Firstly, I want to say that I'd be the first person with their hand up when asked, "So who wants to go to space?". There's nothing I'd love more than to go.
But from looking at the amount of Technology on the Curiosity rover it seems that we shouldn't bother using astronauts. Is it right to say that until mankind find/creates a habitable planet within our reach, shouldn't we just leave it to the robots to do the donkey work?
I'm sure in some cases a robot is even preferred. After all, the only thing that ages is their battery (which is solar powered) and they don't have to worry about things like breathing, mental disorders from prolonged isolation, biological issues from gravity changes or fear of the unknown.
Though a robot doesn't have intuition or common sense the person controlling it does.
Why risk human lives when a robot can be made to do it instead?
So with all the above in mind: