The book is based on the results of studies carried out by a working group which was set up by NATO in 1986 to consider the future potential of satellite communications in the post 2000 era and to identify areas for significant technological thrust. It contains a substantial amount of information, most of it original, on almost every aspect of satellite communications. Starting from certain postulated trends about future SATCOM, it assesses emerging technologies and develops potential SATCOM system architectures, including space, ground and control segments, with particular emphasis on military applications which involve the most advanced and demanding techniques and technologies ranging from materials to signal and speech processing. The mean ideas treated in the book are: techniques and technologies related to signal processing and switching, adaptive antennas, optical and EHF links for inter-satellite communications, AI, and robotics for SATCOM; system architectural concepts utilizing GEO/inclined/Tundra orbits and clustered/tethered/proliferated LEO satellites; national systems and developments; threat (electronic warfare, physical, nuclear); electronic counter-counter measures (ECCM); propagational issues (including nuclear effects); network and transmission issues (implementation); satellite payloads, power generation in space, launch vehicles; system management; cost-performance models and analysis. This book is an excellent reference source and is suitable as a text for advanced courses on the subject of satellite communications.