[_Jim]

"breath on them and they break" fragile tiles

A red herring argument.

MANY of these tiles have survived substanyially intact during a hair 'more than just a breath' while falling from +200,000 feet (NOT to mention some sort of explosion while up there at Mach 18).

I now think that is was the RCC in the left wing's leading edge -

- part of the LESS (Leading Edge Structural Subsystem) system

- that was damaged during lift-off ...

How 'bout them apples?

[Travis McGee]

You sidestep my point. The exposed shuttle tiles ARE fragile, and they are located a few yards from the spray foam insulation on the LOX tank which is in a habit of breaking off in large chunks at mach speed after liftoff.

Russian Roullette.

The Columbia lost.

Much better to keep the reentry vehicle safely away from liftoff and boost phase peril.