low earth orbit

Low Earth Orbit (usually abbreviated LEO) is any orbit that is between 200 and 500 miles above the surface of the Earth. At that altitude, objects travel at 17,000 mph (27,359 kph) and circle the planet every 90 minutes. It is the most popular orbit to place satelites in, as it is relatively inexpensive to get to and it gives the best view of the planet Earth. As of 1999, the USSC has identified more than 8,000 objects in Low Earth Orbit that are the size of a softball or larger.

LEO (Low Earth Orbit) is an acronym that refers to the orbital zone just above the earth atmosphere, it starts about 170 km and extends to roughly 500 km.

An object in LEO has a velocity of about 7.6km/s, about 68% of escape velocity. However, an object in LEO is continually fighting the last vestiges of the atmosphere and will eventually reenter, typically after just a few orbits at 170km or centuries at 500km, (somewhat dependent on the aerodynamics of the body and its density).