Consider just landing there, even for unmanned probes -- Russia's rather poor record attempting it, or Curiosities rather radical solution, which worked perfectly.
Then there's the many month journey. During the Apollo 11 mission, President Nixon actually had composed a letter for the event that Neil and Buzz were left on the moon to die. (One wonders which Nixon speech writer composed it -- please not science illiterate Pat Buchanan or Ben Stein.) In short, how does one shield humans from the radiation of space? That is one of the tough tasks we need to solve before we can even think about landing a human on Mars. Then there's the poop, and so many other issues (no pun intended).
BTW, I am all for spending billions of dollars to solve the problems and do this. We need another Apollo program to go to Mars, and go back to the Moon to stay.
I just wish that their would be more people like JFK, Gene Kranz, James Lovell, and all the lunatic visionaries who had the audacity to dream that we could land humans on the moon and safely bring them back. (I mention Kranz because I just watched Apollo 13 where Ed Harris fairly channels the iconic flight director. Don't get me started about the incredible value of people like Gunther Wendt who held court mostly as the last guy who closed many a spacecraft hatch.) It is often the small people who make the system work so flawlessly as in the Apollo program. And their stories are important.
To those who would argue against manned space missions I would point out the value of the many incredible stories. Consider the multitude of Mars lander failures, and then consider Apollo 13, or the Challenger failure. Human space travel is risky. But the narratives of those who succeed and those who failed are worthy. When human flesh is involved, those stories become so much more than important --we literally have skin in the game. And by the way, Magellan never sailed around the world. He died on a Pacific island. (But that's another story.)
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