echo i press kit 60-237

8/8/2019 Echo I Press Kit 60-237

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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 L E P H O N E S : D U D L EY 2 - 6 3 2 5 . E X EC U TI V E 3 - 3 2 6 0FOR RELEASE: HOLD UNTIL LAUNCH

w-/- 'PROJECT ECHOPAYLOAD AND EXPERIMENTOn todays's launch from the Atlantic Missile Range the United

States will attempt to place a 100-foot-diameter inflatable sphereinto a circular, 1000-mile-altitude orbit. Once in orbit, thelarge inflatable structure will be used as a reflector for a seriesof passive comunications satellite experiments. The sphere willbe launched by a Delta three stage rocket.

1The sphere was fabricated of DuPont Mylar Polyester film, 2mil (.OOO5 inches) thick, about half the thickness of the cellophane ona cigapette Qackage. The satellite's shell is covered with vapor-deposited aluminum to provide radio wave reflectivity of 98$, upto frequencies of 20,000 mc.

Satellite weight breakdown is: plastic sphere - 132 pounds;aluminium covering - 4 pounds; sublimating powder (to provide in-flation) - 30 pounds; two tracking beacons - 1.4 pounds. The con-tainer which carries the sphere into orbit weighs 24 pounds; theDelta third-stage casing which will follow the sphere into orbitweighs about 50 pounds.

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- 2 -The sphere will be launched in a southeasterly direction so

that the orbital plane will be inclined about 47 degrees from theequator. Traveling about 16,000 miles per hour, the satellite willcircle the Earth about once every two hours. The belt covered bythe orbiting satellite will extend 47 degrees north and south ofthe equator. During twilight and evening the sphere, when over-head, will be as visible as a zero magnitude star, about as brightas the star Vega.

Today's launching is part of a long-range program designed toinvestigate the feasibility of global communications systems usingsatellites.

One of the primary missions of the national space program isto develop the necessary technology to enable scientists to channelthe knowledge they are gaining about space and space vehicles intoareas directly benefiting mankind. One of the "practical applications"of space research is in the field of communications.

During the last few years, it has been increasingly apparentthat communications lines are- becoming overcrowded. Telephone andtelegraph lines are barely able to keep up with the demand. Futuredemands on trans-oceanic telephone cables which are alpeady carry-ing a heavy burden, will continue to grow. Worldwide TV trans-mission is still n o t a reality.

Although scientists aren't predicting the end of telephone andTV transmission as we know it today, they do think that earthsatellites will someday provide a much greater capability for globalcommunications. Experimentation in this direction will one day lead


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- 3 -to worldwide W, f o r instance,satellites might a l s o Serve as relay s t a t i o n s fop messages to and

In the years %s come9 communications

from space vehicles,The NASA's communications program is direeked toward determin-

ing the optimum systems for va~ious pplications and the technologyfrom which such systems can be engineered,passive reflector comunicatisns sysbern, in which radio signals(including voice-modulated signals) can be bounced from one painton E a r t h to another via a satellite, is the i"frs% t e p in the program,The first experiment in this Investiga%ion is Project Echo,

Investigation of' a

John R , Pierce, of Bell Telephone bbesatmories,,has beencredited with the f i r s t concrete reconmendation of the use sfartificial Earth satellites as c o m u n i e a t i o n s l inks,paper was published in 1955*tories, under c o n t r a c t to NASA, has joined w i t h t h e NASA ;e%;Propullsion Laboratory to perfom a n a $ o~ o l e in ths Echo proJe:ct,

Although P r o j e c t Echo is an experiment dfreeted by NASA, en-

H fa techrraisalAppmpriately Bell Telephone H;abc~x3a-

dependent researchers in the eosnaralrwieatSom f i e l d the W O F I ~7n3?have been invited to engage in experiments sf t h e i r own,foot sphere hasp in effect, beeoEe a wo~ldwide abg?ratory tx~l,this regard, NASA is assisting all of theas Interested exper%men%??si n the performance of their own experfme~ts y provid ing "sasaeking daCn,

The payload was developed under the d%rectiow of William J,

The 900-I n

QgSuElivan, Head of the Space Vehicles Gssoup f n the Applied Materia28and Physics Division, at NASA!s Langley Research Cewtep,satellite is made of 82 separate f l a t gorsa sf my la^ polyester ftlmpreviously covered with 8 thin coating o f vapor-deposited aluminum,

The


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- 4 -These gores a re f i t t e d a n d cemented togethex? t o Form t h e sphere.Fabr ica t ion o f the spheFe was the rexponsiSiPiSy of' G o T , Sc h je lda h lCompany, Northfield, Minnesota, The National Metal l iz ing Divis ion ofStandard Packaging Corp., Trenton, N ew J e r s ey , was r e s p o n s i b l e f o rthe aluminum covering.

Befo re l au n ch h g , ab ou t 30 pounds of sublimating powders arei n s e r t e d i n t h e sphere . IS i s t h e n fo lded accordlan-fashio9 andplaced inside a 26$-ineh-d iameter magnesium co nt ai ne r which willc a r r y i t i n t o o r b i t , (Kai ser -F lee twings , Inc , , Bristol, Pa., madet h e c o n t a i n e r , )f r e e o f a i r t o decpcase i n f l a t h n rahe at al'cl'c~.de,

Both sphere and container are pumped almsst e n t i r e l y

Two wa fer -li ke tr ac ki ng beacons, each welghing 11 ounce^^ area t t ach ed t o o p p o si t e s i d e s o f th e sphere at; i t s eq ua to r, They weredeveloped by Astro-Ele ct ronic Products Divis ion of Radio Corpora t ionof America. With a power output o f about 10 mw, each w i l l transmiton the same frequency -- e i t h e r 107,,97e OF lS7.9b mc dependingwhich of two payloads i s used, Each beacon, about PO %riches i ndiameter and 3/8-inch thick, i s equipped w i t h 70 sslar c e l l anickel-cadmium storage b a t t e r i e s A small whip a n t e n n a , coi led i .n 'a8 s p i r a l groove i n each beacon, will s p r i n g ouk; from th e s fCe o f &.esphere when i t i n f l a t e s ,

five

The t h i r d stage of the D e l t a vehicle is equipped with atelemetry package. The t h i rd - s t ag e cas i n g w i l l fo l low t h e s a t e l l i t ec l o s e l y d u r i n g the f i r s t few o r b i t s , a n d i t s s i g n a l s (lQ8,064 ne)w i l l as s i s t i n determining the sphe re ' s i n i t i a l ~ r b i t . The t e l emet rywill also show payload separat ion from t h i r d stage which should O C C X Ps h o r t l y a f t e r i n j e c t i o n i n t o m b i t 0

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- 5 -About two minutes after the payload is injected into orbit,

the magnesium container will be split open by an explosive chargeplaced around its middle. The inflatable sphere is released fromits container and gradually begins to inflate with the expansionof the small mo unt of residual air left inside,sublimating powders cause additional inflation: 10 pounds of benzoicacid provide the initial expansion and 20 pounds of anthraqufnoneprovide fo r sustained inflation.

Thirty pounds of

There are two primary stations taking part in the Projec%Echo communications experiment:: ell Telephone Laboratories! f a c i l i t yat Holmdel, New Jerseyl and the NASA-Jet Propulsion Laboratory'sGoldstone station %n California. Radio signals will be bounced be-tween the East and West Coasts of the U,S. via the orbiting satellite,

Following establishment of accurate orbit by beacon, radardand optical tracking, voice modulation transmission will be attemptedusing frequency modulation (FM) techniques

During the experiment, BTL will transmit on a frequency of960 m:/s for reception at Goldstone,signal t o BTE on the East Coast,two 85- fo~ t-d ime te~araboloid antennas -- one a receiver and theother a transm%$ter, BTL will transmit with a 60-foot dish and willreceive with a. special horn-reflector antenna,looks generally like the scoop of a s t e m shoveld f a a recent develop-ment designed to cut down radio noise interference,

JPL will transmit a 2390 meisEquipment at Goldstone includes

This antenna, which

Since JPL is a primary souce of tracking, NASA will n o t try 8communications experiment until a good orbit has been establfshed.


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- 6 -Once accurate orbital elements have been obtained, signals will bebounced tetween the East and West Coasts,

Communications equipments of both JPL and BTL have been exer-cised by bouncing signals between them via the moon and the Tiros Imeteorological satellite.

