Er Global, the Catholic faith still goes with Heaven and Hell, even with the knowledge that the sky is just atmosphere and space is above us etc, with magma beneath us etc. It's more a spiritual place you go to apparantly, not directly under your feet. After all a Soul has yet to be quantified as a physical thing, so why would it exist in a physical place by itself?
Anyway, Ghosts.
Any encounters with your vessels will be interesting. I'll mostly end up calling your ships robotic or something, automated more than undead but it all depends on the encounters.
On the ship side of things, use old freighters too.
What is creepier than an old freighter or mining ship, long abandoned and left to slowly die in the vast expanse of the darkness.