telstar press kit

8/7/2019 Telstar Press Kit

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N E W S RELEASENATIONAL AERONAUTICS AND SPACE ADMINISTRATION400 MARYLAND AVENUE, SW WASHINGTON 2', D C.TrlEPHONES WORTH 2 4i5S' \\/ORTF 3 -1110

FO R RELEASE: SUNDAZ tM4'sJuly 8, .962

REiLEASE NO, 62-151

NASA-TELSTAR CONTRACT

During th e coming week th e Nati.onal Aeronautics andSpace Administration is scheduled to launch a 170-poundTelstar experimental active repeater communication satel l i tefor th e lamerican Telephone and Telegraph Company. A Deltalaunch vehicle will boost the satellite into orbit, fromnCape Canaveral, Florida no earlier than July l.0th.

Te l s t a r is a unique experiment in t ha t it is th e firsttime that a private company has built a satellite and paid

fo r cos t of launching with I ts own funds, It also marksthe first i n t e rna t iona l at tempt to t ransmi t cormmunicationosby using an active repeater satel l i te .

The ProJect Tdl s t a r cooperat ive agreementt was signedon July 27, 3.961 by Dr. Robert C. Seamans, Jr., AssociateAdministrator of N A A and Frederick R. Kappel, thenpres ident and now chairman of th e board of th e AmericanTelephone and Telegraph Company. The agreement providedfor:

1. The Bell Telephone Laboratories to design andbuild th e Teltar satellites at it s

ow n expense, test themaccording to NASA specificatiorxs and deliver them to thelauncth site at Cape Canaveral. Two launchings and twooptionsal backup launchings were included. in th e agreement.

'. AT&T to reimburse NASA for th e Delta launch vehicles,'umuch and t racking services. Cost amounts to approximately$3 mail~lion per launch.

3. Bell System engineers and scientists to conductthe c')mmunications experiments -- television, voice andhigh-sneed data -- using th e company's ground stat ions atAndover, Maine and Holmdel, N. J, Results will be reportedto NASA.

4. "ASA tou provide Bell Telephone Laboratories withtelemetry Pnd'spacecraft acouisition information, includingdata from a rad1tation experiment aboard th e satellite, received,by it s wor).wide Saeveilite Instrumentation Network. (These


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stations are located at Blossom Point, Md.; East Grand Forks,

Minn.; Ft. Myers, Fla.; College, Alaska; Mojave, Calif.;St. Johns, Newfoundland; Woomera, Australia; Winrcfield,England; Johannesburg, South Africa; Antofagasta and Santiago,Chile; Lima, Peru; and Quito, Ecuador).

5. NASA and Bell Telephone Laboratories to analyze thedata and all results be made available by NASA to theworld scientific community.

Results of the Telstar experiment will be applied to theoverall NASA communication satellite research and developmentprogram, the objective of which is tc provide the technologynecessary to establish an operational system of communicationsatellites at the earliest possible date.

NASA's responsibilities in the Telstar project are underthe direction of the Office of Application, NASA Headquarters.Management of these responsibilities is carried out by theGoddard Space Flight Center, Greenbelt, Md., including track-ing and aialyses of data acquired by the tracking network.

GROUND STATIONS FOR TESTING EXPERIMENTALCOMMUNICATION SATELLITES

A cooperative program for testing experimental communi-cation satellites is being undertaken by NASA and communica-tions organizations in the United States, Europe and SouthAmerica. The American Telephone & Telegraph Co., Internation-al Telephone & Telegraph Co., British General Post Office,French National Center fo r Telecommunication Studies, WestGerman Post Office, Brazilian Depai-tment of Posts and Tele-graphs, and Telespazio of Italy are providing groundstations an d will conduct communications experiments.

The organizations in England, France, Germany, Braziland Italy are participating on a voluntary basis. Technicalagreements werernegotiated with NASA and concurred in bythe respective governments. No exchange of funds is involved.Orbital data necessary for conducting the communicationstests will be provided to the stations by the NASA GoddardSpace Flight Center's tracking network operations center.

The station at Andover, Maine and those in England,France, and Italy will be employed fo r trans-Atlantic ex-perimenzs with Telstar and Relay, NASA's active repeatercommunication satellite, this year.

The British station, located at Goonhilly in southwestern

England, is equipped with a steerable parabolic antennaapproximately 85 feet in diameter and a "Maser" amplifier.The station is also equipped to transmit and receive tele-vision and still pictures using British, European and Americanline standards as well as telephone and data communications.The site was selected to obtain a maximum period of mutualvisibility to the United States via the satellites and becauseit is remote from sources of radio interference..

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The French station, located at Pleumeur-Bodou on theBrittany peninsula is almost identical to the AT&T facilityat Andover, Maine and is equipped to conduct television,voice and data experiments.

Telespazio plans to construct a large facility at Fucino(about 50 miles northeast of Rome). However, the organizationwill participate with an interim station this year by receivinevoice signals from the satellites with a 30-foot parabolicantenna.

The Deutsche Bundespost (Post Office of the7 Federal

Republicof Germany) has awarded contracts for construction of

a station near Raisting, about 30 miles south of Munich. Thewide-band antenna will be a 75-foot diameter parabolic dishwith a horn-reflector feed. The performance will besimilarto the stations at Andover, Maine an d Pleumeur-Bodou, France.It is scheduled to be in operation late in 1963.

Voice an d data transmissions vi a RELAY will be conductedfrom the IT&T 40-foot dish at Nutley, New Jersey, and a 30-footdish near Rio de Janeiro, in 1962.

NASA has negotiated contractual agreements with theAmerican Telephone & Telegraph Co. an d the InternationalTelephone an d Telegraph Co. to conduct the RELAY communica-tions tests at their facilities in the United States.

Technical requirements and plans for conducting theexperiments are coordinated by a Ground Station Committee. TheChairman is Leonard- affe, Director of Communication Systems,NASA Headquarters. Daniel Mazur of the NASA Goddard SpaceFlight Center is Alternate Chairman. Members area

Captain C. F. Booth, General Post Office, United Kingdom

.. Sueur, National Center fo r Telecommunications Studies ,

FranceZrnst 0. Dietrich, West German Post Office

Lt. Col. G. Bandeira de Mello, Department of Posts andTelegraph, Brazil

Dr. P. Fanti, Telespazio, I ta ly

:.. F. O'Neil l , TELSTAR Pro jec t Manager, Bel l TelephoneLaboratories

RI. E. Sageman, American Telephone & Telegraph Co.

Louis Pollack, International Telephone & Telegraph Co.

Charles P. Smith, and Joseph Berliner, NASA Goddard SpaceFlight Center

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TELSTAR PROJECT OFFICIALS

N.A.S.A.

