European Communication Satellite (ECS) system

The beginnings of the ECS system go back to the late 1960s when the European Space Research Agency, ESRO, conducted internal studies to determine the usefulness of a satellite system to carry a portion of the long distance telephone traffic between western European countries. In 1970, a number of contracts with European companies were initiated for the development of hardware items needed for the satellites. It was finally decided to develop an experimental satellite, the Orbital Test Satellite, OTS. After an initial failure, OTS-2, was successfully launched on May 11, 1978. In the same year, a program was approved for the development of the operational follow-on to OTS, the ECS satellites. According to the program, the European Space Agency (ESA) was to procure five satellites and four Ariane launch vehicles. ECS-1 was launched by an Ariane-1 on June 16, 1983. ECS-2 was launched in 1984, while ECS-3 is to be placed in orbit in 1985.