Visible through a window on Endeavour's aft flight deck, astronaut Rick Linnehan participates in the mission's third scheduled spacewalk. During the 6-hour, 53-minute spacewalk, Linnehan and astronaut Robert L. Behnken installed a spare-parts platform and tool-handling assembly for Dextre, also known as the Special Purpose Dextrous Manipulator. Among other tasks, they also checked out and calibrated Dextre's end effector and attached critical spare parts to an external stowage platform. The new robotic system is scheduled to be activated on a power and data grapple fixture located on the Destiny laboratory on flight day nine.
