Expedition Six Conducts Second Spacewalk
For the second time during their tour of duty aboard the International
Space Station, Commander Ken Bowersox and NASA ISS Science Officer Don
Pettit conducted a spacewalk. They began their excursion at 7:40 a.m.
CDT (1240 GMT) and concluded it at 2:06 p.m. CDT (1906 GMT) Tuesday. 
Bowersox and Pettit successfully completed their scheduled tasks and
performed some get-ahead tasks. Shortly after the start of the
extravehicular activity, Bowersox reconfigured connectors between the S0
(S-Zero) Truss and the two trusses connected to it -- the S1 (S-One and
the P1 (P-One) -- and Pettit replaced a power relay box in the station's
Mobile Transporter.
Then, the two spacewalkers rerouted power cables to two of the station's
Control Moment Gyros, or CMGs. The gyros provide orientation control to
the station. One of the four CMGs failed last year and will be replaced
during the next shuttle mission to visit the orbital outpost.
Other tasks included the installation of the Spool Positioning Devices
and the securing of a thermal cover on the S1's Radiator Beam Valve
Module.
While Pettit and Bowersox worked outside, Flight Engineer Nikolai
Budarin monitored station systems. 
This was the 51st spacewalk performed at the station. It was also the
26th based out of the orbital outpost and the 17th staged out of the
Quest Airlock.