Standing in the way of a manned mission to Mars is the journey time and funding. The radical Vasimr engine could reduce the journey from 9months to 39days and Nasa's recent course change might have freed up the money to help pay for it.
One of the biggest obstacles facing any manned Mars mission, aside from the financial one, is the sheer length of time it takes to get there. Using conventional rockets, the best journey time we can hope to achieve is six to seven months, during which time your Martian pioneers would lose a bit of their edge. Without gravity, the cardiovascular system weakens and the vertebrae will pull apart. Unused muscles will atrophy and bones will lose so much calcium they become fragile and prone to fracture. That’s not to mention the psychological effects of months of incarceration and isolation. In short, by the time your hero touches down, he will be more Supergran than Superman.