Water found on or near asteroids, their theory goes, could be processed into fuel to extend the useful lives of aging commercial satellites.
“I still consider that mining,” Planetary Resources co-founder Eric Anderson said in a recent interview disclosing the new game plan. “We’re going to take the resources of space and turn them into a usable material.”
Despite the risks, Mr. Anderson remains upbeat. He said test launches are slated for the end of this year and 2015, followed by plans for “sending our first swarm [of telescopes] to an asteroid target” in 2016. He compares Planetary Resources’ proposed depots to building a highway for deep-space exploration. “If it works, it’s a total game-changer.”
Planetary Resources originally envisioned using orbiting swarms of small telescopes–some weighing as little as 30 pounds–to survey some of the thousands of sizable asteroids that come closest to the Earth or the moon, looking for evidence of mineral deposits. A second wave of unmanned spacecraft many times larger would have been dispatched to do the mining.
In mapping out the new trajectory, however, Mr. Anderson acknowledged that technical hurdles and cost considerations have turned the initial vision into a distant dream.
Instead, he said, the company’s immediate focus is on establishing orbiting fuel depots, essentially gas stations for many hundreds of decaying satellites, which otherwise would burn up as they plummeted back to Earth. The plan calls for robotic spacecraft designed to retrieve water from asteroids or their vapor trails–without ever landing on them– and break it down into hydrogen and oxygen for use as propellants. Solar power would be used to heat up asteroids to create water vapor, and the intense cold of space would freeze it for later use.
Commercial communication satellites running low on fuel after a decade or more in service would adjust their orbits to reach the depots and refuel, potentially gaining more years of life. Planetary Resources also envisions scientific, military and even spy satellites, along with deep-space scientific probes, benefiting from such fill-ups.
“Quite honestly, it’s more sexy to talk about…bringing something back to the Earth,” Mr. Anderson said. But that goal, he said, is much more difficult and requires first establishing the same kind of fuel depots the company is emphasizing now. “That certainly will be the emphasis in the early years.”
By some measures, selling fuel at orbiting depots could be as lucrative as digging up minerals. The company, though, continues to talk about eventually setting up remote-controlled mining operations for metals.
But at least for now, even Planetary Resources’ scaled-back proposal faces major hurdles, including the fact that at least two established space companies already have devised competing satellite-rejuvenation projects that don’t depend on such elaborate techniques.
Alliant Techsystems Inc. is marketing a simpler solution. Its plan calls for launching a family of vehicles that would rendezvous with larger, aging satellites and latch onto them. The vehicles would remain attached to the satellites, serving as a propulsion system and replacement fuel tank to keep both spacecraft in orbit.
Alliant’s approach avoids the complex business of tapping into the host spacecraft’s existing fuel lines, an operation that can cause dangerous collisions or venting of chemicals.
Mr. Anderson, however, says his company’s strategy would be substantially less expensive in the long run, because it would avoid the significant cost of launching fuel from the ground. So far commercial satellite operators generally have been ambivalent about signing on to any proposals to extend the lives of their satellites. Alliant has indicated it has at least two firm customers, but it hasn’t identified them.
A spokeswoman said Alliant’s strategy is less risky and more versatile, because it also can be used “to take over for a satellite with a damaged or inoperable propulsion or attitude-control system.”
Chris Lewicki, the company’s president and chief engineer, said water is one of the easiest and most valuable resources “to remotely prospect” and use. It could cost about $50 million to transport a single ton of water from the Earth into orbit, according to Planetary Resources. Mr. Anderson has suggested it is likely to cost substantially less to carry out the entire 2016 mission to start identifying virtually unlimited sources of water on asteroids.