Mission specialists Piers Sellers and Mike Fossum spent the day outside the International Space Station today, completing the second spacewalk of space shuttle mission STS-121. During their 6-hour, 47-minute excursion, the astronauts completed the installation of a spare thermal pump outside the Quest Airlock, and performed maintenance on the mobile transporter. The third and final spacewalk for the mission is scheduled for Wednesday, when astronauts will test out different methods to repair the shuttle’s heat shield.
The second of three spacewalks scheduled for STS-121 is now in the books. Mission Specialists Piers Sellers and Mike Fossum completed both major objectives of the 6-hour, 47-minute excursion, which concluded at 3:01 p.m. EDT.
The first task the orbital duo completed was the installation of a spare thermal control system pump on to the outside of the Quest Airlock.
Then, Sellers and Fossum turned their attention to maintenance on the mobile transporter. They replaced a reel assembly for a cable that provides power and data to the station’s mobile transporter. The completion of this job gives the transporter fully functional primary and backup systems for use during future station assembly tasks.
Pilot Mark Kelly coordinated the spacewalk activities from inside Discovery, and Commander Steve Lindsey monitored vehicle systems and video setups. Mission Specialists Stephanie Wilson and Lisa Nowak were the robotic arm operators.
While the shuttle crew focused on the spacewalk, the Expedition 13 crew concentrated on loading the Leonardo multi-purpose logistics module with scientific experiment results, unneeded items and trash from the station. Leonardo will return to Discovery’s payload bay Friday in preparation for the return to Earth.
The final scheduled spacewalk, which will feature on-orbit shuttle heat shield repair techniques, is slated to begin at 7:13 a.m. EDT Wednesday.
Original Source: NASA News Release