Calif.A part-time observing site has been s e t up at BakerLake, Canadian Northwest Territories by the University ofIllinois. Stanford University has set up a station atthe University of Hawaii.has established an equatorial recording station near themagnetic equator at Huancayo, Peru.

of NASA's Goddard Space Flight Center. J. Carl Seddon isthe Goddard manager. Tracking, after the initial "quicklook," will also be a responsibility of Goddard throughits world-wide Minitrack network.The first "quick look" at data t o determine whetherthe vehicle is performing well and whether the satelliteis. going into the desired orbit will be done by the NASAMarshall Space Flight Center.

The Pennsylvania State University

Coordination and data reduction is the responsibility

The Marshall Center designed the payload, the firststage booster, and is responsible for the launch vehicle.Bill Greever is the Marshall manager.The launch vehicle chosen for this experiment to belaunched from Cape Canaveral is the Juno 11, the 60-tonfour-stage rocket used before in eight launch attempts,including the Pioneer 1x1 and Pioneer IV radiation space

probes, t h e Explorer V I 1 radiation satellite, theExplorer VI11 ionosphere satellite, and the Explorer XIGamma Ray Astronomy Satellite.modified Jupiter first stage.were designed by the Jet Propulsion Laboratory.Marshall designed theThe upper three stages

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If t h e S-45 goes succ es s fu l l y i n to orbit, it w i l lb e assigned an Explorer name and number to indicatet h a t i t has joined more than 4 0 o th e r Un it ed S t a t e ss a t e l l i t e s which have co nt ri bu te d much t o t h e world ' sknowledge of t h e space environment.

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FACTS ABOUT T E IONOSPHERE BEACON SATELLITE (S -45 )The 53-45 satellite configuration is similar tothose of Explorer V I 1 and VIII, It is in the form oftwo truncated cones, the bases of which are attachedto a cylindrical band, or equator. The satellitestructure is 30 inches in diameter, identical in thisrespect to the earlier payloads; the height is 24 inches,six inches less than formerly,The outer shell is constructed of aluminum. Thefourth stage motor case, after burnout, will separatefrom the satellite.The instmentation consists of the followingitems:1. Transmitter -- A single transmitter is used to

broadcast radio signals on six different frequencies atvarying levels of power. This is the largest number offrequencies to be used by any satellite to date. Thebasic oscillator frequency is 1.000255 megacycles persecond; the transmitting frequencies are six harmonics(multiples) of this basic crystal frequency, rangingfrom 20 to 960 megacyeles. The radiated frequenciesare as follows:Harmonic Frequency Est. Transmitter Output Est. RadiatedPower-

0 20,0051 mc40 40.010241 41,01045108 108,02754360 , 918960 e 2448360960

300 mw10010020loo10

160 mw40402010010

By meaBuring a, ground receiving swations thechange in polarization or the Doppler shift of thesignals, it will be possible to determine the ionosphereelectron content between the station and the satellite.The s ix frequencies are developed from a 1.000255mc. quartz crystal oscillator, These frequencies are

made t o be extremely stable by a unique heat f i l t e rsurrounding the crystal which eliminates alternatingchanges in the crystal temperature as the satellite- 5 -


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passes from sunlight into earth's shadow. The trans-mitter is also unique in that it employs high-efficiencycapacity diode harmonic generators and transistoramplifiers t o o b t a i n an overall power efficiency of 35percent.2, Telemetry and Power Supply --a, Telemetering will be done on the 108 mcfrequency.be transmitted. They are: temperature, 7 channels;satellite aspect, 2; voltage of exposed solar cells, 2;voltage of main power supply, 1; calibration, 2.

A total of 14 channels of information will

b. The power supply will consist of both solarcells and nickel cadmium batteries t o operate the pay-load continuously up t o about 13 months, when anautomatic timer is scheduled t o cut off the transmitterto make the frequencies available for other purposes.Four packs of rechargeable ni-cad batteries are locatedat 90 degrees apart on the equator of the satellite.The solar cell arrangement, on both the lower and uppercones of the payload, covers a total o f 4665.6 squarecentimeters (2592 cells). The solar cells are coveredindividually with a sheet o f silicon glass, .0006 o fan inch thick, t o protect them from radiation. Nominaloutput of the main power supply is 15.4 volts.

c. Two additional patches of identical unprotectedsolar cells are mounted on the center band of the satellitein two planes 45 degrees apart and 22.5 degrees respec-tively from the tangent plane of the satellite equator.The patches consist of' 10 cells wired in series with atotal patch output of 3-1/2 volts. As the satelliteorbits, the reduction of the voltage output will in-dicate the extent of dama e to the uncovered cells dueto radiation,the patches will also double as an aspect sensor whenthe voltages of the two patches are compared to theknown value which results from the sun's striking thesurfaces at a 90 degree angle.

