Gears Jammed on Shuttle's Hatch

Jammed gears are to blame for the stuck hatch that kept the crew of space shuttle Columbia from walking in space last week, NASA said. The next step is to take apart the gearbox to find the source of the problem, a NASA spokesman said. A gear tooth could be broken, or debris could be the cause, he said. Columbia returned to Kennedy Space Center in Florida after an 18-day science mission.