NASA Headquarters

Morton J. Stoller, Director, Office of Applications

Leonard Jaffe, Director of Communication SystemsOffice of Applications

Vincent L. Johnson, Chief of Delta ProgramLaunch Vehicle & Propulsion ProgramsOffice of Space Sciences

Goddard Space Flight Center

Charles P. Smith, Telstar Project Manager for NASA

William Schindler, Delta Systems Manager

Robert Gray, Goddard Field Projects Branch atCape Canaveral

Roger V. Tet r ick , NASH Tracking arid -iat.a Manage'.forTetta

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.':n' r i*u) 'I'ielephone ?z Te legraph1i I-1 ( n{a t i Pmceapt.

Ili') Pt')adway, 'ovw Vork, N.Y.

'ri*;,;'i'; liTr '1 rl.: ;TA ? 2AT:I,[,TTh- iO DI14ONeHA'1'A ,VO.TCE, DA.T, PACr,1lr`T`P; SU) TbPV TRjAN;;MIL;:.;Ie

The Bell Systemfs 'To ls ta r satellite is scheduled for an early

morninr2 haunch by NA2A;A a t Cape Canavera l . The programmed o r b i ti.;- apro:.lnmiately two hours and for ty minutes.

Telstar is expected to be "visible" for a few/minutes toth e Andover, Maine, ground s ta t ion about twelve hours a f t e rlaunch. 'Ft is expected tha t th is pass (fifth orbi t ) wil l beused only to verify o r b i t a l information and acqu re more prec isetrackinf an d antenna pointing data. The satell ite wi l l not bewithin re)r e of th e Iolnmei s ta t ion on t h i s fifth pass.

,D)omestlc demonstrat lons are planned during th e next fourorb!t;s (s ix th through ninth - beginning about f i f t een hours

after launch) using th e Andover and Ilolmdel ground stations.Visibillty periods for these four orbits range from about 20 to5C minutes.

Plans for th e initial domestic demonstrations include:a live telephone call between people at two different locations,a video tape, a facsimile transmission of a current news pictureand the sending of high-speed data between two points.

Signals will be sent from the giant horn antenna at Andoverup to Telstar. The satellite wil l receive the signals, amplifythem te n billion times and transmit them at a strength of 24watts back to earth. The extremely weak signals will be pickedup by both the Andover and Holmdel ground stations. The qualityof th e signals received at Holmdel is not expected to be asgood as the signals received in th e larger horn at Andover.The Andover horn has nine times greater antenna surface thanth e Holmdel horn and consequently receives nine times moresignal strength. The Holmdel antenna will not be used to trans-mit signals to th e satellite because of interference problemswith other microwave users in that vicinity.

A transatlantic demonstrat ion, produced by the U. S.television networks, is planned after th e domestic demonstrationsand overseas technical tests have been successfully conducted.

This overseas program will no t occur until th e satel l i te ha sbeen in orbit for about a week. The television networks ar eplanning to transmit about 12 minutes of current news events

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from a number of geographical locations in the United States.This segment will also be shown to U.S. viewers as a part ofa longer program, expected to run from 30 minutes to one hour.Other international demonstrations from the U.S. will includetelephone conversations, and photo and data transmission. Thevoice demonstrations will include a hook-up between people in20 cities in the United States and 20 cities in Europe. Tensuch conversations can be carried out simultaneously. TheUnited States Information Agency is making arrangements forthese voice demonstrations as a part of its sister cityaffliation program.

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American Telephone & TelegraphPublic Relations Dept.19 5 Broadway, New York, N.Y.

PROJECT TELSTARCHE SATELLITE ITSELF

The chief function of the first experimental Telstarsatellite is to receive a radio signal beamed at it from the

ground, amplify this signal -- te n b i l l i on times -- and re-t ransmit th e s igna l on another frequency. In addition, thesatellite wi l l carry equipment to measure its performance andit will carry a package to obtain needed scientific data onthe space environment itself. Th e Telstar orbit is expectedto range in altitude between 600 and 3500 miles, inclined 45degrees to the equator, thus providing a wide sampling of thespace environment.

The i formation on satellite performance and environmentwill be transmitted on a special 'telemetry" radio frequency.Also, radio beacon signals will be transmitted to help groundstations locate the satellite. The satellite is equipped toreceive spacilal "command" signals from the ground, which willturn circuits on and off so that power will not be drainedaway needlessly when the satellite is out of range of theground stations.

The satellite is roughly spherical in shape, with 72flat faces, or facets. It is 34-1/2 inches in diameter andweighs about 170 pounds. The metal framework is made ofmagnesium, the shell of aluminum, coated with aluminum oxidesprayed on by a plasma jet process. Solar cells are mountedon 60 of the facets. On three facets are mirrors that willr.flect sunlight to ground observers using optical tracking

equipment and thus provide information on the angle of thesatellite axis in space.

Two antennas, equator-like, girdle the satellite.These are the receiving and transmitting antennas for thebasic communications function of the satellite; they alsotransmit a precision tracking beacon signal. The antennastransmit and receive with nearly equal efficiency in alldirections except in the direztivn of the "poles" of thesatellite. During launching, the satellite is given a spinof 180 revoultions per minute about this "pole" axis. Thespin gives the satellite a gyroscopic stability so that thepoles tend to point to the same place in space although the

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direction will change very gradually over weeks or months.Direction of launch is so arranged that during the first fewmonths of satel l i te life the satel l i te axis -- an d it s deadspots in the antenna transmitting pattern -- will no t pointdirectly toward the earth when th e satellite is over thenorthern nemisphere.

Another antenna, a Wire hel ix , is located on top of th esatellite. This sp i r a l antenna wi l l serve te lemetry, commandand beacon c i rcu i t s .

The satellite contains some electron tube and 2528 semi-conductor devices -- 1064 tranistois and 1l464 diodes.

Power Supply

Power wi l l be supplied to e lec t ronic c i rcu i t s in th esatellite d i rec t ly by 19 rechargeable nickel-cadmium ce l l s ,of the type used in rechargeable flashlights but speciallydesigned fo r the space environment. They will be charged by3600 solar cells on th e skin of' h> satellite. The solarcell system will convert sunlight into electricity at theini t ial rate of about 15 watts while th e satel l i te is on thesunny side of th e earth and while the sun is perpendicularto th e satellite's equator. It is estimated that the outputof the cells will decrease to 11 watts at the end of a yeardue to th e effects of nuclear part icles in the Van Allen beltand micrometeoroid damage.

The solar cells ai'e mounted on a ceramic base in aplatinum frame, and protected from bombardment by energeticelectrons by coverings of clear, man-made sapphire. Thesematerials and their bondings were al l chosen with an eye totheir endurance in space. The ceramic, platinum and sapphire,for example, al l expand and contract with changes in temper-

ature about th e same as the solar cells themselves, a factwnich is expected to enable them to remain bonded togetherfor many years.

Electronic Chassis

Electronic equipment is sealed in a 20-inch aluminumcanister, which instead of being bolted or welded to theframework will be suspended inside with nylon cord lacings.This arrangement will help to absorb shock an d high frequencyvibration.

