Marecs
Maritime European Communications Satellite

The Marecs satellites were members of Inmarsat's first generation global maritime communications 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.

Spacecraft
Based on British Aerospace ECS platform. 3-axis stabilized to 0.2 deg (pitch, roll) using fully redundant momentum wheels, thrusters, and nutation dampers. Redundant sun sensors provide 0.04 deg knowledge. Two sun-tracking solar arrays provide 955 W (BOL) with 2 NiCd batteries for eclipse power. Hydrazine propulsion system for station-keeping.

Payload
Three repeaters: shore-to-ship with 5 MHz bandwidth, ship-to-shore with 6 MHz bandwidth, shore-to-shore with 0.5 MHz bandwidth. These provide 35 two-way voice channels plus search and rescue capabilities. One 2 m diameter L-Band antenna and 2 horns (one transmit, one receive) for 4/6 GHz channels. All antennas have full Earth coverage.

Country of Origin	Europe
Customer/User	Inmarsat, ESA
Manufacturer(s)	Hawker-Siddeley Dynamics, MESH constortium
Size	Hexagonal body 2.2 m diameter, 13.7 m solar array span
Orbit	A: GEO over Atlantic / B2: GEO over Pacific
Design Life	7 years

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Marecs 1	1981-122A	12/20/81	Kourou	Ariane 1	GEO	582
Maritime communications; leased by Inmarsat
Marecs B	none	9/9/82	Kourou	Ariane 1	FTO
Marecs B intended for maritime communications, planned for lease to Inmarsat; launched with Sirio 2
Marecs B2	1984-114B	11/10/84	Kourou	Ariane 3	GEO	563
177.5 deg E; maritime communications; leased by Inmarsat