A dispute within NASA has emerged into public view over the last few weeks in advance of a meeting that will try to chart the organizations course after Bush. Four years ago Bush declared that NASA should return to the moon. Not everyone likes that idea:

Some see a subtext here — a desire to avoid building expensive lunar infrastructure and instead focus on something more exciting. “The real reason Mars advocates like asteroids is because we aren't going to build a base on an asteroid,” says James Muncy, a space-policy consultant and former adviser to the Reagan and current Bush administrations. The Planetary Society has long pushed for Mars missions, and one of the meeting's conveners is Stanford professor G. Scott Hubbard, a former head of the NASA Mars programme. Hubbard says that, although he personally wants to speed up Mars exploration, there is no preconceived result for the workshop. But Mike Griffin, the NASA administrator, says in an e-mail to Nature that some of the workshop organizers had a long-standing rejection of the Moon as a place to explore. “Balanced choices must be made,” Griffin says. “But they cannot be continually remade if there is to be progress.”

This type of thing really bothers me. Manned space exploration is extraordinarily expensive, and, frankly, impractical. Getting humans to Mars sounds great, but machines can do the job better, and cheaper, and safer. That doesn't mean there isn't a reason to send people to Mars. Manned exploration of space has always been about national prestige. If anyone was going to go to the moon, it was going to be an American. And if anyone is going to go to Mars, I'm all for this country taking the lead. But nobody is going to Mars. Meanwhile, the Chinese are going to the moon--and they're doing it to demonstrate their technological prowess, not to provide "exciting" work for their space geeks.

If the Chinese land on the moon, there should be Americans waiting for them when they get there. This is the only rationale for manned space flight right now, and it's the only way taxpayers will pony up the huge sums of money these programs demand.