Ep. 568: In Situ Resource Utilization

Posted on Apr 29, 2020 in podcast, Space Flight | 1 comment

The key to surviving in space will be learning how to live off the land. Instead of carrying all your fuel, water, and other resources from Earth, extract them locally at your destination. It’s called In Situ Resource Utilization and if we can figure this out it’ll change everything.

Download MP3  | Download Raw Show with Q&A | Show Notes | Transcript

Show Notes

Deforestation in Iceland 

Pacific voyaging and discovery

The Moon is a Harsh Mistress by Robert Heinlein

VIDEO: Making Life Multiplanetary – Elon Musk presentation 

Sabatier reaction

Elon Musk wants to collect fuel on Mars to send spaceships back to Earth (The Verge)

Return to the Moon? 3D Printing with Moondust Could Be the Key to Future Lunar Living (Space.com)

Can Plants Grow with Mars Soil? (NASA)

VIDEO: What Makes Liquid Water on Mars Possible? (NASA Johnson)

Farming for the Future (NASA)

Space Farmers Could Grow Crops in Lunar and Martian Soil, Study Suggests (Smithsonian)

How to Feed a Mars Colony of 1 Million People (Space.com)

Rare Earth Elements (geology.com)

Solving the Challenges of Long Duration Space Flight with 3D Printing (NASA)


“Print Crime” by Cory Doctorow

Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) (NASA)


Transcriptions provided by GMR Transcription Services

Fraser:                         Astronomy Cast, episode 568. In-situ resource utilization. Welcome to Astronomy Cast, a weekly facts-based journey through the cosmos where we help you understand not only what we know but how we know what we know. I’m Fraser Cain, publisher of Universe Today. With me, as always, Dr. Pamela Gay, a senior scientist with the Planetary Science Institute and the director of CosmoQuest. Hey Pamela, how’re you doing?

Pamela:                        I’m doing well. How are you doing, Fraser?

Fraser:                         Good. We sound particularly cheery, for the apocalypse.

Pamela:                        It’s a Friday. I’m going to go in the yard and burn things later today.

Fraser:                         Yeah. We’ve definitely moved from the existential crisis, the deep grief phase of this process to the marathon portion. Where we are settling in for, what is probably going to be, months if not maybe years of on and off again restrictions, lockdowns, and quarantines. And, although it is still terrible out there and please, everybody, you know, we through this collective sacrifice, have made a dent in many countries on the spread of this disease, now we have to lock it in.

Pamela:                        Keep it up.

Fraser:                         Yeah.

Pamela:                        Keep it up.

Fraser:                         Yeah. We have to lock this in. We have to lower the rate that is transmitting to other people to below one and wipe it out of existence.

Pamela:                        Yeah. And New Zealand’s already succeeded. So, this is possible. It requires a massive combination of testing and quarantine and tracking down contacts. But that little island nation, or two-island nation, proved it is possible. Now, a lot of places out there are lifting their shelf-in-place warnings. Well, you’re about to be in trouble in three weeks. So, we’re very sorry.

Fraser:                         Yeah. So, even if the shelter-in-place has been lifted, keep an eye on the spread. Remember how it was spreading back in the beginning, and just think about that as well; and the sort of like, responsibilities on each one of us to ensure the safety of everybody around us. So, take those with a grain of salt. The key to surviving in space will be learning how to live off the land. Instead of carrying all your fuel, water, and other resources from Earth, extract them locally at your destination. It’s called in-situ resource utilization. And, if we can figure this out, it’ll change everything.

All right, Pamela. You know, we should do a bit of a history lesson here when we talk about how, essentially, we couldn’t have done exploration here on Earth without in-situ resource utilization. It’s the key.

Pamela:                        Exactly. Yes. And it has actually reshaped our world. Nowhere more so than the island of Iceland. It turns out that sailing ships require masts, and masts like to break. And, way back when, the great explorers of the northern oceans, the Vikings, came across this place with amazing forests and tall, strong trees, and they settled in, and took the masts they needed, and carried on with their massive trade. We always highlight the pillaging that occurred, but it turned out these were also traders, hunters, gatherers. And, well, Iceland was once a greatly forested land. And now it has almost no forests, and it’s leading to vast amounts of erosion. So, be careful what you take.

