What Does Low Earth Orbit (LEO) Mean?
Low earth orbit (LEO) is a designation for communication satellites whose locus extends from approximately 300 miles above the earth’s surface up to an altitude of 1,491 miles. A non-terrestrial network (NTN) of LEO satellites is called a constellation or swarm.
LEO constellations can provide satellite broadband service to areas where it otherwise would be too costly or even impossible to lay land lines. LEOs, which are not fixed in space in relation to the planet's surface, are known for providing faster throughput and having less latency than traditional geostationary (GEO) satellites because they orbit over 60 times closer to the Earth's surface.
- LEO orbits are typically less than 2,400 km (1,491 mi) in altitude.
- Geostationary (GEO) satellites orbit around the equator roughly 36,000 km (22,369 mi) above the Earth. Geosynchronous Transfer (GTO) is an elliptical orbit into which satellites are often first launched in order to reach GEO.
Techopedia Explains Low Earth Orbit (LEO)
A network of LEO satellite nodes can provide continuous coverage by communicating with Earth-bound transmission stations as the satellites circle the Earth. Their proximity to the planet's surface results in lower latency and the ability to support services that require faster throughput than traditional satellite internet.
NASA, which keeps track of the number of satellites in orbit, estimates there will be about 50,000 LEO satellites orbiting the planet within ten years. Researchers at Los Alamos are working to lessen the risk of collisions by developing an identification system for LEO satellites that is expected to work much like the beacon system used by commercial aircraft.
LEO Satellite Networks
There are several large business initiatives being worked on that intend to use LEO satellites to provide reliable, affordable broadband service to unserved and underserved communities. Well-known initiatives include:
Telesat - This LEO network is composed of almost 300 satellites that can communicate with each other and on-ground data networks.
Project Kuiper - Amazon is building a low Earth orbit (LEO) satellite constellation composed of 3,236 satellites.
Starlink - The U.S. Federal Communications Commission (FCC) has granted SpaceX permission to fly 12,000 satellites.