Discovery’s astronauts took a call from President Bush on Tuesday as they prepared for a task that’s never before been attempted: sending a spacewalker beneath the shuttle to repair filler sticking out between the tiles on the ship’s belly.

“I want to thank you for being risk takers for the sake of exploration,” Bush told the spacefarers. “And I wish you Godspeed on your mission.”

“Obviously, as you prepare to come back, a lot of Americans will be praying for a safe return,” the president added.

Discovery’s commander, Eileen Collins, replied that she and her crewmates believe strongly in space exploration and seeing what’s out there, “so the steps that we’re taking right now are really worth it and we want everybody to know that.”

NASA says the protruding material on Discovery’s belly could cause dangerous overheating during re-entry and lead to another Columbia-type disaster.

The agency planned to put astronaut Stephen Robinson on the end of the space station’s 58-foot robotic arm Wednesday for the improvised maneuver. Astronauts inside the station will maneuver the arm so Robinson can reach the shuttle’s belly.

Once there, he’ll tug out the ceramic-fabric filler with his gloved hands. If that doesn’t work, he’ll use a makeshift hacksaw to cut away the material, which is sticking out about an inch from two spots near Discovery’s nose. The saw was improvised out of a blade, plastic ties, duct tape, Velcro and other items aboard the space station.

“I am pretty comfortable with using tools very carefully,” Robinson said early Tuesday during a crew news conference. “But no doubt about it, this is going to be a very delicate task. But as I say, a simple one.”

The protruding bits of gap filler are small — one is about the thickness of an index card and the other is the size of three index cards bonded together.

“There won’t be any yanking going on at all,” Robinson said. “It will be a gentle pull with my hand. If that doesn’t work, I have some forceps. I will give it a slightly more than gentle pull. If that doesn’t work, I saw it off with a hacksaw.”

Deputy shuttle program manager Wayne Hale says if none of the proposed methods work, there will likely be some head scratching for a day. However, he says the agency will find another method and try the repair again Thursday or Friday.

Engineers simply don’t know enough about potential problems that could be caused by the protruding gap filler.

“When we first heard about it, I think a number of us did have misgivings,” astronaut Andrew Thomas said. “We were concerned about it. We were concerned about the implications of it.”

But after a careful review of information sent from the ground, Thomas said he believes the repairs are justified given “every indication is that the removal of the material should be pretty straightforward and pretty easy.”

“The bottom line is there is large uncertainty because nobody has a very good handle on the aerodynamics at those altitudes and at those speeds,” Hale said. “Given that large degree of uncertainty, life could be normal during entry or some bad things could happen.”

Collins told Mission Control early Tuesday that her crew would reschedule its joint meal with the space station’s crew and instead focus on procedures for the mission’s third spacewalk, expected to take seven hours.

“It’s going to be like watching grass grow,” Robinson said. “Nothing is going to happen fast.”

Spacewalk trainers on Tuesday planned to discuss the repairs with Robinson, who along with his spacewalking partner, Soichi Noguchi, spent more than 300 hours training in a pool where they were weighted down to simulate the zero gravity environment in space.

Spacewalk instructor Cindy Begley said Robinson would have to be careful not to cause any additional damage while under Discovery. He’ll have to secure his safety tethers behind him, leave any unneeded tools behind and make sure his helmet doesn’t bump into the shuttle’s fragile bottom.

Astronauts James Kelly and Wendy Lawrence were aboard the space station reviewing how they would operate the station’s arm so Robinson’s hands would be close enough to make the repairs, but his feet far enough away not to cause any damage

Kelly and Lawrence seemed pleased with the plan.

“We wouldn’t change a thing,” Kelly radioed Mission Control. “We will be ready to fly tomorrow.”

Discovery will remain docked at the station until Saturday. The shuttle is set return to Earth early Monday.

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Source: Yahoo News
Guest Writer: Pam Easton [AP Press Writer]