Medium Earth orbit
MEO is the middle layer of near-Earth space — high enough to be quiet, low enough to stay useful. Its most famous residents are the navigation constellations that your phone talks to every day.
What is medium Earth orbit?
// the factsMEO spans roughly 2,000 km to 35,786 km. It sits between the crowded low orbits and the geostationary belt, and its defining use is navigation: GPS, Galileo, GLONASS and BeiDou satellites all operate in MEO, typically around 20,000–23,000 km.
The orbits are engineered for coverage. A MEO navigation satellite takes about 12 hours to circle the Earth, which lets a constellation of two dozen spacecraft put several satellites in view of any point on the planet at once — the geometry behind worldwide positioning.
MEO is comparatively sparse. Unlike LEO's thousands of spacecraft, MEO holds a few hundred objects, mostly operational navigation satellites plus their disposed hardware. The catalogue below lists every one being tracked.