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22-528: Westar 1 (launched on April 13, 1974) has the distinction of being the USA's first commercially launched geosynchronous communications satellite, following North America's first geosynchronous communications satellite, Canada 's Anik A1 in 1972. Westar 1 was put into orbit at 99° W in the Clarke belt (99° W now being the home of Galaxy 16 ). Westar 2 was launched shortly afterward on October 10, 1974. Westar 3,

44-416: A Telecommunications Satellite Park ) innovation was conceived and developed by Joseph Milano in 1976 as part of a National Research Council study entitled, Telecommunications for Metropolitan Areas: Near-Term Needs and Opportunities". A network of ground stations is a group of stations located to support spacecraft communication, tracking, or both. A network is established to provide dedicated support to

66-618: A teleport in Cedar Hill, Texas , to uplink content to the Westar satellites (it was interconnected to WU's existing terrestrial microwave network at the time), and another teleport that, in addition to uplink services, would become the main TT&;C (Telemetry, Tracking & Control) center for the satellite (and for all of the Westar fleet later on), in Glenwood, New Jersey . A sixth satellite, Westar 6,

88-571: A satellite. In May 1984, the Dallas/Fort Worth Teleport became the first American teleport to commence operation. In Federal Standard 1037C , the United States General Services Administration defined an Earth terminal complex as the assemblage of equipment and facilities necessary to integrate an Earth terminal (ground station) into a telecommunications network. FS-1037C has since been subsumed by

110-399: Is called a ground tracking station , or space tracking station , or simply a tracking station . When a spacecraft or satellite is within a ground station's line of sight, the station is said to have a view of the spacecraft (see pass ). A spacecraft can communicate with more than one ground station at a time. A pair of ground stations are said to have a spacecraft in mutual view when

132-678: The International Consultative Committee for Radio administered standards and regulations now governed by the ITU-R. In addition to the body of standards defined by the ITU-R, each major satellite operator provides technical requirements and standards that ground stations must meet in order to communicate with the operator's satellites. For example, Intelsat publishes the Intelsat Earth Station Standards (IESS) which, among other things, classifies ground stations by

154-661: The ATIS Telecom Glossary, which is maintained by the Alliance for Telecommunications Industry Solutions (ATIS), an international, business-oriented, non-governmental organization . The Telecommunications Industry Association also acknowledges this definition. The ITU Radiocommunication Sector (ITU-R), a division of the International Telecommunication Union , codifies international standards agreed-upon through multinational discourse. From 1927 to 1932,

176-564: The Hughes HS 376 platform, and had 24 transponders available, as opposed to the 12 on Westars 1, 2, and 3. Westar 6, also an HS-376 based satellite, was launched from STS-41-B on February 3, 1984, to be put into service afterward, but the perigee kick motor (also known as the Payload Assist Module , or PAM) on the satellite failed during its approach to geosynchronous orbit, placing it at an improper and inoperable low Earth orbit . It

198-487: The United States is a stub . You can help Misplaced Pages by expanding it . Earth station A ground station , Earth station , or Earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves from astronomical radio sources . Ground stations may be located either on

220-453: The Westar satellite fleet and operations to Hughes in 1988. Hughes then finished development of Westar 6S, and renamed it Galaxy 6. Modifications were made to it, and Galaxy 6 was launched on October 12, 1990. Hughes later launched the Galaxy 4 satellite in 1992 and Galaxy 5 in 1993 to replace Westar 4 and 5 respectively, after the latter satellites reached the end of their useful life. During

242-519: The capabilities of their parabolic antennas, and pre-approves certain antenna models. Eutelsat publishes similar standards and requirements, such as the Eutelsat Earth Station Standards (EESS). The Interagency Operations Advisory Group offers a Service Catalog describing standard services, Spacecraft Emergency Cross Support Standard, and Consultative Committee for Space Data Systems data standards. The Teleport (originally called

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264-535: The first satellite to use TDMA switched data, was launched on August 10, 1979. Westars 1, 2 and 3 were built by Hughes using the HS 333 platform of spin-scan stabilized satellites. They only had 12 transponders on board, as opposed to later C-band communications satellites having 24, and even contemporary satellites of the same era, such as RCA's Satcom 1 . The later Westar 4 (launched on February 26, 1982) and Westar 5 (launched on June 9, 1982) satellites, were based on

