This updated and extended new edition has been compiled from the course material of the highly successful IEE Vacation School of the same name. The vacation school was designed to give a broad introduction to the subject of satellite communications and provide the background knowledge and tools of the trade for those entering the field. The 3rd edition of the book continues this theme and up-to-date information on mobile and personal satellite constellations, navigation and positioning, and military and small satellite systems has been added, as well as a look to future Ka-band multimedia systems. We have also included updated ITU information and sections on history, organisation and the satellite business. The book differs from others on the subject in its pragmatic and engineering-oriented approach. The contributors are all current practitioners from industry or academics specialising in the field. The book is ideal for undergraduate or postgraduate students and practising engineers meeting the subject for the first time. However, it also providers the breadth and detail that make it suitable as a reference text.