Astronauts Begin Final Spacewalk of STS-128

Mission specialists Danny Olivas and Christer Fuglesang began the third and final spacewalk for the STS-128 mission at 4:39 p.m. EDT. Their extravehicular activity will include outfitting and maintenance of station modules.

The two will deploy a payload attachment system on the starboard truss. They will have a special tool with them in the event they encounter any problems with a detent pin that caused problems on similar tasks in previous missions.

Next they will replace a failed rate gyro assembly, which measures rates for any changes in the station’s attitude, with a new one.

With that complete, the two will split up for the next tasks. Olivas will install a Global Positioning System antenna while Fuglesang will remove and replace a remote power control module and install an insulation sleeve on a cable inside the truss. Fuglesang will follow that up with the installation of a second GPS antenna.

The two will reunite for the final task, routing two 60-foot-long avionics systems cables along the station. The cables are being installed in preparation for the arrival of the Node 3 “Tranquility” in 2010.