One Russian and One U.S. satellite collide at 500 miles per second . Collision is believed to be the second of its kind . Dickey spokesman quoted as saying crash produced massive debris cloud . Wreckage from collision expected to burn up in the Siberia 's atmosphere .
One Russian and one U.S. satellite collide at 10 km per second . Collision is believed to be the first of its kind . NASA spokesman quoted as saying crash produced massive debris cloud . Wreckage from collision expected to burn up in the Earth 's atmosphere .