Fraser:                         Yeah, it’s interesting. When you’re there in Iceland, there are no trees.

Pamela:                        Right. That’s because the Vikings.

Fraser:                         Yeah. And, I mean, there’s the occasional tree. Like, a person might have a tree in their yard. And, apparently, there now some efforts to attempt to reforest the island. And in theory it, you know, give it another couple hundred years, and there will be forests on Iceland again. But, clearly, they found what they needed, they were able to survive by cutting down all those trees. Thanks. So, maybe that’s not necessarily the how we want this lesson to work out. But the point being that the only way they were able to survive was the fact that there were resources that they could use.

Trees they could cut down, animals they could hunt, fish they could eat, things – places they could grow things, they were able to survive in what is a very hostile place.

Pamela:                        And this is how we have systemically explored our world. Again, another amazing example of the past is the Polynesians. They knew exactly where all the little islands dotting the South Pacific were located and had amazing celestial navigation skills; and knew, if they went from here to here, there would be freshwater when they got to the next place. There would be food. There would be the things necessary to carry on their carrying on as they moved throughout massive areas of the ocean.

Fraser:                         And so, when we look at the history of space exploration plans. When you look at say, the moon missions, they carried everything. Every calorie that the astronauts would need was carried up from the surface of the Earth. Every drop of water, every molecule of oxygen that they were going to breathe. Everything had to be carried completely from Earth, and then all the way back from the moon. And back in the 50s, 60s, 70s, 80s, 90s, people were planning missions to Mars that would be the same thing. Carry everything to Mars and then carry it to be able to survive on the surface of Mars and carry out a mission.

Pamela:                        It’s not feasible.

Fraser:                         The math just kept breaking.

Pamela:                        Yeah. And this is where it gets really interesting to me, just what is considered in-situ resource utilization. Basically, if you don’t have to take something with you, that means you are utilizing where you go, and if you don’t have to carry all of your own energy with you. So, say you have solar panels. Those solar panels count as an in-situ resource utilization. And it’s something that doesn’t work everywhere in the solar system because we have places, the outer solar system, for instance, where you really need to have those radio thermal generators, those nuclear fuels cells. Whereas, on Mars, unless your curiosity, they just solar power away, and that’s a form of in-situ resource utilization. The sun is in-situ.

Fraser:                         You talk about the power, yeah. Let’s say you don’t have to carry your liquid hydrogen, liquid oxygen. You don’t have – you also don’t have to carry the fuel to carry the liquid hydrogen, the liquid oxygen. So, there is this huge multiplier for every kilogram that you’re trying to carry to the surface of Mars. Many kilograms of propellant to get you there.

Pamela:                        And we first started seeing people think hard about; how do we separate the resources we need from the rocks of other worlds, in the 1960s. And this started to crop up in novels like “The Moon Is a Harsh Mistress,” which, if you haven’t read, is something that is absolutely required reading in modern times. And, in that novel, they were shipping grain seeds from Earth up to the moon utilizing human byproducts and water that was found in the regolith of the moon to grow vast crops that were then shipped back to Earth which, was actually effectively shipping the water from the moon down to Earth.

Fraser:                         Right. That’s interesting. I never thought of it that way. I mean, I think that is probably infeasible. Like, there will never be a time when it will make economic sense to grow things on the moon and then ship them back to Earth. But growing things on the moon to feed the people on the moon, that makes a mountain of sense.

Pamela:                        Exactly.

Fraser:                         I think you could arguably say that space exploration will never be self-sustaining until we have in-situ resource utilization.

Pamela:                        Exactly. And…

Fraser:                         For people – I’m – let’s leave this in. The dog is licking Pamela while she’s attempting to record the call – the podcast. Such a professional.

Pamela:                        So, here we have to figure out: So, what do different places have to offer us. And the three big things that folks are constantly trying to figure out is the oxygen-water situation. I lump that as one thing because if you have water, you have oxygen. The other thing they’re constantly trying to figure out is: Well, how do we build ourselves a shelter? Can we find a way to live without having to take our habitats with us? And the third thing that, well, if you want to come back becomes an issue is, can you make rocket fuel wherever it is that you’re going? Because you can’t solar panel your way off the surface of a gravitational planet.

