Collins’ work in radio astronomy centered on design of a precision tracking device known as the radio sextant. This provided an advanced navigation method for ocean vessels which was not affected by weather conditions.
The first sextant, tested in the early 1950s, detected only energy from the sun, which restricted its effectiveness to daylight hours. However, as advances were made and a more sensitive antenna and receiver were developed, a sextant was built which could track both the sun and the moon. Lunar radiation is about 50 times weaker than that of the sun.
Radio astronomy work at Collins also resulted in a highly significant scientific discovery in the late 1940s.
While tracking the moon with a radio telescope during an eclipse, Collins’ engineers observed that the lunar microwave temperature did not differ greatly from temperatures recorded during direct sunlight on the moon surface. This led to the conclusion that lunar radiation came not only from the surface, but also from layers of material beneath the surface-far enough below the surface that the temperature remained constant.
The radio astronomy and resulting radio sextant achievements gave Collins its initial background and experience in the emerging field of space technology. (Image 2)
With this and other radio propagation research, Collins entered the space age with perhaps as much knowledge as any company had in space communications.
From this start the company has continuously been deeply involved in space and space-related communication activities.
A brief summary of such activities includes:
- Manned spacecraft and satellite communication systems.
- Ground tracking and communication systems for manned space flight and scientific satellites, including deep space probes.
- Significant space research including participation in a 1951 bounce of a radio signal off the moon, and first transmission of a wire-photo through space (bounced off Echo I). (Image 1)
- Missile command and control systems.
- Pioneering efforts in space antenna research, including construction in 1951 of the largest parabolic antenna in the world at that time.
- Commercial satellite communication stations.
- Extensive systems for the Atlantic and Pacific Missile Test Ranges.
- Detailed studies of the Echo satellite, obtained from nearly three years of tracking and experiments.
- Flight testing and evaluation of voice and data communication via satellite between two aircraft or aircraft and ground stations.
- Development of a variety of mobile man-pack, vehicular, airborne and shipboard terminals for tactical communication via satellite.
The most widely known of these space activities is Collins’ participation in the Mercury, Gemini and Apollo manned spacecraft programs. Collins has the distinction of developing and manufacturing equipment which has provided voice communication for every American astronaut in space. Even preceding the Mercury program, Collins equipment was used for communication and navigation aboard the X-15 rocket plane, actually the first vehicle to explore the fringes of space. Collins engineers had long considered the problem of transmitting human voice through space, and were ready when the challenge came. Selection of Collins in 1958 by the McDonnell Company to furnish the Mercury communication system resulted in the compact, high reliability spacecraft equipment for voice, telemetry, tracking and recovery communication used by Astronauts Shepard, Grissom, Glenn, Carpenter, Schirra and Cooper. Experience in the one-man Mercury spacecraft program led to Collins’ participation in Gemini, designing and manufacturing the voice communication system which performed successfully on all 10 of the two-man Gemini missions. (Image 5)
Even before Gemini flights were underway, plans were launched for the Apollo moon-landing program, and Collins, as a subcontractor to North American Aviation, was assigned responsibility for the complex communication and data subsystem aboard the spacecraft.
Development and production of the Apollo system occupied nearly five years, and at its peak period nearly 600 Collins employees were involved in the effort. In addition, five other companies were key subcontractors to Collins for various units of the system, with Collins acting as system manager.
Far more complex and with vastly increased capability over the previous manned spacecraft systems, the Apollo system utilized unified S-band to combine two-way voice and telemetry, ranging, and the down link TV signals in a single transmission method. The system had its most significant test on the moon-circling Apollo 8 mission, when millions of persons throughout the world marveled at the clarity of radio communication and live TV from 240,000 miles out in space.
In addition to unified S-band, the Apollo system includes VHF equipment for near earth communication, and for the Command Module to Lunar Module communication link. The VHF method is similar to that used in Mercury and Gemini.
Equally as necessary and important to the Apollo program as the spacecraft system is the network of unified S-band ground tracking/communication stations, for which Collins was prime contractor to NASA’s Goddard Space Flight Center.
That contract required the design, equipping and installation of 14 stations in all, 11 of them with 30-foot diameter antennas and three with 85-foot diameter antennas, the latter serving as the deep space link on lunar missions. In addition, equipment was provided for tracking ships.
Leading up to such an achievement was years of previous experience and capability in tracking stations and the electronics for maintaining contact with satellites in orbit or traveling to other planets. Still standing atop the Naval Research Laboratory building in Washington, D.C. is a 5O-foot diameter parabolic reflector antenna constructed by Collins and installed there in 1951. At that time it was the largest ever built, and also for several years was the highest gain antenna in existence. The Navy has used the facility through the years in radio astronomy investigations.
Between 1958 and 1963 Collins provided a total of 11 space tracking stations. First of these was at the 85-foot dish antenna facility of the Jet Propulsion Laboratory, at Goldstone, Calif., which has been used in many of America’s deep space satellite probes. Collins supplied all major equipment except the 85-foot reflector, mount and hydraulic servo mechanism.
Not only the electronic equipment but also buildings and access roads were provided by Collins, a pattern repeated in many other station projects.
