Low Earth Orbit (LEO)

Low Earth Orbit (LEO) is the region of space surrounding Earth at distance less than 2,000 km, typically between 400 to 900 km. Most satellites orbiting the Earth lie in this region. Due to their low altitude, LEO satellites can only provide coverage to a small area; however, the short transmission distance allows for a short delay around a few milliseconds. Due to Keplar’s 2nd Law, LEO satellites orbit the Earth at a higher angular velocity than satellites in regions further away and therefore change their relative position to the ground rather quickly. This makes continuous coverage of a local area impossible without a network or constellation of LEO satellites. [1] [2] [3]

A LEO satellite network can provide constant coverage of a desired area by alternating the time in which each satellite is providing coverage.


Analytical Space

Telesat LEO

Blackjack LEO Constellation



See Also

Medium Earth Orbit (MEO)

Geostationary Orbit (GEO)


Related Links

Washington Post Article: Why low Earth orbit satellites are the new space race

SPIE Conference: Free-Space Laser Communications XXXII



SPIE Article: System aspects of optical LEO-to-ground links