Satellite Communications Overview

Abstract

The serious consideration of the provision of satellite communications from space dates from 1945 when the first technical descriptions were written with regard to launching a spacecraft into geosynchronous orbit and the design of space stations as extraterrestrial radio relays was specifically outlined. In the historical section that follows, however, it becomes clear that the idea or concept had been around many years, indeed centuries before. The 1945 article, however, described the possible delivery of telecommunications services from space and presented detailed calculations as to how this might efficiently be done from a special orbit known as the geosynchronous (or sometimes the geostationary) orbit (Clarke 1945). The use of radio waves for long-distance communications up until the 1960s was limited to microwave relay between towers or the use of shortwave or high-frequency (HF) transmissions that were, in effect, bounced off of the ionosphere. This latter technique was quite limited in transmission throughput and unreliable because the ionosphere was subject to distortions largely due to solar radiation and the so-called solar wind and solar storms. Launch technology that could place satellites in orbit came into being in the late 1950s.