Pictured: Mike Possum is attached to the end of the space station's robotic arm moving toward a point where it will replace the mobile conveyor's wheel assembly. Photo: NASA TV.
The second of three spacewalks planned for STS-121 crew members is behind us. Discovery astronauts Pierce Sellers and Michael Possum completed the two main missions in 6 hours and 47 minutes ending at 22:01 Israel time on Monday.
The first task of the two was to complete the installation of the heat controlled pump to the outside of one of the air ducts.
Sellers and Possum then turned their attention to the maintenance of the mobile conveyor belt. They replaced the set of wheels that drive the cable that supplies power and data to the conveyor belt. The completion of this work provided the conveyor with the possibility of full function both in its main engine and in a spare system that will be used in the tasks of assembling additional components of the station.
Discovery pilot Mike Kelly coordinated the activity from Discovery, and Commander Steve Lindsay monitored the spacecraft's systems and video installations. Once again there were Stephanie Wilson and Lisa Novak from the robotic arm operation.
While the shuttle crew focused on the spacewalk, members of the space station's 13th crew loaded the Leonardo module with the results of science experiments, unwanted items and trash from the station. Leonardo will be returned to the shuttle's cargo deck on Friday as part of preparations to return to Earth.
The third and final starting walk, which was actually added at the last minute, in which the heat shield repair techniques will be tested, is scheduled to begin at 14:13 Israel time on Wednesday.
