OK!

That theory about foam hitting
the shuttle Columbia's wing isn't
going away.

And here are the numbers you can crunch; I've already done so on my
pocket calculator!
[NASA estimates:]
Relative velocity of foam hitting
shuttle wing =
500mph [223 meters/second.]
Mass of the foam =
close to 1.2kilograms[2.64Ibs]
Estimated angle that the foam may have
hit the shuttle wing = [roughly] 20 degrees.
Sin(20) = [0.342]

Energy of impact = Sin(20)0.6Kg[223m/s]^2 = roughly 10,000 Joules.

10,000 Joules of energy [41,840cal]
is roughly equal to the chemical energy
of about [27 grams] one-ounce of gunpowder.
Guess what would happen to your fingers if you blew up a cartridge/cylinder/tube
containing one-ounce of gunpowder
in your hand?
Could the shuttle tiles withstand
a blast from a one-ounce gunpowder charge?

Jacob