ISS crew 12 performed the first spacewalk

McArthur, the Expedition 12 commander, and Tokarev, the expedition flight engineer, began their spacewalk from the Quest Airlock at 10:32 a.m. EST. The spacewalk lasted five hours, 22 minutes. Their spacewalk was the first using U.S. space suits since April 2003.

It started about an hour later than planned, because the crew had to re-pressurize the Quest airlock to open a misaligned valve. The valve was 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, the crew easily made up the time. They completed all primary tasks and 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 crew retrieved the camera’s stand from an external tool platform attached to Quest, brought the equipment out to the port truss, installed the camera and hardware on its stand. The camera was powered and provided its first views from space just before 1 p.m. EST.

Next, flight controllers asked the crew to complete a get-ahead task by removing a failed electronics box called a Rotary Joint Motor Controller. The controller will be returned on the next space shuttle mission so engineers can determine why it failed. The analysis will be used to evaluate similar hardware shipped to the station.

The pair then moved hand over hand to the highest point of the station, the P6 truss. It’s approximately 50 feet above the U.S. Destiny Lab. McArthur removed an old experiment called the Floating Potential Probe from its stand and pushed it away from the station. It is expected to burn up in the Earth’s atmosphere in about 100 days.

The experiment was installed during an assembly mission in 2000 to characterize the electrical environment around the station’s solar arrays. Imagery from the last shuttle showed pieces of the experiment were missing or out of place. Since it was no longer used, it was removed and discarded.

The crew moved ahead with the final get-ahead task before calling it a day. They quickly removed a failed circuit breaker from the Mobile Transporter 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 moves along the station's truss structure.

With all tasks completed, McArthur and Tokarev entered the airlock and began re-pressurizing it at 3:54 p.m. EST. It was the 63rd spacewalk in support of station assembly and maintenance; the 35th staged from the station; and 18th staged from Quest. It was the third spacewalk for McArthur and the first for Tokarev.

Source: NASA