MARECS were two geostationary satellites – MARECS A (launched on 20 December 1981) and MARECS-B2 (launched on 10 November 1984 – that formed part of Inmarsat's global maritime communications satellite network. The program began as the experimental Maritime Orbital Test Satellite (MAROTS) in 1973, but subsequently evolved into an operational system resulting in a name change, a satellite redesign, and delayed development.