Alex Terrell wrote:
The pre-launch reason to have foam there is to prevent ice buildup
on the outside of the tank. Because, if you think foam shedding is
bad for Shuttle Tiles and RCC leading edge sections, you should
see what ten pounds of nice solid liquid-hydrogen subchilled
water ice will do to any surface of the shuttle...

If this is the major reason, why not ditch the foam 30 seconds before
launch. Ice build up after that would be negligible.

This was tried on an Ariane stage, which ended up heavier
and less reliable with the detachable foam than it was with
the replacement, glued on permanently fixed foam, according
to Henry.


-george william herbert