[scott-smith_us]

You have to have water storage if you've got people on board. I'd rather have one system that stores both fuel and life-support than have to have two separate systems and then guess exactly what proportions of both I'll need...

[King-Aaron]

Water storage could also be used as a way to mitigate the radiation problem in space. If you had a 'sleeve' inside the hull that contained water, you'd have both a large storage capacity for fuel as well as inbuilt radiation shielding?

(*Note, I am not an engineer)

[lpaone]

I have a friend studying radiology with the hopes of working in the space industry. From what he tells me, I believe this would work.