Echo II Press Kit

8/8/2019 Echo II Press Kit

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30/NEVWS RELEASENATIONAL AERONAUTICS AND SPACE ADMINISTRATION400 MARYLAND AVENUE, SW , WASHINGTON, D. C. 20546TELEPHONES: WORTH 2-4155 ----- WORTH3-6925FOR RELEASE: P.M.'s TuesdayJanuary 21, 1964

RELEASE NO: 64-li

NASA TO LAUNCH SECOND ECHO COD4EMTICATIONS SATELLITE

Another Echo passive communications satellite will belaunched by the National Aeronautics and Space Administrationno earlier than January 23.

The 135-foot diameter balloon will be injected into a800-mile-high circular, near-polar orbit at an inclinationof 82 degrees by a Thor-Agena launch vehicle from VandenburgAir Force Base, Pacific Missile Range, Calif. Without acces-


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continued as a cheniicaliin-,de Echo changrs nto gas, fullyexpanding the balloon. anpnister opSng and inflation wisllbe witnassecd by scientists iJn Pretoria, South Africa. via atelevi. ion srst-er.' mounted on the Agena rocket.

The spacecraft is desigi-ed to perm-Lit co-nduWcti.on o'f passivesatellite corinun-.cat:ons ',;:pcriments (radio, tbelet-ype andfacsimnie) as well a.. to accumulate data about the spacecraft'sorbital environ-nent. It is designed to be rigid enough towithstand the stresses of space and rem-ain spherical withoutcollapsing after the in-flating gas has leaked out.

Echo C is expected to show whether such a satellite willstay spherical as long as it is in orbit. Ii it does, it willprovide a large and unchanging reflecting surface, long life-timc and multiple access (many tranumi;3:s.`on"s from differentground stations at the sams time). In addition, unlike active


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-3-The spacecraft was built b- the G. T. Schieldahl Co.,NIorthfield, Minn.; the inflation system by GeophysicA4Corporation of America, Viron Division, Anoka, I'inn.; thecanister by Grumman Aircraft Engineering Co., ]3sthpagea ,.Y.;the TV system by Hallamore Electronics Division of the 2-eglerCorp., Anaheim, Calif.; and the beacons by Aero Geo AstroCorp., Alexandria, Va.

The tfhor-Agena B launch vehicle is built by the.DouglasAircraft Co. (Thor), Santa Monica, Calif. and the LockheedMissile and Space Co. (Agena), Sunnyvale, Calif. Launch isby the U.S. Air Force 6595th Aerospace rest %ling under thedirection of GSFC's Field Projects Branch. Vehicle systemsmanagement is under NASA's Lewis Research Center, Cleveland,Ohio.

On its first orbit, Echo C will not be visible to most


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moving satellite 800 miles above the dark Earth below.Tfhis occurs at dawn or dusk.

Precise orbital elements and visibility predictions maynot be available for several days after launch becauseinitial efforts of tracking experts must go into computingpointing data (the precise direction from a ground location tothe satellite) for experimenters.

Among the experimenters are the Collins Radio Co., Dallas,Tex., under contract to GSFC; the Naval Research Laboratory,Washington, D.C.; and the Naval Electronics Laboratory, SanDfego, Calif.

As in the case of Echo I, still in orbit, still visibleand still partly effective as a radiowave reflector, the newEcho is expected to be seen by more persons than any otherman-made object in the historyr of the world.


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1i th tho i: ->-3onr;tom to be te.ted on this flight,the 135- foo' -:lherc *.zfl utili-ze a ;l.o rer more controlle7tin-la'A;ng r.et'hod t:h.ch ril' take about 0 min.ute- to comnplet.TPhts wj.ll allo-i t.hs zatoll':te to hold muchhi . essurezandc w-i.th slo'!S :.tiOl thc-re 'ff.ll -lot ob az:im'ch cfhance aspre-i.ously fo- uttr n too much stress too fat on the thinskin, thus cautirnag it to bur:;t. The slhin lz made of Mylarplastie .00035 inche7, thick with .00018 inch thick aluninumalloy foil bonded on both side,;.

In order to prevent heat reflected from the Sun fromdariainf: the track-ing beacons on the spacecraft or the laminateitself, the balloon ts coated Uith alodine, a chemical acid,:hich changes the surf~ae to improve its reflecting properties.

