Medium Earth orbit
Medium Earth orbit, sometimes called intermediate circular orbit, is the region of space around Earth above low Earth orbit and below geosynchronous orbit.
The orbit is home to a number of artificial satellites – the most common uses include navigation, communication, and geodetic/space environment science. The most common altitude is approximately, which yields an orbital period of 12 hours, as used, for example, by the Global Positioning System. Other satellites in medium Earth orbit include Glonass and Galileo constellations.
Communications satellites that cover the North and South Pole are also put in MEO.
The orbital periods of MEO satellites range from about 2 to nearly 24 hours. Telstar 1, an experimental satellite launched in 1962, orbited in MEO.
