High Earth orbitHigh Earth orbit (HEO) is a region of space around the Earth where satellites and other spacecraft are placed in orbits that are very high above the planet's atmosphere. This area is defined as an altitude higher than 35,786 km (22,236 mi) above sea level, which is the radius of a circular geosynchronous orbit. HEO extends to end of the Earth's sphere of influence. Satellites in HEO are primarily used for communication, navigation, scientific research, and military applications.
Signal transmissionIn telecommunications, transmission is the process of sending or propagating an analog or digital signal via a medium that is wired, wireless, or fiber-optic. Transmission system technologies typically refer to physical layer protocol duties such as modulation, demodulation, line coding, equalization, error control, bit synchronization and multiplexing, but it may also involve higher-layer protocol duties, for example, digitizing an analog signal, and data compression.
Fixed-satellite serviceFixed-satellite service (short: FSS | also: fixed-satellite radiocommunication service) is – according to article 1.21 of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as A radiocommunication service between earth stations at given positions, when one or more satellites are used; the given position may be a specified fixed point or any fixed point within specified areas; in some cases this service includes satellite-to-satellite links, which may also be operated in the inter-satellite service; the fixed-satellite service may also include feeder links for other space radiocommunication services.
OrbcommORBCOMM is an American company that offers industrial internet and machine to machine (M2M) communications hardware, software and services designed to track, monitor, and control fixed and mobile assets in markets including transportation, heavy equipment, maritime, oil and gas, utilities and government. The company provides hardware devices, modems, web applications, and data services delivered over multiple satellite and cellular networks. As of June 30, 2021, ORBCOMM has more than 2.
Satellite internet constellationA satellite internet constellation is a constellation of artificial satellites providing satellite internet service. In particular, the term has come to refer to a new generation of very large constellations (sometimes referred to as a megaconstellations) orbiting in low Earth orbit (LEO) to provide low-latency, high bandwidth (broadband) internet service.
TelesatTelesat, formerly Telesat Canada, is a Canadian satellite communications company founded on May 2, 1969. The company is headquartered in Ottawa. Telesat began as Telesat Canada, a Canadian Crown corporation created by an Act of Parliament, in 1969. Telesat Canada launched Anik A1 in 1972 as the world's first domestic communications satellite in geostationary orbit operated by a commercial company; this satellite was retired from use in 1981.
Transit (satellite)The Transit system, also known as NAVSAT or NNSS (for Navy Navigation Satellite System), was the first satellite navigation system to be used operationally. The radio navigation system was primarily used by the U.S. Navy to provide accurate location information to its Polaris ballistic missile submarines, and it was also used as a navigation system by the Navy's surface ships, as well as for hydrographic survey and geodetic surveying. Transit provided continuous navigation satellite service from 1964, initially for Polaris submarines and later for civilian use as well.
Cable television headendA cable television headend is a master facility for receiving television signals for processing and distribution over a cable television system. A headend facility may be staffed or unstaffed and is typically surrounded by some type of security fencing. The building is typically sturdy and purpose-built to provide security, cooling, and easy access for the electronic equipment used to receive and re-transmit video over the local cable infrastructure. One can also find head ends in power-line communication (PLC) substations and Internet communications networks.
Relay programThe 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. Relay 1 was launched atop a Delta B rocket on December 13, 1962, from LC-17A at Cape Canaveral Air Force Station.
Delta (rocket family)The Delta rocket family is a versatile range of American rocket-powered expendable launch systems that has provided space launch capability in the United States since 1960. Japan also launched license-built derivatives (N-I, N-II, and H-I) from 1975 to 1992. More than 300 Delta rockets have been launched with a 95% success rate. The series has been phased-out in favor of the Vulcan Centaur, with only the Delta IV Heavy rocket remaining in use as of June 2023.
