A 1980 article in the Washington Monthly entitled “Beam Us Out of This Deathtrap, Scotty!” gives a scary description of the heat resistant tiles on the ship. Here are a few quotes:
“Columbia must be fitted out with 33,000 of these tiles, each to be applied individually, each unique in shape… they’re also a bit of a letdown in another respect–they’re so fragile you can hardly touch them without shattering them. “
“Fixing them to the Columbia without breaking them is like trying to eat a bar of Bonomo Turkish Taffy without cracking it. Most of the technicians swarming over Columbia are trying to glue down tiles. The tiles break so often, and must be remolded so painstakingly, the installation rate is currently one tile per technician per week.”
“The tiles are the most important system NASA has ever designed as “safe life.” That means there is no back-up for them. If they fail, the shuttle burns on reentry. If enough fall off, the shuttle may become unstable during landing, and thus un-pilotable. The worry runs deep enough that NASA investigated installing a crane assembly in Columbia so the crew could inspect and repair damaged tiles in space. (Verdict: Can’t be done. You can hardly do it on the ground.)
So, even if the Astronauts went on a space walk and saw the damaged tiles, they couldn’t fix them.
“According to the computers, as long as you can bring the shuttle back into the atmosphere, you can fly it to the airfield even if the tiles are damaged. Former Apollo astronaut Richard Cooper doubts the computers know what they’re meeping about.”
” Computers have never flown with the unpredictable combination of damaged tiles that a shuttle may experience. They’ve never been whacked by a sudden, nonprogrammed gust of jetstream wind. They’ve never flounced like a twig on the crazy rapids of “bias”–the bland physics term for unexplained variations in the earth’s gravitational and magnetic fields. These are the wild, uncharted rivers of space. Unknown; unknowable; beyond programming.”