1 . 3 Configuration of a Satellite

Satellite communications are the outcome of research in the area of communications and space technologies whose objective is to achieve ever increasing ranges and capacities with the lowest possible costs. The Second World War stimulated the expansion of two very distinct technologies—missiles and microwaves. The expertise eventually gained in the combined use of these two techniques opened up the era of satellite communications. The service provided in this way usefully complements that previously provided exclusively by terrestrial networks using radio and cables. The space era started in 1957 with the launching of the first artificial satellite (Sputnik). Subsequent years have been marked by various experiments including the following: Christmas greetings from President Eisenhower broadcast by SCORE (1958), the reflecting satellite ECHO (1960), store-and-forward transmission by the COURIER satellite (1960), powered relay satellites (TELSTAR and RELAY in 1962) and the first geostationary satellite SYNCOM (1963). In 1965, the first commercial geostationary satellite INTELSAT I (or Early Bird) inaugurated the long series of INTELSATs; in the same year, the first Soviet communications satellite of the MOLNYA series was launched.