The two astronauts ventured outside the space station's Quest airlock to install the first of two international docking adapters (IDAs) onto Pressurized Mating Adapter-2 (PMA-2), located on the forward end of the Harmony module.

Working on the port side of the orbiting complex's backbone, or truss (ITS), the astronauts retracted a thermal radiator that is part of the station's cooling system. The radiator is a backup that had been deployed previously as part of an effort to fix an ammonia coolant leak. They also tightened struts on a solar array joint, and installed the first of several enhanced high-definition television cameras that will be used to monitor activities outside the station, including the comings and goings of visiting cargo and crew vehicles.