If humanity is to become a multi-planetary species, we can't forever remain dependent on Earth's resources. That's where space resource extraction comes in. So how would space mining work, what problems would it solve, and how long will we have to wait? To answer those questions, I'm joined in this episode by Kevin Cannon. Kevin is a professor of space resources and geology and geological engineering at Colorado School of Mines in Golden, Colorado. He's also author of the Planetary Intelligence newsletter on Substack.
In This Episode
How mining in space could benefit Earth (1:13)
The basic economics of space mining (3:56)
Space resources and multi-planetary civilization (9:32)
Public and private sector space exploitation (14:00)
The next steps for space resource extraction (17:56)
The criticisms and hurdles facing space mining (26:15)
Below is an edited transcript of our conversation.
How mining in space could benefit Earth
James Pethokoukis: You've written that building a space-based civilization is all about raw materials. Given your academic specialty, these are raw materials out there, not down here. But if I am not interested in building a space-based civilization, do I care what's out there, what materials, what elements I can find out there?
Kevin Cannon: Let me give you two examples of how this could kind of come back to Earth. One is something that's being talked about increasingly lately, and that's this idea of space-based solar power. We want to undergo this energy transition, switch to renewables. Solar power, the issue there is the scaling and the land that's available. You only have so much land that you can put up more solar panels on. So if we wanted to have a truly energy-abundant future, one way to do that is to actually put up structures, satellites, in orbit that collect solar power and beam it back to the Earth via microwaves. And it turns out the only way to really make this economic is to actually make those structures out of raw materials that are found in space, either from the Moon or from asteroids. If you try to launch everything that you need, it's just too expensive. It's too difficult. So that's one example.
A second example related to that, there's obviously a lot of talk about climate in general, and there's still this idea out there that we can get through this climate issue by just reducing emissions. I think at a higher level, the discussions out there are that that's not going to be enough, that we're not drawing down those emissions fast enough, and that we may need to use different geoengineering techniques. There are different ways to do that. You can inject stuff into the atmosphere. You can put stuff into the ocean. Those are a little bit problematic politically. One alternative is to actually just block out a small fraction of the sun's radiation with something called a planetary sun shade. You put up a structure in space at the L-1, the Lagrangian point between the sun and the Earth, and that structure blocks out, say, 1 to 2 percent of the sunlight and cools the planet and helps as a mitigation effort. And again, that structure is so large that we could not possibly launch that into the space. We would have to build that out of materials that we find. So even if you don't want to leave the Earth, you're happy here, you still have problems on Earth. And there are solutions to those that could potentially be found by using raw material on the Moon or on asteroids.
The basic economics of space mining
You're saying that even with the decline we've seen in launch costs in recent years, and even assuming some continued progress, it would be more affordable to build these two examples with the regolith — or the surface dirt from the Moon or Mars or from some other place, some asteroid — than just getting it out into space with a rocket, even if it's a rocket that goes up pretty cheaply compared to the rockets of the past.
The thing you have to understand is that as those launch costs come down, it also becomes cheaper to put the factory on the Moon that makes the components, that assembles the structure in space. And it's also the case that we wouldn't build 100 percent of the structure. You would still be launching the intricate parts, the dopants for your solar panels, the wiring, things like that. It's kind of the bulk structure that we would make, what we call the “dumb mass” as opposed to the “smart mass.” But yes, as the launch costs come down, it's easier to put things in orbit, but it's also easier to put construction material and assembly material to do this kind of space-based construction effort.
That’s always the big concern: trying to make the economics work. I find that people aren't fully aware of what possibilities have been opened up because it's gotten a lot cheaper to launch rockets into space. And hopefully it will get a bit cheaper still.
We're anticipating right now in the months ahead, the first orbital launch of the SpaceX Starship. SpaceX has brought the launch costs down dramatically just with the Falcon 9, through reuse, through the Falcon Heavy. But the possibility for Starship is really a step function. It's not just a continuation of that smooth decline, but really a potential leap in our ability to put massive amounts of stuff into space. If that design is proved out, then hopefully other competitors will start to copy that and improve on it and we'll see an even more dramatic reduction.
