Telstar is the name of various communications satellites. The first two Telstar satellites were experimental and nearly identical. Telstar 1 launched on top of a Thor-Delta rocket on July 10, 1962. It successfully relayed through space the first television pictures, telephone calls, and telegraph images, and provided the first live transatlantic television feed. Telstar 2 was launched May 7, 1963. Telstar 1 and 2—though no longer functional—still orbit the Earth.[1]
Six ground stations were built to communicate with Telstar, one each in the US, France, the UK, Canada, West Germany and Italy. The American ground station—built by Bell Labs—was Andover Earth Station, in Andover, Maine. The main British ground station was at Goonhilly Downs, Cornwall. The BBC, as international coordinator, used this location. 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[lower-alpha 1]. The Canadian ground station was at Charleston, Nova Scotia. The German ground station was at Raisting in Bavaria. The Italian ground station (Fucino Space Centre) was at Fucino, near Avezzano, in Abruzzo.
The satellite was built by a team at Bell Telephone Laboratories that included John Robinson Pierce, who created the project;[4]Rudy Kompfner, who invented the traveling-wave tube transponder that the satellite used;[4][5] and James M. Early, who designed its transistors and solar panels.[6] The satellite is roughly spherical, measures 34.5 inches (880mm) in length, and weighs about 170lb (77kg). Its dimensions were limited by what would fit on one of NASA's Delta rockets. Telstar was spin-stabilized, and its outer surface was covered with solar cells capable of generating 14watts of electrical power.
The original Telstar had a single innovative transponder that could relay data, a single television channel, or multiplexed telephone circuits. Since the spacecraft spun, it required an array of antennas around its "equator" for uninterrupted microwave communication with Earth. An omnidirectional array of small cavity antenna elements around the satellite's "equator" received 6GHz microwave signals to relay back to ground stations. The transponder converted the frequency to 4GHz, 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 received telecommands from a ground station.
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 into an ellipticalorbit completed once every 2 hours and 37 minutes, inclined at an angle of approximately 45 degrees to the equator, with perigee about 952km (592mi) from Earth and apogee about 5,933km (3,687mi) from Earth[7]:3-5 This is in contrast to the 1965 Early BirdIntelsat and subsequent satellites that travel in circular geostationary orbits.[7]:3-5
Due to its non-geosynchronous orbit, similar to a Molniya orbit, availability of Telstar 1 for transatlantic signals was limited to the 30 minutes in each 2.5-hour orbit when the satellite passed over the Atlantic Ocean. Ground antennas had to track the satellite with a pointing error of less than 0.06 degrees as it moved across the sky at up to 1.5 degrees per second.[citation needed]
Since the transmitters and receivers on Telstar were not powerful, ground antennas had to be 90ft (27m) tall. Bell Laboratory engineers designed a large horizontal conical horn antenna with a parabolic reflector at its mouth that re-directed the beam. This particular design had very low sidelobes, and thus made very low receiving system noise temperatures possible. The aperture of the antennas was 3,600sqft (330m2). The antennas were 177ft (54m) long and weighed 380 short tons (340,000kg). Morimi Iwama and Jan Norton of Bell Laboratories were in charge of designing and building the electrical portions of the azimuth-elevation system that steered the antennas. The antennas were housed in radomes the size of a 14-story office building. Two of these antennas were used, one in Andover, Maine, and the other in France at Pleumeur-Bodou. The GPO antenna at Goonhilly Downs in Great Britain was a conventional 26-meter-diameter paraboloid.
