Telecom

Antenna enables advanced satellite communications testing

On the rooftop of an MIT Lincoln Laboratory building sits a 38-foot-wide dome-shaped radio antenna enclosure, or radome. Inside the climate-controlled environment, shielded from the New England weather, a steel structure ...

Telecom

ESA technology for safer, smarter European roads

An agreement signed yesterday looks to extend the use of ESA space technology along European roads. The Agency's Navigation Directorate has finalized a Memorandum of Intent with ERTICO, the organization for the European Road ...

Telecom

Software-defined satellite enters commercial service

Satellite operator Eutelsat has sold six of its eight beams—used for data and mobile communications—to organizations including governments and other users. It is expected that the entire satellite capacity will be sold ...

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Satellite

In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavor. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon.

The first artificial satellite, Sputnik 1, was launched by the Soviet Union in 1957. By 2009 thousands of satellites have been launched into orbit around the Earth. These originate from more than 50 countries and have used the satellite launching capabilities of ten nations. A few hundred satellites are currently operational, whereas thousands of unused satellites and satellite fragments orbit the Earth as space debris. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Venus, Mars, Jupiter and Saturn.

Satellites are used for a large number of purposes. Common types include military (spy) and civilian Earth observation satellites, communication satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.

Satellites are usually semi-independent computer controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control and orbit control.

This text uses material from Wikipedia, licensed under CC BY-SA