Aspects of Synchronous Communication Satellites

Before 1980, satellites will probably be a wellestablished means for point-to-point communication on earth. A wide variety of passive and active satellite systems are being studied, and some studies are supplemented by experimental programs. The active systems seem more promising because of their larger capacity for a given weight in orbit with a given investment in ground terminals. Of the active systems, that which offers the greatest capacity is the geocentric stabilized station-keeping satellite in a synchronous equatorial orbit. This satellite is in direct line of sight of almost half of the earth's surface. The orbit is unique in that the satellite may have little motion about the line of sight; this may permit the use of large stationary ground antennas, in addition to the directive antennas on the satellite which cover the visible earth. This report concerns the satellite design and payload weight required to provide a given channel capacity. It is oriented toward commercial point-to-point communication, where costs dictate conservative techniques. (Author)