Satcom (satellite)

From Wikipedia, the free encyclopedia
Jump to: navigation, search

"Satcom" is also an acronym of, and generic term for, satellite communications.
Satcom K1 being placed into orbit by the Space Shuttle Columbia in 1986. The illuminated (right hand) side of the satellite is one set of solar panels which were extended when the satellite propelled itself to its geostationary orbit

The Satcom series was a family of communications satellites originally developed and operated by RCA American Communications (RCA Americom). Satcom was one of the early geostationary satellites; the first were the Syncom series, in 1964. The first Satcom satellite, Satcom 1, was launched on December 13, 1975. The last satellite, Satcom K2, was placed into orbit on November 27, 1985 and was de-orbited in February 2002. Satcom was first superseded and then replaced by the GE series of satellites.

Satcom (which stands for "satellite communication") is an artificial satellite that is used to help telecommunication by reflecting or relaying signals into space and back down to Earth. It is the most powerful form of radio and can cover far more distance and wider areas than other radios. It can also communicate with words, pictures and other forms of information.

The Satcom system passed to General Electric with its purchase of RCA in 1986. RCA Americom became GE American Communications (GE Americom) and the satellite construction division became GE Astro Space. GE Astro Space was sold to Martin Marietta (now Lockheed Martin Space Systems) in 1993. In 2001 GE sold GE Americom to SES Global, creating SES Americom.

History[edit]

Most early commercial communications satellites were built for and operated by telecom companies. RCA, with its own RCA Astro Electronics satellite construction business, identified a role for itself as a satellite owner/operator.

Satcom 1 was used as the launching ground for many cable TV services including HBO, Superstation TBS, Nickelodeon, the CBN cable network (now ABC Family), ESPN, and The Weather Channel. The satellite spurred the cable television industry to unprecedented heights with the assistance of HBO (who moved their programming from the competing Westar 1, where they had been since their nationwide debut in 1975, to Satcom 1 in February 1976). Cable television networks relay signals to ground-based cable television headends using satellites, which allowed cable TV to enter into the suburban and metropolitan markets, thus allowing HBO to accumulate 1.6 million subscribers by the end of 1977.

A notable legal battle involved Ted Turner suing RCA to get a Satcom 1 transponder in 1980 for the launch of CNN on June 1, 1980. CNN had been scheduled for a Satcom 3 transponder but that satellite had been destroyed upon launch on December 7, 1979.

Shortly after its launch, Satcom 1 was the first satellite used by broadcast TV networks in the United States, like ABC, NBC, and CBS, to distribute their programming to some of their local affiliate stations which had before, and at that time, relied on AT&T's terrestrial microwave & coaxial networks to distribute & relay programming (although some of NBC's local affiliates were receiving programming via the satellite on an experimental basis in the late '70s). The networks fed to both Satcom 1 and AT&T's network at the same time (for the benefit of those stations who hadn't yet been equipped with earth station equipment for reception of the satellite) up until the breakup of AT&T in 1984, when the networks switched exclusively to satellite distribution on Satcom 1 (and later satellites), due to the much lower transmission costs, as well as due to AT&T's divestiture itself.

The reason that Satcom 1 was so widely used by both cable and broadcast TV networks is that it had twice the communications capacity of the competing Westar 1 (24 transponders as opposed to Westar 1’s 12), which resulted in lower transponder usage costs in general.

Satellite details[edit]

Model Manufacturer Launch date Launch vehicle NSSDC ID Comments
Satcom 1 RCA Astro Electronics December 12, 1975 Delta 3000 1975-117A
Satcom 2 RCA Astro Electronics March 26, 1976 Delta 3000
Satcom 3 RCA Astro Electronics December 7, 1979 Delta 3000 1979-101A Failure during GTO, destroyed
Satcom 1R RCA Astro Electronics April 11, 1983 Delta 3000 Replaced Satcom 1
Satcom 2R RCA Astro Electronics September 8, 1983 Delta 3000
Satcom 3R RCA Astro Electronics November 20, 1981 Delta 3000 Replaced destroyed Satcom 3
Satcom 4 RCA Astro Electronics January 16, 1982 Delta 3000
Satcom 5 RCA Astro Electronics October 28, 1982 Delta 3000 Aurora 1, still on 105.2'W (2006)[1]
Satcom 4R Hughes November 8, 1984 STS-51-A (Discovery) Launched as Anik D2, purchased in orbit
Satcom C1 GE Astro Space November 20, 1990 Ariane 42P Replaced Satcom 1R
Satcom C3 GE Astro Space September 11, 1992 Ariane 44LP
Satcom C4 GE Astro Space August 31, 1992 Delta II (7925) 1992-057A
Satcom C5 GE Astro Space May 29, 1991 Delta II (7925) 1991-037A Aurora 2 [2]
Satcom K1 RCA Astro Electronics January 12, 1986 STS-61-C (Columbia)
Satcom K2 RCA Astro Electronics November 27, 1985 STS-61-B (Atlantis)
Satcom K3 GE Astro Space March 2, 1991 Ariane 44LP 1991-015A Sold during construction to SES; launched as Astra 1B
Satcom K4 GE Astro Space June 9, 1992 Atlas 2 Sold during construction to Intelsat

External links[edit]