Polyurethane, a pink plast ic foam which becomes rigidwhen it sets, was poured into and molded around each elec-tronic subassembly. When these blocks were completelyassembled in the -anister, th e canister wa s filled with

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polyurethane to form a firm stnucture highly immune to theeffec ts of shock and vibrat ion. T'ie Iorm plas t ic techniquewas first developed by Bell Laboraories in missile-guidancework. The sealed cask was partially evacuated of air andf i l led with gas to a pressure somewhat below atmospheric. Ifin the emptiness of space a micrometeoroid puncture shoulddevelop, the loss of pressure is no t expected to affect theoperation of the satellite. Th e high voltage of the t raveling-wave tube will be turned off if necessary as th e pressurecorsses a cri t ical point where electrical arcing or "corona"occurs.

Temperature of the canister will be regulated by con-t rol l ing the amount of heat radiated. The top of the canisteris covered with a thermally controlled li d which will openor close as required to control the internal canister temper-ature.

Broadband Communications Circui t

Signals are sent up to th e satellite on th e frequencyof 6390 megacycles, or 6.39 billion cycles per second, anddown to the ground on a lower frequency, 4170 megacycles,or 4.17 billion cycles pe r second.

The incoming 6390 me signal .a s mixed with the output ofa quartz crystal-controlled beat oscillator to produce asignal centered at an intenueuiate frequency of 90 megacycles.This lower frequency is within the range of reliable, long-life transistors. Fourteen germanium (diffused base) trans-istors will be used to amplify the signal about one milliontimes during normal operation. Total amplification will beheld by an "automatic gain control" to se t limits. Thus theoutput of the satel l i te will be very nearly constant --about 2-1/4 watts -- regardless of the strength of th e signal

coming in from earth, and regardless of slight aging oftransistors or other small variations in th e amplificationcircuit.

Th e amplified 90 mc signal wil l then mix with anothercrystal-controlled oscillator frequency so that the result ingmixture is centered at the 4170 frequency for retransmissionfrom the satellite. But before transmission it will beamplif ied once more by the only electron tube in the satellite.Th e traveling-wave tube is a foot-long, pencil-thin glasstube containing a spiral wire. For size an d weight, atraveling wave tube is the only device in th e world capableof such amplification (10,000 times) with such a broadbandsignal. The Telstar satel l i te wil l not, however, give thet raveling-wave tube it s f irst ride into space, Another but

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similar version has proved it s ruggedness in the Bell Labora-tories - Western Electric command guidance system aboardmissiles and will in fact be used again aboard the Delta rocketto launch Telstar.

The traveling-wave tube amplif ies also a 4080 me singlefrequency signal along with the broadband communicationssignal. This L;080 me signal will be transmitted at lowerpower -- abouttwo-hundredths of a watt -- to serve as a beaconfor precision trackers on th e ground.

Radiation and Solar Aspect Measurement

On e of the principal purposes of the Telstar satel l i teis to learn more about the nature of the space environment inwhich communication satel l i tes must operate, particularlyregarding radiation in space. Previous space research ha sresulted in th e discovery that a band of space around theearth. -- the Van Allen Belt -- has a high density of energeticparticles. These particles can be damaging to communicationdevices to an extent which varies markedly with th e particleenergy. Therefore, to obtain th e needed specific information,Bell Laboratories has incorporated into th e Telstar satel l i te

a radiation experiment to probe th e inner part of the VanAllen belt. Th e findings of this experiment will of coursebe shared with th e entire scientif ic world and should besignificant in advancing the use of space in other ways.

This experiment has tw o principal functions: to makescientif ic measurements of radiation in space; and toestablish for communications technology th e actual effecton semiconductor devices of the radiation there.

The measurement of energetic particles wil l beaccomplished through th e use of four special si l icon diodes

producedin Bell Laboratories for the purpose, and through

associated circuitry designed with the assistance of theInstrumentation Division of Brookhaven National Laboratories.The electrical response of each of th e four diodes is indirect proportion to th e amount of energy a part icle losesin striking or passing through the diode. They ar e locatedat th e skin of the satellite. Three of them are used tocount and measure the energy of protons; th e other to countan d measure th e energy of electrons.

(Technical note: Two are almost unshielded. On e ofthese at a fixed bias measures electron density and energyfrom 1/4 to 1 Mev.' The other has a varying bias to measure

protons in each of five energy regions between 2 and 25 Mev.

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nwo others have a thicker shieliing. One measures only pro-tons above 25 Mev, while the other, with the thickest shield-ing of all, measures protons above 40 Mev.)

The second function of the radiation experiment, tomeasure ac tua l damage to semiconductors, is performed by twotypes of semiconductor devices: so l a r ce l l s and t rans i s to r s .Three so l a r ce l l s w i l l be monitored to learn th e decreasein t h e i r s h o r t - c i r c u i t cur ren t output over a period of time.Each is shielded a different amount.

Also, six silicon transistors, specially fabricated byBell Laboratories with a wide "base" region to make themunusually sensitive to damage by radiation, ar e mounted atthe satellite skin in pairs, each pair shielded by a differentamount. Their output will be monitored and compared over aperiod of time with th e output of a seventh transitor similarto th e others except that it has been pre-radiated. Thatcompletes th e radiation experiment, but on e other group ofmeasurements taken at the skin of the satel l i te is functionallyconsidered part of th e ' radiation package".

Six special solar cells, pre-radiated, ar e dispersedabout the skin of the satel l i te as light detectors. A com-

. , p a r i s o n of the amount of light falling on each one at anyparticular instant can be used to determine which side ofthe satellite at that instant is nearest th e sun. The amountof light each receives is telemetered back to earth. A se tof these measurements over a period of time can be analyzedin a computer to determine the angle between th e spin axisof the satel l i te and th e sun.

Another measurement of th e att i tude of th e spin axiswill be provided by visual observation of mirrors mounted on

the satellite. When sun, satel l i te and ground observer areat the right positions, th e observer, using a telescopictracker, will see f lashes of sunlight reflected to him for afew seconds.

Telemetry

A large part of th e Telstar satel l i te is given over tothe measurement of environmental conditions, th e measurementof circuit and device performance, and the transmission ofth is information to the ground.

In all, 115 i tems are measured and reported. Includedar e such items as density and energies of free protons an delectrons, temperature at the skin of th e satel l i te an dinside th e electronic chassis, press ure inside th e chassis,

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the amount of sunlight being received at several points on

the skin, and th e currents an d voltages of dozens of electronic

components.

The measurements ar e reported to ground stations over a

special radio transmitter at 136 megacycles, radiat ing a power

of a quarter watt. The transmitter radiates constantly, even

when information is not being transmitted, thus serving a

second purpose as a radio beacon to assist ground stations in

tracking th e satellite.

