The Clarke Belt Geostationary Orbits above the Earth

The Clarke Belt has become the term used to describe a Geostationary Orbit from a Science Fiction author, Arthur C. Clarke in 1945 who popularized this orbit as an ideal for communications satellites. A Geostationary Orbit is a Geosynchronous Orbit which is located at a latitude of zero degrees, directly above the Earth’s Equator. If one were standing on a hill and saw one of these geostationary objects such as a communications satellite, it would appear to be staying in one spot.

A Geostationary Orbit is a common interest for launching communications and television satellites. Arthur C. Clarke may have popularized this method in Science Fiction but the idea was first introduced by Herman Potocnik in 1928

The Clarke Belt is actually the part of space that is about 35,786 kilometers above the average height of the sea (Mean Sea Level=MSL).

Geostationary Orbits are advantageous because they make satellites appear in a fixed position while the Earth rotates. This makes it possible for antennae and Earth stationed satellites to keep in the direction of artificial satellites at all times. Artificial Satellites are those that are placed into orbit by mankind.

Despite the orbits keeping the satellites aligned the Geostationary Orbit does have limits. Occasionally artificial satellites can be taken out of orbit by comets, asteroids, solar flares and other celestial events. This is known as Orbital Perturbation. In this event, the artificial satellite can be put back into the orbit by Station Keeping Maneuvers. These are basically ways of putting the satellite back into orbit either from Earth Stations or automatically. Station Keeping Maneuvers do consume fuel and power putting a limitation on satellite lives.

There can only be a limited number of artificial satellites within the orbital parameters because each satellite has to be in a separate geostationary orbit. They must be in or above the orbital ring above the equator. Because a limited amount of satellites can occupy the orbits countries have had conflicts over deciding who will launch their satellites in an orbital ‘slot’. Some of the known satellites are US GOES, Meteosat from Europe, Japanese GMS, and India’s INSAT series. In 1964 a Delta-D rocket launched the first satellite called the ‘Syncom-3’.

The Clarke Belt is commonly used by satellite companies for usage in homes for satellite television such as ‘DirecTV’ and ‘Telesat’. Because of the Clarke Belt’s orbit around Earth home satellites do not have to rotate for a station signal.