Here is a description of the operations involved in thecommunications experiment:

The NASA Goddard Space Flight Computing Center will send orbitalcalculations to JPL and BTL, These orbital data will be used toposition the receiving and transmitting equipment. The transmittingantenna is "slaved" to the receiving antenna at each site so thatthe satellite will be "illuminated" by radio waves. Following ac-quisition at Goldstone, its transmitter and receiver can be used asa self-tracking radar system. An optical boresight system which canbe used when visibility conditions exist will assist the trackers insatellite acquisition,

To set up a communication link, BTL will illuminate the spherewith a 960 mc/s signal,in all directions. A portion of the scattered energy will be piekedup by the Goldstone station where the receiver is pointed toward the

This signal will bounce off the satellite

satellite. To complete the communication link, Goldstone willtransmit in the same manner a 2390 mc/s signal for reception at BTL.Transmitted power will average about 10 kw,

The time of mutual visibility between the East and West Coa s t sfor any one pass of the sphere is not expected to exceed 16 minutes,

Among others, the U.S. Naval Research Laboratory will cooperatein the experiment by attempting to receive signals from JPL at its

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- 7 -facility at Stump Neck, Md., and in addition will attempt t o transmitt o BTL.

The sphere will be in continuous sunlight for about two weeks,After this time, the satellite's orbit and the Earth's rotationaround the sun will be such that the sphere will be in the EarthPsshadow.

Sunlight plays an important part in maintaining the spherelsshape,slightly above freezing. Unless in sunlight, the temperature ofthe satellite will be well below freezing.the sphere's temperature will average about 239 degrees F,

The sublimating powders turn into gas at temperatures

In continuous sunlight

Once out of sunlight, gases used to keep the satellite inflatedw i l l return to a solid state. Scientists are interested bo learn ifand. in what form the satellite will re-inflate when returning tosunlight. There is a question as to the amount of sublimating powdersremaining after two weeks.ever punctures exist from micrometeorites. Unless the satellitereturns to its spherical shape, it will not be useful f o r communi-cations experiments because of the non-uniformity of reflectedsignals from a misshapen surface.

Some will have seeped out through what-

The internal satellite pressure at altitude will be about.00004 pounds per square inch,pressure is at least 25,000 times the pressure due to solar radiationand air drag.

Scientists estimate that this

The Echo satellite, with a surface of about 31,000 square feet,is a large, lightweight structure as opposed to the Earth satelliteswith higher densities which have been launched before. The effects


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- 8 -of air drag and solar radiation on a three-foot metal payloadof the same weigh6 as Echo would be negligible, These forceswill, however, influence the velocity and orbit of the 100-footsphere, Scientists will be interested to find out how much,This can be done by comparing orbital data of the sphere withthe Delta third-stage casing.

What effect will micrometeorite impact have on the sphere?Scientists predict that under expected conditions the spherew i l l remain physically usable as a reflector for at least aweek, A week's lifetime would be extremely valuable to thecommunications experimenters. Despite a number of spaceexperiments concerning micrometeorite impact, the status oftechnical knowledge of their number, size, energy, and sizeof hole they produce is in an early stage of evolution. TheEcho experiment should add t o the fund of knowledge nowbuilding on the subject,

The first attempt to orbit the 100-foot inflatable sphere,May 13, 1960, was not successful due to a malfunction in thelaunching vehicle. However, the sphere has undergone a numberof pre-orbital flight tests under the supervision of theLangley Research CenSer, General Mills, Inc,, Minneapolis,Minn., took part in the initial development of this type ofinflatable structure, These suborbital launches from NASA'sWallops Station on Virginia's eastern shore began October 28,1959. These shots were used to test the inflation and ejectiontechniques of the Echo sphere, This type of testing is part of a

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- 9 -NASA program aimed a t research on advanced in f la tab le spaces t r u c t u r e s ,

I n addi t ion t o the suborb i ta l shot , l as t October i n which th esphere a t ta ined a n a l t i t u d e of 250 miles and distance out over theAt lan t i c of 500 miles, ot he r launches were: January 16, up 250miles and out 490 miles; February 27, up 225 miles and out 540miles; A p r i l 1, up 200 miles and out 570 mil es; May 31, up 210miles and out 540 miles.

