As much as anything, those guys were doing their bit to secure funding at a time when their budgets are under really huge pressure. A lot of that stuff is aimed at Senators who decide budgets. They respond well to this kind of thing. I wouldn't be surprised if Charles Bolden also has political ambitions, that was quite a 'statesman-like' speech he gave.

It also plays well to the people who don't know any better, the people who say 'why are we spending all this money on space when I can't get a job?'. You'll notice that the straighter and more senior heads - Pete Theisinger the PM, and John Grotzinger the chief scientist, did not go all Team America during the press conference, but did make similar points - 'The money isn't sent to Mars, it's spent here on Earth' - again speaking to the pressure that they're under.