33 Communications satellites

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. As of 1 January 2021, there are 2,224 communications satellites in Earth orbit. Most 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.

Boeing 702 is a communication satellite bus family designed and manufactured by the Boeing Satellite Development Center, and flown from the late-1990s into the 2020s. It covers satellites massing from 1,500 kg (3,300 lb) to 6,100 kg (13,400 lb) with power outputs from 3 to 18 kW and can carry up to approximately 100 high-power transponders.

The ACTS Gigabit Satellite Network was a pioneering, high-speed communications satellite network in the years 1993-2004, created as a prototype system to explore high-speed networking of digital endpoints. The system was jointly sponsored by NASA and ARPA, implemented by BBN Technologies and Motorola, and was inducted into the Space Technology Hall of Fame in April 1997.

Alcomsat-1 is the first Algerian communications satellite. It was carried by Chinese launcher Long March 3B from the Xichang Satellite Launch Center, located in Sichuan Province, 2,200 km southwest of Beijing.

ARSAT-3K is a geostationary communications satellite bus designed and manufactured by INVAP of Argentina for the local telecommunication company ARSAT S.A.. It is a small three axis stabilized platform designed, manufactured and tested completely in Argentina. It is capable of carrying up to 350 kg (770 lb) of payload with a maximum power consumption of 3.4 kW at the end of life. It currently uses only chemical propulsion, but an hybrid solution which would use bi-propellant propulsion for orbit raising and electric propulsion for station keeping is being developed. A purely electric propulsion version is planned.

Applications Technology Satellite 3, or ATS-3, was a long-lived American experimental geostationary weather and communications satellite, operated by NASA from 1967 to 2001. It was at one time reputed to be the oldest satellite still in operation. As of 1995, NASA referred to the ATS-3 as "The oldest active communications satellite by a wide margin."

Boeing 702 is a communication satellite bus family designed and manufactured by the Boeing Satellite Development Center, and flown from the late-1990s into the 2020s. It covers satellites massing from 1,500 kg (3,300 lb) to 6,100 kg (13,400 lb) with power outputs from 3 to 18 kW and can carry up to approximately 100 high-power transponders.

The Broadband Global Area Network (BGAN) is a global satellite network with telephony owned by Inmarsat using portable terminals. The terminals are normally used to connect a laptop computer to broadband Internet in remote locations, although as long as line-of-sight to the satellite exists, the terminal can be used anywhere. The value of BGAN terminals is that, unlike other satellite Internet services which require bulky and heavy satellite dishes to connect, a BGAN terminal is about the size of a laptop and thus can be carried easily. The network is provided by Inmarsat and uses three geostationary satellites called I-4 to provide almost global coverage.

Gonets is a Russian civilian low Earth orbit communications satellite system. It consists of a number of satellites, derived from Strela military communications satellites. The first two satellites, which were used to test and validate the system, were launched by a Tsyklon-3 launch vehicle from the Plesetsk Cosmodrome on 13 July 1992, and were designated Gonets-D. The first operational satellites, designated Gonets-D1, were launched on 19 February 1996. After launch, the first three satellites were given military Kosmos designations, a practice which was not continued with the other satellites.

The Intersputnik International Organization of Space Communications, commonly known as Intersputnik, is an international satellite communications services organization founded on 15 November 1971, in Moscow by the Soviet Union along with a group of eight formerly socialist states.

The KAUR was a very successful satellite bus designed and manufactured by ISS Reshetnev. It is a pressurized bus originally developed in the 1960s, it has been used from low Earth Orbit to medium Earth orbit and even to GEO. It has four different generations and its different versions have been used from civilian communications to satellite navigation.

Koreasat 7 is a South Korean communications satellite operated by KT SAT, a subsidiary of KT Corporation.

The Lincoln Experimental Satellite series was designed and built by Lincoln Laboratory at Massachusetts Institute of Technology between 1965 and 1976, under USAF sponsorship, for testing devices and techniques for satellite communication.

