During the 8-hour, 17-minute spacewalk, Williams and Hoshide were unable to install a new Main Bus Switching Unit (MBSU) on the International Space Station’s s-zero truss. After removing and stowing the failed unit, the spacewalkers had difficulties driving the bolts to secure the replacement switching unit in the s-zero truss.
Williams and Hoshide used a long-duration tie-down tether to secure the replacement MBSU to the space station for a future spacewalk.
Prior to this task, Williams was able to successfully connect one of two power cables in preparation for the future arrival of a Russian laboratory module. The third objective, replacing a camera on the Canadarm2 robotic arm, was not completed.
The first Expedition 32 spacewalk was performed by Commander Gennady Padalka and Flight Engineer Yuri Malenchenko on Aug. 20. The primary task during their 5-hour, 51-minute excursion was the move of the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module. Other tasks included the installation of micrometeoroid debris shields on the exterior of the Zvezda service module and the deployment of a small science satellite.