In service
Telstar 1 relayed its first, and non-public, television pictures—a flag outside Andover Earth Station—to Pleumeur-Bodou on July 11, 1962.[8] Almost two weeks later, on July 23, at 3:00 p.m. EDT, it relayed the first publicly available live transatlantic television signal.[9] The broadcast was shown in Europe by Eurovision and in North America by NBC, CBS, ABC, and the CBC.[9] The first public broadcast featured CBS's Walter Cronkite and NBC's Chet Huntley in New York, and the BBC's Richard Dimbleby in Brussels.[9] The first pictures were the Statue of Liberty in New York and the Eiffel Tower in Paris.[9] The first broadcast was to have included remarks by President John F. Kennedy, but the signal was acquired before the president was ready, so engineers filled the lead-in time with a short segment of a televised game between the Philadelphia Phillies and the Chicago Cubs at Wrigley Field.[9][10][11] The Phillies' second baseman Tony Taylor was seen hitting a ball pitched by the Cubs' Cal Koonce to deep right field, caught by fielder George Altman for the out. From there, the video switched first to Washington, DC; then to Cape Canaveral, Florida; to the Seattle World's Fair; then to Quebec and finally to Stratford, Ontario.[9] The Washington segment included remarks by President Kennedy,[10] talking about the price of the American dollar, which was causing concern in Europe. When Kennedy denied that the United States would devalue the dollar it immediately strengthened on world markets; Cronkite later said that "we all glimpsed something of the true power of the instrument we had wrought."[9][12]
That evening, Telstar 1 also relayed the first satellite telephone call, between U.S. vice-president Lyndon Johnson and the chairman of AT&T, Frederick Kappel. It successfully transmitted faxes, data, and both live and taped television, including the first live transmission of television across an ocean from Andover, Maine, US, to Goonhilly Downs, England, and Pleumeur-Bodou, France.[13][clarification needed] (An experimental passive satellite, Echo 1, had been used to reflect and redirect communications signals two years earlier, in 1960.) In August 1962, Telstar 1 became the first satellite used to synchronize time between two continents, bringing the United Kingdom and the United States to within 1 microsecond of each other (previous efforts were accurate to only 2,000 microseconds).[14]
The Telstar 1 satellite also relayed computer data between two IBM 1401 computers. The test, performed on October 25, 1962, sent a message from a transmitting computer in Endicott, New York, to the earth station in Andover, Maine. The message was relayed to the earth station in France, where it was decoded by a second IBM 1401 in La Gaude, France.[15]
Telstar 1, which had ushered in a new age of the commercial use of technology, became a victim of the military technology of the Cold War era. The day before Telstar 1 launched, a U.S. high-altitude nuclear bomb (called Starfish Prime) had energized the Earth's Van Allen Belt where Telstar 1 went into orbit. This vast increase in a radiation belt, combined with subsequent high-altitude blasts, including a Soviet test in October, overwhelmed Telstar's fragile transistors.[16][17][18] It went out of service in November 1962, after handling over 400 telephone, telegraph, facsimile, and television transmissions.[10] It was restarted by a workaround in early January 1963.[19] The additional radiation associated with its return to full sunlight[clarification needed] once again caused a transistor failure, this time irreparably, and Telstar 1 went back out of service on February 21, 1963.
Telstar was considered a technical success. According to a US. Information Agency (USIA) poll, Telstar was better known in Great Britain than Sputnik had been in 1957.[20]
Newer Telstars
Subsequent Telstar satellites were advanced commercial geosynchronous spacecraft that share only their name with Telstar 1 and 2.
The second wave of Telstar satellites launched with Telstar 301 in 1983, followed by Telstar 302 in 1984 (which was renamed Telstar 3C after it was carried into space by Shuttle mission STS-41-D),[21] 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 destroyed shortly after launch in 1994.[22] 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.
Goonhilly Satellite Earth Station is a large radiocommunication site located on Goonhilly Downs near Helston on the Lizard peninsula in Cornwall, England. Owned by Goonhilly Earth Station Ltd under a 999-year lease from BT Group plc, it was at one time the largest satellite earth station in the world, with more than 30 communication antennas and dishes in use. The site also links into undersea cable lines.
A geosynchronous orbit is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds. The synchronization of rotation and orbital period means that, for an observer on Earth's surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Over the course of a day, the object's position in the sky may remain still or trace out a path, typically in a figure-8 form, whose precise characteristics depend on the orbit's inclination and eccentricity. A circular geosynchronous orbit has a constant altitude of 35,786 km (22,236 mi).
A geostationary orbit, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 km (22,236 mi) in altitude above Earth's equator, 42,164 km (26,199 mi) in radius from Earth's center, and following the direction of Earth's rotation.
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit 22,236 miles (35,785 km) above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently.
Syncom started as a 1961 NASA program for active geosynchronous communication satellites, all of which were developed and manufactured by the Space and Communications division of Hughes Aircraft Company. Syncom 2, launched in 1963, was the world's first geosynchronous communications satellite. Syncom 3, launched in 1964, was the world's first geostationary satellite.
A very-small-aperture terminal (VSAT) is a two-way satellite ground station with a dish antenna that is smaller than 3.8 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Bit rates, in most cases, range from 4 kbit/s up to 16 Mbit/s. VSATs access satellites in geosynchronous orbit or geostationary orbit to relay data from small remote Earth stations (terminals) to other terminals or master Earth station "hubs".
