A two-man crew retreated safely inside the international space station early Friday after extending their spacewalk so that they could replace a video camera on a construction platform at the orbiting outpost.

The task was the last during the 61/2-hour spacewalk for Russian commander Pavel Vinogradov and U.S. flight engineer Jeff Williams, who successfully completed their half-dozen maintenance jobs. They got behind schedule, though, and the camera chore was still unfinished when the decision was made to extend the spacewalk for less than an hour.