The paper traces the development of satellite communication for commercial purposes up to the present day, and looks at the prospects for the next decade. A review of experimental programmes and of the institutions set up to provide satellite facilities is followed by an examination of the external constraints that mould system development, principally traffic demand, orbital geometry, choice of radio frequency and cost of launching. Next come Sections dealing with transmission, satellite design and earth-station design, with particular emphasis on systems serving large, high-performance, fixed earth stations such as are in use today. Finally, the prospects of development for these existing services are reviewed, and also those for new ones serving smaller fixed earth stations, ships and aircraft, and brief consideration is given to ways in which congestion in orbit, which will eventually result from expansion in the use made of satellite communication, can be minimised.