When a radio command (over a separate command circuit)

is given the satel l i te from the ground, the satel l i te transmits

th e measurements until a command is given to stop. Each itemis sent once every minute. This "telemetry" information is

sent in th e form of coded pulses.

(Technical note: Th e pulses frequency-modulate a

3 kilocycle frequency, plus or minus 225 cycles. The result-ing signal is then used to amplitude-modulate the 136 mega-

cycle carrier, thus producing a PCM-FM-AM signal. This

method is used in order to maintain radiation of the center

frequency -- th e beacon -- at constant power and phase tofacilitate tracking.)

Command

When all e lec t ronic func t ions of the experimentalsatel l i te operate simultaneously, they will drain more elec-

trical power from the battery than the average rate at which

power is replenished by solar cells ( including the periods

when th e satel l i te is in the earth 's shadow). Therefore, to

conserve power for use when it is really needed -- when th e

satel l i te is above th e horizon from a ground stat ion -- pro-

vision is made for turning off and on th e principal communi-cat ion function of th e satellite and also th e telemetry

information it sends back. The equipment for performing this

function in the satel l i te is called th e "command" system.

The command system includes a pair of radio receivers

to receive pulse-coded commands from the ground on a frequency

of about 12 0 megacycles; a pair of decoders to translate the

received pulses into usable instructions; a switch control

net; and nine relays -- electrically operated switches --

which turn appropriate circuits off and on.

The receivers and decodersare installed in pairs to

insure that this important operation ca n be carried out even

though some device should fail. This is th e only use of

'redundancy" in th e satellite.

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Before any command car, be giv n the satellite, a specialenable" code, similar in eff cl- to the combination lock on

a safe, must be sent to the satel ite. Other commands ar eto turn on and off telemetry, elements of the traveling wavetube, apparatus to measure radiation effects, and receiversand encoders.

When the telemetry package is turned off, power will nolonger be consumed in the hundreds of semiconductors an dother devices that make up the package. Th e 136 megacyclesignal itself will continue to radiate as a constantbeaconfo r tracking stations in the U.S. and around the world. After

a time lapse of two years, a timing device will irrevocablycut of f transmission from this beacon so that its frequencyca n be used for other purposes without interference. Theprincipal frequency of 4170 me an d it s companion 4080 incprecision tracking beacon ca n be cut off by command: an dshould command fail, they will drain the batteries to thepoint that transmission will be ended in a few hours.

The command an d telemetry functions relate almostentirely to the "experimental" nature of the satellite:Telemetry, to send back information on environment and opera-tion of devices and circuits in space; command to enable areasonably small satellite to provide the equivalent of "bigsatellite" electrical power for the duration of communicationexperiments. Command an d telemetry account for a largeportion of the weight and complexity of the satellite: fo rexample, they use 2354 semiconductor devices, or 93 per centof the 2528 total.

Testing Regimen

Each component, each subassembly, and each completedsatellite was subjected to a rigorous test and retest pro-cedure. For example, 58,800 transistors and diodes -- severaltimes the number that were eventually assembled into satel-

lites -- were subjected to several months of life tests. Arecord was kept on each. These "pedigree papers" accompaniedthe components as they were assembled into subassemblies ina superclean atmosphere. These assemblies underwent elec-trical and vibration tests an d accumulated further recordseach step along the way.

Completely assembled satellites were subjected tobalancing, vibration, magnetic drag, an d electrical trans-mission tests at the Hillside, N.J. laboratory, and thenfurther transmission checks at Murray Hill, N.J. Satelliteswere transported in a sealed, nitrogen pressurized boxcontaining shock absorbers and mounted on other shockabsorbers in a spec ia l , a i r-condi t ioned "satellite vehicle"

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truck. They were taken to the Whippany, N. J., laboratoriesfor several days' test in a "thermal-vacuum" chamber simulating

as nearly as possible th e environment of space. This tank

wa s pumped out to a very high vacuum. Black walls, cooled to

about 300 0 F below zero, absorbed radiated heat, while sunlightsimulated by arc lamps streamed through a system of lensesto heat the spinning satel l i te and to illuminate solar cells.

Temperature of the satel l i te and transmission of the satellitewere observed.

F5inally, at C;pe Canaveral, solar cells, antenna, satellitetransmission and telemetry are checked again in the days pre-

ceding launch. An d even after th e satel l i te is placed atopthe launching rocket, transmission and telemetry ar e checkedfro). antennas three miles away. Telem~etry will be receivedand recorded during launch until th e satel l i te vanishes over

the horizon.

Orbit

The expected orbit will be elliptical, with a perigee(closest approach to earth) of about 600 miles and an apovee

furthest departure from earth) of 3500 miles. It s incl i-nation, or angle with the equator, wil l be about 45 degrees,

which means th e satel l i te wil l loop to about 45 degreesl a t i t ude north and south of th e equator. The period of orb i tw i l l be about two hours and fo r ty minutes.

The apogee at f irst will occur near th e equator on th e

south-to-north crossing, while th e perigee will occur near

the equator on th e north-to-south crossing. Over a period

of months this ellipse is expected to "precess," or movegradually, so tiat the apogee will occur in th e northernhemisphere, then continuing to precess until th e apogeecrosses th e equator into th e southern hemisphere, and so on.

The satel l i te wil l be given a spin of about 18 0 rpm about

it s own axis, so that while moving about th e earth in it selliptical orbit, th e satel l i te axis wil l constantly point

in th e same direction in space. Eventually this axis is

expected to precess too, but a means will be available to

control this precession: loops of wire, energized on com-mand from the ground, will produce a megnetic f ield an d

t imed properly will cause th e satellite to precess back into

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American Telephone & Telegraph Co.

?ublic Rela'ions Dept.I.,) 3roadway, New York, N.Y.

GR~r:;, ATZC>

Th e principal ground stat ion fo r conducting experimentswith Telstar satel l i tes is ir Andover, Maine, about 15 milesnorth of the city of Tiumford.I

Another stat ion that will receive transmission experi-ments is a Bell Laboratories installation on Crawford Hill,Holmdel, New Jersey, "the first telephone terminal to outerspace," buil t in 1959-1960 for the now historic experiments inNASA's Project Echo.

(At th e Atlantic Missile r-ange, Cape Canaveral, Florida,satel l i tes will be given final prelaunch check-outs an dsatel l i te telemetry will be received during and after th elaunch. This is adjacent to an Air Force facil i ty used byBell Telephone laboratories fo r missile guidance at the Cape.)

Several foreign countries will participate in satel l i tecommunications experiments. Th e British have buil t an 85-footdish antenna at Goonhilly near FaLmout, I':ngland. Th e Frenchar e constructing a ground stat ion at Pleumeur Bodou near Lannionon th e Brittany Peninsula. This station is th e same as th e on eat Andover, Maine. Ground stat ions also ar e under constructionin italy and West Germany.

