With help from shuttle robotic arm operator Jim Kelly and space walk choreographer Susan Helms, Richards and Thomas installed a stowage platform for spare station parts and attached a spare ammonia coolant pump to the platform. They also finished connecting several cables put in place by Astronauts Jim Voss and Susan Helms during their nearly nine-hour-long space walk Sunday. The cables, on the exterior of the Destiny laboratory module, will provide power and control of the station's Canadian-built robotic arm. Known as the Space Station Remote Manipulator System, the arm will be delivered and installed by the STS-100 crew in April.
Commander Jim Wetherbee deactivated and then reactivated Leonardo's DC-to-DC power converters and checked out the Lab Cradle Assembly, installed during the first space walk, which eventually will be used to connect the station's large truss structure to Destiny's hull.
Richards and Thomas also scaled the station to the top of its 240-foot-wide solar arrays and were successful in engaging a fourth latch for the port-side array's structural brace. Several other get-ahead tasks also were accomplished during the space walk, including a check of a Unity module heater connection and inspection of an exterior experiment called the Floating Potential Probe that has been operating intermittently. The space walkers reported they did not see any status lights on the probe; investigators on the ground will use that information to continue troubleshooting.
"Well, Andy, we were on top of the world there for a while," Richards said as the pair began returning to the airlock. "Yes, we were," Thomas replied.
The second and final planned space walk of the mission began at 11:23 p.m. Monday, and concluded at 5:44 a.m. Tuesday. The 6-hour, 21-minute space walk brings the total exterior construction time on the station to 124 hours over the course of 18 space walks, and the total EVA time in shuttle program history to 392 hours, 36 minutes over 62 separate space walks.
As Richards and Thomas worked outside the station, returning Expedition One Cosmonauts Yuri Gidzenko and Sergei Krikalev - now members of the Discovery crew - exercised inside the shuttle to help prepare their bodies for the return to Earth after four and a half months in orbit.
Inside the station, Expedition One Commander Bill Shepherd, and Expedition Two Commander Yury Usachev and Flight Engineer Jim Voss continued to unload the Leonardo logistics module. Among the five tons of gear being transferred is the first station research rack, the Human Research Facility, which will be installed inside Destiny this evening.
Discovery's crew will go to bed at 9:42 a.m. CST, and will get an extra half-hour of sleep before being awakened at 6:12 p.m. All station and shuttle systems are working well.