It is all fun and games until you have to make the consolation calls to the families.
No 'fun and games' at all because you have volunteers understand the risks up front with no bullshit. That the radiation shields are experimental and they'll likely be insufficient to prevent an involuntary sterilization at the least.
The understanding that, as the first out there, there's absolutely no chance of rescue should things go wrong.
But it's THE CHALLENGE of overcoming seemingly impossible odds with a reasonable chance of success that WILL find great people stepping up to willingly do so.
Without colonizing off this blessed rock and eventually beyond our solar system we're through when the next dinosaur-exterminating rock falls or even the Yellowstone volcanoes erupt as hard as some predict.