Andover, Maine

The principal station for carrying ou t experiments with th eTelstar communications satellite is on a 1,000 acre hil l topbract owned by the Long Lines Department of A.T.&T. Co. inAndover, Maine, about 15 miles north of the city of Rumford.Th e site, informally named "Space Hill," is in a shallow bowl,r inged

by mountains which help protect the site from interferenceby other raio transmissions.

The station will include means for tracking the satellite,computing orbit, sending commands, receiving telemetry infor-mation, and carrying out the principal purpose of th e Telstar pro-ject, experiments in broadband transmission by wa y of thesatellite.

Th e power of the broadband communications signal radiatedfrom the satel l i te is about 2-1/4 watts. This radiation spreadsout uniformly in almost al l directions and by th e time it reachesthe earth from 3,000 miles in space it is very

weak indeed. Toreceive and amplify even a single voice channel bandwidth ofsuch a weak signal would have been very difficult a few yearsago. To receiveand amplify such a signal strength over a 25megacycle oandwidth is difful t today; especially when th etransmitter is a 34-inch object moving through space about16,000 miles per hour.

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To scoop up as much as pu.3slblbe of this very weak signal, itis necessary to build a very large antenna. In addition, itis desirable to screen the sensi t ive element of the antenna fromthe radiation emitted by trees, earth and even people themselves.To meet these tw o objectives, Bell Laboratories and McKiernan-Terry Corp. engineers designed th e largest horn antenna yet built.The large opening -- about 3,600 square feet -- is expected toscoop up about a billionth of a watt of th e broadband signal;and the sides of th e horn will keep out unwanted ground radiation.The steel and aluminum rotating structure weighs about 380 tons,

has an overal l length of 177 feet, and carries two fair-sizedhouses containing transmitter and receiver equipment.

Th e horn is patterned after a 50-foot-long Bell. laboratorieshorn at Holmdel, N. J. , which wa s used in Project Echo experi-ments and which will be used to participate in the Telstar experi-ment. Unlike t- e horn at Holmdel, th e large horn at Andover willbe used both to t ransmit to the satellite and receive signalsfrom it.

The mammoth horn at Andover ha s imposed requirements moreexacting than any other structure of it s size ever built, for itmust t rack it s tiny target smoothly and continuously, to anaccuracy of better than a fiftieth of a degree. Design engineershad to consider that th e weight of th e antenna itself would intro-duce bending, and a different amount of bending for every positionit takes. It is, therefore, butlt as rigidly as possible and --for it , size -- more accurately than a fine watch. A 70-footdiameter rotating wheel, for example, is machined to a toleranceof less than one thirty-second inch. To remove the factors ofwind stress, icing and rapid temperature changes, the entirehorn is covered with an inflated radome, 210 feet in diameter and161 feet high.

The radome replaced a temporary inflated shelter of essentiallythe same size that was put up in September, 1961, to provideweather protection while the horn wa s being built. Fabricatedand inflated by Bird-Air Structures, they are the largest inflatedshelters ever built. Th e permanent radome is made of Dacron andsynthetic rubber, essentially transparent to radio energy. Asixteenth of an inch thick and large enough to cover three acresif laid ou t flat, it weighs 20 tons. But it is held rigidly inplace against Maine's strongest winter gales by air pressure ofless than one-tenth of a pound per square inch.

Large and sensitive as the horn is, the experiment wouldnot be possible without two other receiver elements pioneered in

Project Echo: a maser and a frequency-modulation feedback circuit.

The maser is an extremely sensitive amplifying device havinga man-made ruby crystal as a central element, cooled by liquidhelium to minus 45 6 degrees Fahrenheit .

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Although the mafer is new, .engineers have reached into thepast fo r the other impor,5ant ele.arint of the receiver -- th efrequency-modulatior. fee ,ura k ;j.r(Juit. It was invented at BellLaboratories in the i930's . In effect, it acts as a very rapidautomatic tuning device, tuning a narrow-band receiver to theexact frequency being transmitted at any instant, although thesignal varies over a band 25 megacycles wide. Thus the receiverpicks up only the background noise in a rather narrow bandinstead of the much greater noise that would be received bybroad-band receivers without this feature.

Both the maser and the f-m feedback circuitry'are housedat the apex of the horn antenna, in the 28-foot-wide by30-foot-long "~cab."

Also located in this laboratory is the transmitter equipmert.The transmitter is a special unit of the newest Bell Systembroadband type, called a "TH," plus the addition of greater am-plification supplied by one of the largest traveling wave tubesyet built -- a water-cooled device four feet, three inches long.Power output on the 25 megacycle bandwidth transmitter is abouttwo kilowatts. While this power does not approach the power ofordinary commercial radio and television transmitters, the Andovertransmitter is significant in combined characteristics of high

power, extreme bandwidth and continuous operation (rather thanintermittent pulsing as in a radar transmitter).

A larger house, with a width of 28 feet and a length of 63feet, is lower on the structure. It contains antenna-controland power-amplification equipment, and a separate transmittersupplied by NASA for its Project Relay experimental communica-tions satellite scheduled to be launched later this year.

Control Building -

A quarter mile from the horn antenna, Bell Laboratories

engineers carry out communications experiments, track the satelliteand transmit command signals from a one-story control buildingcovering about a third of an acre. The center of activity is in -a console area, flanked by tracking equipment and computers.Engineers observe television signals on a group of monitorsincluded in one console or on larger monitors mounted overhead.

Just outside the building are two Tracking antennas. Oneis a quad-helix (spiral) command-tracker which picks up thesatellite's 136 me beacon and telemetry and transmits commandsto the satellite on about 120 me. Once the satellite has begunto transmit its broadband communications signal and a 4080 me

precision tracking signal, the other antenna, an eight-footdish, tracks on this signal with much greater precision.

Information to correct for slight error in prediction anderror in calibration is provided by the horn antenna itself fromthe 4080 me broadband signal. When the horn tracks just aslight bi t off the center of the satellite signal, the 4080 meenergy will be propagated in a different manner through the


18/31

-Ahat atLtwe'nes to th e th roa t Of th e horn. This change in

.mode'l of propagation is used as an e r ro r s igna l to correctpo)inting of th e horn. The system is called the vernier auto-track.

Errors in calibration of th e horn are very small. Theamount of pointing error was determined by focussing th e antennaon radio energy emitted by stars and comparing dial readings Ofth e horn's position with the known position of th e stars. Th estars used for this purpose ar e not visible -- they radiate nolight, but do emit radio energy.

In a similar manner, engineers calibrated the precision

tracker on the center of the sun, which emits a largeamount of

radio energy.

In conducting experiments with the satellite, engineers willobtain a great deal of valuable information by transmitting upto the satellite from Andover and receiving back the satellite'ssignal there also -- a "back-to-back" operation. This can bedone while working witn another distant station, for th e satellite'stransmitted signal can be received at any number of locationsthat have adequate receiving equipment. The Holmdel, N.J.,station will also receive th e satellite signals and then maysend them by way of the telephone network to Andover. There,engineers will display the signals on monitors and directly com-pare TV signals transmitted from Andover with those receivedat Andover.