Placed at 85 degree angles to each other,

d. Aspect Sensor -- While the exposed solar cellpatches (above) serve as a backup or spare indicator ofsatellite aspect, the payload incorporates a specificaspect sensor, that is, an instrument t o determine thesatellite's orientation with respect t o sources oflight. The aspect system, located on the payload'sequator, uses two photodiodes, one sensitive to thesun's rays and the other to the earth's albedo, orreflected light.


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e . Temperature, -- Seven temperature sensorsare inc luded i n t h e payload, i n th e fo l lowing loca t ions :Two on protec ted so la r c e l l s , one on exposed so l a r ce l l ,one i n a ba t t e ry pack, two i n th e t ransm i t te r , and oneon t h e equator of the s a t e l l i t e . Thus, fou r ex te rn alo r s k i n measurements and th re e in te rn a l measurementsare provided.f . Antenna -- Two a n t e n n a s are i n s t a l l e d on t h es a t e l l i t e , both of which were developed by the MarshallCenter , and are be ing used for th e f i r s t t i m e . A loopantenna, s ix f e e t i n diameter, extends from t h e s a t e l l i t eequator soon a f t e r t h e f o u r t h stage rocke t case i sseparated. I t i s h e l d i n p lace by cen t r i fuga l fo rce .The loop antenna radia tes t h e 20, 40 and 41 mc fr eq ue nc ie s.The second i s a sp ik e antenn a, 19-3/4 inc he s i n l e ng th ,which i s mounted i n f r o n t o f t h e s a t e l l i t e a l o n g t h e s p i naxis. The 108, 360 and 960 mc s i g n a l s are t r a n s m i t t e dfrom i t .g. Payload Weight - - The weight of the payload i sas follows:

Ionosphere beacon antenna assemblyUpper cone assembly 11.1L o w e r cone assembly 10.2Center r i n g 12.7S h e l l assembly 6,1Instrument column 16 .4Sk g a r a t i o n device 3.0Battery packs (four) 6.5Wiring 2.7Fasteners 3.0Balance weights .6

2.7 pounds

T o t a l 75.0 pounds


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S-45 TRACKING AND DATA ACQUISITIONThe Goddard Space Flight Center World-Wide MinitrackSystem i s r e s p o ns i b l e f o r t r a c k i n g t h e Ionosphere BeaconS a t e l l i t e S-45, us ing t h e 108 mc beacon freq uen cy du rin g

i t s a c t i v e l i f e - t ime of approximate ly thir teen months.M i n i t r a c k s t a t i o n s l o c a t e d a t Woomera, Australia;Johannesburg, South Africa; Santia go, C h i l e ; Antofagasta,Chile ; Lima, Peru; Q ui to , Ecuador; Antigua, B r i t i s h WestIn di es ; San Diego, Cal ifor nia ; F t . Myers, Fl or id a; andBlossom Point, Maryland w i l l p a r t i c i p a t e u s in g i n t e r f e ro m e t e rt rack ing techniques . The Wink field, England and E a s t GrandForks, Minnesota Mini track s ta t ions w i l l be used f o r t e l e m e t rya c qu i s i t io n pu rpose s on ly .

During the launch and ea r l y or b i t phases (de f ined asextending from l i f t -o ff , through power f l i g h t , and f o r t h ef i r s t t h r e e s a t e l l i t e o r b i t s ) a d d i t i o n a l " q u i c k l o o k "t r a c k i n g data w i l l be supp l i e d by t h e Marshall Space F l igh tCenter Doppler Sta t ion, Huntsvi l le , Alabama; t h e ARGMADoppler Station, Redstone Arsenal, Alabama; The MarshallSpace Fl ight Center Doppler Sta t ion a t Cape Canaveral,F lo r id a ; the Goddard Space F l ig h t Cente r Mini t rack S t a t io na t Cape Canaveral, Florida; t h e Goddard Space F l i g h t Centerpo r t a b le Dopp le r s t a t ions a t Atlant ic , North Carol ina;Paynters H i l l , Bermuda; and Van Buren Maine; th e GoddardSpace F l i g h t Cente r Mini t rack S ta t ions a t Blossom Point,Maryland; Johannesburg , Sou th Af ri ca ; and Woomera,A u s t r a l i a ; t h e B a l l i s t i c s Research Laboratories DopplerS t a t i o n a t Aberdeen, Maryland; t h e F o r t Monmouth, NewJersey Dopple r S ta t ion ; t h e J e t Propulsion LaboratoryDoppler Sta t ion a t Cape Irwin, Ca li fo rn ia ; t h e MassachusettsIn s t i t u t e of Technology Lincoln Labora tor ies Mi l l s tone H i l lRadar S t a t i o n a t Westford, M assachusetts, and th e J o d r el lBan k , England, r ad io te l esc ope .

