Telstar
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Telstar is the name of various communications satellites, including the first ever such satellite.
The first two Telstar satellites were "Telstar 1", launched July 10, 1962 and operational until February 21, 1963, and "Telstar 2", launched May 7, 1963 and operational until May 16, 1965. They were experimental, and nearly identical. Telstar 1 relayed the first television pictures, telephone calls and fax images through space and provided the first live transatlantic television feed.
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[edit] Description
Belonging to AT&T, the original Telstar was part of a multi-national agreement between AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National PTT (Post, Telegraph & Telecom Office) to develop experimental satellite communications over the Atlantic Ocean. Bell Labs held a contract with NASA, reimbursing the agency three million dollars for each of the two launches, independent of success. The US ground station was Andover Earth Station in Andover, Maine, built by Bell Labs. The main British ground station was at Goonhilly Downs in southwestern England, and it was used by the BBC. It was the international coordinator and the standards 525/405 conversion equipment (filling a large room) was researched and developed by the BBC and located in the BBC Television Centre, London. The French ground station was at Pleumeur-Bodou (48°47′10″N 3°31′26″W / 48.78611°N 3.52389°W) in north-western France.
The satellite was built by a team at Bell Telephone Laboratories, including John Robinson Pierce who created the project,[1] Rudy Kompfner who invented the traveling wave tube transponder used in the satellite,[1][2] and James M. Early who designed the transistors and solar panels for it.[3] The satellite is roughly spherical, measures 34.5 inches (880 mm) in length, and weighs about 170 pounds (77 kg). Its dimensions were limited by what would fit in one of NASA's Delta rockets. Telstar was spin-stabilized, and its outer surface was covered with solar cells to generate electrical power. The power produced was a tiny 14 watts.
The original Telstar had one innovative transponder to relay data, which was a television channel or multiplexed telephone circuits. An omnidirectional array of small antenna elements around the satellite's "equator" received 6 GHz microwave signals to be relayed. The transponder converted the frequency to 4 GHz, amplified the signals in a traveling-wave tube, and retransmitted them omnidirectionally via the adjacent array of larger box-shaped cavities. The prominent helical antenna was for telecommands from a ground station.
Unlike most of today's communications satellites, Telstar was on an elliptical orbit, which meant[clarification needed] the ground antenna had to track the satellite as it came around the world approximately every 2.5 hours. Because the transmitting and receiving radio systems on board the satellite were not nearly as powerful or capable as ones on today's satellites, the ground antenna had to be huge. Morimi Iwama and Jan Norton of Bell Laboratories were in charge of designing and building the electrical portions of the system that steered the antennas. The aperture of the antennas were 3,600 square feet (330 m2). The antennas were 177 feet (54 m) long and weighed 380 tons. The antennas were housed in radomes the size of a 14-story office building. The challenge was to steer the huge antenna to track the satellite that moved up to 1.5 degrees per second with a pointing error of less than a .06 degree.
Launched by NASA aboard a Delta rocket from Cape Canaveral on July 10, 1962, Telstar 1 was the first privately sponsored space launch. A medium-altitude satellite, Telstar was placed in an elliptical orbit (completed once every 2 hours and 37 minutes), inclined at an angle of approximately 45 degrees to the equator, with perigee about 1000 km from Earth and apogee about 6000 km from Earth.[4] Because of this, its availability for transatlantic signals was limited to 20 minutes in each orbit that passed over the Atlantic Ocean.
[edit] In service
Telstar 1 relayed its first television pictures (of a flag outside Andover Earth Station) to Pleumeur-Bodou on the date of its launch. Almost two weeks later, on July 23,[dubious ] it relayed the first live transatlantic television signal. The first broadcast was to have been remarks by President John F. Kennedy, but the signal was acquired before the President was ready, so the lead-in time was filled with a short segment of a televised major league baseball game between the Philadelphia Phillies and the Chicago Cubs at Wrigley Field. (Box Score.) The batter Tony Taylor was seen hitting the ball to the right fielder George Altman. During that evening,[dubious ] Telstar 1 also relayed the first telephone call to be transmitted through space, and it successfully transmitted faxes, data, and both live and taped television, including the first live transmission of television across an ocean (to Pleumeur-Bodou). (An experimental passive satellite, Echo 1, had been used to reflect and redirect communications signals two years earlier, in 1960.)
Telstar 1, which had ushered in a new age of the benevolent use of technology, became a victim of technology during the Cold War. The day before Telstar 1 was launched, the United States had tested a high-altitude nuclear bomb (called Starfish Prime) which energized the Earth's Van Allen Belt where Telstar 1 went into orbit. This vast increase in radiation, combined with subsequent high-altitude blasts, including a Soviet test in October, overwhelmed Telstar's fragile transistors;[5] it went out of service in early December, but was restarted by a workaround in early January 1963.[6] The additional radiation associated with its return to full sunlight once again caused a transistor failure, this time irreparably, and Telstar 1 went out of service on February 21, 1963.
