On Wednesday the European Space Agency achieved a remarkable feat, successfully landing a probe on the surface of a speeding comet, 317 million miles from earth. The success of the Rosetta mission was a banner day for space exploration. It also made one small, quixotic industry suddenly seem a lot less like science fiction: asteroid mining.
David Gump is the vice chairman of Deep Space Industries, one company currently planning to send probes on one-year prospecting trips to near-earth asteroids. In an e-mail, he said such trips would be “much easier” than Rosetta’s mission, which required a decade of travel past Mars. Rosetta’s landing, he hopes, will make his company’s plans look more realistic to investors and customers.
Asteroid mining is an idea that’s developed over the last decade, as scientists have identified increasing numbers of near-earth asteroids, bodies relatively accessible because their paths around the sun are similar to our own.
The attraction begins with the fact that it’s extremely expensive to lift anything from earth into space because of the huge amounts of fuel needed to escape gravity. Asteroids, by contrast, have almost no gravity at all, which makes it easy, from a fuel perspective, to get on and off them. So a mining operation might harvest some kind of propellant from an asteroid - perhaps derived from the water they’re believed to hold - and deliver it cheaply to a geosynchronous satellite orbiting earth. Though the asteroid might be very distant, many times farther away than the moon, the operation would take relatively little fuel, because it completely eliminates the costly trip off the earth’s surface.
“Right now it costs $17 million per ton to get anything up to geosynchronous orbit,” says Gump. “If we can beat whatever that price is in 2022, we’ll have a big market.”
Deep Space Industries would compete in that market with other asteroid mining companies, and also with companies considering similar business models based on mining resources from the moon. Gump was in fact president of one of those lunar-focused companies, Astrobotic, before he jumped to Deep Space Industries in 2012. He thinks the moon’s gravitational pull—which is slight compared to earth’s, but far more powerful than an asteroid’s—makes it impractical to transport resources off the lunar surface. “We’ll duke it out and see if [the moon companies] can compete against us for work in free space,” he says.
Providing services in space is one idea. Another is to find resources on asteroids and bring them back to earth. For the most part, Gump says, “the rule of thumb is you use space resources where you find them,” because of how expensive it is to leave and reenter the earth’s atmosphere. But Eric Anderson, CEO of Planetary Resources, another asteroid mining outfit, thinks that if they can find asteroid resources on a big enough scale, re-entry might be worth it.
“An asteroid 30 or 40 meters wide has more platinum on it than five years of platinum trading on earth,” says Anderson. “We could bring platinum back at cost of $300 per ounce and that could go way down over time.” (Terrestrial platinum currently trades at $1,185 per ounce.) He says his company is in the early stages of a prospecting phase to determine the composition of different asteroids and identify the ones that are the best bets for mining. Deep Space Industries is developing prospecting plans, too, and Gump anticipates this reconnaissance work will take five or six years. “By 2022 or 2023,” he says, “we will have asteroid products for sale in high-earth orbit, primarily propellant to start with.”
Anderson envisions a similar timeline. Within a decade, he expects to see “the easiest and the closest asteroids being exploited for fuel. Hopefully see maybe 15 or 20 fuel depots and I think that’s very possible.”Kevin Hartnett is a writer in South Carolina. He can be reached at firstname.lastname@example.org.