[Mamzelle]

Just how different is this formula from common porcelain? I recognize some of the ingredients.

The tiles themselves would scare you...intuitively, they look insubstantial and too much like styrofoam. Kind of crumbly and brittle and unlike much of anything you'd trust. Amazing stuff.

Reentry sounds a lot like a kiln. Regular porcelain liquifies before hardening.

[NormsRevenge]

I wish I could speak intelligently to the differences of composition of the tiles versus porcelain. I agree, they are amazing. To look at and hold a tile, you think "This is gonna handle hitting the atmosphere at Mach 18 or whatever and not disintegrate?", but they have and they do.

The most critical tiles are on the underbody of the shuttle. Those are not very likely to be either damaged or suspect, tho' they are replaced after missions frequently in small numbers and in a routine manner. But to look at them , "This is gonna get me home?".

Space Flight is the ultimate act of faith... but you better believe in your vehicle.