#* 6® Project Echo and the Telstar® experiments were pioneering steps in the development of a global satellite communications system. As successful

ventures in government-private enterprise cooperation, they were tangible evidence of the Bell System's constant effort to create new and b e t t e r c o m m u n i c a t i o n s f o r t h e n a t i o n

it serves. Operational communications by satellite is a reality today. The hundreds of Bell System people who contributed to the success of the Echo

and Telstar projects are justifiably proud of the role they played in bringing people of different lands into

closer contact with one another.

.. America's new star in the skies bears one other indisputable and praiseworthy distinction. It is a work oi peace, Telstar threatens no one, menaces no one, does not carry within itself the potential of disaster. It

seeks to build, not to destroy. All those who had a hand in putting it into space can view their work with satisfaction, and the country in which it was developed can present it to Excerpt from an editorial tliat appeared in the New York Herald Tribune on July 11, the world with pride ..." 1 9 6 2 , t h e d a y a f t e r Te l s t a r I w a s l a u n c h e d . satellite communicetions-tiie deginnlngs

Communication by satellites orbiting the earth was considered to be pure science fiction only a quarter of a century ago. Even the very idea of launching a satellite into space then seemed, in terms of years, remote indeed to the scientific community. Yet in 1945, Arthur C. Clarke, a noted English scientist and writer, seriously suggested such an idea in an article published in Wireless World, Clarke envisioned a manned satellite in space acting as a relay station for television signals between continents. Although this proposal seemed far in advance of its time, events were soon to catch up A. ^ ^ to and even by-pass many of the initial theories. □ On January 11,1946, the U.S. Army Signal Corps facility at Ft. Monmouth,

N. J., began a series of tests known as Project Diana. During these experiments, microwave radar signals were bounced off the moon and back to earth again, proving for the first time, that relatively low power could transmit signals over extremely long distances. □ Dr. John R. Pierce of Bell Telephone Laboratories advanced proposals for a space satellite communications system in a formal paper delivered at Princeton University in November 1954. Five months later, Pierce's concept, similar to what was to eventually embody the Telstar experiments, was published in Jet Propulsion magazine under the title, "Orbital Radio Relays." □ On October 4,1957, the Soviet Union astounded the world and catalyzed United States space efforts by launching and successfully putting into orbit the first satellite. Sputnik I. This scientific breakthrough was followed only a month later with the successful orbiting of Sputnik II. The real research and development work on satellite communications now began in earnest. □ The United States formally entered the "Space Age" on January 31, 1958, when the U.S. Army successfully launched Explorer I into orbit. Five months later. Congress, now fully aware of the critically important scientific and political implications of this new frontier, passed the National Aeronautics and Space Act, setting up the National Aeronautics and Space Agency (NASA). One of the principal areas of endeavor for this new agency was to be satellite communications experimentation. □ Score, the first satellite to be used for voice communications, was launched by the U.S. Air Force on December 18, 1958. Score was equipped with tape recorder units that transmitted prerecorded messages back to earth on receipt of signals. The day after it was launched, a Christmas greeting to the world recorded by President Eisenhower was transmitted. Score continued to transmit for 12 days before its batteries became too weak for further use. □ Project Moonbounce, which carried the experiments of Project Diana several steps further, was the predecessor to the forthcoming Echo experiments. In November 1959, scientists at Bell Telephone Laboratories' Holmdel, N. J., location and at the Jet Propulsion Laboratories in Goldstone, California, accomplished live voice transmission by using the moon some 250,000 miles away as a passive reflector. Signals were bounced off the moon, received, and understood on the opposite side of the continent. The transmission delay was about six seconds. Altogether, 17 moon-bounce tests were successfully conducted. echo I-the first passive communications sateiiite

The Bell System's role in satellite communications experimentation began in the early morning hours of August 12, 1960, at Cape Canaveral (now Cape