To keep as even temperature as possible between the Sunside and the shade side of the sphere, the inside surface is


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-6-In order for proper inflation to occur, the small

plastic bags are fastened on one side to the inside skin ofthe balloon in a definite pattern. When the sphere is injectedinto orbit and is partially inflated by residual air into asoft, round shape, solar heat begins its work. It first meltsa wax sealant on the outer edge of each plastic bag. Thiscauses the bag to expand and unfold inside the satellite. Thisin turn exposes thousands of tiny perforated holes on the innerfolds of the small bags which allow the pyrazole to escape in-side the balloon in the form of gas. Because the chemical en-velopes are positioned in such a way that each releases gas ata different time, the gradual pressure build-up is achieved.It will take about 90 minutes to achieve full pressure, thusallowing higher pressures to be contained than were previouslyobtainable. This means a stronger space structure and betterreflectivity.


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inflation. Other STADAIT stations are located at Fairbanks,Alaska; Winkf'ield, England; St. Johns, Newfoundland; Santiago,Chile; Lima, Peru; '1uito, Ecuador; Woomera, Australia; BlossomPoint, Md.; Fort myers, Fla.; East Grand Forks, Minn.; GoldstoneLali, Calif.; and a Pacific Missile Range Station at SouthPoint,Hawaii, will obtain balloon skin temperature and otherdata. The Smithsonian Astronomical Observatory tracking net-work will also participate.

Based on an agreement between the U.S. and the U.S.S.R.(The Dryden-Blagenrovov agreement), communications experimentsusing the Echo satellite, are expected to be carried on in 1964,although no definite schedule for such experiments has beenestablished.

The Echo Team


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-8-Joseph tMahon, Agena Program Manager.

Goddard Space Flight Dr. Harry J. Goett, Director.Center: Herbert Eaker, Echo Project Manager.Norman Martin, Project Coordinater.John M. Thole, Assistant Echo ProjectManager.E. A. Rothenberg, Agena Coordinator.Thomas E. Ryan, Goddard Tracking &Daba Systems Manager.Joseph Schwartz, Associate Chief,Goddard Launch Operations Branch.

Lewis Research Center: Dr. S. C. Himmel, Project ManagerThor-Agena systems management.

Contractors

G. T. SchjelAahl Co.: BalloonGrumman Aircraft Canister


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-9-TECMIfCAL DESCRIPTION

The Spacecraft

Echo C will be folded in a cocoon-liko canister atopthe Agena B stage of the booster as it stands on the padbefore liftoff.

It is made of Mylar plastic .0035 inches thick,.with.00018 inch thick aluminum alloy foil bonded to either side.This laminate is coated on both sides with alodine. Theinside surface is coated with black India ink.

The spacecraft is made of 106 gores, each 4j feet wideat the balloon's equator, joined together by simple buttsplicing. There are 54-inch end caps on.both poles of theballoon, with overlapping joints. All joints are bonded to-gether with 1-inch strips.

Bea-cons


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which power the beacon when the modules are in darkness.The beacons, with a power output of 35mw, operate in the36 mc range, with subcarrier frequencies telemetering datafrom sensors about balloon skin temperature and internalpressure. Beacon and power supply systems weigh 12 pounds.

Tracking

Improved acquisition and tracking ia a goal of EchoC. The communications capability of Echo I was often limitedby the time required for the two ground stations to acquirethe satellite. Experiments are planned at high frequer.ciesand narrow antenna beamwiidths in order to make the experimentsharder, the results more meaningful.

Tracking facilities and radar will be used to evaluateseveral search modes, in both bistatic and monostatic tests.One such will be done by an array of small 30-foot parabolic


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Collins Radio Company of Dallas, Texas, under contract toGSFC. The U.S. Air Force and Lincoln Laboratory iill par-ticipate, as will the Bell Telephone Laboratories. Experi-ments are expected to be conducted between the United Kingdomand the Soviet Union. The American Radio Relay League (hamoperators) is planning independent experiments.

Radar experiments to evaluate the shape and surfacequality of Echo will be correlated with data from Echo staticinflation ground tests.

In post-injection phase, optics will help determine theorbit and its perturbations and aid in air-density studies.O)tics swill also be used to di3cover Irregularities in balloonshape, if any.

Propagation experiments will be performed: path loss,Faraday effect, Doppler effect, dispersive effects, selectivefading; and signal statistics.


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Pulse-code modulation and single sideband tests will

be made with equipment available.

