The LEASAT Communications Satellite

Abstract

Beginning in 1982 communication services will be provided to the U.S. Navy by a series of UHF communications satellites known as LEASAT. The communications payload will be carried on a new spacecraft bus developed as an optimum bus for space shuttle launches; the program is the first of its kind to take advantage of the full 15 foot shuttle payload bay diameter. Several new spacecraft design concepts are employed in this optimized bus. The communications payload incorporates transponders in the UHF and SHF regimes. Four distinct types of transponders are employed: wideband, narrowband, relay, and fleet broadcast. The functional characteristics of each type is described in detail. The frequency plan leads to a significant potential for passive generation of intermodulation products, and intermodulation considerations are an integral part of the spacecraft design.