The Space Reviewin association with SpaceNews

Moon and hand
Grasping the resouces of the Moon, in particular the water ice at the lunar poles, might be the best near-term step for space exploration and, eventually, settlement. (credit: J. Foust)

Where first for space resources?

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For the last year the future direction—and destinations—of America’s space exploration efforts has been the subject of intense debate in the space community. Should the country retain the goals of the Vision for Space Exploration, most notably a human return to the Moon by 2020, or exchange them for other objectives, such as President Obama’s call in his April speech at the Kennedy Space Center to mount a human mission to a near Earth asteroid by 2025 and a mission to orbit Mars in the mid-2030s? That debate revolved around several key issues, including cost, national prestige, and scientific return.

“Mining water on the Moon is going to be a lot easier than we thought,” said Spudis.

One issue that largely was not a factor in the debate this year, though, is the resource potential of these destinations. These resources, ranging from water ice and metal ores to solar energy and helium-3, could play a major role in the long-term affordability and sustainability of any future exploration initiative. These resources can directly support exploration activities, be shipped back to Earth for terrestrial uses, and even—in the long-term vision of many space activists—sustain a permanent human presence beyond Earth. When those issues are taken into account, as they were during a panel session at a recent conference, a different picture emerges regarding where humans should go next.

The case for the Moon

The question of where to go first in the solar system from a resource perspective was the central topic of a panel session that kicked off the Space Studies Institute’s Space Manufacturing 14 conference October 29 in Sunnyvale, California. While the session’s title was “Moon, Mars, Asteroids: Where to Go First for Resources?”, the debate among the panelists was between the Moon and near Earth objects (NEOs)—no one advocated for going to Mars first, and the Red Planet went virtually unmentioned in the discussion. And in that debate, advocates of lunar missions made a strong case of going there first.

Among the biggest backers of lunar exploration and utilization was Paul Spudis, a senior staff scientist at the Lunar and Planetary Institute. “There’s three reasons to go to the Moon: it’s close, it’s interesting, and it’s useful,” he said. “Of those, the first and the third—close and useful—I think are most relevant in terms of resource utilization.”

While the Moon has potentially a wide range of useful resources, including platinum group metals left behind from asteroid impacts and the oft-discussed helium-3 for as-yet-nonexistent fusion reactors, Spudis argued the best initial resource on the Moon is water ice, concentrated in permanently-shadowed craters at the lunar poles. That belief is buoyed by research from NASA’s Lunar Reconnaissance Orbiter (LRO) and Lunar CRater Observation and Sensing Satellite (LCROSS) spacecraft, released a week before the panel, which not only confirmed the presence of water ice but also found that in some locations it may be in the form of nearly pure crystals.

“We know now that the water there is free water; it is unbound,” he said. “Fundamentally all you have to do is to scoop it up and heat it to 100°C and it vaporizes.” That makes it much easier to extract, he said, than if the ice crystals were chemically bound to the lunar regolith. “Mining water on the Moon is going to be a lot easier than we thought.”

That mining need not involve humans present on the Moon. Greg Baiden, chairman and CTO of Penguin Automated Systems Inc., a company that develops technology for automated mining on the Earth, said such systems could also find use on the Moon. He said he’s been working with the Canadian Space Agency for the last four years on a strategic plan for mining the Moon. “We’re at a point now with teleoperation of mining equipment that I think it’s feasible to mine the Moon,” he said.

“Mining the Moon is not going to be an easy thing to do,” he admitted, but added, “I could easily make a business case for going to the Moon” given his experience mining in remote locations on the Earth.

“Once we start extracting and using anything, from anywhere, for any purpose, the incremental cost of adding one more kind of resource that we extract and use is next to nothing compared to the cost of getting there in the first place,” Greason said.

But what do you do with the water you mine on the Moon? One use, of course, would be to support any human settlements there. Spudis, though, argued that a bigger market for lunar water is for a “cislunar transportation system”, using that water (or, more likely, its elemental composition, hydrogen and oxygen) as propellant. “If you can do that, if you can build a system with, for example, reusable landers and propellant depots that can routinely access the lunar surface, you can access any other point in cislunar space,” he said. “That’s where virtually all of our satellites reside.” The government would be the obvious initial customer for such a system, he said, but others would make use of it once it’s available.

Another advocate of first utilizing lunar resources was Jeff Greason, president of XCOR Aerospace and a member of last year’s Augustine Committee. “I think if you ask the question of what’s going to happen first, especially in light of all that’s come out in the last 10 to 15 years about the Moon,” he said, “I think the Moon is clearly the answer.”

Greason also sees water ice as the first resource to access on the Moon, with governments as likely initial customers. “The probability is great that one or more governments around the planet are going to maintain a human space exploration program,” he said. “And if you’re planning on doing human space exploration, you’ve got to have a lot of propellant.” Even something on the scale of Apollo, he said, would generate demand for several hundred tons a year of propellant.

