>sometime in the future, humanity goes through another Ice Age as the climate changes
>once humans develop space-travel, they become known for their cold-resistant ships and technology, even carving ships out of ice to travel in
>what are pressure vessels and why can't we make them out of ice
>my ice ship just turned into a slush ship SHIFUCK
>holy shit these humans have SPACE HEATERS!
>literally every space ship is cold resistant
>even carving ships out of ice to travel in
Might work of it's ice and rock near the edge of a solar system.
Instead of using earth ice, you could use ice and metal from the Kuiper belt. There are some pretty large chunks there - if you wanted to make what was basically an Ork Rok to fly through space in, it would save resources.
To protect the ship under it from random interstellar particles and dust, which would otherwise hurt the ship going at 0.99c. Also to smooth it so it's aerodynamic and goes through gas clouds easier or something.
.I remember space only approaching vacuum when you are mostly stationary, but didn't ships there already were 40k-HUEG and massive with some REALLY FUCKING THICK hulls of hyperdimond?
Ultranaut ships have nanomagic to the the point of creating sections with functional ecospheres in them on the fly. Fuck me if they have any troubles with repairs. The only reason why Nostalgia for Infinity appears to be in disrepair and disarray is because all that broken shit is not needed anyway, and Volyova prefers these atmosphere-rich decorations to a vast emptiness and containing only the elevator and 3,5 sections that she actually uses.
Technically space isn't all that cold because there's no matter for you to lose heat to via conduction.
Really, it's far more important to make sure your spaceship is resistant to heat because shit gets really hot during both takeoff and reentry.
Ice ships are a really bad idea.
Ice ships pop up in many sci fi settings. It's a decent structural material that can also be used as a propellant.
Otherwise, congratulations, you've reinvented the chiss. From the Star wars EU.