Space Forum / Shuttle / February 2005

NASA Picks Shuttle Shield Repair Tests

Reuters
Feb. 11, 2005 - Looking to accomplish the most work in the shortest
period of time, NASA managers have decided to test two techniques to
repair heat shields during one spacewalk when the space shuttle
returns to flight, agency officials said on Friday.

NASA had been considering a series of tests to figure out the best way
to repair the shuttle's heat shield.

Keeping the shields in good shape has been a higher priority since the
Feb. 1, 2003, Columbia accident. All seven astronauts were killed and
the shuttle was lost because a piece of foam insulation fell off the
fuel tank at launch and smashed a hole in the ship's wing.

NASA has scrapped a demonstration of a complex device to inject a
heat-resistant goo into damaged shuttle tile, Johnson Space Center
spokesman Kyle Herring said in a teleconference with reporters.

Program managers decided that caulking the shields still had too many
engineering problems and would be too time-consuming to be tested when
during the flight, set for May 14. That launch will be the first since
the Columbia disaster.

Rather, officials opted to test a technique that requires a
spacewalking astronaut to dab a paint-like thermal barrier onto
samples of damaged heat tiles -- a job which should take 60 to 90
minutes, said Johnson Space Center spokesman Rob Navias.

While shuttle Discovery spacewalker Steve Robinson performs the tile
repair test, crew mate Soichi Noguchi will practice repairing small
cracks in a sample shuttle wing panel.

Combined, the tests should take less than 25 percent of the mission's
first 6 1/2-hour spacewalk. The rest of the time would be devoted to
preparing for two other spacewalks to install a critical new gyroscope
for the space station and to position a platform of spare gear at the
outpost.

"The program's decision was made to try to get the biggest bang for
the buck," Herring said.

At least one and possibly two caulk guns and a supply of the
heat-resistant goo known as STA-54 will be packed aboard the shuttle
for possible use in case the shuttle actually sustains significant
tile damage.

During Discovery's mission, Noguchi and Robinson also will test a
method to plug holes in wing panels, but the demonstration will take
place in the shuttle's crew cabin rather than outside the ship.

Discovery will have aboard a fifth heat shield repair option -- an
overlay that could be installed on a damaged tile. However, like the
caulking guns, NASA is not planning to test this procedure during the
shuttle mission.