We've got a lot to figure out before we get there.
And I think commercial spaceflight will help pave the way. I figure Space Flight, compared to aviation, has yet to really see its "Golden Era" yet. There's not enough competition in there yet but its coming. Everyone agrees we have the know how to do it, its just the enormous resources it takes.
There's a reason why only governents can afford this stuff.
But, commercial companies own and operate satellites. And as Rutan showed, flying up and down can be done. Now they are trying to do it, profitably and safely...maybe even making is routine.
So, folks, this is good stuff.
We also need to sort out the physiology. Our bodies come apart after long time zero g. 6 months to get to Mars at best course/trajectory. How can we simulate gravity to help our bodies adapt? The fine folks at the ISS are leading the charge on that.
And propulsion continues to evolve, with ion engines with more power having recently been launched (Dawn has two).
We live in interesting times. I view the 70s and 80s and great losses of space technoogy and exploration. But hopefully with the Shuttle Program and Orion's development...and the SpaceX stuff, things will march along swifter