Astronomer: Could Cameron's asteroid-mining project really work?

Phil Plait is an astronomer and major sci-fi geek. He writes the Bad Astronomy Blog for Discover Magazine and is also the host of the Discovery Channel's science show "Phil Plait's Bad Universe." You can follow him on Twitter at @BadAstronomer.

One of my favorite clichés in movies—and by "favorite" I mean "makes me want to fly to the screenwriter's house and stab them in the eye with a red editing pen"—is when a character comes up with a ridiculously top-heavy and overly complex scheme, and another character says, "That's so crazy it just might work!"

A couple of weeks ago, a company called Planetary Resources announced it was planning on mining asteroids. My first thought was "That's crazy."

Then, after talking with their chief engineer, so help me my next thought was "...but it just might work."

I sit here with a red editing pen metaphorically sticking out of my eye.

So what's the deal? Can this really work? Can we really mine asteroids for fun and profit? Amazingly, I'm thinking the answer is yes, though we need to keep a healthy dollop of skepticism handy.

First off, let me be clear: The idea is not to launch a fleet of rockets to floating space rocks, mine their platinum and gold, bring the booty back, and become rich beyond the dreams of avarice. If that's the first step, then you won't get far. The initial cost of doing something like that would make a billionaire cry, and we simply don't have the tech to do it yet.

Instead, Planetary Resources has an incremental plan to tap into, um, dwarf planetary resources. Step 1 is to launch small telescopes into orbit to find and characterize likely asteroidal targets. And I do mean small; one of these 'scopes—named Arkyd 101—could easily fit into the back seat of a car. They'd share a ride into space with other satellites, saving cost, and be very simple. Planetary Resources is already cutting metal on these birds and expects to start launching in the next two years or so.

Step 2, to be implemented after a few likely asteroids are located, is to upgrade the Arkyd 101 telescopes with rocket motors and other features that will allow them to pay the rocks a visit. The best asteroids are ones that pass near Earth at relatively low velocity, making them an easy rendezvous. Once there, the Arkyd 101+ will survey the target and see, literally, what it's made of.

That part is critical. What Planetary Resources is looking for is not precious metals, but something even more important for space travel: water. If you want to stay in space, that may be the single most important substance. We drink it, obviously, and it can be broken down chemically to make air to breathe. Using sunlight and solar cells for power, water can in principle be turned into hydrogen peroxide, which is a potent rocket fuel (though the details of the process are complex). It can even be used as a radiation shield to protect astronauts from solar storms.

Water is extremely expensive to launch from the Earth's surface: $10,000 per pint! Planetary Resources is looking to extract it from asteroids and leave it in orbiting tanks, removing the need to lift it out of Earth's oppressive gravity. Water may be common in asteroids, making it possible to manufacture a ring of supply depots circling the sun (and passing the Earth every few weeks) which could be available to future astronauts.

This is the key to Planetary Resources' strategy. I talked to Chris Lewicki, their chief engineer—an ex-NASA engineer with a lot of experience getting probes to other planets—and he told me that the investors—a half-dozen billionaires, like James Cameron, Ross Perot Jr., and Google executives Larry Page and Eric Schmidt—aren't looking to make money (at least right away) on this venture. Their goal is to ensure a permanent human foothold in space. The plan to extract water is a critical step toward that.

Of course, that water in space is valuable, and I expect they'll want to sell it to future space travelers to recoup their cost. And once that's working, then Step 3 is starting to look more and more like it'll be mining those metals that we covet so much here on Earth.

It's at this point that my skepticism kicks in. Planetary Resources, both online and in their press conference, didn't give details on just how they'd do this extracting of water and mining of metals. I suspect this is most likely because they're keeping it close to the vest—though some people I've talked to have speculated that the company simply has no idea how to do it. But I keep looking at that list of billionaire investors and thinking they wouldn't give money to the company unless they had an idea how to do it, and the impressive list of ex-NASA folks who are involved in the company gives me pause as well.

It's too early to know if this venture will fail, or actually be the first step to making humans a space-faring race. Time, of course, will tell.

But I grew up reading Heinlein, and the idea of a spunky group of can-do engineers and private backers has a sort of visceral appeal to me. And with the private company Space X (and several others) potentially about to make space travel easier and far less costly ... well. I'm not the naïve kid I was back then. I know the kind of dangers, disasters and plain ol' pain-in-the-butt difficulties that can derail space travel, especially space travel for profit.

But that kid in me is still there, somewhere in my brain. And he's cheering this company on.

Crazy? Yes. But maybe, maybe, it just might work.

Phil Plait is an astronomer and blogger for Discover Magazine.