This Could Be Easier Than First Thought

NASA engineers, scientists and astronauts may have a better way. Instead of a high-tech, high-cost, high-flying application that employs the shuttles' robot arms, space-walking astronauts could simply use something we all probably have at home: a foam paint brush.

It's exactly the contemplation of developing new technology that stumped NASA from putting a repair kit on shuttles in the first place. The space agency had considered putting kits on board, but decided that the tools and the complexity of the space walk would simply put such a program out of reach.

But the Columbia Accident Investigation Board (CAIB) insists that an in-flight repair capability is essential to NASA's "Return To Flight" program.

So, after taking another look at the problem, O'Keefe said engineers have decided that patching a heat shield hole may be "elegantly simple."

Here's the plan now under consideration: Experts have developed an applicator that would squirt two compounds into a heat shield puncture or tear. The compounds would chemically combine, forming a patch that would expand when heated by the friction of re-entry.

"The easiest way to spread the compound without having it stick to the instrument turns out to be a simple thing — a foam brush," O'Keefe said. It's the kind of brush commonly available at your local paint and hardware store and is routinely used by millions of homeowners when painting their houses. 

O'Keefe said the compound has been tested with an electrical arc that heats the surface in question to 3,000 degrees. That's the temperature shuttle heat shields have to endure during shuttle re-entry. Astronauts, he said, are testing application of the compound onboard the "vomit comet," a KC135 flown in a way to give a few seconds of relative weightlessness inside the cabin.

FMI: www.nasa.gov