Holmdel Ground Station -

"The First Telephone Terminal to Outer Space," a BellTelephone Laboratories station on Crawford Hill in Holmdel, N.J.,

famous for it s now-historic experiments with NASA's Echo satellite,has been're-wired" and expanded to participate in Project Telstar.

It will receive transmissions from the Telstar satel l i te . Butthe Holmdel station will not transmit to the satellite as it didduring Project Echo. Reason: frequencies allotted by the Federal

Communications Commission for experiments in satellite communica-t ions are in the "common carrier band" -- that is, in th e band offrequencies already allotted for the microwave relay of telephonetype traffic. In th e populous "corridor" of New Jersey,transmission to the satellite with the high power necessarywould interfere with this normal traffic. It appears that th e

particular common-carrier frequency used from satellite to

ground, however, will be free enough from interference enough of

the time to conduct some experiments.

Holmdel's receiving equipment has been modified to pick up

the Telstar frequency, and to receive a broad-band signal, con-

siderably broader than the Echo signal. To accomplish this,a

second maser has been added to Holmdel's horn antenna. It is

hoped that a home-quality television signal may be received at

Holmdel, although of course it is not expected to be as goodas the signal received in the larger horn at Andover, which ha s

nine t imes greater antenna surface and, therefore, receives nine

times more signal strength.

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In order to improve the pointing and tracking accuracy ofthe Holmdel horn, the 960 mc radar receiver used on the Echo Isatellite has been modified to angle-track the satellite beaconat 4080 mc.

In the control room on Crawford Hill an operator monitoringthe radar screen will see Telstar in relation to a set of crosshairs that will indicate how closely the horn is tracking thesatellite and wil l make appropriate corrections in pointing.

Another modification is the installation of equipment toreceive and display TV pictures received from the satellite,and to send the pictures back to Maine over regular groundcircuits, so that engineers there can observe results.

AlsL installed at Holmdel is optical tracking equipment todetect flashes of sunlight reflected by three mirrors on thesatellite. Pinpointing the time and location of the satellitewhen reflection occurs will give one measure of the angle of thesatellite's axis in space.

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20/31

American Telephone & Telegraph Co.Public Relations Dept.195 Broadway, New York, N.Y.

PROJECT TELSTAR

FACT SHEET

PROJECT TELSTAR: A Bell System experimental communicationssatellite system.

SPONSOR: American Telephone and Telegraph Company, with technicaldirection by Bell Telephone Laboratories. (In cooperationwith National Aeronautics and Space Administration.) Over800 Bell Telephone Laboratories' subcontractors.

FACILITIES INVOLVED: Bell System Ground Stations at Andover,Maine, and Holmdel, N.J., NASA Goddard Space Flight Center andWorldwide Tracking Stations. Atlantic Missile Range atCape Canaveral, Florida. British Ground Station at Goonhillynear Falmouth, England. Frenct Ground Station at PleumeurBcdou in Brittany. Other ground stations are under way inItaly and West Germany.

PURPOSE: Test broadband microwave communications in space; studyradiation and micrometeoroid effects; test satellite trackingtechniques.

FIRST TESTS: Transmit and receive Andover to Andover. Receiveat Holmdel with land relay back to Andover. (Telephone,data, TV and facsimile transmission).

LATER TESTS: Between Andover and Britain and France. West Germanyand Italy plans under development.

FIRST LAUNCH DATE: Summer 1962 with 2 month backup.

FISCAL ARRANGEMENTS: AT&T will pay about $3 million to NASAfor cost of each launch and services.

SECOND POSSIBLE LAUNCH DATE: Fall 1962 with about 2 month backup.

LAUNCH VEHICLE: Delta built by Douglas Aircraft Company for NASA.

GUIDANCE: Command guidance system developed by Bell TelephoneLaboratories and manufactured by Western Electric Company.

ORBIT:Elliptical, inclined 450 to Equator. 3500 mi. apogee,600 mi. perigee.

ORBIT PT 'IOD: .bout 160 minutes.

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TELSTAR SATELLITE:

DIAMETER: 341- WEIGHT: 170 lbs.

FRAMEWORK: Magnesium SHELL: Aluminum, coated withaluminum oxide.

NO. OF SOLAR CELLS: 3,600. Ceramic base, platinum frame,sapphire covering.

NO. OF SEMICONDUCTORS: 2,528 total; 1,064 transistors; 1,464 diodes.

STORAGE BATTERY: 19 nickel-cadmium cells, rechargeable.

SOIAR BATTERY OUTPUT: 15 watts initially; estimated 11 wattsa year later, due to effects of Van Allen radiation andmicrometeoroid damage.

CIRCUITS:

COMMUNICATIONS: Broadband channel; capable of providing600 one-way voice channels or one TV channel orequivalent in data, teletype, facsimile, etc.(While not primarily designed for two-way telephony,system could provide fo r 60 simultaneous two-waytelephone conversations. Tests will be made toconfirm this bu t grcund station will have "multi-plexing" equipment sufficient to carry only 12

( two-way conversations at any one time.)Total Ampliflication: 10 billion

Transmit Freq.: 4170 mc - 24 watt output throughtraveling wave tube (TWT).

Transmit Power Drain: 30 watts

Receiving Freq.: 6390 mc. IF Freq.: 90 mc.

TELEMETRY: Narrow band PCM-FM-AM

Transmit Freq.: 136 mc at 350 mwType Transmission: Pulsed EM at 3 kc i 225 cps to be

used with 136 mc AM.

COMMANDRECEIVERS (2): (Either one may function independently)

Freq.: 120 mc (Receive coded pulses.)Function: To control the communications transmitter

and the telemetry functions.

BEACONS:

Precision: 4080 mc at 25 mw thru broadband TWT.

Coarse: 136 mc at 250 mw of telemetry transmitterwhich operates constantly.

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ANTENNAS: 2 microwave broadband girdle center, one to tralsuitand one to receive; 1 UHF (120-136mc) helical for telemetryand command.

VISUAL SPOTTING AID: Mirrors

FUNCTIONAL LIFE: Planned two years. 136 mc Beacon to beirrevocably shut off.

BELL SYSTEM ANDOVER, MAINE GROUND STATION (Space Hill)

LAND AREA: 1,000 acres.

FUNCTIONAL STRUCTURES: Horn antenna with radome and controlbuilding.

FUNCTION OF STATION: Transmit and receive broadband communicationsignals. Tracking, computing updated orbital information,sending commands, receiving telemetry information.

PERMANENT RADOME: World's largest. (Would cover 3 acres if flat."

DIAMETER: 210 ft. HEIGHT: 161 ft . WEIGHT: 20 tons

MATERIAL: Dacron and synthetic rubber, 1/16 inch thick.