286-680: The ground station is the parabolic antenna . Ground stations may have either a fixed or itinerant position. Article 1 § III of the International Telecommunication Union (ITU) Radio Regulations describes various types of stationary and mobile ground stations, and their interrelationships. Specialized satellite Earth stations or satellite tracking stations are used to telecommunicate with satellites — chiefly communications satellites . Other ground stations communicate with crewed space stations or uncrewed space probes . A ground station that primarily receives telemetry data, or that follows space missions, or satellites not in geostationary orbit ,

308-511: The life of the Westar fleet, Western Union operated these dedicated uplink sites (now defunct, unless noted) for Westar: Westar 1 Westar 1 was America's first domestic and commercially launched geostationary communications satellite , launched by Western Union (WU) and NASA on April 13, 1974. It was built by Hughes for Western Union, using the HS-333 platform of spin-stabilized satellites. It operated until May 1983. Westar 1

330-569: The stations share simultaneous, unobstructed, line-of-sight contact with the spacecraft. A telecommunications port — or, more commonly, teleport — is a satellite ground station that functions as a hub connecting a satellite or geocentric orbital network with a terrestrial telecommunications network , such as the Internet . Teleports may provide various broadcasting services among other telecommunications functions, such as uploading computer programs or issuing commands over an uplink to

352-458: The surface of the Earth , or in its atmosphere. Earth stations communicate with spacecraft by transmitting and receiving radio waves in the super high frequency (SHF) or extremely high frequency (EHF) bands (e.g. microwaves ). When a ground station successfully transmits radio waves to a spacecraft (or vice versa), it establishes a telecommunications link . A principal telecommunications device of

374-463: Was launched in 1984 but failed to reach orbit and was retrieved by the STS-51-A Space Shuttle mission later that year. It was later refurbished and relaunched in orbit of Asia as AsiaSat 1 in 1990. Westar 1 was used by Western Union for its own internal communications, such as for sending telegrams and mailgrams to Western Union bureaus and U.S. post offices respectively. It also

396-481: Was partially funded by the insurance companies led by Lloyd's of London who insured the launch of those two satellites. An on-ground spare satellite to Westar 6, Westar 6S, was in development by Western Union and Hughes when Western Union decided to divest themselves of their telecommunications -based assets starting in the early 1980s after suffering heavy financial losses. This resulted in Western Union selling

418-555: Was retired from service in April 1983. The 15-meter dishes used to communicate with it at the Cedar Hill site have been decommissioned, but they can still be visited today by contacting Westar Satellite Services. The former main TT&C & uplink site for Westar in Glenwood, is now (as of 2015) the satellite uplink facility for SiriusXM Radio. This article about one or more spacecraft of

440-563: Was retrieved on November 16, 1984, by the STS-51-A mission of NASA 's Space Shuttle , where it was brought back to earth. It was then resold to AsiaSat in Hong Kong , who refurbished it and relaunched it on April 7, 1990 as AsiaSat 1 aboard a Long March 3 rocket. The Space Shuttle mission to retrieve Westar 6, as well as the Palapa B2 satellite which shared the launch payload with Westar 6,

462-589: Was the first of five Westar satellites launched by Western Union from 1974 to 1982. Westar 1 was launched from Cape Canaveral on a Delta 2914 launch vehicle from Complex 17 on April 13, 1974. The launch vehicle delivered the satellite to a geosynchronous transfer orbit. After transiting to a near geosynchronous apogee, the satellite employed an apogee kick motor to raise the perigee of the orbit and reduce inclination to near-geostationary. Westars 1, 2, and 3 were 12- transponder satellites while Westar 4 and Westar 5 were launched with 24 transponders. Western Union built

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484-642: Was utilized by outside customers such as PBS , NPR and the Mutual Broadcasting System , using it for sending television and radio programming via satellite to their local affiliate stations throughout the 1970s and '80s. It was also employed to enable communications with offshore oil platforms. Westar 1 was also used for a short time by HBO for its nationwide debut using satellite distribution to cable companies in 1975 (HBO later moved to RCA's competing satellite, Satcom 1 , in February 1976). Westar 1

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