Leonard Jaffe i s NASA's Chief o f Communications SatellitePrograms.i s Echo Project Manager,Laboratories i s W i l l i a m Jakes.f o r th e J e t Propulsion Laboratory.

Robert J. Mackey, J r , NASA's Goddard Space Flight Center,Echo Project director for Bell Telephone

W. K. Victor i s pro jec t d i r ec to r

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No. 28/69J&JyCE ;T,yz:m

This i s the second launch of tke Sel-tn -~rehic:ie. !-3x4--.+_--2 * 7 r % -VCl,.> 83unsuccessful attempt t o lau ich a 100-foot i n f k t a b l e sphere May 13, 1960.

The DougJ..as Aircraf t Conpaay7 Ix tc:.Lz;r cs~


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- 2 -the second stage.a thrust of approximately l 5 O , O O O poiu?d.s e

The f i r s t stage weighs about 100,000 pomds fueled and hasIt i s propel led by liquid oxyge-3

and kerosene.The second stage i s an Aercjet-General AJl0-118 l iquid engihie which

was modified from the aecorid s t w e of Vasgpzd arm2 Thor-Able vehicles. IC,weighs more thar? 4,000 pounds and develops a thrust of about 7,500 poup1d.s.The stage, paclraget?. by Dougles, a l s o corbaiss a pidance compartment forthe Bell Teleplnoiw 2abo::atories rad io gaidance system. Co-contractor withBell f o r the grcidmce systen i s Rerni-w>oxEand UnSvac of St. Paul, K i m .

ThePCh i r d stage i s ari A-llegany Sallis-tics Laboratory ABL-248 so l i dpropellaxt rocket a l s o origiiiated fo r the Y m g a r d and TS?or--ilble 1% weighsmore than 500 pounds3,000 pounds.

including p ropellant end produces a thrust of aboutI n the stage, a l s o b u i l t by rhuglds, the ~ ~ ~ - 2 4 8otor is

mounted on a sp in t ab le .I n the f i r i n g sequence, the %or f i r s t stage provides about 160

seconds of powered flight during which the rocket i s gJic2ed by the BellTelephone Laboratories Guibnce Systerr. art?,roll and pitch programmers.A t burnout of t h e Thor, it separates and see-ei-iters the atmosphere.

The second s tage ign i tes a lmost imel l ia te ly a f t er f i r s t s tageAfter 20 seconds of powered f l i g h t the nose fai r ing whichut-off .

protected the payload and third stage during launch i s j e t t i soned .The second sta ge fi r e s for about 1.15 seeonas a l s o being s-teeredby theBTL guidance system.

After the second stage i s com nde d of f , t he veh ic le coas ts f o rabout 15 minutes with the second stage s t i l l at tached. During t h i s period,the vehicle and payload coasts some 800 miles up into spaxe and about

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- 3 -I t s a t t i t u d e i s cofitrolled during c o a s t .300 miles down range.

After coEst, i n rapid sequence, the th ir d stage i s s y m up t o 120 spmby small sp in rocket s t o s t ab i l i z e i t s f l i g h t , the th i rd s t age ign i t es , andthe second stage i s separated by explosive bo lt s.about 11.0seconds achieving orbital veloci ty aC' bout 16,000 miles per hour.

The t h i r d s t age f i r e s f o r

After th ir d stage burnout , de-spin rockets s l o w the rot at io n. Theempty third stage casing, weighing abcu-b 50 pounds, i s separatekl from thepaylced by a s p r i n ~ hich r e t a r d s i t s veloci ty and i s tumbled by a l a t e r a lrocket so it w i l l not i nte rf er e with the payload.

A telemetry transmitter weighing 15 pouszds i s mounted on an instrumentrack 01: op of t he third stage motor just below the payload separation band.Four poles of th e t u r n s ti le antenna ar e folded down over the t h i r d sta ge motoru n t i l t he f a i r i n g i s j e t t i soned .

The transmitter w i l l operate a t a frequency of 108.06 /lC continuouslyf o r two or three days s o that the thi rd s tage casing can be t racked.power i s 300 milliwatts.near enough t o th e in fl a te d sphere long enough t o assis t i n determiningaccura te o rb i t a l data on the sphere.

I t sThe th i r d stage i s expected t o remain i n o rb i t

i W A Headquarters Delta Project Manager i s Vincent L . Johnson.W i l l i a m Schindler i s the Del ta technical di rector a t the Goddard SpaceFl ight Center .Elissile Range i s Robert Gray.

