This shouldn't surprise anyone. Explorers have been doing since the first "man" left Africa. When you are going where no man has gone before, the prospect of dying there is a real possibility.
Especially when space travel is involved. Armstrong and Aldrin actually had pretty low chances to return from the moon. They actually expected they would die there. That didn't stop them from going.
When boldly going where no one has gone before, death is always a possibility. Just let some one else wear the red shirt. Why tempt fate?