Kennedy), Fla. A Thor-Delta missile was launched on that day with the world's first passive communications satellite intricately folded and tucked away in a capsule underneath its nose cone. The missile was commanded and guided by a system designed by a Bell Laboratories-Western Electric team. □ Echo I, an inflated ten-story-high balloon, was put into a circular orbit around the earth approximately 1,000 miles up. Its speed was more than 16,000 mph. The balloon was made of an aluminized Mylar-coated skin half as thick as the cellophane on a cigarette package. □ Some 80 minutes after launch. Echo I was spotted over Woomera, Australia. A half hour later it was picked up at Goldstone, California, and seven minutes after that Bell Laboratories engineers at Holmdel picked up the balloon's reflection of Goldstone's radio beam. (Upper Left) The receiving horn antenna used in both Project Echo and Telstar experiments at Holmdel, N.J. (Left Center) The Delta space vehicle with the 100-foot deflated "Echo I" satellite canister shown on top of rocket. (Lower Left) Ten-story-high Echo I Satellite. The sphere was made of .0005-inch thick Mylar plastic coated with aluminum. (Right) Bell Laboratories William C. Jakes (hand on belt) awaits confirmation of transmission test on the Echo I satellite. o In the ensuing weeks, a number of two-way telephone conversations as well as transmission of music and data were sent between Holmdel and Goldstone using this balloon as a passive relay station in the sky. Communi cations were also made to other points in the United States and Europe. □ Echo I continued to be used for many weeks, demonstrating that a passive satellite would work and providing valuable data for future experiments in satellite communication. After several months, the once-smooth balloon, punctured by tiny meteorites, shriveled in space, thus reducing its effectiveness as a radio mirror. □ Project Echo, a joint undertaking by the Bell System, The Jet

Propulsion Laboratories and NASA, was the first major effort in an experi ment to study long-range communications using an orbiting earth satellite. The success of these experiments was due in large part to extensive research and development efforts carried on over the years at Bell Laboratories. □ A horn-reflector antenna originally designed for cross-country radio relay proved adequate to scoop up the tiny microwave reflection (millionths of a billionth of a watt) expected from Echo. Engineers employed a method of receiving microwave signals known as wideband frequency modulation with negative feedback. Invented 23 years before at Bell Laboratories and little used until then, this method was employed with modern circuitry at Holmdel and Goldstone and performed well. New types of low-noise

amplifiers using solid-state masers gave excellent results. For example,

a ruby maser, unlike previous amplifiers, created virtually no radio "noise" Transmitting antenna used on Project Echo experiments. of its own and enabled scientists to "hear" the very tiniest of signals from outer space. And tracking of the satellite by electronic computers,

by radar, and by telescope proved to be extremely reliable. □ Project Echo was undoubtedly the first important milestone in the development of an operational satellite communications system. The success of these experiments caught the imagination of the world. People in distant lands were fascinated as night after night they watched this 100-foot-high silverized balloon, clearly visible to the human eye, streak past in the sky overhead. □ Stripped of its dramatics, however. Project Echo was the first practical demonstration of extending communications facilities into space. The stage was now set for the first Telstar experiment. the teistar project is hern

The success of the Echo experiments, coupled with new technological advances at Bell Laboratories, prompted the American Telephone and Telegraph Co., parent unit of the Bell System, to continue experiments in satellite com munications on a much broader scale. In January 1961, AT85T was authorized by the Federal Communications Commission to establish an ex perimental communications link across the Atlantic Ocean. Two 170-pound active repeater satellites were to be launched by NASA^ and all launching costs were to be paid by AT&T. In addition to enlarging facilities .at Holmdel, N. J., a new satellite communications ground station would be built in Maine. □ During these forthcoming experiments, a microwave signal would be beamed from a ground station to the satellite. The satellite would pick up the signal, amplify it, and retransmit it back to earth again on a different frequency. The recently completed Echo experiment involved the transmission of only one two-way telephone conversation at any one time. These new experiments would be aimed at transmitting a broadband signal capable of carrying a number of voice or data channels, or alternately, a single live television signal. □ Thus, the Teistar project was born. Eventually, it would involve As satellite (1) comes over the horizon, the efforts of more than 1,000 people in the Bell System, including some the Command Tracker ( 2 ) acquires the satellite, and passes hold information 400 scientists, engineers, and technicians at Bell Laboratories. to the Precision Tracker (3) which directs More than 800 firms, three-fourths of them small businesses, would provide the Horn Antenna (4) to lock on the satellite for communication signals. Over services. And the entire project, with a series of experiments that were all coordination is handled by personnel to extend over three years, would cost about $60 million. located in the Control Building (5). microwave radio reiay

