U.S. and Russian space satellites collide

Space war!

OK, not really, but news of the first known collision of two satellites in orbit around the earth has some worried that this could be the start of a chain reaction of collisions of objects orbiting the planet, as the commonly-used orbital altitudes get more heavily crowded.

The Russian satellite was an allegedly defunct communications satellite, but the U.S. satellite involved in the incident was an operational Iridium satellite, used as part of the company's satellite phone network. There has been no response yet from Iridium as to whether this will impact phone service, or where service may have been compromised.

The collision of these two spacecraft may be just the beginning of trouble in the narrow and critical zone that circles the earth at about 485 miles up. Heavily used by weather and communication satellites, the worry now is a sort of domino effect of crash after crash. As David Byrden posted on a popular technology mailing list: "The nightmare scenario here is that the fragments from the collision will gradually spread out, each one capable of destroying a further satellite.... resulting eventually in a layer of high-speed debris all around earth, such that no rocket can safely be launched, locking in the human race."

The U.S. military says it is now tracking up to 600 new pieces of debris from this incident, about a three precent increase to the 18,000 bits of space junk that were already being tracked in orbit. Is it too late to ask for NASA to look into cleaning up the orbital junkyard?

Update: Iridium says it will replace the lost satellite with an in-orbit spare (it has eight) within 30 days.