Endeavour Incident Moves Up On-Orbit Demonstration

A planned test of on-orbit repair procedures for cracks and other breakages in the thermal tile heat shield onboard the space shuttle has been moved up over a year, after last month's flight of the shuttle Endeavour almost had to put those theories to the test for real.

NASA plans to test a tile patch repair on next month's flight of the shuttle Discovery, according to The Associated Press.

A fifth spacewalk will be added to Discovery's two-week flight to conduct the test, in which two astronauts will squirt a salmon-colored thick liquid -- similar in consistency to peanut butter -- onto a deliberately damaged shuttle tile. Astronauts will then use small foam brushes to smooth the material.

Shuttle program manager Wayne Hale called the demonstration "a confidence builder," adding the test has been conducted several times on the ground, but never in space.

The liquid tends to bubble on Earth, according to NASA, and the agency wants to know whether the same problem will occur in space. The repaired tile will be returned to Earth for analysis.

The repair procedure was one of three NASA considered last month, to repair a gouge in heat resistant tiles on the belly of the shuttle Endeavour (below). As ANN reported, the damage was caused by foam insulation striking the orbiter during its August 8 launch.

NASA ultimately decided no repair was necessary, and Endeavour returned to Earth safely. Fears the damage would lead to secondary, non-catastrophic heat damage to the orbiter's aluminum skin also proved to be unfounded.

Dr, Scott Parazynski, the astronaut who will conduct the simulated repair, compared the work to delicate surgery.

"This is a very exciting time for us to finally get the ground truth if you will -- or the space truth -- on how this material behaves," he said, adding he was confident the repair could have worked on Endeavour's damage.

NASA hasn't tested the procedure before, over concerns of toxicity and the unwieldly tools required to conduct the repair. Some progress has been made in both areas since the procedure was first developed after the 2003 loss of Columbia.

A caulk-line gun replaced a much-bulkier applicator, and NASA determined a smaller amount of the toxic substance than first thought is necessary for most repairs.

FMI: www.nasa.gov