Low Earth Orbit (LEO)

Low Earth orbit refers to the area situated closest to the Earth, below GEO and MEO. Satellites in LEO are located at an altitude of less than 2,000 km but could be as low as 80 km above Earth according to some experts (although there is some contention over whether a satellite can be considered to be in LEO at that low of an altitude). LEO satellites can be inserted into any plane bisecting the equator, meaning their orbit can be tilted relative to the rotational motion of the Earth. This is the orbit that is most commonly used for satellite imaging of Earth, due to its proximity to the surface of the Earth, which allows for higher resolution images. Certain communications satellites are also placed in this orbit; in fact, LEO is the orbit where very large constellations of satellites are being launched to provide Internet on Earth, and is the orbit where all of the kinetic anti-satellite (ASAT) tests have been held. It is also the orbit where the International Space Station (ISS) and the Tiangong Space Station are located.