The Mechanics of Low Orbiting Satellites Implications in Communication

Low orbiting satellite communication networks will be competing with geosynchronous satellites for a share of the communications market. In world-wide communications that do not require immediate real time transmissions, low orbiting satellites are competitive with geosynchronous satellites because the system is reliable and low in cost. Since satellites are a clear example of Newtonian laws, the distinct patterns they make in their orbiting process are predictable. Newton\u27s law states that an object will remain in uniform motion unless acted upon by a force: a satellite remains in motion around the earth because there is no atmosphere to slow it down. A satellite stays in orbit because the pull of gravity inward is balanced by centrifugal energy outward. The rate which a satellite orbits the earth and the lifetime of the satellite depend on its altitude. Low orbiting satellites trace unique paths over the surface of the earth -- the satellite is accessible for communication if the path o the satellite comes within 1500 kilometers of a ground station. Unless there are 50 to 80 low orbiting satellites, the system is not useful for exclusive real time communication and thus requires a different operating structure. The low orbiting satellite will use a combination of two modes for communication: the transponder mode, and the store and forward mode