Milstar is a constellation of military communications satellites in geosynchronous orbit, which are operated by the United States Space Force, and provide secure and jam-resistant worldwide communications to meet the requirements of the Armed Forces of the United States. Six spacecraft were launched between 1994 and 2003, of which five are currently operational; the third launch failed, both damaging the satellite and leaving it in an unusable orbit.

The Multiple Paths, Beyond-Line-of-Sight Communications (MUBLCOM) satellite, built for the Pentagon's Defense Advanced Research Projects Agency, was launched in May 1999 by a Pegasus. Its mission was to demonstrate a capability to provide space-based digital voice and data communications to combat forces or commercial users that were previously considered out of range of standard radio communications systems.

The Orbital Test Satellite (OTS) programme was an experimental satellite system inherited by the European Space Agency (ESA) in 1975 from its predecessor, the European Space Research Organisation (ESRO). OTS was the first three-axis-stabilised Ku-band satellite, and its design has inspired the conception of almost 30 other satellites in Europe. Its successors, the Maritime European Communications Satellite (MARECS) and European Communications Satellite (ECS) series of satellites, consolidated Europe's position in communications satellite technology and manufacturing.

Palapa is a series of Communications satellites owned by Indosat, an Indonesian telecommunications company. Starting with the first in July 1976, at which time Indonesia became the first developing country to operate its own domestic satellite system. The estimated cost for the project was US$1 billion.

The Relay program consisted of Relay 1 and Relay 2, two early American satellites in elliptical low 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.

"Satcom" is also an acronym of, and generic term for, satellite communications

Satcom on the Move (SOTM), or satellite communications on the move, is a phrase used in the context of mobile satellite technology, specifically relating to military ground vehicles, Maritime and Airborne platforms. The basic principle behind Satcom On The Move is that a vehicle equipped with a satellite antenna is able to establish communication with a satellite and maintain that communication while the vehicle is moving.

The Satellite Data System (SDS) is a system of United States military communications satellites. At least three generations have been used: SDS-1 from 1976 to 1987; SDS-2 from 1989 to 1996; SDS-3 from 1998 to the present. It is believed that these satellites were known by the code name Quasar. The first generation were named simply 'SDS', the second generation were named 'Quasar' and the third generation each carried their own designation names.

SBS 3 was a geostationary communications satellite designed and manufactured by Hughes on the HS-376 platform. It was ordered by Satellite Business Systems, which later sold it to Hughes Communications. It had a Ku band payload and operated on the 94°W longitude.

SBS 4 was a geostationary communications satellite designed and manufactured by Hughes on the HS-376 platform. It was ordered by Satellite Business Systems, which later sold it to Hughes Communications. It had a Ku band payload and operated at 94°W longitude.

SCORE was the world's first purpose-built communications satellite. Launched aboard an American Atlas rocket on December 18, 1958, SCORE provided the second test of a communications relay system in space, the first broadcast of a human voice from space, and the first successful use of the Atlas as a launch vehicle. It captured world attention by broadcasting a Christmas message via shortwave radio from U.S. President Dwight D. Eisenhower through an on-board tape recorder. The satellite was popularly dubbed "The Talking Atlas". SCORE, as a geopolitical strategy, placed the United States at an even technological par with the Soviet Union as a highly functional response to the Sputnik 1 and Sputnik 2 satellites.

The Symphonie satellites were the first communications satellites built by France and Germany to provide geostationary orbit injection and station-keeping during their operational lifetime. After the launch of the second flight model, they comprised the first complete telecommunications satellite system. They were the result of a program of formal cooperation between France and Germany.

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 launched May 7, 1963. Telstar 1 and 2—though no longer functional—still orbit the Earth.

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.

Milstar is a constellation of military communications satellites in geosynchronous orbit, which are operated by the United States Space Force, and provide secure and jam-resistant worldwide communications to meet the requirements of the Armed Forces of the United States. Six spacecraft were launched between 1994 and 2003, of which five are currently operational; the third launch failed, both damaging the satellite and leaving it in an unusable orbit.