Two big communications satellites collided in the first-ever crash of two intact spacecraft in orbit, shooting out a pair of massive debris clouds and posing a slight risk to the international space station. NASA said it will take weeks to determine the full magnitude of the crash, which occurred nearly 805 kilometers over Siberia on Tuesday. NASA believes any risk to the space station and its three astronauts is low. It orbits about 435 kilometers below the collision course. There also should be no danger to the space shuttle set to launch with seven astronauts on Feb. 22, officials said, but that will be re-evaluated in the coming days. 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. The Russian satellite was out of control. The Iridium craft weighed 560 kilograms, and the Russian craft nearly a ton. No one has any idea yet how many pieces were generated or how big they might be.