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Originally Posted by mikey23545

Actually, they carry a tile repair kit on board now. Of course it's never been tried before.

Tests in Space on Repairing Shuttle Tiles


By JOHN SCHWARTZ
Published: March 21, 2008

Two NASA astronauts left the International Space Station on Thursday evening to test techniques for repairing delicate shuttle tiles with a kind of orbital spackle.

NASA has been looking for ways to repair the tiles and panels, which protect the shuttle from the heat of re-entry, since the loss of the shuttle Columbia and its crew in 2003.

Several techniques have been developed. This test used what mission managers called a “goo gun”; it is formally known as a tile repair ablator dispenser.

During the tile repair demonstration, the astronauts filled a series of neat holes and rough gouges. The results will be examined upon the shuttle’s return.

Ginger Kerrick, the station flight director, said in a briefing on Thursday that before NASA could rely on the material chosen for the task, it must be convinced that it acts as it should and that the applicator does its job properly.

Mission managers have said repeatedly that they already have confidence in the material and the applicator. The technique has been tested both in vacuum chambers and under the punishing temperature extremes found in space.

But they could not duplicate the microgravity environment of space, aside from brief bits of time spent in steep descent in specially equipped airplanes. So this experiment will show whether the lack of gravity impairs the putty’s performance.

Zebulon C. Scoville, the lead spacewalk planner for this mission, said the open question concerned bubbles that could occur as the material was laid and began to set.

“In zero gravity, are those bubbles going to rise to the surface?” Mr. Scoville said at a briefing for reporters, “Or are they going to act more like a bread loaf as it bakes, with the gas expanding in the material and being evenly distributed bubbles that then cause the surface to rise up over the top?”

A repair that leaves the putty bulging over the top of the tile could be worse than a shallow gouge, he said, because it can disrupt the flow of superheated gas over the bottom of the shuttle and cause uneven heating downstream of the bump.

The trip outside for Maj. Robert L. Behnken of the Air Force and Capt. Michael J. Foreman of the Navy began with a different task: replacing a circuit breaker that routes power to one of the four gyroscopes that help maintain the orbiting laboratory’s attitude.

But the main event was the work of Captain Foreman, who was hailed as “Mr. Goo” by his colleagues; they also compared him to Rembrandt and called him “grout and tile specialist.” To the last, he replied, “hope we don’t need one.”

http://www.nytimes.com/2008/03/21/sc...21shuttle.html