Geostationary maritime communications satellites, which form part of INMARSAT's world-wide maritime communications satellite network. The program began as the experimental Maritime Orbital Test Satellite (Marots) in 1973, but was subsequently changed to an operational system resulting in a name change, a satellite redesign, and delayed development. Marecs is operated by ESA for Inmarsat. Major Events: .

• 20 December 1981 MARECS 1 Spacecraft: ECS/OTS. Mass: 582 kg. Launch Site: Kourou . Launch Vehicle: Ariane 1. More details

  MARECS-A was a geostationary maritime communications satellite, which formed part of INMARSAT's world-wide maritime communications satellite network. MARECS-A moved to a new position on the geostationary orbit. Old position: 334E. New position: 22.5 E. The Marecs satellites were members of Inmarsat's first generation global maritime communications network.

• 09 September 1982 MARECS B Spacecraft: ECS/OTS. Launch Site: Kourou . Launch Vehicle: Ariane 1. More details

  Marecs B intended for maritime communications, planned for lease to Inmarsat; launched with Sirio 2. Geosynch orbit.

• 09 September 1982 Sirio 2 Spacecraft: SIRIO. Launch Site: Kourou . Launch Vehicle: Ariane 1. More details

• 10 November 1984 MARECS 2 Spacecraft: ECS/OTS. Mass: 563 kg. Launch Site: Kourou . Launch Vehicle: Ariane 2/3. More details

  Stationed at 177.5 deg E; maritime communications; leased by Inmarsat. Geostationary position 177.5 deg E. MARECS PAC 1 is a geostationary maritime mobile communication satellite which will form part of the INMARSAT world-wide maritime communication satellite network. 1985 Jul 1. Move to a new position. Old position: 177.5E. New position: 345 deg E.