Astronauts lost a piece of shielding that they were installing at the International Space Station during a spacewalk on March 30. Cameras spotted the item floating away. The shield is not on track to come back to the station.The shielding is used to protect the station against micrometeorite debris. The piece that was lost was one of four to be installed on the Tranquility module, according to reports.This was the eighth spacewalk by Peggy Whitson – a record for the world’s most experienced spacewoman.