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Satellites crash in orbit
Two communications satellites have collided in the first-ever crash of two intact spacecraft in orbit, Nasa said.
The collision occurred on Tuesday nearly 500 miles over Siberia. The crash produced a pair of massive debris clouds, and the magnitude of the situation will not be known for weeks at least, said Nasa spokesman Kelly Humphries.
However, any risk to the international space station, which orbits below the collision course, is thought to be low. There should also be no danger to the forthcoming space shuttle flight, targeted for lift-off no earlier than February 22, "but they're continuing to analyse any possible risk," Humphries said.
The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be non-functioning.
Each satellite weighed well over 1,000 pounds (455 kgs).
There have been four other cases in which space objects have collided accidentally in orbit, Nasa said.
But those were considered minor events and involved parts of spent rockets or small satellites.