One has to wonder if you couldn't eventually just build a large centrifuge on the Moon. Put a toroid on some kind of magnetic bearing and rotate it. It should be easier than on Earth anyway since you're supporting only one sixth of the weight of the structure. Even just as sleeping/recreational facilities, it still might be worth it in the long run.
(Low gravity is extremely unhealthy. And even a relatively short 1-week stay in such conditions severely affects cardio muscles, so that super-healthy astronauts have to exercise for several hours per day to keep their heart in shape)