Beginning work on Tuesday, following the Labor Day holiday, Commander Valery Korzun and Flight Engineers Peggy Whitson and Sergei Treschev charged and discharged batteries used in the U.S. extravehicular mobility unit spacesuits in preparation for three spacewalks that will originate from the station's Quest airlock module. Whitson also did some troubleshooting on the battery charging assembly associated with that task.
The entire crew participated in emergency training sessions, practicing their assignments and responsibilities in the event of either an emergency depressurization of a station module, or a medical emergency affecting a crewmember. The training sessions are scheduled periodically to make sure the crew is always prepared to react quickly and effectively in the event of an emergency.
Whitson resumed research in the Destiny Laboratory and its new Microgravity Science Glovebox, conducting two runs with an experiment studying semiconductor formation in space. That experiment, Solidification Using a Baffle in Sealed Ampoules, uses a special furnace to control the initial melting, fluid motion and bubbles as the crystals form in an effort to make larger, purer semiconductor crystals. Two more samples will be processed before Whitson reconfigures the glovebox for the next, the Pore Formation and Mobility Invesigation, which focuses on the bubbles that often become trapped in a metal or crystal sample and diminish the material's strength and usefulness.
Thursday was robotics day on the station, with Whitson and Korzun taking turns at Canadarm2's controls both to increase their proficiency and to continue to check out the Mobile Base System on the station's truss structure. The pair "flew" the arm into position so that the Latching End Effector (LEE) of the arm could look directly into the LEE of the Payload and Orbital Replacement Unit Accommodation (POA), and vice versa. This allowed television cameras to downlink views of the snare and latching mechanisms for flight controllers and engineers to inspect.
Next, they moved the arm in a survey of the Mobile Base System and its four Power and Data Grapple Fixtures (PDGFs). Once the survey was complete, they grappled and ungrappled the fourth and final PDGF to be checked out. All of the major objectives of the arm operations and grapple fixture checkout were successful.
Maintenance was the major activity Friday, and the crew powered down about half of Destiny's systems in order to replace a Remote Power Control Module (RPCM) which switches power to various systems on the station. The systems power down and replacement of the module went well, and flight controllers were restoring power to the systems that had been shut down as the crew began preparing for bed Friday afternoon.