Damaris B. Sarria is a NASA employee who works on the space shuttle program. After an orbiter is launched, her standard M.O. is to fly from Florida to the Johnson Space Center in Houston to help analyze photographic data and determine what, if any, damage occurred to the spacecraft while it made the journey into space.
I believe they did at least some of this even before the Columbia accident, as the launch pad, orbiter, and surrounding area contain a multitude of cameras which record the launch from every conceivable angle.
Anyway, she writes first hand about the options available to NASA on her web site:
We have the black emittance wash, which will keep heat from building up in the cavity. Another option is a gun that ejects a heat-resistant, caulk-like material into the cavity. The third repair option is the overlay, which is a 15″ x 24″ sheet of silicon carbide that gets augered into the tiles to cover up the damage.
Damaris says they might also bring the shuttle home without making any repair.
One might wonder why they wouldn’t a) make a repair anyway, even if it’s probably not needed, and b) utilize all three repair options just as a precaution. Use the wash, inject the caulk, and then cover it with an overlay (aka “speed tape”). I believe the answer is that the TPS tiles on the orbiter are fragile and any work done on the shuttle could have the effect of making the damage worse.
Of course, this assumes I know what I’m talking about. Which I don’t. If I was up there, I’d call the Auto Club and tell them I wanted a tow to the nearest shop. Or call the the dealership and ask their service department for a repair quote (“that’ll be about $50 million, sir”).
The options available to NASA sound a lot like the ones available to a homebuilder. A sort of composite repair in space, albeit with materials which can absorb 2300 degrees of heat and still be cool enough to hold in your hand.
Speaking of homebuilding, this begs the question of who would sign it off? I mean, who holds the repairman certificate on a space shuttle, anyway?