Human space exploration and colonisation beyond near Earth orbit is bullshit.
http://www.antipope.org/charlie/blog-static/2007/06/the-high-frontier-redux.html
Colonize the Gobi desert, colonise the North Atlantic in winter - then get back to me about the rest of the solar system!
From 2007
Of course what I'm really getting at is the "Rapture of the Nerds" viewpoint that this planet is used up so we'll just move on and use up another one. So Elon Musk style colonisation of Mars just ain't going to happen.