BLOOMBERG NEWS: U.S. and Russian satellites collided over Siberia yesterday in the first crash between such objects at orbital speed, space agencies from both countries said. The collision occurred 491 miles (790 kilometers) above Siberia at 11:55 a.m. New York time yesterday, destroying an Iridium Satellite LLC communications satellite and a defunct Russian Cosmos 2251 craft, National Aeronautics and Space Administration spokesman John Yembrick said in an e-mail, without identifying the cause. It was the first crash between two intact space craft traveling at orbital speed, about 17,500 miles per hour, NASA spokeswoman Beth Dickey said by phone. While the resulting debris clouds elevated the risk to the International Space Station, which orbits at about 220 miles, it is within acceptable limits, Dickey said. She estimated the debris field contained between 200 and 300 objects. MORE