The "quick look" t racking data obta i ned by th e aboves t a t i o n s w i l l b e t r a n s m i t t e d as soon as p o s s i b l e v i ae l e c t r i c a l means t o t h e Marshall Space F l i g h t Center wherei t w i l l b e quick ly e va lua t ed and used i n de te rmining t h eJuno I1 ve hi c le performance, in je c t io n parameters , andi n i t i a l o r b i t a l e lements. The "quick look" data w i l la l s o be t r a n s m i t t e d t o Goddard Space Flight Center whereit w i l l be used, along w i t h t h e Mini t r ac k Di r e c t ionCosine Data, t o determine a more precise s e t o f o r b i t a lelements and t o compute predic ted t racking and te lemetrys t a t i o n a c q u i s i t i o n times.

The s a t e l l i t e w i l l t r a nsm i t s i x f r e que nc ie s which w i l la l low experimenters a l l over the ea r th t o pu rsue ionospher i cs t ud ie s by ground based observa t ion of t h e s a t e l l i t e s i gn a l s .

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The principal experimenters and their observing stationlocations are as listed below:Mr. Fernandez de MendoncaRadio Science LaboratoryStanford UniversityStanford, CaliforniaD r . J. E. TitheridgeUniversity of AucklandAuckland, New ZealandM r . Robert S. LawrenceNational Bureau of StandardsCentral Radio Propagation LaboratoryBoulder, ColoradoD r . G. W. SwensonDepartment of ElectricalEngineeringUniversity of IllinoisUrbana, Illinois

,Dr. W. J. RossThe Ionosphere Research LaboratoryPennsylvania State universityUniversity Park, PennsylvaniaThe University of Illinois, Pennsylvania State University,and Stanford University also have substations which arelocated in South America, Hawaii, and Canada.It is the responsibility of each of the above experimentersto publish the results of his research in technical journalsand/or scientific reports.

tracking and for telemetering satellite aspect and environ-mental data. Telemetered data will be received by theGoddard Space Flight Center Minitrack Stations and theMarshall Space Flight Center Station at Huntsville, Alabama.This data will be analyzed by both Goddard and Marshalland, the results forwarded to the participating experimentersfor use in their respective research.

The 108 mc satellite beacon signal will be used for both

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. I

JUNO I1 FACT SmET1st Stage

2nd Stage

2rd Stage4 t h Stage

Shroud -Guidance

Height ofWeight -Speed (a t

Modif ied Jup i te r .t anks extended t h r e e f e e t to g a i n 20 secondsburning time. Fuel - LOX and kerosene.Modif icat ion by Marshall SFC. Engine b u i l tby Rocketdyne Division of North American Aviation.

B o o s t e r s e c t i o n a nd p r o p e l l a n t

Clus t e r of e l even so l i d p ro pe l l an t m otor s,f i t t e d in to spin tub mounted on f i r s t s t a g e .C l u s t e r of t h r e e s o l i d r o c ke t s .S ing l e solid r o c k e t . (Three upper s t agesor ig ina l ly developed by JP L f o r J u p i te r C(Composite Reentry T e s t Vehic l e ) Bu i l t byCooper Development Corp., Monrovia, C a l i f . )Over upper stages and payload.S t a b i l i z e d p l at fo r m i n b o o s t e r i s "space-f ixed"on t a rg e t . Dev ia t ions from a t t i t u d e s ensed bys e n s o r s and a l t e r e d by swive l l i ng t h e r o c k e tn o z z l e . B u i l t by Ford Instrument Co.

r o c k e t - About 76 f e e t .60 t ons a t l i f t o f f .

burnout of f i r s t s t a g e ) - 11,000 m i les pe r hou r .T o t a l f l i g h t t im e (L i f t o f f t o o r b i t ) - About ei g ht minutes.I n c l i n a t i o n - 50 degrees t o t he equa to r .Apogee - About 1,600 miles .Perigee - About 240 miles .Per iod - About 116 minutes.F l i g h t p rocedu re - F i r s t s t a g e b u rn s o u t i n a bo u t t h r e eminutes. A t burnout rocket i s t i l t e di n t o t r a j e c t o ry angle . Boosterse pa ra te s from ins t ru ment compartmenti n a few seconds by expl osive b ol ts .Ret rograde rocket s slow f i r s t s tage.

Upper s t ages coas t be fo re sh roud i se j e c t e d by exp los ive bo l t s and shun tedas ide by a kick rock et . Second stagei g n i t e s a f t e r f i ve m inu tes . T h i r d andTwo minutes a f t e r f o u r t h s t a g e b o o st s pay-l o a d v e l o c i t y t o d e s i r e d l e v e l , t h e burned-out motor ca se i s sepa ra t ed and t h e loopantenna i s extended.

f o u r t h s t a g e s a r e f i r e d i n q u ic k s u cc es si on .

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ionosphere beacon satellite s-45 press kit 052161

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