That said, I think even the most charitable observers see the Space Shuttle/ISS combination as basically a 30-year long detour in terms of any real accomplishment. The public -- not unreasonably -- likes to see actual results for their money, and an important part of that is basically seeing the government doing something new every once in a while. But the SS/ISS combo wasn't really about that, it was bureaucratic circular reasoning made manifest. Why do we need the space station? Because that's where the Space Shuttle will go. Why do we need the Space Shuttle? Because it's the way we'll get to the Space Station. Simple, right?
Of course, the Soviets -- then the Russians -- managed to maintain a much more robust space station program without a space shuttle. But that's just details...
One of the most depressing things about the Bush Administration's approach to space is one of those things I could almost grudgingly praise. Scrapping the Shuttle? Good start! Giving NASA Mars as a goal? I'm with ya. But there's this curious Moon detour. Landing astronauts on the Moon will do basically nothing to really prepare NASA for a Mars landing, given the dramatic differences between the two. It will consume a great deal of capital -- financial and political -- and probably kill any serious attempt at the Red Planet.
So I'm a much, much bigger fan of this idea: a bunch of NASA insurgents, calling themselves the "Asteroid Underground" are trying to push for a piloted rendezvous with a Near Earth Object (asteroid).
An asteroid-bound crew would therefore need to “bring mission control on board,” says Korsmeyer, in the form of highly automated decision-making software. “When something bad happens, which tends to happen quickly, the crew and systems will have to manage it on their own. This is something humanity hasn’t done yet. But that makes it the best of all possible testing grounds for Mars, which, without an asteroid mission, will be like jumping into the deep end without practicing in the shallow end.” In comparison, “the moon is like the baby pool. I don’t mean to minimize that—Apollo 13 showed us you can drown there too.” But, he says, an asteroid “would really be someplace fabulously new. You’re talking 2.5 million miles, more than 10 times the distance between Earth and the moon. You’d be so far away you could cover up Earth with your finger. It would be no more than a beautiful, pale blue star.”An asteroid mission would be a meaningful test of a lot of the Constellation hardware (zero-gravity, deep deep space, long-endurance space flight) that can't necessarily be fully duplicated in orbit of the Earth, no matter how high up you go. It frankly makes a lot more sense to do something like this, instead of going back to the Moon to play around.
If you could guarantee it wouldn't detract from the goal of landing on Mars, and if you could guarantee long-term political support, I'd say America can easily afford to do both: a full-spectrum space program would cost a tiny fraction of what America is spending to lose two wars, after all. But in the real world, I think any attempt to spend a lot of time on the Moon will come at the expense of a Martian goal.
Plus, NASA's new spacesuits meet the all-important requirement of looking cool.