Inmarsat-4 F3
COSPAR ID2008-039A Edit this at Wikidata
SATCAT no.33278Edit this on Wikidata
Spacecraft properties
BusEurostar E3000
ManufacturerEADS Astrium
Launch mass5,960 kilograms (13,140 lb)
Start of mission
Launch date18 August 2008 (2008-08-18)
Launch siteBaikonur 200/39
Entered service7 January 2009
Orbital parameters
Reference systemGeocentric
Longitude98° West

Inmarsat-4 F3 is a communications I-4 satellite operated by the British satellite operator Inmarsat. It was launched into a geosynchronous orbit at 22:43 GMT on 18 August 2008,[1] by a Proton-M/Briz-M Enhanced carrier rocket. It is currently located at 97.65° West longitude, providing coverage of the Americas.[2] It entered service on 7 January 2009.

Like the earlier Inmarsat-4 F1 and F2 satellites, Inmarsat-4 F3 was constructed by EADS Astrium, using a Eurostar E3000 bus. It has a mass of 5,960 kilograms, and is expected to operate for 13 years.[3] It was originally slated for launch using an Atlas V 531, but was transferred to Proton due to a large backlog of Atlas launches.

In the United States, Inmarsat ground stations are licensed to operate at 1525-1559 MHz and 1626.5-1660.5 MHz. The 1544-1545 MHz and 1645.5-1646.5 MHz bands are reserved for safety and distress communications.[2]


  1. ^ "ILS PROTON SUCCESSFULLY LAUNCHES INMARSAT-4 F3 SATELLITE". International Launch Services. 2008-08-19. Archived from the original on 2008-09-23. Retrieved 2009-02-15.
  2. ^ a b "Inmarsat List". US Federal Communications Commission. Archived from the original on March 23, 2014. Retrieved March 22, 2014.
  3. ^ Krebs, Gunter. "Inmarsat-4". Gunter's Space Page. Retrieved 2009-02-15.