The Canister and Support equipment

The canister into which Echo is folded is an oblatespheroid of magnesium alloy about .1 inch thick, built oftwco flanged half shells meeting at the equator. The folded

balloon rests within the danister; the compartment is 39.6

inches in diameter and 29.3 inches deep.Fiberglass covered

plastic foam and a plastic sheet protect the balloon fromdamage from vibration or shifting. The canister and balloon

are protected frown temperature extremes by a thermal-balancecoatings on the canister's outside surface.

Atop the canister as it rests in its support adapter

attached to the Agena base are two silver-zinc batteries whiahshaped charge, thus opening the


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The adapter atop the Agena B stage is of .064 inch thickmagnesium alloy, shaped like a truncated cone, 60 -nches indiameter at the bottom, 42 inches at the top and 16 incheshigh. The canister's bottom half is clamped against the pres-sure of four separation springs (which fit into cutouts aroundthe adapter wall) by a machined ring.

The clamp is a Marman band, secured against the pressureof the four separation springs by four explosive bolts, which,when fired in space, will break the band, eJect the canisterfrom the adapter at a velocity of about 6 feet per second.

A microswitch will activate a 90-second-delay time, whichallows the canister time to clear away from the adapter andorient itself before the shaped charge fires and severs thetyrex lacing binding the canister flanges, upon which the twohalves will fly apart and release the balloon.


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transmitter will beam FM signals, at about 255 mc with morethan 50 watts of power, to a 65 foot parabolic antenna atthe ground station in the Republic of South Africa. Two re-ceivers and two video tape recorders will permit projectofficials there to obtain a permanent record of Echo's in-flation as they communicate by SCAMA (switching, conferencingand monitoring arrangement) telephone and teletype with officialsat the launch site, and the Goddard Space Flight Center.

The Launch Vehicle

The launch vehicle is the Thor-Agena B, 86 feet high asit stands on pad 1 of launch complex 75-1 at Vandenburg AirForce Base, Pacific Missile Range, before launch.

The booster is the Thor which has contributed to so manysuccessful NASA launchings.


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First Stage VehicleThor stands 56 feet high, measures 8 feet in diameter,

anzi-receives power from its Rocketdyne engine which burnsRP-1 fuel, oxidized with liquid oxygen; two smaller Rocketdyneengines are usel for roll control and final adjustments tothe vehicle's flight trajectory. After 90 seconds of flight,the ground controlled Bell Telephone Laboratory guidance sys-tem steers the vehicle. Thor produces 170,000 pounds of thrustat liftoff. The Douglas Aircraft Co., Santa Monica, Calif.,builds Thor.

Second Stage VehicleThe second stage vehicle, the Agena B, is 20 feet long a'n!.*

5 feet in diameter. Its engine burns UD1rTH (unsymmetrical di-methylhydrazine) fuel and IRFNA (inhibited red fumting nitricacid) oxidizer. It generates a thrust of 16,000 pounds andburns for four minutes; Agena Aas re-start capability in space.


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The Thor ma.1i. eng1 ne will bu.rn for 148, secondo,. Thevehicle will continue its flight powered by the vernierengines, which position the vehicle in response to signalsfrom the ground. The ver'nier engines will cut Off when thevehicle has reached its desired altitude and velocity, about157 seconds after launch; a 30 second coast period vjill occurbefore Agena fires.

Agena is attached to the Thor by an adapter which issecured by pull pins. A radio command troom the ground-basedBTL guidance system fire small charges which actuate the pinpuller to release Agena from the Thor. Retro rockets willpull Thor away from Agena for a clean separation.

During tha.s coast period, and shortly after separation,a control systiem in Agena will command the vehicle to pitchdown 15 degrees toward Earth making the Agena parallel to thecurvature of the Earth.


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from 100 miles high to 800 miles. When this altitude isreached, Agena will fire for four seconds placing it intoa 800 mile circular orbit.

Two pairs of ullage rockets give tihe vehicle the accel-eration necessary to force fuel and oxidizers to the pumpsbefo:re ignition when the vehicle is at zero-g condition.

V Ana B has an inertial guidance system assisted byhorizon scanners and, during powered flight, the vehicleis controlled by gas Jets. In the coast phase of flight,gas jets control all three axes -- pitch, yaw and roll.Spacecraft Separation

Approximately 20 seconds after- the Agena will completeits second burn, the vehicle will begin a 180 degree turn-around in space. The second stage will be facing backwards


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Echo II Press Kit