People have a hard time understanding the economics of going and mining an asteroid to bring back to build things on Earth. Would that be economical versus using that material to build things out in space?
There's only a very narrow case you could make for a certain class of materials. And specifically, that would be things like the platinum-group metals. Those meet a number of criteria: They're very expensive — for example, the metal rhodium sells for about $400,000 per kilogram — and we only mine a very small amount of those per year. It's measured in single-digit or double-digit tons: 20 or 30 tons of these materials per year. Possibly, you could make an economic case to bring back some of those platinum-group metals. But for something like copper, we mine millions of tons per year, and that's never going to make sense. That's kind of the big misnomer about space resources that's out there in the public perception: that what we're talking about is going out into space and bringing stuff back and selling it into existing commodity markets. And that's really not what the main focus is. The main focus is using local materials that we find to help expand civilization into space rather than bringing everything with us. But maybe, just maybe, you could make a case for something like some of these platinum-group metals.
What you're doing is not speculative. This is something that you think will have practical application and you're graduating students who are getting hired to begin to think and do this, right?
It's still in the early stages, but it's not science fiction and it's not theoretical. Let me give you a couple examples of what's been happening in the last few years. Last year on Mars, there's a small instrument on board the Mars Perseverance rover, the NASA rover, called MOXIE. And this is a demonstration that sucks up a little bit of the CO2 atmosphere of Mars and converts it into breathable oxygen. This is the first time in history we've taken a raw material on another planetary body and actually turned it into a valuable product. It's the first creation of a resource in space.
Second example: A couple months ago, we had the launch of a private lander from the company ispace. This is going to be the first attempt at a commercial landing on the Moon. And as part of that mission, they're going to try to scoop up a small amount of the regolith. And NASA has already signed a contract to purchase that material. It's a very small dollar amount. The real point of that is to set a precedent that if you go out and mine material in space, that it is yours to then sell to someone else. So if that's successful, around April that will be the first sale of a resource in outer space. There are a wide variety of companies working on this. We have the Space Resources Program at Colorado School of Mines. And just an example there, Blue Origin — not a lot of people know about this — in the past year or so they've hired about 30 full-time employees working just on space resources [in situ resource utilization].
Space resources and multi-planetary civilization
As you've been talking, I've been trying to quickly dig up a quote from one of my favorite books and TV shows, The Expanse, which touches on this issue of the resources out there. Let me just quickly read it to you: “Platinum, iron, and titanium from the Belt. Water from Saturn, vegetables and beef from the big mirror-fed greenhouses on Ganymede and Europa, organics from Earth and Mars. Power cells from Io, Helium-3 from the refineries on Rhea and Iapetus. A river of wealth and power unrivaled in human history came through Ceres.” That’s the big sci-fi dream, that there is this vast field of resources out there that we can tap into. And if we can tap into it, it will be primarily for creating this space civilization.
Yeah, that's exactly right. The atoms are out there. We know all of the atoms in the periodic table are found on every planetary body. It's a matter of concentration, and it's a matter of having the energy to separate those out and turn them into useful products. As long as we can figure out how to do that, then we have the resources available, just in the solar system, to support a massive population of people to live at a very high level of well-being. The long-term promise is that we can expand into space and have a thriving civilization that is built on top of those resources.
I love how you put it in one of your tweets. You wrote, “Space resources are optional to gain a foothold in space, but necessary to gain a stronghold.”
If you look back at what we've done so far in human space exploration, we've landed 12 people on the Moon, they walked around for a few days, and then they came back. Since then, we've sent people up to low-Earth orbit to the International Space Station or the Chinese equivalent. They stay up there for a few months, and they come back. In those cases, it makes sense to bring everything that you need with you: all the food, all the water, all the oxygen. If we have greater ambitions than that, though — if we want to not just walk around on the Moon, but have a permanent installation, we want to start growing a city on Mars that becomes self-sufficient, we want to have these O'Neill cylinders — you simply just can't launch that material with you. And that's because we live in this deep gravity well. We can just barely get these small payloads off the surface with chemical rockets. It just economically, physically does not make sense to try to bring everything with you if you have these larger ambitions. The only way to enable that kind of future is to make use of the material that you find when you get to your destination.