Fraser:                         So, let’s break down, you know, you talked about these things here; let’s talk about some of things core resources that we use of a ton of. Like, it’s okay to bring your 3D printer from Earth. It’s okay to bring your communication system from Earth. But let’s talk about some of the big bulk things. And so, the number one thing I think is just going to be propellant. Fuel. For your ship. So, where does this come from, and how could we try to make it?

Pamela:                        There’s so many different kinds of fuel. Here on Earth, we’re often looking at liquid oxygen systems. But Elon Musk is actually talking about on Mars, creating a…what he calls methamilox. This is a fuel system that is made of methane, CH4, and is created through melting of the water ice that can be found in the regolith and the poles of Mars; and mixing it with carbon drawn out of the atmosphere of Mars. Mixing it together in the right ways and you end up with methane that, using hand waviness that he said in the telecon related to this announcement, these are details to discuss offline. He actually said that.

Fraser:                         Yeah. I mean, the process of creating methane out of the atmosphere is well understood. It’s been done for a hundred years; that you take water, break it apart, use the hydrogen, use carbon dioxide from the atmosphere, mix them together. Again, details, look at them offline.

Pamela:                        The bacteria in our gut does this naturally.

Fraser:                         Yeah. I think it’s called the Sabatier process. But anyway, the point being that you can do this, no problem, and produce methane. The key and this was – I mean, the big problem always was that there – they weren’t sure if there was going to be accessible water on Mars. If you don’t have water, then you don’t have the hydrogen to make the methane with. So, you’d have to bring the hydrogen. But now we know the water is there.

Pamela:                        Well, and accessible remains the keyword.

Fraser:                         Yes.

Pamela:                        I – One of the issues that has led to no ending stream of crank emails is engineers who believe they have found the most efficient way to somehow strip lunar rock of its water. The minerals of the moon, many of the minerals on Mars, have H2O locked in to the lathasies, the matrixes, of the rocks. And if you tear apart the molecules in the minerals, you can liberate water. This was particularly visible when LCROSS bombarded the moon back in 2009 and sent that plum of material up above the surface, allowing us to sample and study exactly what is the mineralogy of the moon made of.

But getting that water out is a highly energetic process. And if you’re already strapped for energy, it doesn’t help if you have to use massive amounts energy to get the water out to use the water to make methane to make your rocket fuel. That’s just kind of not a useful process.

Fraser:                         But if – even just, like, if you just have water, you split it into hydrogen and oxygen, and that is the fuel system that was in the space shuttle. You’ve got…Right? So, if you just have water and energy to – for the electrolysis, then you can break them up, and you’ve got yourself fuel. So, there’s a ton, tons of them. There’s other ideas, like, have you seen this idea of like a steam-powered rocket?

Pamela:                        Yeah. I just…I know the gravity is a whole lot less out there, but…

Fraser:                         So, you take in water, you don’t try to break it up into it’s hydrogen and oxygen, but you then heat it up. Super-heat the water, and then you can then spray it out of your rocket, just as a propellant, as steam. And it provides a level of thrust, and it requires a simpler, you know, you don’t have to be storing cryo cold…

Pamela:                        And the way this works is the massive volume change that takes place between water and steam. Water takes up a whole lot less volume than steam does. And so, as that escaping, expanded now gas form of water flies out the thrusters of your rocket, up and away. It’s just not as efficient as other means.

Fraser:                         But what it lacks in that it makes up for in simplicity. You just dump water in, heat it up, spray it out; you’ve got yourself a thruster. So, there’s many different ways. And, I mean, we could do a whole show just about manufacturing propellants in various in-situ – and that accounts for the vast majority. So, once that gets cracked. Imagine, you can refuel, which we talked about last week, just how important that’ll be if you’re able to refuel. What other resources will we use that we’ll be able to find out there in space?

