Two large communications satellites, one American and one Russian, collided in space 490 miles over Siberia, NASA reported Wednesday. The collision involved an Iridium commercial satellite, launched in 1997, and a Russian satellite, Cosmos 2251, which was launched in 1993 and believed to be non-functioning. The Iridium satellite weighed 1,234 pounds, and the Russian craft weighed 1,984 pounds. Air Force Lieutenant Colonel Les Kodlick of the U.S. Strategic Command said:”We believe it’s the first time that two