Satellite communications: Technological evolution

From their beginning, the Satellites have played a fundamental role all over the world for the scientific, technological, economic and social development, in particular the communications systems have constituted an essential part of the Space Supersystem, for the support of platform telemetry, telecommand and ranging facilities, as for the big variety of applications, which are onboarded, for many different missions. The satellite broacasting, in particular, has become very important along many years, for various satellite application areas: - Scientific satellites, for the distribution of a variety of scientific data, to the earth laboratories and research centres - Telecommunication satellites, for supporting audio, video, data and multimedia user services - Observation satellites, for the transmission of environmental data to world research centres and institutions - Navigation satellites, for global distribution of navigation signals and data to users, in order to provide positioning, location and timing services Although there is a variety of satellite broadcasting applications, the most popular for the citizens have been telecommunications services, therefore the present contribution will be focused on this topic, mainly on the technological evolution of the satellite communications in the last two decades.