Astronaut repairs shuttle during spacewalk

Tests ordered to find out whether thermal blanket will also need to be fixed

August 04, 2005|By John Johnson Jr. | John Johnson Jr.,LOS ANGELES TIMES

HOUSTON - Hours after Discovery astronaut Steve Robinson made the first repair of a shuttle by a human walking in space look easy, NASA said yesterday that it has ordered more tests to determine whether another spacewalk will be needed to fix a damaged thermal blanket.

Yesterday's emergency repairs had been expected to take much longer than the few seconds it took Robinson to pull two pieces of fabric from the shuttle's underside. Tethered to a robotic arm in space, Robinson used his gloved fingers to gently extract the protruding gap fillers.

"It looks like this big patient is cured," Robinson said after extracting the second piece.

"Even though it looks easy, it was not," N. Wayne Hale Jr., deputy shuttle program manager, said at an evening news conference. "It is a tribute to the crew that executed it and the crew on the ground that planned it that it looked so easy."

Discovery's robotic arm was also used to inspect a damaged thermal blanket that NASA was studying to see whether it could pose a problem when the shuttle returns to Earth. Discovery is scheduled to land at the Kennedy Space Center in Florida before dawn Monday.

As has happened several other times during the Discovery mission, scientific analysis was unable to give a definitive answer to whether the situation poses a hazard. The fear is that the blanket, which weighs less than an ounce, could become loose and that a piece of it could damage Discovery.

NASA is sending three models from the Kennedy Space Center to the Ames Research Center in Northern California, where scientists will perform wind tunnel tests to determine what might happen, Hale said.

Results will be ready this morning and flight managers will then decide whether another space walk, the mission's fourth, will be needed.

The blanket issue follows questions about the dangers from the gap fillers and from foam debris created during Discovery's launch. The foam concerns led NASA to halt all future shuttle flights until the problem is fixed. It was foam debris that damaged Columbia, causing it to disintegrate during reentry in February 2003.

Hale said Discovery has had fewer problems than most other shuttle flights have.

Because of the Columbia disaster, inspection and examination of Discovery during the flight have been markedly increased. Many problems of the kind usually discovered after a shuttle has returned are being found much earlier. Once found, Hale said, the problems have to be dealt with during flight instead of on the ground.

He said the potential problem with the thermal blanket was unexpected.

The gap fillers consist of thin fabric placed between the thousands of silica tiles that cover the underside of the spacecraft. They keep the tiles from rubbing together during liftoff.

Two fillers had protruded about an inch from the tiles, creating a small break in the smooth underside. At high speeds, the rough area could generate excessive heat.

NASA said it could not determine whether the protruding gap fillers would be a problem but that it was taking no chances.

The repair during yesterday's previously scheduled space walk was the first of its type.

Astronauts' apprehensions about the repair mission ended after the plan was outlined. NASA officials said the crew members were elated by the successful repair.

"I call that one pretty good day in space," said Cindy Begley, mission manager for spacewalk activities at Johnson Space Center in Houston. "It was clear that they were happy."

The Los Angeles Times is a Tribune Publishing newspaper.

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