The astronauts plan to enter Harmony for the first time at 8:03 a.m. Saturday after Mission Specialist Paolo Nespoli and Expedition 16 Commander Peggy Whitson open the hatches. The stationís newest pressurized module adds 2,666 cubic feet of volume, increasing the stationís living space by nearly 20 percent (from 15,000 to 17,666 cubic feet).
Mission managers today determined a focused inspection of Discoveryís heat shield is not necessary Saturday following detailed review of the imagery gathered over the last two days. The Mission Management Team declared the shuttleís Thermal Protection System is cleared for reentry. A routine final inspection focusing on the wing leading edges is planned for late in the mission.
Station managers also decided to add a 360-degree visual inspection of the stationís starboard Solar Alpha Rotary Joint (SARJ) during the second spacewalk on Sunday. The SARJ has shown increased friction for the past month and a half. Though the increase is not constant and averages less than a tenth of an amp, managers decided to add the inspection because the spacewalkers will be near the joint.
During the spacewalk, astronauts will remove the multi-layer insulation covers on the joint to better see the swing bolts beneath and document their inspection with photographs.
Parazynski and Wheelock began the spacewalk at 5:02 a.m. and wrapped up at 11:16. First, the two removed and stowed the S-band Antenna Structural Assembly which is being returned to Earth on Discovery. Next, they secured a Payload and Data Grapple Fixture onto Harmony that could not be in place during launch, removed contamination covers and disconnected the power cables linking Harmony to Discovery.
Once the spacewalkerís preparations were complete, Mission Specialists Stephanie Wilson and Clay Anderson and Expedition 16 Flight Engineer Daniel Tani used the stationís robotic arm to remove Harmony from the payload bay and move it to its position on the port side of Unity. Nespoli coordinated spacewalk activities.
Harmony will be relocated to the front of the Destiny laboratory after the shuttle departs. It will provide the docking ports for laboratory modules from the European Space Agency and the Japan Aerospace Exploration Agency that are to arrive late this year and early next year. Outfitting of the stationís newest module will continue throughout the mission.