Hard labor. That's my guess. They're not going to pay people to lay around. You're going to be outside in the cosmic rays, doing construction work, which I'm sure is the reason they wouldn't have me. How hard can you work when you're 84? Not very. They'd love you at 50, though. But I think that's a little too young. Life expectancy isn't going to be that great, a few years, what with constant radiation exposure, work hazards and rudimentary medical care. Well, that's just my guess, but I wouldn't go at 50.
In Mars Greavity youwould still bench press 250 and feel like Superman.
Kind of like an extreme version of the French Foreign Legion. Except in this version you get Martian citizenship.