What’s it like to be 70 years old in space? “All those little aches and pains heal up.”

Don't have to be in zero G. Just make a large enough structure to spin slowly and generate a little bit of gravity through centrifugal force. The moon's gravity at about 16% should be enough to make things move in the correct directions while not being crazy high. Not only that, but we get to experiment on a bunch of rich fucks, because we know that zero-g is not good for the human body, and we know that one-g is fine for the human body, but we know nothing about long-term exposure to different g-forces, such as the moon's gravity. By doing that we might find out that the moon's gravity is perfectly serviceable for humans or we might find out that there is still problems and that higher gravity is needed.