A portal 2 mod set on the moon (Or more specifically inside the moon) Aperture hollowed out a lot of the moon during the space-race and made testing facilities in the hollowed out rock which was later re-purposed for mining moonrock for gel. You are awoken from slumber in a relaxation pod years in to the future when the underground facilities are crumbling and close to collapse. Find a way to the surface and back to earth..
Im not a very good artist but this is my vision of a "space suit" for space walking and stuff.