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.[4]
Spacecraft
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.[4]
On 10 February 2009, at 16:56 UTC, at about 800 km altitude, Kosmos 2251 (1993-036A) (a derelictStrela satellite) and Iridium 33 collided, resulting in the destruction of both spacecraft.[5]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.[6][7][8][9]
^Wade, Mark. "Proton". Encyclopedia Astronautica. Archived from the original on September 13, 2008. Retrieved 2009-02-12.
^ ab"Iridium 33: Display 1997". nssdc.gsfc.nasa.gov. NASA. 14 May 2020. Retrieved 5 June 2020. This article incorporates text from this source, which is in the public domain.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Crewed flights are indicated in underline. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets).