|SpaceX’s vision for a human outpost on the Moon.|
Anyone, if we can get that far, we are going to have people living on the moon for days going on weeks, and given what happens to a body hanging out in the International Space Station for a long time (it's bad), we can probably expect similar effects on the moon. One way to compensate would be to build a centrifuge. I proposed building a train that would travel in a circular tunnel at high speed. The long radius would reduce the difference in force between the head and feet and so should be similar enough to the Earth's gravitational field that there would be no ill effects.
|Graviton Carnival Ride|
|The city of Philadelphia could easily fit inside a theoretical lunar lava tube. (Image credit: David Blair/Purdue University)|
(The whole point of going underground is to reduce the effect of radiation which is pervasive outside of the Earth's magnetic field. Domes on the surface can be covered with dirt, but a spinning cylinder is going to need some kind of structure to protect it. If a natural cave could be located, that would be perfect.)
Problem with caves on the moon is that they are devoid of air. And even if you could find one that could be sealed (perhaps by coating the interior with some kind of polyurethane), depending on moon rocks for the air you breath (don't you dare move, you rocks you) might not be prudent. Better to have a self contained air-supply, and that means air locks.
|Moon Man exits the Quest airlock at the start of U.S. EVA-51. Photo Credit: Oleg Artemyev / Roscosmos|