The question I always get is, why bother doing any of this? Is that a question you spend a lot of time trying to answer? Or are you convinced it's going to happen and you've just moved beyond the question?
I think enough people have made the case for why we need to do this. You can look at it from different perspectives, from one of scientific discovery to one of existential risk to the planet that, if we stay here on Earth, eventually something is going to come along that presents an existential risk to civilization. What I'm trying to do is work with the people, with the companies who are actually trying to do this and help them using my perspective, this kind of unique perspective that's based around the science and the composition of these planetary bodies and how to make use of these resources. I don't concern myself too much with the question of why we should do that. I'll kind of leave that to more of the philosophers, the other people who have worked on that. I agree that I'm kind of past that and I am really deep in the nitty-gritty details of how to actually do this: how to turn the regolith into metals and ceramics; how to get rocket propellant out of ice at the pools of the Moon. That's what I spend my time focused on.
Public and private sector space exploitation
There was a boom in some planetary resource startups a few years ago which didn't last. What has changed between now and back then? Is it just the drop in launch costs? The technology has gotten better? Up until very recently, we had very low interest rates, it was easy to finance things? We're in like a second wave of this. What is making this second wave possible?
I think the launch costs and technology do make a difference. I think the other thing is the way that some of these newer companies are going about it. That first wave that started back around 2012, you had these two main companies, Planetary Resources and Deep Space Industries, and they tried to do this as kind of a typical venture capital–funded endeavor where they went through their seed round, their series A, series B. And that's pretty difficult to do if you want a return on your investment in five to seven years. So what we're seeing lately are companies coming into this space who have already amassed a lot of capital. They might have founders or backers who have the money to actually put up missions without first raising capital.
I think that's what's going to start to make more of a difference and make this second wave last and have longer legs. Some of the companies that are coming into this: I mentioned one, of course, Blue Origin with Jeff Bezos, who is pumping in about a billion dollars a year, very active in this space, not talking about it a lot publicly. But there are some newcomers that have also shown up in the last couple of years. One that we're working with is called KarmanPlus. They are a new asteroid mining company who are going to be setting up shop here in Colorado. They have the money upfront to be able to make a splash without having to go through the typical kind of VC funding route at the very beginning.
How supportive is NASA of this general concept of seeing space as a resource to be extracted or exploited, whether it's to do things here on Earth or build a space civilization? Are they all on board? Do they view this as, “This is a private sector thing; we're going to focus on exploration and doing science, and this is a different thing and we really don't care”?
NASA historically has always put a little bit of money into this field and the field of space resources. They have kept it going even as interest has waxed and waned. What they've never done, though, is made it a critical part of their missions. For example, right now they're working towards the Artemis program: landing people back on the surface of the Moon. They're exploring ideas of prospecting for ice at the poles of the Moon. They have this upcoming VIPER mission. They're funding technology to extract oxygen from the lunar regolith. But what they're not doing is saying the Artemis astronauts are going to breathe that oxygen and that's going to be a critical part of the Artemis program. So they're funding it; they're bringing it along. They are supporting it to some extent, but they're not making it a key part of their missions. I think what we're going to see is continued activity in the private sector. And then what we're also seeing, though, is a lot more interest lately from the Space Force and from DARPA. Those government agencies are starting to get a lot more interested in these topics.
The next steps for space resource extraction
When you think about this, what is the timeline that is reasonable using space resources to create a permanent base on the Moon, on Mars, to go further out and extract resources, not from the regolith on the Moon, but from actual asteroids and using those resources? What is your loose timeline of how you think about it? You don't have to give months and days and dates. But just broadly.
