ABSTRACT
Radio is integral to almost all uses of space. It is essential for most tracking, and for all telemetry, command and control. All satellites depend on the ability to receive and to transmit data to Earth. The frequencies modern satellites use lie in the higher frequency ranges. Only these can penetrate the Heaviside Layer of ionised gases above the Earth, and only they can allow the necessary precision of complex signals. When the exploration and utilisation of space began there already was an international organisation dealing with such matters at the terrestrial level. Tracing its origins back to the electric telegraph, the International Telecommunication Union (ITU) had built significant expertise on communication by telephone, telegraph and radio. The history of the International Telecommunication Union has two major strands, the one relating to wired services — the telegraph and the telephone — and the other to radio.
