science

I wrote earlier about an article in The Atlantic Monthly by Gregg Easterbrook, called The Sky Is Falling. In it, Easterbrook laid out some reasons why we should perhaps be more attentive to the possibility of disaster raining down on us from space, in the form of Earth-impacting asteroids. The probability is small that we’ll be smacked by a planet-killer, but the cost if it happens could be civilization itself. Go ahead and read the article; it’ll open in another window. Done? Unfortunately, it suggested arming ourselves for asteroid by abandoning our plans to return to the Moon. Here’s my response. (The Atlantic didn’t publish it, so I’m publishing it here.)

Gregg Easterbrook gets it half right in “The Sky is Falling” (The Atlantic, June 2008). He argues incisively for the need for those in the space community to take seriously the planetary threat of wayward asteroids and comets. NASA isn’t interested, as Easterbrook says, and the Air Force is hardly seizing on it with gusto, either. I spoke recently with a USAF officer whose job is strategic planning, and his unofficial comment was that the Defense Department could be considered criminally negligent in its failure to recognize planetary defense as a crucial part of its job description. If an asteroid-strike occurs (or threatens), are NASA and the Air Force just going to shrug and say “Not my job”? As Easterbrook says, that needs to change.

Where he gets it wrong is his dismissal of the return-to-the-moon program as a waste of money, detracting from other efforts. While balancing funding is always difficult (and the space budget is vastly smaller than most people think, accounting for only about half of one percent of the U.S. budget), a return to the moon could be a promising next step indeed. Learning to homestead other worlds is the next step toward what Captain Kirk famously called “the final frontier.” The point is not that a lunar base will be a launch point for a Mars mission–no one suggests that. It is that living on the moon will give us necessary experience for future exploration (to Mars and elsewhere), in a place where help is three days’ travel time away, not six to twelve months’ travel time. Further, a moon base could be the first place for serious mining of extraterrestrial resources, signaling the beginning of the end of humanity’s sole reliance on Earth-based metal and energy resources. Why mine minerals on the moon? Well, if you want to get metals into space–for example, to build satellite-based solar energy systems to beam nonpolluting energy to Earth–it’s potentially a lot cheaper and easier to lift tonnage from the low-gravity moon than from Earth, especially if you build solar-powered electric launchers for the purpose. This is a good argument for mining asteroids, as well.

This brings us back to the wayward asteroid and comet problem. While Easterbrook mentions several promising technologies, the best long-term solution may be to build an infrastructure for living and working productively in space–not just one low-Earth space station, but a community of space habitations, complete with multiple, varied, and redundant transportation systems. Instead of hoping someone can get off a nuke to deflect one of those wayward asteroids, let’s build a permanent capability to move large objects in orbit. If a deadly ball of rubble comes along, we could nudge it away. If a metal-bearing asteroid comes along, we could move it to a parking orbit. Then, instead of watching it destroy our civilization, we could turn it into a mineral-lode, and put it to work building our new future in space.

That’s what I told The Atlantic, and I still think it’s true. Sometimes you just have to bring your own soapbox.

“The two most powerful warriors are patience and time.” —Leo Tolstoy