Microwave radio relay refers to very short wave, high-frequency radio Microwave radio relay tower u s e d f o r b u l k c o m m u n i c a t i o n signals, billions of cycles per second. These frequencies are capable of carry services. Microwave systems ing a great deal of information but, unlike lower frequency signals, usually require amplifying towers about every thirty-miles. travel only in straight lines and do not bend around the curvature of the earth. For this reason, microwave radio systems need relay towers every 30 miles or so. A signal beamed across a large body of water like the Atlantic Ocean, for example, would simply soar off into space. □ Microwave is used today for bulk communications over land and represents a major method by which long distance telephone calls and TV programs are transmitted across this country's nationwide communications network. □ Obviously, it wasn't feasible to build a string of microwave radio relay towers across the ocean. But a communications satellite orbiting at an altitude visible from both continents could provide a "line-of-sight" microwave link as long as it was above the horizon at both places. A sys tem of such satellites operating in this manner could provide continuous ser vice and greatly augment present submarine cable and radio-telephone facilities for world-wide communications. This was the basic concept under lying the Telstar experiments. objectives of the teister experiments

The primary purpose of the Telstar experiments, of course, was to prove that a broadband communications satellite could transmit telephone messages, data, and television. Beyond that, however, there were secondary objec tives almost as important as the communications aspects of the project. □ These included testing—under the stresses of an actual launch and the hazards of space—some of the electronic equipment that had been developed for satellite communications, the measurement of radiation that a satellite might encounter in outer space, the best ways to track a moving satellite accurately, and the test for the special satellite communications antennas and ground station equipment. □ The first Telstar satellite was equipped with special testing devices to report on facts about the environment in space and the possible effects of radiation, par ticularly in the Van Allen Belt, on its solar cells and transistors. Telemetry equip ment was put in the satellite to enable it to record and transmit back to earth a large number of these measurements, along with the temperature and pressure inside its shell, its orientation with respect to the sun, and the current and voltage in various parts of its electronic circuitry. To help in tracking, the satellite was equipped to beam a continuous radio beacon signal back to ground stations. □ Finally, the satellite was designed so it could be "commanded" from the ground to turn itself on or off to conserve its solar power plant. the andover ground station

We have already seen that Project Telstar was an extension into space of (Right) Horn antenna at microwave communications principles that had been thoroughly proved out Andover, Me., transmits and receives communica and put to successful commercial use on the ground. For Project Echo and tions from space satellites. other early experiments in satellite communications, Bell Laboratories built ( B e l o w ) Q u a d - h e l i x c o m mand tracker, located at a large horn-reflector type antenna at Holmdel. For the Telstar Project a horn- Andover, Me., "acquired" Telstar I on first visible antenna was designed similar to, but much larger than, the one at Holmdel. It was pass, July 10, 1962. located in a relatively isolated spot near Andover in the western part of Maine. The site is protected by a surrounding ring of low hills, high enough to keep out interfering radio signals yet low enough not to block line-of-sight to satellites when they appear in their orbits over the horizon. □ The Andover horn-antenna is a steel and aluminum structure 177 feet long, 94 feet high. It weighs 380 tons. A giant opening of 3,600 square feet tapers down to a cab where the highly sensitive receiver and powerful transmitting equipment are located. The antenna and its associated equipment — horn, cab, and supporting framework—moves smoothly on tracks that allow it to rotate in a 360-degree circle around its vertical axis (changing azimuth). The horn of the antenna also can rotate about its horizontal axis from the horizon up to the zenith (changing elevation). Despite its size the antenna is built to tolerances normally associated with fine watches. □ The horn's 68-foot-wide mouth funnels down to a wave guide with a

one-square-inch aperture and then to a pencil-thin tube that leads to a ruby maser, the heart of the ultra-sensitive receiving equipment. □ The entire antenna structure and its associated equipment are protected from the weather by a huge inflated "radome"—a bubble made from Dacron and synthetic rubber only about a sixteenth of an inch thick but measuring 210 feet in diameter and 160 feet high (as high as an 18-story building). It is one of the largest air-supported structures of its kind ever erected. □ The Andover ground station includes additional equipment, most of it associ ated with tracking satellites, computing their orbits, sending and receiving command and telemetry signals, and interconnecting satellites with regular telephone and television land lines. A majority of this equipment is located in a control building about a quarter of a mile from the giant radome.

