Low earth orbit (LEO) satellites systems orbit below 2000 km from the earth’s surface, i.e. below the lower Van Allen belt. They move at very high speeds and may not have any fixed space with respect to the earth.
The following diagram depicts LEO satellites in their orbits.
A network of LEO satellites are needed for global coverage as their orbits are not geostationary.
These satellites are not as powerful as the MEO and GEO satellites.
Due to their high speeds, satellites move in and out of the earth station’s range from time to time. So, data is handed off from one satellite to the other to achieve uninterrupted data communication.
They are very much energy efficient. It takes much less energy to place the LEO satellites in their orbits, in comparison to MEOs and GEOs. Also, their amplifiers consume less power.
They are quite cheap in comparison with other data communication modes. So, they can be used as a more economic way of communication for underdeveloped areas.
They can be used for establishing networks in remote terrains where it is not feasible to lay land lines.
Communication Satellites − They are used for low cost data communication.
Earth Monitoring Satellites − They are used for monitoring ground features. They are better than satellites placed far away since they have a clearer view of the earth’s surface.
International Space Station − They provide research laboratory to conduct experiments within space environment. It is suited for testing spacecraft systems.