Commander Bill McArthur and Flight Engineer Valery Tokarev began their spacewalk from the Quest Airlock at 9:32 a.m. CST as they placed their suits on internal battery power. The spacewalk lasted 5 hours and 22 minutes. The spacewalk started about an hour later than planned. The crew had to repressurize the Quest airlock to open a misaligned valve in the interior portion of the two-chambered module. With the valve properly positioned, they again depressurized the outer chamber to begin their work outside.
Once out the door, McArthur and Tokarev made up the time easily and completed all of their primary tasks as well as some get-ahead jobs. They installed a television camera on the outboard end of the port truss segment. The camera will be an important aid during future assembly work when additional truss segments are added to the port side of the complex. The camera installation job had originally been planned to be performed during the STS-114 space shuttle mission of Discovery in August. It was not performed during that mission, however, when a job to remove gap fillers from the shuttle heat shield was added in its place.
McArthur and Tokarev first retrieved the camera’s stanchion from an external tool platform attached to Quest, brought the equipment out to the port truss, installed the camera on top of the stanchion and installed the hardware. The camera was powered up and provided its first views from space just before 12 p.m. Central time.
Next, flight controllers asked the spacewalkers to complete a get-ahead task by removing a failed electronics box called a Rotary Joint Motor Controller (RJMC). The RJMC will be returned on the next shuttle mission so engineers can determine why it failed. The analysis will be used to evaluate future similar hardware to be shipped to the station
The pair then moved hand over hand to the highest point of the station, the P6 truss, about 50 feet above the U.S. Destiny Lab. There, McArthur removed an old experiment called the Floating Potential Probe from its stand and pushed it away from the station. It floated up and behind the station. It is expected to burn up in the Earth’s atmosphere in about 100 days.
The experiment was installed during a station assembly mission in 2000 to characterize the electrical environment around the station’s solar arrays. Imagery from STS-114 showed that pieces of the experiment were missing or backing out of place. Since it was no longer used, managers decided to remove the unit and discard it.
The crewmembers then received approval to move ahead with the final get-ahead task before calling it a day. They quickly removed a failed circuit breaker from the Mobile Transporter (MT) and installed a new one. Called a Remote Power Control Module, the breaker provides power for redundant heating on the transporter. The transporter is a type of space rail car that can moves along the station's truss structure.
With all tasks completed, McArthur and Tokarev entered the airlock and began repressurizing it at 2:54 p.m. CST. It was the 63rd spacewalk in support of station assembly and maintenance, the 35th staged from the station and the 18th staged from Quest. It was the third spacewalk for McArthur and the first for Tokarev.