Right now we're in the phase where we're testing and developing the technology in the laboratory space and then just starting to deploy it as these kind of demonstrations on the Moon or on Mars. I mentioned the MOXIE experiment converting the atmosphere of Mars into oxygen. In the next couple years, there are going to be a lot of these small commercial landers going to the Moon. A lot of those have demonstration payloads where they're going to do things like trying to 3D print with the regolith or trying to extract oxygen from it. The next step, I'd say maybe three to five years from now, is to get to the point where we have kind of a pilot plant. Maybe we're extracting water from the poles of the Moon or oxygen from the regolith and we have something a little bit bigger than these tiny experiments. So we’d have something like a pilot plant. Maybe 10 years out, we have full-scale production of a simple resource like rocket propellant. And then I think we're in maybe the 15- to 20-year time scale for starting some of those larger efforts: starting to land supplies on Mars that would go towards this city that SpaceX has talked about, starting to 3D print a structure on the Moon that would be a permanent installation. That's kind of the timeline that I think about.
And then in terms of the investment part of this, there is another piece to this in that a lot of the companies who are working on these technologies also have a component of it that's focused on Earth-based technologies. One example is a company in Texas called ICON Technologies. Their main business is actually on Earth, and it's to 3D print entire houses to address the housing crisis. But then they also have a segment where they're applying those same techniques to be able to 3D print structures on the Moon or Mars. So for investors looking to get into this, there are a set of companies that have those shorter-horizon terrestrial applications, but then those also feed into these longer-term space-based goals.
In 2019, you co-wrote a piece, “Feeding One Million People on Mars.” That would certainly qualify as a pretty large space colony. Can you briefly tell me how you would do that, and are we talking that being possible this century?
The thing that I think a lot of people get wrong about the food piece of this is that they assume we're going to keep this paradigm that we've had for 10,000 years of growing our food in the dirt. There's a lot of work out there that's being done — it's not always very good quality — of, “Let's try to grow plants in the regolith. Let's add fertilizer to these fake regolith samples and try to grow plants.” And that's simply not very efficient. I think that as we go into space, we're going to abandon this idea of growing all of our food in dirt. I think it's going to be all through bioreactors, through cellular agriculture. I think that's kind of the main way that we're going to produce food in space.
In terms of the logistics to do that on Mars, the challenge there is, let's say your end goal is you want a city with a million people on Mars — and that's what Elon has stated is kind of the end goal — the question is, how do you get there? And what you eventually want is for that city to be self-sustaining so that if the ships stopped coming from Earth, it would be able to persist. What you have to do is you have to transition from that city or that base making zero percent of the calories that are being consumed on Mars to eventually 100 percent. The challenge is figuring out how you scale from that zero to 100 percent. It's going to involve a massive number of ships that are sending supplies. But the question is, do you try to switch to being 100 percent self-sufficient at the beginning, or do you kind of slowly ramp up over time? That's kind of the main problem with the logistics: When do you stop sending the material from Earth and when do you send the machine that makes the material on Mars? That's a tricky problem.
I would assume you were pretty happy to hear about this nuclear fusion breakthrough, because I doubt any of this really works, probably, unless you have nuclear fusion reactors?
In space, there are some advantages to solar panels. If you are in orbit or on the Moon or near an asteroid, you don't have clouds, you don't have an atmosphere to attenuate the solar radiation. But I think, eventually, we are going to have to make that transition to something like fusion. People have talked about the potential for helium-3 on the Moon. I'm not 100 percent sold on that. There are other roots to get to fusion. But I think certainly that extra energy, that ability to scale the energy, really opens up the resources that are available. One thing we find is that on Earth we have a lot of ore bodies where certain elements have become very concentrated relative to the rest of the crust of the Earth. And that's where we set up mines and extract these materials. On other planetary bodies, those processes haven't happened to the same extent. And so we don't really have a lot of good ores that we could mine. And so what we're going to have to do is actually figure out how to extract something like rare-earth elements or copper from a raw material that doesn't have very much of those elements, doesn't have those ore minerals. And that's going to take an enormous jump in energy. Something like fusion is probably necessary to really achieve that self-sufficiency, to be able to get every element of the periodic table we need from raw materials that don't have very high concentrations.
Perhaps a question I should have asked earlier: What is there a lot of out there that there's just not very much of here? I imagine whatever that is, it’s the stuff that we're going to focus on first or potentially bring here. Is there stuff that's particularly abundant that we just don't have very much here?
