U.S. astronauts Mike Foreman and Randy Bresnik wrapped up the second space walk for space shuttle Atlantis's STS-129 mission on Saturday, NASA said. This is a file photo of Astronaut Robert L. Satcher Jr. works outside the International Space Station as he participates in Space Shuttle Atlantis' first spacewalk of mission STS-129 as construction and maintenance continue on the International Space Station in this photo released by NASA and taken November 19, 2009.[Xinhua/Reuters File Photo]

U.S. astronauts Mike Foreman and Randy Bresnik wrapped up the second space walk for space shuttle Atlantis's STS-129 mission on Saturday, NASA said.

The start of the space walk, which lasted six hours and eight minutes, was a little later than planned, about 9:30 a.m. EDT (1430 GMT), because a false depressurization alarm had sounded on the station at 9:53 p.m. Friday (2:53 a.m. GMT Saturday), interrupting the crews' sleep and the space walkers' campout in the Quest airlock. The space walkers completed the process of reducing the nitrogen in their blood by exercising while breathing oxygen.

Foreman and Bresnik installed an antenna assembly on a Columbus module handrail, relocated the station's floating potential measurement unit to the Port 1 truss and deployed a second Payload Attachment System (PAS) on the upper part of the Starboard 3 (S3) truss.

After completing the installation of a wireless video system onS3 an hour ahead of schedule, the space walkers had time to perform a get-ahead task. Foreman and Bresnik deployed a third PAS, this one on the Earth-facing side of S3. This task, originally schedule for the mission's third space walk, was accomplished smoothly and quickly.

Atlantis lifted off from Kennedy Space Center in Florida on Monday. Its 11-day flight will include three space walks and the installation of two platforms to the station's truss, or backbone. The platforms will hold spare parts to sustain station operations after the shuttles' retirement.

One more space walk is planned on Monday. The shuttle will remain at the station until the day before Thanksgiving. Landing would be the day after.

Atlantis' STS-129 mission is NASA's fifth and last shuttle mission for 2009. There are just five more shuttle launches scheduled before the planned September 2010 retirement of the space shuttle fleet.

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