Pamela:                        So, we have the water that…we need water, or we die. It’s kind of a thing. And then, of course, there’s the oxygen that we need to breathe. And again, if you have water, you have the oxygen we need to breathe, and you have rocket fuel. So, those all tie together. The other big thing is just the ability to build the stuff that you live in. You take your 3D printer, but you need stuff to feed the 3D printer. And there’s some really cool research that has gone into trying to figure out how to use lunar dust to build stuff.

And one of my favorite breakthroughs that I’m sure I’ve brought up dozens of times, at this point, here on Astronomy Cast, is some researchers in Tennessee a number of years ago figured out that if you hit lunar regolith with just the right wave of length of microwave radiation, it gets melty and will solidify. So, you can take all this dust, and essentially, if you’ve ever seen a street cleaner with all of the little swirly bits on the bottom, replace those with microwave transmitters. Role along and just create your road behind you.

Fraser:                         That’s really cool.

Pamela:                        It’s amazing.

Fraser:                         There’s a great photograph that someone did. I think it was from the European space agency. They had a pile of simulated lunar regolith. So, lunar soil. That they had processed, I think they had heated it up and had gotten rid of the oxygen out of the stuff. Because, when you look at this stuff, it’s actually like iron oxide, or magnesium oxide, or aluminum oxide. Like it’s all – or silicone oxide. Like, it’s essentially these various minerals bound up with up with oxygen. You want the oxygen. But you’re leftover. And so, they showed you because the oxygen is a lot less dense than these metals, you bake one of these piles of lunar regolith, and you end up with a pile of metal, right?

That you could then use to feed into your 3D printer. We have 3D printers now that will print metal. That will print titanium. That will print iron. That will print aluminum. No problem. So, you can imagine just you take lunar regolith, dump it into your 3D printer, and then you just print girders on the moon to construct your spacecraft.

Pamela:                        It can be even better than that. So, one of my quiet little fantasies is I’ve been keeping an eye on 3D printed houses. I’d – And these are often these gorgeous arcing structures that you can’t really make any other way because you set your 3D printing machine in the center, and it has an arm on a pivot that can go out to different distances. So, everything that you do is some sort of an ellipse or arc with a maximum radius that is whatever the length that arm can be. And they can be in the center with all of their extruder material, and then build around building up these houses that look like they’re straight out of a children’s book.

I don’t know if you remember any of those children’s books where you had the big round big round blobby characters that would basically lump mud around them, and then that was how they built their homes.

Fraser:                         That’s funny. No. No. I have no idea what you’re talking about. Clearly, we had different childhoods.

Pamela:                        It – It’s all right. It’s all right. But we can essentially go to the moon and build our little regolith minor. I’m thinking spice minor from Dune here. I read way too much science fiction.

Fraser:                         Or not enough. Whatever it is, yeah.

Pamela:                       Or not enough. And plop it down and have it digging up stuff from the center, processing it through like a reverse collimation tower, extruding it out the arm, and then just building these arcing facilities all around out of nice thick blocking radiation regolith. And this might be the one that way we can readily build things with thick enough walls to keep us safe.

Fraser:                         That’s really cool. So, we’ve got out propulsion, our breathing, our liquid. We’ve got the building materials to build our homes, to build potentially things that we may want out of metal. What about eating? Because again, we have to carry all of this food from Earth. So, can we do that locally?

Pamela:                        You have to carry your own seeds. That just, flat out, there’s nothing already there.

Fraser:                         Yep.

Pamela:                        There are certain likens that, it’s thought, might be able to grow in the wilds of Mars, the way Mars is today. But that’s not a good diet.

Fraser:                         No. No. Unless you’re a reindeer.

Pamela:                        Yeah. Even then, I’m not sure it would grow enough that that would be a good diet. So, you’re really looking at asking instead: Is there anything that can be done to the existing soils to make it so that you can use the soils to grow plants? With the moon, we have this problem that moon rock is so sharp it will shred up seed in this case. It’s un-weathered crushed glass. So, you’re not growing things on the moon.

Fraser:                         You could throw it in the equivalent of a tumbler. A rock tumbler.

