I have been pondering the relative advantages of placing a base near the Moon's equator, or at the poles. The poles have been defended as having a superior business case because of deposits of volatiles, and the peaks of (mostly) eternal light. I lean more towards the equator because:
you can place it between a mare and a highland and thus have access to the resources of both
and if several fueled stages or fuel depots (let's say fuel depot, shall we?) have been parked around the equator for handy rendezvous, there would be launch opportunities several times a day.
But how many times a day, supposing that the base is right on the equator? Which is to say, how long would it take for the fuel depot to make a full orbit?
And how long would the gaps be when the depot's orbital inclination means it isn't passing overhead for a while, if a base was, say, 20°N, where the Apollo 17 mission landed, which seems like a nice place to put a base according to the parameters mentioned above?
How many stages or depots would be needed to be in orbit in order for one to be sufficiently well aligned for rendezvous, once it passes overhead, at any time?