There's another question that's bugging me when thinking about this. It concerns launches from earth.
Obviously, equatorial launches from earth are the most efficient. But most of the launch targets would be somewhere within the confines of lunar inclination. So we have two possibilities: Launching into an equatorial orbit around earth and then change planes, or launching inclined. Just an equatorial launch requires less DV than an inclined launch, but an inclined launch requires less DV than launching equatorial and then aligning planes.
But: In the later case, the DV required for the plane change could be supplied from orbital sources, which is cheaper than slogging it up from earth. The question becomes, though, just how
much cheaper? Enough to give equatorial launches a competitive advantage?
This seems difficult to answer without an unreasonable amount of math, and my experience is way too limited to even make an educated guess (honestly, I haven't done many launches from earth surface...)
Plus, here's some additional considerations:
- All the propellant being produced mostly on the moon and at the lagrange points would have to be brought into earth equatorial inclination, so it would effectively have to be paid twice.
- A lot of the orbital infrastructure would probably be located in lower MEO between the two radiation belts (2000 to 13000 km) to stay well clear of any atmospheric friction. To make the best out of the inclined launch, payloads would have to be boosted to that altitude directly. If that eats into the payload mass too much, there would have to be a transfer station in LEO from where the cargo can be boosted on to higher altitudes. If such a thing would be required anyways, I figure it might as well be in an equatorial inclination.
- Geography and politics would play a certain role. Everybody will want access to space, but different launch sites in different countries are better or worse for launches to different inclinations. So it would be well imaginable thatthere would be a mainstream approach and a couple nations who do things differently to maintain independance from internationally centralised launch infrastructure.
Personally, I like the concept of a busy transfer station in LEO as a gateway to the wider area of space, but that preference is purely aesthetical, not practical. Anybody experienced enough to make a more educated guess?