Pamela:                        Yeah. That takes a whole lot of energy. So, I foresee more a1 several generations of composting going on. And once you do enough composting, you’re probably okay. But with Mars, it looks like Mars had this amazing liquid past with oceans that would have tumbled down a lot of the sands on Mars to make them not as sharp and awful. And so, here what we see is soil that first of all, has perchlorates in it that will kill anything. So, you need to –

Fraser:                         Wash it.

Pamela:                        – get rid of those – yeah, wash it – get rid of the perchlorates. And then you just need to add in the nutrients. And what is fascinating to me is we don’t even know how much nutrient we need to add in because we keep getting more and more evidence that there’s already organics in the soils on Mars. And so, the question becomes: Once you get rid of the perchlorates, which is one heck of a problem, how bad is it? I’m hoping that it’s like trying to grow things in dirt found in Death Valley, which is really just gross sand. It’s not going to be like trying to grow something here, where

I’m in the Midwest where you sneeze, and your sneeze is now sprouting things you don’t want to think about. Our front yard already has knee-high weeds three weeks later. But there is the potential that we can use the soil without huge amounts of modification. We don’t have to tumble it the way we do with the moon. It’s just cool.

Fraser:                         But even if we don’t use necessarily the local regolith, I mean, NASA has gotten really good at hydroponics and aquaponics. So, you can grow your material in a medium. You can grow it just in water with lots of additional nutrients added to it. So, that’s technology’s actually been very well worked out. And I guess, when you think about it, it’s back to your very original point at the beginning, which is that it’s really just sunlight. That your just turning sunlight into human mass. Right?

Pamela:                        Yeah. And there are limits to hydroponics. You can’t grow an apple tree hydroponically because it’s root system won’t have anything to grip onto. So, if you can figure out how to create a diet that isn’t just nutritionally satisfying but is also satisfying to the soul. I mean, we call food soul food for a reason. Comfort food. If you can figure out that combination of things. I hope to someday see domed cities on Mars that have perhaps only in the occasional column of soil those trees that we’re trained to see growing. And sure, get the rest of your food through hydroponics. But we need those trees.

Fraser:                         There was an interesting study that came out. Some people were looking at what it might take, and they saw like, essentially, tunnels underneath the surface of Mars where you have, you know, these tunnels go for kilometers, and they would be filled with plants that are growing hydroponically because that keeps them safe from the radiation. You can control the environment and, I forget the exact amount, but you need some set amount of square meterage per human being to feed them. And it’s a lot, but it’s not a ludicrous amount. So, we’ve already knocked off the vast majority of the mass that we need to carry.

If we’re going to try to survive on a place like the moon or Mars, and we’re able to handle all of these things, we’ve got most of what we need, but we’re not full true self-sufficiency yet. We’re still going to rely on stuff from Earth. So, what remains and what, maybe, can we do to solve those last problems?

Pamela:                        We don’t have mining capacity on other worlds. And, at the end of the day, we’re going to have to rely on technology to live in other environments. And this means you need rare earth elements, which, I guess, rare Mars, rare moon elements? We need rare elements. We need the copper for this, the silicon for that, that is of the premium grades. So, this is where you need to send all those base metals. Whether – Whatever form you can, as well as the fabrication equipment. But the key is you don’t have to send everything already fabricated. As we move into better and better printing CNC machines, we need the ability to build things up and cut them down.

If you have those two machines and you have the base materials, then you can manufacture everything you need. So, you can almost imagine, hopefully someday, having our little robot minors out there tearing through the asteroids to find what’s needed.

Fraser:                         But you can imagine say, you need a bulldozer on Mars. And so, you send the bulldozer, the key components that can only be manufactured on Earth, and then the rest is the instructions for the Martian 3D printers. And so, they take the central processing unit, and some of the key hydraulics, or whatever it is, and then they print out all of the treads, and the bucket, and all that kind of stuff out of local resources, and then they build these things. And so, you can imagine, getting a tiny little care package that is a bulldozer that you then have to spool up your 3D printer and build the rest of it.

Pamela:                        And this is going to usher in a day where we have to think completely differently about manufacturing, even here on Earth. And we’re starting to see hints of what this will look like. We have a Glowforge here in our house. We don’t have a 3D printer yet because I’ve seen the carnage a 3D printer can wreck. I am only adult enough right now for a Glowforge.

