The spacewalk began at 8:13 a.m. CST. Both astronauts are on battery-powered life support as they float over 210 miles (338 kilometers) above the Earth. Their primary job today is to attach a handle (called a Power Data Grapple Fixture) onto Columbus to that Melvin can grab onto the module with his robotic arm and lift Columbus out of Atlantis’ cargo bay.

The spacewalking astronauts will also detach nitrogen lines and begin other work to remove the Nitrogen Tank Assembly, a part of the station’s thermal control system, from the P1 truss.

German astronaut Hans Schlegel, originally scheduled to participate in this first spacewalk was taken ill two days ago. His illness has not been revealed by NASA due to medical privacy rules, but Schlegel is reported to be feeling better.

Schlegel is scheduled to participate in the second spacewalk, starting at 8:35 a.m. CST, with Walheim on Wednesday. The Nitrogen Tank Assembly, removed on the first spacewalk, will be replaced with a new one on this spacewalk. The old tank was running low on nitrogen, necessitating its removal.

Then, on Friday, Walheim and Love are scheduled to perform the third spacewalk, which will attach two scientific instruments onto Columbus.

Schlegel is a long-time astronaut for Germany. He is a twenty-year veteran, having flown on the space shuttle Columbia in 1993, launch on April 26 and landing on May 6, for mission STS-55. German physicist Schlegel helped with the reuseable German Spacelab D2 payload, a microgravity research project of several experiments.

Two possible problems were earlier found and investigated.

The Atlantis astronauts found that a small triangular-shaped tear in the fabric covering the right side of the tail (near the right orbital maneuvering system [OMS] engine) has been slightly been pulled apart at the seams.

NASA is looking into whether to fix the problem (and how to fix it) or to leave it as-is.

If to be fixed, a similar problem occurred in June 2007, on the STS-117 mission with Atlantis, and the astronauts on that mission used a surgical stapler to fix the damage.

Please read on for additional information on the continuing inspection of the shuttle.