In what’s believed to be the most significant incident of its kind, a derelict Russian Kosmos 2251 military satellite has collided with a U.S. communications satellite that’s part of the Iridium satellite communication network. The collision occurred approximately 500 miles over Siberia, and has produced a cloud of debris containing at least 600 objects that are currently being tracked by NASA and other agencies. Although the debris doesn’t pose any immediate threat to the International Space Station (ISS) or the space shuttle launch planned for later this month, the debris cloud makes an already-complicated task of finding launch windows that much more difficult…and the debris could pose a risk to the Hubble Space Telescope.
Officials and trackers hope that most of the debris is in unsustainable orbits and will eventually descend and burn up in the earth’s atmosphere.
The International Space Station actually has a limited maneuvering capability which, if implemented well ahead of time, can be used to shift the station’s orbit away from hazardous debris. The station has shifted its orbit on more than half a dozen previous occasions as a precaution.
The incident highlights the increasingly crowded space in near-earth orbit, which is now crowded with satellites, debris, leftovers from boosters and space flights, and even a few stray parts—such as a toolkit that got away from an astronaut recently on a space walk. The sheer number of objects in near-Earth orbit represent a significant risk to shuttle flights; as of the beginning of 2009, space agencies were tracking over 17,000 objects over 10cm in size; of those, about 6,000 are satellites, of which roughly half are still functional.
Iridium reports that its satellite communications service remains operational despite the loss of a functioning satellite, although customers may experience some disruption of service through Friday, February 13. The company plans to move one of it’s in-orbit standby satellites into position to take over the duties of the destroyed unit.