Fraser:                         We owned one, and we sold it. Because it was just too complicated, and too much of a mess. So, yeah. Yeah.

Pamela:                        I’m not detailed-oriented enough.

Fraser:                         Yeah.

Pamela:                        But there’s a day, in our future, that is coming, where, already with our Glowforge, we can look up patterns for things. And we’ll spend five dollars for the pattern, or just innovate something ourselves. I’m using a teleprompter to record the daily space that was cut entirely out of acrylic on our Glowforge, and just slotted together beautifully. And –

Fraser:                         That’s amazing.

Pamela:                        – it’s a $200 teleprompter made with 20 bucks of acrylic.

Fraser:                         And a multi-hundred-dollar Glowforge.

Pamela:                        We’re not going to talk about how expensive the Glowforge was.

Fraser:                         Right.

Pamela”                       But we use it for so many different – Amazon boxes now actually occasionally have purposes where we make stuff out of them.

Fraser:                         Oh, that’s cool. We slice them up.

Pamela:                       And things that I would normally have been purchasing before like, the cardboard that I use to pad my paintings when I mail them out. Instead of buying the cardboard cake rounds that I was buying before, I’m just taking the best cardboard shipping boxes I have that have nice shiny on the inside, cutting those up. And so, copyright starts to change when you’re buying the patterns instead of buying the thing.

Fraser:                         Right. But you can definitely imagine this future where almost everything can be manufactured remotely, and you’re down to just a few key components that does require a chip fabrication lab to actually build. And then we will be very close to a lot of these places being completely self-sufficient. It’s amazing to think about that future.

Pamela:                        And one of the great people whose thought about it is Corey Doctorow. And all of you out there, if you haven’t read his books; his short story print crime is one of my favorite short stories, and it’s only about two pages long, so it’s a really short, short story. Check out his books and start to get insights on the real world near-future potential of these devices.

Fraser:                         Yeah. And if you think this stuff is science fiction, I mean it mostly is, but the Perseverance rover is going to have an experiment onboard that is designed to see if it can produce fuel on the surface of Mars out of atmospheric oxygen. So, stay tuned. Pamela, do you have some names for us this week?

Pamela:                        I do. As always, we are here, thanks to the generous contributions of people like you. And I just want to say; I know a lot of you are struggling right now. I see it in the donation levels that have dropped. I see it in the people who have disappeared after years. We’re here for you. You come first. Yes, we do take your donations and turn them in to pay for people who turns it into food for people. We’re going to get by, no matter what. We’re here for you. And those of you who are still contributing; oh my goodness, we are so grateful, and I’m just going to read some of your names:

So, thank you to Sharkdon Spherey, who someday please, please, please tell me the pronunciation of your name. To Sinai. To Steven Shewalter, To Bill Hamilton. To Joshua Pearson. To Frank Trippin. To Richard Rivera. To Alexis. To Thomas Sepstrup. To Silvan Wespi. To Jeff Collins. To Arcticfox. To Brian P. Cox. To Marek Vydareny. To Nate Detweiler. To Brian Gregory. To Ron Thorson. To Philip Walker. To Matt Rucker. To Dave Lackey. To Kevin Nitka. To Cooper. And to Chris Scherhaufer. Thank you.

Fraser:                         Thank you, everybody. And we’ll see you next week, Pamela.

Pamela:                        See you later. Astronomy Cast is a joint product of Universe Today and the Planetary Science Institute. This episode was edited by Chad Webber. Astronomy Cast is released under a Creative Commons Attribution license. So, love it, share it, and remix it. But please, credit it to our hosts, Fraser Cain and Dr. Pamela Gay. You can get more information on today’s show topic on our website, astronomycast.com. This episode was brought to you thanks to our generous patrons on Patreon. If you want to help keep this showing going, please consider joining our community, at patreon.com/astronomycast.

Not only do you help us pay our producers a fair wage, you will also get special access to content right in your inbox, and the invites to online events. We’re so grateful to all of you who have joined our Patreon community already. Anyways, keep looking up. This has been Astronomy Cast.

1 Comment

  1. The Space Development Network has a set of web pages and space conference videos discussing the various aspects of ISRU.


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