MOSCOW (AP) — U.S. and Russian officials traded shots Thursday over who was to blame for a huge satellite collision this week that spewed speeding clouds of debris into space, threatening other unmanned spacecraft in nearby orbits. The smashup 500 miles (800 kilometers) over Siberia on Tuesday involved a derelict Russian spacecraft designed for military communications and a working satellite owned by U.S.-based Iridium, which served commercial customers as well as the U.S. Department of Defense.- – – -Contact The Daily Reveille’s news staff at [email protected].