Mission Specialist Leopold Eyharts and Pilot Greg Johnson used the station's robotic arm, Canadarm2, to move Dextre to its newest position on Destiny, where it was attached to one of the lab's power and data grapple fixtures. This position clears the way for Canadarm2 to be used for future robotic missions.
Johnson and Flight Engineer Garrett Reisman then used Canadarm2 to move the Spacelab Logistics Pallet, where Dextre was assembled during the first spacewalk of the mission, from the station's truss to Endeavour's cargo bay. The pallet will return to Earth aboard the shuttle. Canadarm2 will be moved to the station's mobile base system, where it will be transported to another worksite in preparation for Thursday's fourth spacewalk.
Mission Specialists Robert L. Behnken and Mike Foreman will conduct that spacewalk, and the focus will be to test a heat shield repair technique by using a caulk-gun-like tool named the Tile Repair Ablator Dispenser (T-RAD) to dispense a material called Shuttle Tile Ablator-54 (STA-54) into purposely damaged heat shield tiles. Those test samples will be returned to Earth to undergo extensive testing on the ground.
Mission managers in Houston are considering a second attempt to install the Materials International Space Station Experiment 6, or MISSE 6, onto the Columbus module during the fifth and final spacewalk of Endeavour's mission. During yesterday's spacewalk, latching pins were unable to properly engage and secure the suitcase-sized packages used to expose experiments to the environment of space. If approved, one of the objectives of the spacewalk -the reinstallation of a spare trundle bearing assembly on the starboard Solar Alpha Rotary Joint (SARJ) -would be deferred to make room for MISSE 6.