Eutelsat I F-1, also known as European Communications Satellite 1 (ECS-1) is a decommissioned communications satellite operated by the European Telecommunications Satellite Organisation (Eutelsat). Launched in 1983, it was operated in geostationary orbit at a longitude of 13° East, before moving to several other locations later in its operational life, before it was finally decommissioned in 1996. It was the first of five satellites launched to form the first-generation Eutelsat constellation.