A low Earth orbit (LEO) is an Earth-centered orbit close to the planet, often specified as an orbital period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of the Earth.
The term "LEO region" is also used for the area of space below an altitude of 2,000 km (1,200 mi) (approximately one-third of the radius of Earth). Objects in orbits which pass through this area, even if they have an apogee further out, or are sub-orbital, are carefully tracked because they present a collision risk to the many satellites in LEO.
All crewed space stations to date have been in LEO. From 1968 to 1972 the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, there have been no human spaceflights beyond LEO.
referenceEver curious about what that abbreviation stands for? fullforms has got them all listed out for you to explore. Simply,Choose a subject/topic and get started on a self-paced learning journey in a world of fullforms.
Allow To Receive Free Coins Credit 🪙