Huge horn antenna at Andover, Me., during construction resembles giant erector set. The completed horn, with its 3,600-square foot mouth, is used to transmit and receive communications from space satellites. Picture (upper right) shows placement of the permanent radome over temporary cover used during construction. The cranes gently pull new cover in place. Photo (far left) shows radome foundation as it appeared in spring of 1961. 'mm testing and refinement

All components and sub-assemblies of the active repeater Telstar satellites were subjected to a great number of exacting tests with performance records kept and evaluated for each item. Throughout these vigorous exam inations, a number of refinements were made to insure that the satellites would perform faultlessly in space. □ At Bell Laboratories locations in New Jersey, the fully assembled models were put through balancing, vibration, magnetic drag, and transmission tests followed by several days of testing on a centrifuge and in a chamber designed to stimulate the thermal-vacuum conditions expected in outer space. Construction and testing of the actual "fly" models were performed under hospital-like, dust-free conditions. (Left) Technicians apply insulated blan □ Still more tests—solar cells, antennas, transmission, and telemetry—were ket to Telstar canister. Preparing Telstar for launch was handled in an operating- made in Florida. Some testing continued even after they were room atmosphere. (Above ) Solar cells be mounted on their Delta launch rockets. ing installed on the Telstar satellite. telstar I

In the pre-dawn hours of July 10, 1962, a Thor-Delta rocket launched Telstar I into its orbit, almost exactly according to plan, from NASA's space center at Cape Canaveral. On Telstar's sixth orbit around the earth—at 7:26 p.m.—the first transmission to and from the satellite took place. During this pass, telephone calls, television, and photos were transmitted between Andover and Holmdel. Some of these signals also were picked up at ground stations in Europe. □ On the next day a taped television program was transmitted via Telstar from France to the United States and a live program came from England's satellite communications ground station at Goonhilly Downs in Cornwall. □ In the next several months, more than 400 transmissions were handled by Telstar I, including 50 television demonstrations (both black and white and color), the sending of telephone calls and data in both di rections, and the relaying of facsimile and telephotos. □ In addition, this new "radio relay tower in the sky" performed more than 300 valuable technical tests. Radio transmission was as good as expected, and communications equipment functioned normally with no apparent damage from the shock and vibration of launch. □ Temperatures inside the satellite were maintained at proper levels and the satellite was successfully stabilized—prevented from tumbling over and over in its orbit around the earth. The solar cells worked almost exactly as planned and much extremely valuable data about radiation in space was reported. In the meantime, the ground stations were accurately tracking this fast-moving satellite in almost routine fashion. □ Four months after Telstar I was launched into orbit, it began to experi ence difficulties in some of the transistors in its command circuit. Apparently the satellite had met radiation in space estimated to be 100 times more intense than was predicted. As a result, the command circuit stopped operating completely on November 23, 1962.

□ At Bell Laboratories, engineers worked out an ingenious "trick" command (Left) Thor-Delta rocket off the pad at Cape Kennedy with the Telstar I satellite. signal which succeeded in by-passing the affected transistors. On Telstar I was used for hundreds of space December 20, Telstar I was returned to normal operation. Some time communication experiments. (Above) E. F. O'Neill, Bell Laboratories, displays later, however, the satellite again failed to respond to commands "thumb of success" after getting word that from the ground, and on February 21, 1963, it went silent. Europe had received signal from Telstar I. teistar ll