According to the US Space Objects Registry, Telstar 1 and 2 were still in orbit as of June 2009.[7]
Experiments continued, and by 1964, two Telstars, two Relay units (from RCA), and two Syncom units (from the Hughes Aircraft Company) had operated successfully in space. Syncom 2 was the first geosynchronous satellite and its successor, Syncom 3, broadcast pictures from the 1964 Summer Olympics. The first commercial geosynchronous satellite was Intelsat I ("Early Bird") launched in 1965.
[edit] Newer Telstars
These were similar to the previous Telstar satellites in name only. The later ones were much more advanced electronically and mechanically, geosynchronous satellites, and built for commercial applications, and not just experimental or developmental satellites.
The second wave of "Telstar" satellites launched with Telstar 301 in 1983, and it was followed by Telstar 302 in 1984, and by Telstar 303 in 1985.
The next wave, starting with Telstar 401 came in 1993, which was lost in 1997 due to a magnetic storm, and then Telstar 402 was launched but destroyed shortly after in 1994.[8] It was replaced in 1995 by Telstar 402R, eventually renamed Telstar 4.
Telstar 10 was launched in China in 1997 by APT Satellite Company, Ltd.
In 2003, Telstars 4–8 and 13 — Loral Skynet's North American fleet — were sold to Intelsat. Telstar 4 suffered complete failure prior to the handover. The others were renamed the Intelsat Americas 5, 6, etc. At the time of the sale, Telstar 8 was still under construction by Space Systems/Loral, and it was finally launched on June 23, 2005 by Sea Launch.
Telstar 18 was launched in June 2004 by Sea Launch. The upper stage of the rocket underperformed, but the satellite used its significant stationkeeping fuel margin to achieve its operational geostationary orbit. It has enough on-board fuel remaining to allow it to exceed its specified 13-year design life.
[edit] Derivative uses of the name
Joe Meek composed a popular instrumental recording in 1962, named Telstar after the satellite; it was originally performed by The Tornados and covered by The Ventures among many others. Sound effects on the record, intended to symbolize radio signals, were produced by Meek running a pen around the rim of an ashtray, and then playing the tape of it in reverse.
In the Netherlands, a football club formed from a merger was named SC Telstar after the satellites.
The Scottish band Telstar Ponies included Teenage Fanclub drummer Brendan O'Hare.
The Telstar was also the name of a Ford car sold in Asia, Australasia and Southern Africa.
Telstar Regional High School in Bethel, Maine, is named after the satellite.
The Adidas Telstar football (soccer ball) was designed for use in the 1970 and 1974 FIFA World Cup tournaments.
Project: Telstar is an anthology of robot-and space-themed comics published in 2003 by AdHouse Books.
The Coleco Telstar was a 1970s video game console based on the General Instruments AY-3-8500 chip
[edit] See also
[edit] References
- ^ a b Helen Gavaghan (1998). Something New Under the Sun: Satellites and the Beginning of the Space Age. Springer. ISBN 0387949143. http://books.google.com/books?id=z3bN76jIBjkC&pg=PA180&dq=telstar+pierce&as_brr=3&ei=6PnZRorJEpzmpwKop-GSCw&sig=l5Qi-eC5I0hPWDcH-Eq1QpwhNcA.
- ^ Leo Sivan (1994). Microwave Tube Transmitters. Springer. ISBN 0412579502. http://books.google.com/books?id=o2o1R7I8rvEC&pg=PA3&dq=telstar+twt+kompfner&ei=WPjZRqmtFY2EpgLNqN2SCw&sig=kJAfqeIYoElj6Up3a-ahij0IJIU.
- ^ John Markoff (2004-01-19). "James Early, Engineer, 81; Helped Create A Transistor". Obituaries. The New York Times. http://query.nytimes.com/gst/fullpage.html?res=9F0DE0D71739F93AA25752C0A9629C8B63.
- ^ An Introduction to Satellite Communications, page 3, D. I. Dalgleish, 1989
- ^ Daniel R. Glover (2005-04-12). "TELSTAR". NASA Experimental Communications Satellites. http://roland.lerc.nasa.gov/~dglover/sat/telstar.html. Retrieved on 2007-09-01.
- ^ Ralph D. Lorenz, David Michael Harland (2005). Space Systems Failures: Disasters and Rescues of Satellites, Rocket and Space Probes. Springer. ISBN 0387215190. http://books.google.com/books?id=g-UOdh34utQC&pg=RA2-PA266&dq=telstar+transistors+radiation+starfish&ei=Cc3ZRsr6FIKmowKO3eySCw&ie=ISO-8859-1&sig=WUcdA_54_3BVeGJNPokAmRrhBYk.
- ^ "Space Objects Listed by International Designator (updated 06-2009)". US Space Objects Registry. http://usspaceobjectsregistry.state.gov/registry/dsp_DetailView.cfm?id=90&searched=1. Retrieved on 2009-06-24.
- ^ SAT ND