SUPPORT: Held up by air pressure about 1/10 psi.

;ONTRACTOR: Bird-Air Structures.

HORN ANTENNA STRUCTURE: (Horn with two cab structures)

OVER-ALL LENGTH: 177 ft . HEIGHT: 94 ft . WEIGHT: 380 tons

HORN OPENING AREA: 3,600 sq. ft .

ROTATING STRUCURE: Steel and aluminum

SIZE OF ELEVATION GEAR: 70 ft. diameter

REASON FOR HORN STRUCURE: Sides keep out ground radiation.

POINTING ACCURACY: 0.020

UPPER CAB SIZE: 28 ft. width x 30 ft. length. Transmit t ingand receiving equipment.

LOWER CAB SIZE: 28 ft. width x 68 ft. length. Control andpower equipment.

CONTRACTOR: McKiernan-Terry Corp.

HORN RECEIVER:

RECEIVING FREQ.: 4170 mc Broadband

RECEIVING INPUT; Maser ( crys ta l ) cooled to -4560 F


23/31

INPUT IGNAL: Varies from 1 billionth to 1/10 of a billionth-- f-a wa~tt.

RECEIVER BEAMWIDTH: 0.20

HORN TRANSMITTER:

TRANSMIT FREQ.: 6390 me

TRANSMIT POWER: 2 kw, using TWT output

TRANSMITTER BEAMWIJDTH: 0.160EqUIPMYNT: Modified Bell System TH microwave with additions.

CONTROL BUILDING: (1/4 mile away from Radome)

FUNO'ION: Telemetry, tracking an d command, with standardtelephone and TV terminal equipment fo r radio entrancelink.

MAIN EQUIPMENT:

a) 136 mc Beacon an d Telemetry Receiverb) 120 me Command Transmitterc j2j' General Purpose IBM 1620 Computersd 1 Helical Tracking Antenna (136 me receive,

12 0 me t ransmit)(e) (1) 8-ft. Cassegrainian Antenna (precision tracking

of 4080 me beacon)(f) Radio Link to Portland, Maine, Relay Terminal

Equipment (Bell System TJ)

BELL SYSTEM HOIMDEL. N.J.. GROUND STATION (Crawford Hill-Echo IStation)

FUNCTION: Receive broadband signal, Angle track on 4080 me.(Will no t transmit)

EQUIPMENT: Will use original Echo horn receiver similar tobu t smaller than Andover, modified to work with Telstar.

ATLANTIC MISSILE RANGE LAUNCH AND TEST FACILITIES:

LAUNCH PAD: Operated by Douglas Aircraft Co. fo r NASA.

GUIDANCE FACILITY: Command Guidance Facility operated byBell Telephone Laboratories for NASA.

TELSTAR TEST FACILITIES:

(a) 3 trailers to house, test an d trackb( "Quad-helix" tracking antenna

Q2) broadband test antennasd) Misc. test equipment at launch and guidance

facilities.


24/31

SUMMARY OF TELSTAR TELEMETRY SYSTEM:

DEFINITION OF TELEMETRY: A technique of transmitting infor-mation Irom remote measuring instruments. In th eTelstar satellite, the system will connect to variousmeasuring devices and transmit their readings to groundstation recorders.

TELEMET..RY FREQ,: 136 me

NUMBER OF MEASUREMENTS: 3.15 i tems to be measured andtelermeteri each minute,

TYPICAL MEASUREMENTS:

(a) Density and energy of e lec t rons and protons inVan Allen bel t

b 'emperature of satellite skinc Temperature of i n t e r io r e lec t ronic circuitsd Pressure inside electronic chassise Radiation effects on semiconductor devicesf Sunlight measurements to indicate angle of spin axisg Condition of electronic circuits in satellite

h Condit ion of battery

SEMICONDUCTORS USED IN MEASUREMIEN*TS:

(a) RADIATION MEASUREMENTS* (4 silicon diodes to be usedwith c rcui cideveloped in conjunction with BrookhavenNational .Laboratories)

(1) Almost no shielding, with fixed bias, will measureelectrons 1/ 4 to 1 MEV (Million Electron Volts.)

(1) Almost no tshielding, with varying bias, will measureprotons in 5 energy regions between 2 to 25 MEV.

(1) Thicker shielding, will measure protons above 25 MEV.

(1) Thicker shielding, will measure protons above 40 MEV.

(b) RADIATION DAMAGE: (10 semiconductors)

(3) solar cells, each shielded a different amount, ar emonitored for damage.

(6) unradiated si l icon transistors, in pairs, on skin ofsatellite are compared with

(1) preradiated silicon transistor

(c) LIGHT DETECTORS:

(6) special preradiated solar cells

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SUMMARY OF TELSTAR COMMAND AND CONTROL SYSTEM:

FUNCTION: Turn on and turn o ff equipment in satellite.

COMMND FREQUENCEY: 120 me band

COMMAND MODULATION: Pulse code.

COMMAND TRACK BEAM: 200

SUMMARY OF ACQUISITION AND TRACKING OF SATELLITE:

PRELIMINARY INFORMATION ON LAUNCH: NASA Goddard Space Flightcenter.

ORBIT INFORMATION ON EARLY PASSES: NASA Worldwide TrackingStations.

METHOD OF FEEDING ORBITAL INFORMATION TO ANDOVER TRACKERS:Magnetic tape.

COMPIYERS PROCESSING ORBITAL INFORMATION: (2) General purposeIBM 1b20 Computers a t Andover, Maine, working in p a r a l l e l .

TRACKING SIGNALS: 136 mc Beacon and 4080 me (Precision).

BEAM WIDTH OF COMMAND TRACKER: 200 - Should pick up target( even if tapes are inerror.

MAGNETIC TAPE POINTING INFORMATION: (Complete informationevery 4 seconds)

1. Exact times identified with:

2. Azimuth and elevation.

3. Azimuth and elevation velocities.

4. Range to satellite (used to adjust transmitter poweron ground).

5. Compensation for known errors in pointing of hornfor that particular azimuth and elevation.

ANTENNA CONTROL GROUP: (Lower bui ld ing of horn)

FUNCTION: Get point ing information from t rackers to itsspecial purpose digital computer and

1. Check validity of new information.2. Synchronizes timing with station clock.3. Interpolates 12 8 times per second between 4-second data

points .4. Compares pointing directions with actual positions of

horn through servo system.5. Adds calibration correction and error signal from "vernier

auto track." (Precision Tracker)


26/31

NATIONAL AERONAUTICS AND SPACE ADMINISTRATIONOffice of Public Information

Washington 25, D.C.

