Astronaut Dale A. Gardner wearing a manned manouvering unit, a motorised backpack, approaches the damaged Westar VI communications satellite. The object he is carrying is a stinger, which enables him to bring the satellite under control. The effector end of the remote manipulating arm, controlled from within the shuttle cabin, can be seen on the left. It will be employed in capturing the satellite & returning it to the shuttle for repair. Shuttle Discovery, mission 51-A, was on an eight day flight, which lasted from 8-16th November 1984. Two communications satellites were retrieved & two were launched.