we could sell juice in the moon base for extra money .
Juice? You think too small.
Alcohol, meat, wine, baked goods, whiskey, fruit, booze, T-shirts, moon rocks, beer, kitschy hand-made rock crafts and mugs, various sorts of intoxicating beverages...
And, yes, juice.
EDIT: And why am I only listed as the threadmaster of the modding branch*? I'm also the F.O.R.G.O.T.E.N.B.E.A.S.T. of B.I.O.-G.L.a.D.O.S. Or maybe the department could be named M.O.N.S.T.E.R. See
here for acronym explanations.
*Which is more of a training-simulation-development branch...Heuristic Aiding Computing: Krazily Editing the Raws Society?