TPT Pykrete is quite good at stopping fast DEST bullets, but a bit worse in absorbing a set amount of heat.
@ApertueScientist: Or go find the Mythbusters episode on it.
@ApertureScientist If you want to know more just look it up :P
It was planned to be the hull of an gigantic british Aircraft carrier in the North Atlantic to protect the convoys from german submarines
Pykrete is a material formed out of ice and sawdust, invented around the beginning of World War II. It's not used in any practical applications but it has some interesting properties!