There have been numerous books written on satellite communications, but none on the communications satellite itself. This book is the first to concentrate on the details of the hardware and the design philosophies of the communications satellite and, as the principles involved are common to all satellite systems, the book will be of interest to anyone wishing to understand satellites in general. The first part of The Communications Satellite describes each of the major satellite subsystems in turn, giving comprehensive descriptions and explanations, rather than concentrating on mathematical formulations. A constant theme throughout the book is the interdependence of all the systems, which is important in the design of each individual system. Also included are chapters on the hardware at each end of the communications link, and chapters on other aspects of the industry, such as launch vehicles and insurance. The second part is a detailed description of a direct broadcasting satellite system, which is one of the most widely used applications of the communications satellite. The final chapter derives the link budget for the system; this is the most fundamental calculation in satellite communications and has never before been explained and derived in a book. The Communications Satellite is unique in its coverage and will be an invaluable source of information to all spacecraft engineers and to anyone with an interest in satellites.