Mining water on the Moon, he added, could open the door for accessing other lunar resources. “Once we start extracting and using anything, from anywhere, for any purpose, the incremental cost of adding one more kind of resource that we extract and use is next to nothing compared to the cost of getting there in the first place,” he said. “It really is an irreversible tipping point. Once we figure out how to make it make money for anything, we can start figuring out how to make it make money for everything.”

The case for NEOs

Other panelists, though, focused their interest on making use of the increasing number of known NEOs. Like the Moon, NEOs have both mineral and volatile resources, including water ice, but NEOs have one advantage the Moon currently lacks: it is an explicit goal of NASA’s exploration plans.

“We probably do want to go to NEOs, because that’s where NASA wants to send people, at least under the current administration,” noted Mike A’Hearn, a professor at the University of Maryland and principal investigator for NASA’s EPOXI mission, which flew past comet Hartley 2 earlier this month. “By going somewhere where NASA wants to go also, you can do some mutual piggybacking and come out ahead.”

The biggest drawback of utilizing resources on NEOs, though, is accessing them. While many objects are small enough and come close enough to permit round trips with delta-V’s less than a landing on the Moon, repeated such opportunities to the same object are infrequent. That makes utilizing a NEO’s resources difficult unless you can extract them all in a single visit.

“A lot of people in the space business don’t really believe this is possible. They don’t believe space resources and space resource extraction and utilization can be done,” Spudis said.

“I have tried over the years to make a business case close for doing NEO resource exploitation. It’s hard,” Greason said. “The reason it’s hard is the revisit time.” One solution, he said, is the “De Beers model”, where you extract all the resources you plan to take from a single object on one visit, and then parcel it out over an extended period of time. An extension of that would be to simply move the object itself back to Earth, or some other more readily accessible location. “Among other things, I think the legal regime is going to have an enormous amount of evolving to do before that’s a practical business proposition,” he said.

“There is a steady-state asteroid mining market, at some point in the future,” Greason added later, once there’s greater knowledge about the composition of these objects and what is economically feasible to extract from them. “I see that happening some day, but some day is not any time very soon.”

The access issue has even advocates of asteroid resource utilization suggesting that lunar resources may be a better near-term prospect. “Net present value and the time cost of money is crucial, and that’s one of the things that has me swinging back away from asteroids and towards the Moon,” said Mark Sonter, an Australian mining consultant who has studied asteroid mining.

John Lewis, professor emeritus of planetary sciences at the University of Arizona and a long-time advocate for the study and utilization of asteroids, also acknowledged that lunar resources might be more viable in the near term. “You have to respond to any opportunity that opens up,” he said. “Historically I’m identified with asteroid resources, but if we had a manned, federally-sponsored program for going back to the Moon right now, I’d be right at the head of the line saying that we should go after lunar resources.”

Attaining economic escape velocity

While the evidence grows that there are accessible and usable resources in the inner solar system, and particularly on the Moon, making the leap to actually accessing and using those resources isn’t easy. This is particularly the case for lunar resources, given that lunar exploration isn’t a priority—or, at least, isn’t as high a priority for human missions—under NASA’s new direction.

One major challenge, Spudis argued, is that many don’t believe that resource utilization is viable, for one reason or another. “A lot of people in the space business don’t really believe this is possible. They don’t believe space resources and space resource extraction and utilization can be done,” he said. “Most of these people are in decision-making positions in both NASA and the US Air Force.” Some kind of demonstration mission, he said, is needed for this “to become not laughable.”

If we can achieve sustainable resource extraction in space, Greason said, “the stars are ours.”

Spudis and other advocates of lunar resource utilization believe that accessing these resources requires a partnership between the public and private sectors, with the government making an initial investment. “The government goes, demonstrates that this is possible, demonstrates some of the technologies you need to do it, and then it passes it on,” he said. “Let the government lead the way, and let the private sector follow.”

Greason argues that the role of government is to invest in infrastructure needed to access the resources and provide a market for them. There may be private demand for, to take one example, propellant derived from lunar water and transported from the Moon to low Earth orbit, but “nobody’s going to redesign their satellites to accept that propellant until after the propellant supply is there,” he said.

“It is the classic transportation infrastructure problem,” he said. “It is a legitimate function of government to invest in that kind of basic transportation infrastructure that everyone can use.”

There’s also research that needs to be done on the technology of extracting those resources. “We have a little bit of work to do before we get there, like a mining method that’s going to work on the Moon in a partial gravity environment,” Baiden said. “There’s absolutely no research going on in how to figure that out.”

Advocates of lunar resources on the panel, though, were not deterred by the challenges. “We’re spending roughly $20 billion a year on a federal space program. I think we ought to get something useful for that,” Spudis said. That would come not from the “super Apollo” visions of exploration that NASA previously put forward for human lunar missions, he said, but instead by going to one place in the lunar polar regions, learn how to extract water ice, and start exporting it for government and, later, commercial users.

“The importance of resource extraction and export back to the home society is not that it’s the be all and end all of what you do, but that once you can do that, you have reached economic escape velocity,” Greason said. “It may or may not be a necessary step, but it’s a sufficient one, and if we can get there, the stars are ours.”