|Operator||Eutelsat / ESA|
|Mission duration||7 years planned|
13 years achieved
|Spacecraft type||Eutelsat I|
|Launch mass||1,050 kilograms (2,310 lb)|
|Start of mission|
|Launch date||16 June 1983, 11:59:03UTC|
|Launch site||Kourou ELA-1|
|Entered service||12 October 1983|
|End of mission|
|Deactivated||16 December 1996|
|Longitude||10° East (1983)|
13° East (1983-88)
16° East (1988-91)
17.5° East (1991-92)
25.5° East (1992-93)
48° East (1993-96)
36° East (1996)
|Semi-major axis||42,561.59 kilometres (26,446.55 mi)|
|Perigee altitude||36,123 kilometres (22,446 mi)|
|Apogee altitude||36,258 kilometres (22,530 mi)|
|Epoch||5 June 2014, 10:14:27 UTC|
|Band||12 Ku band|
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. 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.
A Eutelsat I spacecraft, F-1 had a mass at launch of 1,050 kilograms (2,310 lb). Constructed by British Aerospace, it was designed to be operated for seven years and carried 12 Ku band transponders, two of which were set aside as spares. Unlike the later Eutelsat I satellites, F-1 did not have the two additional "SMS beam" transponders in the 12 GHz band. It also only had partial eclipse protection, requiring some channels to be turned off during eclipse periods around the spring and autumn equinoxes. The satellite contained a Mage-2 solid rocket motor to perform orbit circularisation at apogee.
ECS-1 was launched by Arianespace, using an Ariane 1 carrier rocket, flight number L06. The launch took place at 11:59:03 UTC on 16 June 1983, from ELA-1 at Kourou. Successfully deployed into geosynchronous transfer orbit, ECS-1 raised itself into an operational geostationary orbit using its apogee motor. Following commissioning operations conducted by the European Space Agency at a longitude of 10° East, the satellite was moved to its operational slot at 13° East, entering service on 12 October.
After five years in service, Eutelsat I F-1 was replaced by the newly launched Eutelsat I F-4. For the next three years it covered a new slot at 16° East until the launch of Eutelsat II F-3. After brief operations at 17.5 and 25.5 degrees between 1991 and 1993, the satellite was moved to 48 degrees East for most of its last three years of service. Between February and March 1996 the spacecraft was moved to 36 degrees West, where it remained until November. The satellite was decommissioned in December 1996; leaving geosynchronous orbit on 11 December before deactivation on 16 December. As of 5 June 2014 the now-derelict satellite was in a 36123 × 36258 km × 15.15° (22,446 × 22,530 mi) graveyard orbit.