Wednesday, August 3 2005 19:16 Hrs (IST) - World Time -

Space Center (Houston): Armed with forceps and a makeshift hacksaw, a Discovery astronaut today (Aug 3, 2005) floated from the ship's airlock for an unprecedented spacewalk to eliminate a potential source of dangerous overheating during the shuttle's re-entry.

Astronaut Stephen Robinson described his job as delicate, but simple: pull out or slice off two dangling pieces of filler material from Discovery's belly.

"OK Andy, I'm in the great outdoors," Robinson told astronaut Andy Thomas after he followed spacewalking partner Soichi Noguchi out of the shuttle's airlock as it passed over Australia.

First, however, he and Noguchi, set out to install an external tool platform on the international space station, where Discovery has been docked since Thursday.

The platform's installation was the key task of the mission's third spacewalk until NASA officials determined the exposed ceramic-fiber fillers could lead to overheating and a repeat of the 2003 Columbia tragedy during Discovery's re-entry next week.

Columbia broke apart over Texas in 2003 as its crew returned to Earth from a 16-day mission. The disaster was blamed on a chunk of foam that fell from the external tank during liftoff and gashed one of spacecraft's wings. All seven astronauts died.

Discovery, set to land Monday, is the first shuttle to return to orbit since the tragedy. New damage surveys developed in Columbia's aftermath detected the drooping material on Discovery.