Well, families with children make things a bit less likely, but I 100% would be on a list to go if I was childless. Even knowing it was a one way trip. Life is already short and if you cannot do something truly meaningful (subject to personal interpretation), then what are you doing with your life? Meaningful to me happens to include space exploration. Having had kids that list also includes raising my part of the next generation to be good members of the human race.