On May 7,1963, Teistar II was launched into an elliptical orbit almost twice as large as that of Teistar I, ranging from an apogee of 6,697 statute miles to a perigee of 604 statute miles. The availability of an improved, more pow erful Delta rocket made it possible to place this satellite into an orbit with a greater apogee, about 3,000 statute miles further out in space. □ As a result, Teistar II provided almost 50 per cent more simultaneous visibility on each pass between Andover, Maine, and ground stations in Europe. Also, it was on occasion simultaneously visible with Japan, which later permitted experiments with the Orient. □ The greater apogee enabled Teistar II to spend more time in areas of less intense radiation and, therefore, it was subjected to less radiation damage. In addition, it allowed the satellite to report on areas of space—particularly in the outer Van Allen Belt and the "slot" between the belts—that Teistar I didn't reach. □ Teistar II was basically the same in appearance as its predecessor. Modifications within its shell, including some new radiation-measuring equipment, added about four and a half pounds to its weight. The satellite's radiation measuring devices had a greater range of sensitivity, and there were six new measurements (118 in all) that it reported back to earth. □ Teistar II was able to send its telemetry reports via microwave as well as on the VHP (Very High Frequency) beacon used by Teistar I. A simplified method of operation for the Andover horn-antenna was used, with the autotrack alone employed for precise tracking and pointing. To help prevent the kind of damage that occurred in the transistors of Teistar I's command decoders, the second Teistar satellite used an improved type of transistor. □ Teistar II's first successful television transmission took place on the day it was launched and a new series of technical tests, radiation measurements, and experiments in transoceanic communications began. (Left) Teistar II gets final inspections prior to launch □ Two years later, as scheduled, an automatic timer in the satellite turned f r o m C a p e K e n n e d y. off the telemetry beacon. The reason for this "turn off" during Teistar II's Improved Delta Rocket placed Teistar II about 4,736th orbit around the earth was to release the 136 mc/s radio fre 3,000 miles further out in space than Teistar I. quency for use by other satellites. The main communications function of ( A b o v e ) Te i s t a r I a n d I I the satellite, however, was still operative. typical orbits, May, 1963.

first commercial satellite communications service

The first commercial transoceanic communications service between the United States and Europe by way of a satellite was inaugurated on June 28, 1965. In ceremonies which included an international telephone hook-up with world leaders in London, Paris, Bonn, Rome, and Bern, Switzerland, President Lyndon B. Johnson in Washington hailed the event as "a milestone in communications between people and nations." □ Establishment of commercial telephone service between the U.S. and 12 European countries was initiated by the Communications Satellite Corporation (Comsat) through the facilities of its Early Bird satellite. □ Comsat was created by the Communications Act of 1962. As a government

sponsored but privately owned company, it was formally incorporated on February 1, 1963. Ownership is vested in private stockholders as well as other international communications carriers, including AT85T. □ Early Bird was built for Comsat by the Hughes Aircraft Corporation and (Left) American flag with successfully launched by a Thrust-Augmented-Delta (TAD) rocket from Andover radome in back Cape Kennedy on April 6, 1965. Successfully tracked and commanded from ground was first television transmission by Telstar I. the Andover ground station, the satellite went into a high synchronous orbit (Above) The Communica about 22,300 statute miles above the earth. Early Bird's speed, about tions Satellite Corporation's " E a r l y B i r d " s a t e l l i t e , 7,000 m.p.h., is synchronized with the rotation of the earth so that its position p r o v i d e s 2 4 0 - t w o w a y appears to be fixed in one spot as it is viewed from the earth. telephone channels. bell telephone laboratories'contributions to space communications

THE TRANSISTOR—a tiny, solid-state amplifying device which made practical the miniaturization of so many

components. Telstar I was less than a yard wide yet contained some 15,000 parts.

THE SOLAR CELL—3,600 of these cells mounted on ceramic bases in a platinum

frame on the satellite's skin converted sunlight into electricity for Telstar's power.

T H E T R A V E L I N G W A V E T U B E — a

12-inch-long, pencil-thin electron tube in the satellite which boosted the strength of radio signals received from earth by as much as 10,000 times.

THE HORN-ANTENNA AND RECEIVER—the

highly sensitive receiver at Andover used a ruby crystal maser operating at the temperature of liquid helium (a few degrees above absolute zero) to amplify signals as weak as a trillionth of a watt. Satellites are basically a practical

extension of existing transoceanic

radio-telephone and submarine cable facilities. As new technology adds

f u r t h e r r e fi n e m e n t s a n d

improvements in transmission,

satellites will make communications

between continents as convenient and

diversified as the service we in the

United States now enjoy. In addition,

satellites will provide access to countries difficult or impossible to

reach by radio or submarine cable. The successful development of

communication satellites marks still

another significant step in man's

continual effort to communicate over

great distances more effectively. The introduction of operational

satellites is probably one of the most

exciting milestones in modern communications history. To many

people throughout the world, this new dimension in global communications

nurtures the hope for increased

mutual understanding and a strengthening of the cause of peace among nations. SB# A!®®'*

VC# Btt#®