Following the Goldstone installation was another tracking station in Puerto Rico, used to track down-range flights of missiles from Florida. (Image 4)
Other NASA installations include Rosman, North Carolina; Fairbanks Alaska; Newfoundland, and Australia. Including the Unified S-band network, Collins has installed or participated in work on more than 25 space tracking/communication stations throughout the world. Collins’ research activities and facilities have added much to space tracking and communication knowledge. The facilities include a 60-foot diameter parabolic reflector at Dallas, erected in 1962 and used since then to investigate many aspects of satellite communication.
One of the latest stations, near Moree, New South Wales, Australia, was equipped and built under contract to the Australian Overseas Telecommunication Commission. Equipped with a 90-foot diameter antenna, the station provides a satellite communication link for Australia with North America and Asian nations. At full capacity, the station has the capability of transmitting and receiving 600 voice channels and one television channel simultaneously.
Among early space communication research activities of Collins was a moon relay in 1951, a project involving the company and the National Bureau of Standards.
On two occasions when the moon position was favorable, Collins engineers at Cedar Rapids, Iowa, and NBS scientists at Sterling, Virginia, aimed antennas toward the moon. Using a 20-kilowatt transmitter powered by an ultra high frequency Resnatron tube developed by Collins, a coded signal was sent toward the moon. The moon served as a reflector to return sufficient radio energy to the NBS station, 800 miles from the transmitting site. Although not the first “moon bounce,” the Collins-NBS experiment was the first use of UHF frequencies for that purpose.
Another area of study which provided extensive data on tracking was the work of Collins involving the Echo I inflatable balloon satellite. Echo I, which had a considerably longer life than originally expected, was tracked by Collins engineers at intervals for nearly three years. Measurement of signal strength and variations in the signal as Echo passed in range of the Cedar Rapids tracking station indicated changes in the balloon’s size and shape.
Collins conducted experiments with Echo in 1960 which included live voice communication between Cedar Rapids and Dallas via the satellite, and transmitting a wire-photo picture of President Eisenhower. Echo research yielded valuable data on orbital variations, acquisition and tracking of a satellite, and radio propagation from earth into space.
In the cases of both the moon bounce and the Echo experiments, transmissions were the first ever made between distant points on earth via a man-made satellite or the moon. Collins did considerable work starting in the 1950s on providing components and guidance and control systems in several U.S. missile programs. The Collins’ Autotune® was adapted for use in several of these.
Among programs in which the company participated by developing and producing systems or partial systems were the Bomarc, Sergeant, Terrier, Nike-Ajax, Atlas and Firebee missiles.
Communication systems linking stations within the Atlantic and Pacific Missile Ranges, and equipment to assist in tracking of those facilities, is another area of extensive activity in the space field.
Collins antenna systems and high frequency equipment, as well as microwave systems, are employed for communications between launch control centers and downrange stations.
America’s most massive and comprehensive rocket-spacecraft preparation and launching facility is the Launch Complex 39, at Kennedy Space Center, Fla. This is where the giant Saturn-V rocket stages are assembled, the Apollo spacecraft sections are mated with the rocket, and the entire vehicle is transported to the launch pad and sent on its space journey.
Basically the Complex 39 includes the gigantic Vehicle Assembly Building, the control center for checkout and launch, the crawler-way, mobile launch towers and service tower, and two launch pads.
To tie all the facilities together, aversatile intercommunication system was developed and installed by Collins throughout the 39 facilities of the Launch Complex. Consisting of some 2,000 operator stations and coaxial cable links, the system is called RADIC (for Radio Interior Communication).
In addition to manned spacecraft communication systems, Collins has familiarization with unmanned satellites through systems supplied for Explorer series satellites, specifically two of them for which Dr. James A. Van Allen of the University of Iowa was responsible for instrumentation.
The lnjun Explorer satellites carried command receivers and antenna systems designed by Collins. (Image 6)
Another space communication area in which Collins has done a great deal of work to gain detailed engineering knowledge is in use of VHF frequencies for communication via satellite. Use of this method is advocated in many aviation circles for long range air to ground or air to air communication, particularly for flights over oceans.
Collins has collected extensive data through use of a test package installed on airline jet freighters on regular flights, including trans-Pacific flights. Data obtained by recording transmissions between the aircraft and ground stations via a synchronous orbit satellite is analyzed to obtain necessary equipment design and operational information.
For the past two years Collins has been involved in developing a series of UHF ground terminals for use in a joint military service tactical satellite communication program.
Known as TACSATCOM, the program involves delivery of terminals ranging from a one-man alert receiver to a three-man team pack, vehicular configurations, and airborne and shipboard systems. The terminals will be used by the military services to test and evaluate communication by satellite relay for tactical situations.
Also Collins is currently working as a major subcontractor on the communication system for the U.S. Air Force Manned Orbiting Laboratory (MOL) program.
The era of the missile, the satellite and manned space flight has depended upon and stimulated knowledge in nearly every area of science and technology. Equally important with all other disciplines for space exploration is communication.
Collins has furnished and continues to provide significant contributions to space communication.