|Operator||Iridium Satellite LLC|
|Launch mass||700 kg|
|Start of mission|
|Launch date||14 September 1997, 01:36 UTC|
|Rocket||Proton-K / DM2|
|Launch site||Baikonur, Site 81/23|
via International Launch Services
|End of mission|
|Destroyed||10 February 2009, 16:56 UTC|
Collision with Kosmos 2251
|Perigee altitude||779.6 km |
|Apogee altitude||793.9 km|
|Epoch||10 February 2009|
Iridium 33 was a communications satellite launched by Russia for Iridium Communications. It was launched into low Earth orbit from Site 81/23 at the Baikonur Cosmodrome at 01:36 UTC on 14 September 1997, by a Proton-K rocket with a Block DM2 upper stage. The launch was arranged by International Launch Services (ILS). It was operated in Plane 3 of the Iridium satellite constellation, with an ascending node of 230.9°.
Iridium 33 was part of a commercial communications network consisting of a constellation of 66 LEO spacecraft. The system uses L-Band to provide global communications services through portable handsets. Commercial service began in 1998. The system employs ground stations with a master control complex in Landsdowne, Virginia, a backup in Italy, and a third engineering center in Chandler, Arizona.
The spacecraft was 3-axis stabilized, with a hydrazine propulsion system. It had 2 solar panels with 1-axis articulation. The system employed L-Band using FDMA/TDMA to provide voice at 4.8 kbps and data at 2400 bps with a 16 dB margin. Each satellite had 48 spot beams for Earth coverage and used Ka-Band for crosslinks and ground commanding.
On 10 February 2009, at 16:56 UTC, at about 800 km altitude, Kosmos 2251 (1993-036A) (a derelict Strela satellite) and Iridium 33 collided, resulting in the destruction of both spacecraft. NASA reported that a large amount of space debris was produced by the collision, i.e. 1347 debris for Kosmos 2251 and 528 for Iridium 33.
|Wikinews has news coverage of the 2009 satellite collision: