Warhammer 40K Fluff Discussion XVI: Where the Ordnance is Hand-Delivered!

[The Glyphstone]

I get that. I don't get how they can survive if the Navigator isn't at the helm 24/7 for months of journey, and the man has to sleep, eat, and defecate no?

There is, IIRC, explicitly a Navigator power in the RPG that suppresses or removes Fatigue. If we take that as quasi-canon, it's part of a Navigator's training/abilities to go extremely long periods of time without rest or sustenance, which would make sense as a feature to build into their geonome.