If we think of this from the level of chemical elements the answer is, not really. I mean, you could make a case that Helium-3 falls into that. But that's only true if you go out to the outer planets, Neptune and Uranus, they have a lot more helium-3 than the tiny amount that's kind of sprinkled in the lunar soil. The thing that's most abundant in space in terms of solid material is just the dirt. Almost every planetary body — the Moon, Mars, asteroids — they're all covered in this layer of regolith or dirt. And that really is the raw material that is going to have to be the feedstock for all these things we're talking about: the metals, the ceramics…
We're going to have to make a lot of aluminum.
Fortunately, actually, that is one thing: If we look up at the Moon at night, you have the bright regions, those are the lunar highlands. Those are almost entirely made of a mineral called anorthite that has a lot of aluminum. So there are very good sources of those kind of light structural metals on the Moon in particular.
The criticisms and hurdles facing space mining
Do you anticipate somebody at some point saying, “We've already overexploited the Earth. Now we're going to ruin the Moon too? And we're going to ruin Mars and asteroids — is this our galactic heritage?”
Those conversations are already happening. For example, last month there was a preprint published that made the case that we should declare a moratorium on the entire north pole of the Moon, that it should be set aside for only scientific activities. Those conversations are just starting. Right now, there's no kind of legal framework to prohibit this kind of activity. Certainly, people are free to express their concerns and to propose ideas like this. But as of yet, we don't have some kind of widely ratified agreement or framework for how to responsibly use resources in space. Certainly, the people in the field of space resources, we're conscious of this. And we're not proposing to go out and strip mine the entire solar system. But I think the argument is that the potential benefits, especially in terms of well-being, just how many people could be supported with those resources, that outweighs the concerns about disturbing these natural environments.
Are there types of mining that we do here right now which are kind of proofs of concept or might resemble what we would do on the Moon or Mars or an asteroid? Or would it just be totally different and these are all new technologies that we would have to innovate?
Yes, there is a very good analogy, and it's something called heavy mineral sands deposits. These are not like your typical open-pit mines or your underground mines. These are kind of vast areas of loose sand on the Earth that have some very valuable elements locked up in these dense minerals. And so what happens is you go out and just scoop up these loose sediments and then you're sifting them to sort out those dense minerals that you want. So because almost every planetary body is covered in this loose unconsolidated regolith, I think that is a pretty good analogy for what we'll be looking at. You'll have excavators that scoop up that loose material, they bring it back to a processing site, and then you're sorting the minerals. It's kind of like a needle in a haystack to get the ones you want. And then the ones you don't want, you could still use those for other applications. You can melt them down, turn them into bricks, and do other things with them. That's probably the best analogy on Earth, these heavy mineral sands deposits
Are the biggest hurdles making the economics work? Is it getting the basic science and technology to work? Is it sort of political support, because, at least for a long time, I would imagine even if it's a private effort there’s going to be a lot of government money floating around here?
I'm not worried about the fundamental technology to take material in space and turn it into useful resources. I think that's been well demonstrated in the lab, and there's a lot of research being put into that right now. It's a tractable problem. I think on the technical side, the biggest challenge is getting Starship into orbit in the near term. The progress on that seems to have stalled a little bit. And that's getting a little bit concerning, because something like that, that kind of launch capability and the cadence that allows, is really going to be necessary to enable the kind of kinds of things we talked about. On the technology side, it's really just the launch piece of it.
The economics: I think people have made some pretty good business cases for things like propellant mined from the poles of the Moon and, I think, with some of these ideas around things like space-based solar power, planetary sunshades. So that's not too concerning. I think it's the combination of the launch piece of it and then the political support for this. If that were to really take a turn for the worse, that would not be good for these kinds of ambitions. I do think, though, this emerging space race with China…
As long as China's interested, we're going to be interested, right?
Yes. That is what's drawing in the interest of the Space Force, of DARPA. I think that's going to kind of keep things going for at least the medium term, as long as we're in that competition.
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