> Many people want to go outside and do something every now and then... but on the way to/from Mars there's nowhere to go, and every moment you're in space you know that on the other side of thin shield of metal lies death.

Not much changes when you get there, too. I think at best we will have something like McMurdo Station, for researchers on 2-3 year stints. Maybe less, since the round-trip is long and cosmic rays remain a significant health concern even when you are on Mars itself—no appreciable magnetic field and no ozone layer.

Even when you're there, excursions will be limited and planned well in advance, probably not much different from spacewalks today. The rest of the time you'll be in a tiny underground bunker.

Under current projections, anybody who took a trip to Mars with a ~1 year stay would exceed their lifetime radiation allowance, and would never be able to fly again. (Assuming a solar flare doesn't kill you mid-trip. Unlikely, we think, but possible.) If you're the first astronaut, or even the first dozen, this might be worth it. After that, though...? I'm sure there would be no shortage of volunteers, but we won't just need bodies, we'll need talented scientists at the top of their game who are physically and mentally healthy enough to make the trip in the first place.