Very. This is the first thing that pops up when you google 'carbon composite': https://en.wikipedia.org/wiki/Carbon_fiber_reinforced_polymer https://en.wikipe

Very. This is the first thing that pops up when you google 'carbon composite': https://en.wikipedia.org/wiki/Carbon_fiber_reinforced_polymer https://en.wikipedia.org/wiki/Carbon_fiber_reinforced_polyme... I had a vision of a massive porous mass of carbon (a la water filters and the like) storing all that lox, but it seems not to be the case.