I don't know if I would realistically accept, but I think it would be fun to go to space!! I know it takes a long time to get to Mars and I'm not sure I'd want to leave my family for that long... but space would be cool!!
As much as I use to love rollar coaster rides I think I would get board of floating in 25% gravity (or whatever it is).
Funny enough, we were watching a documentary on Sunday about a mission to mars. For 40 days to explore Mars, it would have to leave in 2012/2013 I think it was...take 4 months to get there and then 6 months to return home based on the alignment between Earth and Mars.