TCS Daily

Destination: Mars

By Glenn Harlan Reynolds - January 22, 2003 12:00 AM

Recent reports from the Los Angeles Times and indicate that President Bush may announce a spectacular new Mars initiative, aimed at putting humans on Mars by 2010. Having been through this with a previous President Bush, who announced similar plans only to see them shot down, interestingly enough, by the maneuverings of NASA bureaucrats, I confess to a bit of skepticism. But there's reason to think that this time it could work.

One reason for optimism is that this time around cost, and technology, have gotten a lot more thought. Nuclear propulsion is at the forefront this time - back then, it was a political non-starter. It's possible to go to Mars using chemical rockets alone, but just barely. Using nuclear space propulsion - where a reactor heats gases to form high-speed exhaust rather than using chemical explosions to do so - cuts travel times from six months to two, and, because of better specific impulse (efficiency), allows for higher payloads. (There are no plans, as far as I know, to use Orion-style nuclear-explosive propulsion, of the sort I've written about here, and here. Should I turn out to be wrong about this, it will probably be a sign that somebody somewhere is very worried about something.)

The United States experimented with nuclear propulsion as part of the Kiwi and Nerva projects in the 1960s and early 1970s. The results were extraordinarily promising, but the projects died because, with the United States already abandoning the Moon and giving up on Mars, there was no plausible application for the technology. Nuclear propulsion is mostly useful beyond low-earth orbit, and we were in the process of abandoning everything beyond low-earth orbit.

That appears to be changing, and it's a good thing. It has certainly won praise from the Mars Society, whose President, Robert Zubrin, calls the Bush decision a "tremendously positive step. It will greatly enhance the prospects for human exploration and settlement of the Solar System." He's right about that, and like him, I think that the "settlement" part is as important as the "exploration" part. And while exploration is possible based on chemical rockets alone, settlement without using nuclear power will be much more difficult.

Of course, as this article by Ken Silber notes, nuclear space propulsion has had its critics and opponents for years, though weirdly their opposition stems largely from fears that it will lead to "nuclear powered space battle stations." This isn't quite as weird as Rep. Dennis Kucinich's legislation to ban satellite-based "mind control devices," but it seems pretty far down the list of things we should be concerned about. With worries about earthbound nuclear weapons in the hands of Iraq, North Korea, and perhaps assorted terrorist groups, it's hard to take seriously claims that possible American military activity in space, spun off from civilian Mars missions, might be our biggest problem. Indeed, the whole concern about "space battle stations" has a faintly musty air about it, redolent of circa-1984 "nuclear freeze" propaganda. Who would we fight in space today? Aliens? And if we needed to do that, wouldn't nuclear-powered space battle stations be a good thing?

Nor are environmental concerns significant. Space nuclear reactors would be launched in a "cold" (and thus safe) state, and not powered up until they were safely in orbit. And again, compared with the environmental threat caused by rogue nuclear weapons, their dangers seem minuscule.

We also have to weigh the dangers of not acting. Earth, as we have seen, is an increasingly dangerous place. Some years ago I attended a small workshop on high-technology terrorism, focusing on such future threats as bioterror, abuse of nanotechnology, and so on. As we left the room after one session, another participant remarked "I think I just became a fan of space colonies."

She was right. Many of the threats posed by advanced technologies are, for the most part, manageable. But in the aggregate, they are significant. And the increasingly small Earth is, as I have written here before, too tiny and too fragile a basket for all our humanity's eggs.

The administration's Mars proposal is at least a step in the right direction, and its adoption of nuclear space propulsion indicates more realism than the flags-and-footprints approach favored by the previous Bush administrations. What's more, the use of nuclear propulsion, which makes interplanetary travel both cheaper and faster, greatly increases the likelihood of going beyond flags and footprints to true space settlement. It's about time.

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