Replies to post #6530 on Zeev's Turnips Talk Politics (ZTTP)

[webster groves]

<<I still do not understand the impact forces involved in a low differential speed impact of less than 3 pounds of polyurethane with a 10000 pound wing>>

The foam doesn't damage the wing. It damages the tiles that cover the wing. The tiles are not hard like the flooring in your home. They are soft, brittle, and can be crushed betweeen your fingers. The most glaring weakness in the Shuttle design is the fragility of these "tiles". But 20 years ago there wasn't much choice if you wanted a reusable launch vehicle.
The tiles function well if undisturbed, but that's the rub.
To get a rough idea of the forces involved, throw a 5 lb bag of potatoes out a second floor window and let it fall on a plate of untempered window glass on the ground below.

-wg