Telephone: Area Code 202 WO 2-4155'.0 3-6925

DELTA LAUNCH VEHICLE

Tineo beloa l enc l e , developed fo r NASA by the Douglas

Air' raptk Co., has the follows ng chiaracteristics:

90 feet

:,ax. Diame te r: 8 feet

Lif t -off Weight: A little less than 112,000 pounds

Firs t Stage (Mlodified Douglas Thor):

Fuel: Liquid (LOX and Kerosene)

Thrust: About 150,000 poundsBurning Time: 160 seconds

Second Stage (Aerojet General propulsion system):

Fuel: Liquid

Thrust: About 7,500 pounds

Burning Time: 109 seconds

ThirdStage (Allegany Bal l i s t i c s Laboratory X-248 solid motor):

Fuel: Solid

Thrust: About 3,000 pounds

Burning Time: 40 seconds (After 6 minute coast)

Guidance System (Bell Telephone Laboratories)

Firing Sequence:

The f i r s t stage fa l l s away on burnout. The second stageignite@ ImmeQae4ly, The nose fairing which covers third stageand payload iJ jQtti8Qned durinr, second stage burning, Theasoond and third otaga 0Qa0at for six min4too after a.oon;d

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27/31

stage burnout. Then, the third stage is spin stabilized,and the second stage falls away, and the third stage isignited. The third stage reaches an orbital velocity ofalmost 17,000 miles per hour.

Th e Delta vehicle has scored nine successful satellitelaunches fo r NASA. They are:

Echo I - August 12, 1960

Tiros IT - November 23, 1960

Explorer X - March 25, 1961

Tiros II I - July 12, 1961

Explorer XII - August 16, 19061

Tiros TV - February 8, 1962

Orbit ing Solar Observatory - March 7, 1962

Ariel (NASA-United Kingdom cooperative experiment) -Aprll 26, 1962

Tiros V - June 19, 1962

(h During the first Delta launch, May 1960, th e thirdstage did not ignite which fai led to orbit an Echo passivecommunication satellite.

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28/31

American Telephone & Telegraph Co.Public Relations Dept.195 Broadway, New York, N.Y.

PROJECT TELSTAR

BACKGROUND TO SATELLITE COMMUNICATIONS

RADIO, CABLES, MICROWAVE

Spanning th e Oceans

The first voice went overseas in 1915.

In t ha t year, th e Bel l Telephone System, in cooperation withth e United States Navy, demonstrated a voice-radio hookup betweenHonolulu, Washington, D.C., and Paris.

In 1921, the Bell System extended telephone cables to Cubafrom Key West, Florida.

Commercial transatlantic telephone service -- by radio --wa s offered by th e Bell System in 1).7. About 11,000 overseascalls were made that year.

Voices Travel Undersea

During the years that followed, Bell System scientists lookedagain toward the bottom of the sea as a pathway fo r the human voice.

The big problem was to devise small repeaters that could besubmerged as part of the cable to amplify voice signals many timeson their long journey across the oceans. Without that frequentreinforcement, the voice signals would become so weak they wouldbe lost in the transmission noise that is always present. Tobe economically practical, the cables had to be designed togive uninterrupted service for 20 years or longer.

By 1956, required facilities had been developed, and the firsttransoceanic submarine telephone cable linked this continent withGreat Britain.

The improved quality of service, plus the additional circuits,greatly increased the number of calls to Great Britain within ayear -- to over a quarter million in 1957.

Other cables were laid in quick succession.

To Alaska in 1956 ... to Hawaii in 1957 ... to continentalEurope in 1959 ... to Puerto Rico in 1960 ... to Bermuda in 1962.

By 1961 the yearly volume of overseas calls had soared toover 4,300,000.

Future Needs ... World-Wide

The volume of overseas communications is rapidly increasing.28


29/31

Also, the demand fo r overseas television channels is buildingup. and television requires channels of great frequency bandwidth. A single program requires an electrical path wide enoughto carry 600 separate telephone conversations.

Today, computers and other business machines are "talking"to each other in constantly growing numbers, As foreigneconomies expand, it is certain that great volumes of data willbe sent between machines from one side of the world to the other.High-speed data transmission, lso requires wide band.

And there is an increasing demand, of course,"forspecial

overseas communications services fo r defense an d security.

The Bell System currently operates more than 6oo telephone-grade circuits for overseas comnunications.

By 1965, it Is estimated -- conservatively -- that twicethat many will be needed.

By 1970, t h i s f igure wi l l be more than doubled again -- to3,000 circui ts -- and there will be a need fo r overseas t e l ev i s ionchannels.

By 1980, about 10,000 circui ts wil l be needed for telephoneuse alone. An additional 2,000 circuits will be needed for variousspecialized communications; and, of course, television require-ments will have jumped also.

More Cables on the Wa.

To meet current needs, additional undersea cable systemsare being built.

A cable is planned fczr Jamaica during late 1962 with a laterextension to South America. An additional cable will be opened

to Europe in 1963. Plans are underway fo r a cable to Japan. Anda co-operative use of foreign-owned cables -- present and planned --will continue.

Undersea cables will continue to be improved and will be animportant part of world-wide communications for decades to come --as will short-wave radio-telephone.

But it would take 50 undersea cables, of present design,Just to handle the estimated 1980 requirements for telephone anda fe w other services alone. And today's cables couldn't handlewide-band television at all. So, even though cables of larger

capacity may be installed, other possibilities must be fullyexplored. - 29 -


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Towers on Land

The communications paths for the future must be many in numbeito accommodate the great volume of messages. And they must havethe capacity to accommodate the special requirements of ' televisionand complex data transmission.

Microwave is the answer .. . fo r cables of present design andradiotelephone can meet only part of the requirements.

Microwave is a broadband radio systenm, It has tremendouscapacity. It can handle all types of

communications.Microwave radio is used widely ir n overland communicat ons.

It was first used by the Bell System 15 years ago. A largepercentage of Bell Telephone long distance messages today arecarried on microwave. Service is dependable -- and of high quality.

However, microwaves travel in a straight line. Numerous relaytowers are needed to intercept and amplify the signal repeatedly.

Up to ,ne present, mic:cowave -;.,ansmisBion hai not beenpractical across wide bodies of water. A signal sent across theAtlantic, fo r instance, would soar off ' into space. Instead offollowing the curve of th e earth, There is no way to build thetowers needed to intercept and amplify the signal.

SoJ for microwave transmission overseas, a very special kindof "tower" is needed -- a tower in the sky D- a satellite.

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American Telephone & TelegraphPublic Relations Dept.195 Broadway, view York, N.Y.

TELSTAR PROJECT OFFICIALS

BELL SYSTEM

Bell Telephone Laboratories:

Alton C. Dickieson, executive director, transmissiondevelopment division.

Eugene F. O'Neill, project director

Irwin Welber, test conductor, andover, Me.

William C. Jakes, Test conductor, Hclmdel, N.J.

Robert H. Shennum, head, satellite design department

H. Nelson Upthegrove, head, satellite launch operationsdepartment

song Lines Department, A.T.&T.

Robert E. Sageman, transmission planning engineer

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DID ---

telstar press kit

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