A five-foot (1.5-meter) debris shield being installed on the International Space Station floated away on Thursday during a spacewalk by two veteran U.S. astronauts, a NASA TV broadcast showed. Peggy Whitson, who became the world's most experienced female spacewalker during the outing, told ground control teams that a bag containing the debris shield floated away at about 10 a.m. EDT/1400 GMT. At the time, Whitson, 57, and station commander Shane Kimbrough, 49, were about midway through a planned 6.5-hour spacewalk to prepare a docking port for upcoming commercial space taxis and to tackle other maintenance tasks.