Wednesday, August 3 2005 12:40 Hrs (IST) - World Time -

Houston: Discovery astronauts are gearing up for today (Aug 3, 2005) space walk to fix two pieces of material protruding from the space shuttle's underside to ensure the shuttle can make a safe return to Earth.

President George W. Bush called the astronauts yesterday (Aug 2, 2005) morning to thank them for flying as part of NASA's return-to-flight mission and to wish them a safe return home on Monday.

NASA has decided to send astronaut Steve Robinson unrehearsed to venture under the Shuttle on the tip of the International Space Station's robotic arm, locate the protrusions and gently tug until they come out.

Astronauts inside the station will bend and maneuver the arm carrying Robinson so he can reach the shuttle's belly.

Robinson will try to gently pull the gap fillers out, pull a little more stringently with modified forceps and cut the gap fillers with a special hacksaw, to be assembled yesterday.

If that does not work, Robinson will have tools to cut off the protrusions.

"I am pretty comfortable with using tools very carefully," Robinson said during a crew press conference from aboard the space station.

"But no doubt about it, this is going to be a very delicate task. But as I say, a simple one," he said.

The orbital stroll 4:14 a.m. EDT today by Robinson and Mission Specialist Soichi Noguchi will be the third for the mission, the first after the 2003 Coulmbia disaster that killed India-born Kalpana Chawla and six other astronauts.

"I just wanted to tell you all how proud the American people are of our astronauts," Bush told the seven Discovery crewmembers and two astronauts aboard the international space station.

"I want to thank you for being risk takers for the sake of exploration. And I wish you Godspeed in your mission. I know you've got very important work to do ahead of you. We look forward to seeing the successful completion of this mission. And obviously, as you prepare to come back, a lot of Americans will be praying for a safe return," he said.

Commander Eileen Collins thanked Bush for his call and then remarked about the view of his home state from orbit.

"We did fly over Texas yesterday and had a good look at it," Collins said.

"It looks beautiful. About 20 minutes before the President's call, STS-114 Eileen Collins radioed Mission Control and reported that her crew was a 'go' for yesterday's space walk," he said.

Crewmembers have reviewed the revised timeline and prepared equipment for the excursion. Other tasks for the space walk include the installation of an external stowage platform onto the Station.

'We are all going to be very busy' during the repair walk, Discovery Commander Eileen Collins told reporters.

"I think we're all going to be involved somehow," he said.

Collins praised Noguchi and Robinson for their work on earlier space walks, saying they did all the tasks they had been assigned faster than expected. They have done absolutely fantastic," he added.

About Noguchi, she said "Soichi s a genius with everything that has to do with cameras. He's done a great job."