While supersix2 definetely has me reevaluating whether I think it would be more useful to get to Mars first or focus on the ability to indefinitely remain in space here is a video I have come across from TED which discusses some of the important issues relating to returning to Mars. It goes into some of the goals with ARES but it seems a bit beside the point to me, as after all it is titled "Why We Need to Go Back to Mars"