The Relay program consisted of Relay 1 and Relay 2, two early American satellites in elliptical medium Earth orbit. Both were primarily experimental communications satellites funded by NASA and developed by RCA. As of December 2, 2016, both satellites were still in orbit. Relay 1 provided the first American television transmissions across the Pacific Ocean.
Telstar 1 is a defunct communications satellite launched by NASA on July 10, 1962. It was the satellite that allowed the first live broadcast of television images between the United States and Europe. Telstar 1 remained active for only 7 months before it prematurely failed due to Starfish Prime, a high-altitude nuclear test conducted by the United States. Although the satellite is no longer operational, it remains in Earth orbit.
Andover Earth Station was one of the first satellite earth stations, located at Andover in the US state of Maine. It was built by AT&T in 1961 to communicate with the Telstar 1 satellite, the first direct relay communications satellite. It provided the first experimental satellite telephone and television service between North America and Europe. It was also used with the Relay satellite. The giant horn was dismantled in the mid 1980s along with the visitor center.
Project Echo was the first passive communications satellite experiment. Each of the two American spacecraft, launched in 1960 and 1964, were metalized balloon satellites acting as passive reflectors of microwave signals. Communication signals were transmitted from one location on Earth and bounced off the surface of the satellite to another Earth location.
Telesat, formerly Telesat Canada, is a Canadian satellite communications company founded on May 2, 1969. The company is headquartered in Ottawa.
The Anik satellites are a series of geostationary communications satellites launched for Telesat Canada for television, voice and data in Canada and other parts of the world, from 1972 through 2013. Some of the later satellites in the series remain operational in orbit, while others have been retired to a graveyard orbit. The naming of the satellite was determined by a national contest, and was won by Julie-Frances Czapla of Saint-Léonard, Québec. In Inuktitut, Anik means "brother".
A tracking and data relay satellite (TDRS) is a type of communications satellite that forms part of the Tracking and Data Relay Satellite System (TDRSS) used by NASA and other United States government agencies for communications to and from independent "User Platforms" such as satellites, balloons, aircraft, the International Space Station, and remote bases like the Amundsen-Scott South Pole Station. This system was designed to replace an existing worldwide network of ground stations that had supported all of NASA's crewed flight missions and uncrewed satellites in low-Earth orbits. The primary system design goal was to increase the amount of time that these spacecraft were in communication with the ground and improve the amount of data that could be transferred. These TDRSS satellites are all designed and built to be launched to and function in geosynchronous orbit, 35,786 km (22,236 mi) above the surface of the Earth.
Commercial use of space is the provision of goods or services of commercial value by using equipment sent into Earth orbit or outer space.
Land Launch refers to a service product of Sea Launch SA. There is no entity or company called Land Launch. Sea Launch created the Land Launch offering to address lighter satellites directly into geosynchronous orbit or into geosynchronous transfer orbit, while Sea Launch continues to address the heavy satellite launch market.
AMC-11 , previously GE-11, is an American geostationary communications satellite which is operated by SES. It is currently positioned in geostationary orbit at a longitude of 131° West, from where it is used to relay cable television across North America for onward distribution. It broadcasts to Canada, the Caribbean, Mexico and the United States.
A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Such a satellite returns to the same position in the sky after each sidereal day, and over the course of a day traces out a path in the sky that is typically some form of analemma. A special case of geosynchronous satellite is the geostationary satellite, which has a geostationary orbit – a circular geosynchronous orbit directly above the Earth's equator. Another type of geosynchronous orbit used by satellites is the Tundra elliptical orbit.
The Intelsat VI series of satellites were the 8th generation of geostationary communications satellites for the Intelsat Corporation. Designed and built by Hughes Aircraft Company (HAC) in 1983-1991, there were five VI-series satellites built: 601, 602, 603, 604, and 605.
Telstar 2 is a defunct communications satellite launched by NASA on May 7, 1963. It remained active for 2 years. As of 2023 Telstar 2 remains in orbit.
Pleumeur-Bodou Ground Station was an early ground station in north-west France, and one of the first in the world. It was the site of the first satellite transmission between the US and Europe in the early morning of 11 July 1962, lasting 19 minutes on the satellite's seventh orbit.
↑ Glover, Daniel R. (April 12, 2005). "TELSTAR". NASA Experimental Communications Satellites. Archived from the original on September 5, 2007. Retrieved September 1, 2007.
↑ Early, James M. (1990). "Telstar I – Dawn of a New Age". Southwest Museum of Engineering, Communications and Computation. Retrieved July 11, 2012.
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