Head of Goddard's Fi el d Pr oj ec ts Branch a t t he At l an t i c

Horace Irwin i s the Delta project engineer a t Douglas Aircraf t i nSanta Monica, Calif. Douglas manager a t AMEl i s B i l l E. S t i t t .

-END-

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No. 38/60PROJECT ECHO

TRACKINGTracking during the Project Echo experiment is under the over-

a l l direct ion of NASA's Goddard Space Flight Center.f o r th e NASA experiment w i l l be provided by:st at io n, Cape Canaveral, Fla .; th e A i r Force 's radar t e s t s i t e i n T rin id ad ,B.W.I., operated by the Rome (New York) A i r Development Center; the NASA-J e t Propulsion Laboratory's Goldstone st at io n, Camp Irwin, Ca li f. ; LincolnLaboratory's Millstone H i l l radar station, Westford, Mass.; NASA's Minitracknetwork; and op ti ca l t rackin g sta t io ns operated fo r NASA by the SmithsonianAst rop hys ica l Observatory, Cambridge, Mass.

Tracking servicesB e l l Telephone Laboratories'

BTL's guidance radar a t Canaveral w i l l prov ide i n i t i a l t r a j ec t o ryDuring th e launch phase, Minitrack st a ti o ns a t Ft. Myers, Fla.,ata.

Antigua, B.W.I., and the down-range station a t Ascension, U.K. , w i l l t r ackthe Delta third-stage which carries a beacon transmitting on 108.06 mcwith a power output of 60 mw.After payload separation, Trinidad w i l l "skin track" the payload by radart o observe i nf la t i on of t he 100-foot sphere.tra ns mi tte d t o Goddard's Computing Center f o r a rough determination of thes ph er e' s i n i t i a l o r b i t .s ent ou t t o t h e o the r s t a ti ons taking par t i n the Echo projec t .

Trinidad w i l l a l so t rack the th i rd s t age .

Tracking data w i l l be

These orbital computations w i l l m e d i a t e l y be

Goldstone and Millstone w i l l radar and beacon track the sphere whenit comes within contact.

The Minitrack stat ions w i l l t ra ck th e beacons ca rr ied by the sphere,Since thend the instrumented Delta t h i rd s t age as long as it t ransmits.

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- 2 -th i rd-stage casing w i l l follow closely behind the 100-foot sa te l l i t e duringt h e i n i t i a l o rb i t s, t ra c ki ng data f rom t hese s t a t i ons w i l l be use fu l i ndetermining th e Echo sphere's o rb it . Minitrack st at io ns are located a t :Antigua, B.W.I.; Antofagasta, Chile; Blossom Point, M d . ; Li m a , Peru;Quito, Equador; Santiago, Chile; Woomera, Australia; Johannesburg, SouthAfrica; San Diego, Calif .; and Fo rt Meyers, Fl a.

Optica l tra cki ng fig ur es importantly in the experiment. TheSmithsonian operates 12 st at i on s equipped with s a t e l l i t e t r ackin g Baker-Nunn cameras. These are located a t : Organ Pass, N .M . ; Olifantsfontein,South Af ric a; Woomera, Aust ra li a; San Fernando, Spain; Tokyo, Japan;Naini T a l , India; Arequipa, Peru; Shiras, Iran; Curacao, N.W.I. ; upi t e r ,F l a . ; V i l l a Dolores, Argentina; and Maui, H a w a i i . I n addit ion , 45l'Moonwatchll teams around th e world, composed of amateur opt i ca l t rackersrep orti ng t o th e Smithsonian Astrophysical Observatory, w i l l assist i nt racking.

Data from all t rack ing s t a t ions w i l l be tr ans mit ted t o Goddardwhere the sphere's orbi t w i l l be continually re-evaluated.Computing Center w i l l send current orbi ta l data t o a l l s t a t ions t akingpa r t i n t he p ro j ect .

Goddard's

A nuniber of independent groups ar e expected t o tr ac k the sphereThe Goddardn connection with t h e ir own communications experiments.

Space Flight Center w i l l provide these independent experimenters orbitalinformation as soon as it i s acc ura tely determined.- END -

echo i press kit 60-237

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