I think they are men and women of great courage as I would not have the guts to do this job.
I would always be worried, being a pioneer in a field like this, could go so horribly wrong. While it might be an exciting thing to do it is not something I would have considered when I was younger and had a young family, as it is just too risky.
I DO however think, a lot of them are also explorers and want to be at the forefront of technology and space, and the fame and glamour it could bring.