“Houston We Have a Podcast” is the official podcast of the NASA Johnson Space Center, the home of human spaceflight, stationed in Houston, Texas. We bring space right to you! On this podcast, you’ll learn from some of the brightest minds of America’s space agency as they discuss topics in engineering, science, technology and more. You’ll hear firsthand from astronauts what it’s like to launch atop a rocket, live in space and re-enter the Earth’s atmosphere. And you’ll listen in to the more human side of space as our guests tell stories of behind-the-scenes moments never heard before.

Episode 55 features John Gruener and Steve Hoffman who discuss in-situ resource utilization (ISRU), the ability to find and use natural resources beyond Earth. This episode was recorded on May 23, 2018.

Transcript

Gary Jordan (Host): Houston, we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center Episode 55, “Living Off the Land.” I’m Gary Jordan and I’ll be your host today. So in this podcast, we bring in the experts, NASA scientists, engineers, astronauts, all the coolest people. We bring them right here in the show and talk about all the coolest information that’s going on right here at NASA. So today, we’re talking about in-situ resource utilization. Here, we call it ISRU. This is the ability to find and use natural resources beyond Earth. I’m especially excited for this episode because ISRU is how we’re going to terraform other planets and make them habitable for humans to live. Planet colonization opens up a whole new world of space exploration. How will we derive the resources we need from the bare landscape of the moon? How will the first Martian colonies survive? Such an unforgiving environment. And most importantly, will they miss Netflix? So today, we’re talking to John Gruener and Steve Hoffman. John Gruener has been at NASA since 1986. He currently works in Astromaterials Research and Exploration Science.

This is the ARES division, A-R-E-S. He works on advanced mission planning for the future human and robotic exploration of the moon and Mars. In the past, he’s worked for mineralogy laboratories developing a mineral-based substrate for the plant growth and regenerative life support systems. He also supported the Mars Exploration Rover Missions of Spirit and Opportunity. Gruener can be described as not only a rocket scientist but also a systems engineer, a space farmer and a planetary scientist. Steve Hoffman received a bachelor’s, master’s and doctorate in Aeronautical and Astronautical Engineering from the University of Illinois and he has 35 years of experience in the space industry. He’s been involved with everything from program management to spacecraft design to orbital mechanics. And he now supports the Exploration Mission Planning Office here at the Johnson Space Center. And he supports a variety of missions for human exploration beyond low Earth orbit with a particular focus on Mars. Obviously, both of these guys are the real deal. So with no further delay, let’s go light speed and jump right ahead to our talk with John Gruener and Dr. Steve Hoffman.

Enjoy.

[ Music ]

Let’s do it, yes. Seriously, let’s go straight from there because that leads into — that’s the whole point. ISRU spells out in-situ resource utilization, right?

John Gruener:That’s right.

Host:It just means living off the land. You got, you only have so much you can bring so what is there that you can utilize, that you can turn into something useful? And it sounds like you already have a lot of ideas about ISRU, right?

John Gruener:Yes, for both the moon and Mars.

Host:Both the moon and Mars.

John Gruener:You know, Steve just mentioned the atmosphere on Mars. Of course, the moon has no atmosphere. And so what you’re looking at are the rocks and soils are for the longest idea, the longest time, we thought, you know, that’s what we’re going to use on the moon, the rocks and the soil. And just recently, within the last 10 or 15 years or so, we’ve had measurements of water ice in the polar regions of the moon, right. So now, it’s not just rocks and soils anymore. Now, it’s ice. And of course, water is going to be the most critical thing out there in space for people. A lot of people say it’s going to be more valuable than gold. Because, of course, we need water or we die fairly quickly. You can split water into hydrogen and oxygen and we need that oxygen to breathe or we die very quickly. And hydrogen and oxygen are great rocket propellants. So water is going to be, you know, hugely important out there and there are science fiction TV shows on television right now and at the movie theaters that focus on this theme of resources and people battling over resources and all that.

So they’re going to be critically important. So we’re really happy we found water on the moon because there’s a way to make water on the moon out of the rocks and the dirt, right.

Host:Yeah.

John Gruener:The more —

Host:The rocks and the dirt that are everywhere or just in the polar regions?

John Gruener:All over the moon.

Host:Oh.

John Gruener:Right, yeah, so the Apollo astronauts brought back about 800 pounds of rocks and soil when I was a little kid. And scientists measured those and you learn about all the chemical elements and the minerals, right. So it’s really the mineralogy that’s important. And most of the minerals on Mars or on the moon are silicate minerals, right. And so, part of those silicate minerals is a lot of oxygen, all right, like 40, 45% by weight oxygen just sitting in those minerals.

Host:Wow.

John Gruener:The problem is you have to break the chemical bonds. So those oxygen are bonded to silicones and are bonded to irons and magnesiums and calciums. So you got to break these chemical bonds which require lots of energy, okay. And so it’s like, well, yeah. We can make water on the moon out of the minerals. The hydrogen comes from the solar wind. So since the moon has no magnetic field like the Earth does, you know, in school, we all learned about this thing called the geomagnetic tails or the radiation from the sun hits our magnetic fields and then kind of goes around, kind of like a teardrop shape. So they — the magnetic field protects it from all that. Well, on the moon, since there’s no magnetic field, that solar wind is just hitting the surface of the moon all the time. And a huge constituent of the solar wind is hydrogen, right. And so you have hydrogen slamming into the moon and being retained by the soil and the minerals on the moon. You have oxygen. So now, you have all you need to make water, right.

And not only are we finding out that there is water ice in the polar regions but we’re finding out there’s not quite water but hydroxyl. So that’s kind of a water ion, O and H, but it could be water as well but mostly hydroxyl. Just by the combination of that solar wind when hitting these minerals, finding oxygen and making these little bonds. So there’s small amounts of hydroxyl and possibly water all over the moon. And of course, we didn’t know any of this until we started putting robotic satellites in orbit starting in the mid-90s and then all the way up today. We have lunar reconnaissance orbiter around the moon right now.

Host:Right.

John Gruener:And one of the instruments on there is the neutron spectrometer looking for that water ice. We have a UV spectrometer looking for that water frost, you know, in some of these regions. So water is critical and we have it at the moon now. So that would probably be one of the very things people working in the in-situ resource utilization field, the ISRU field — water production will probably be one of the first things people will try to do. Because if you have water, you can now sell water, right? And you don’t really care what your customers use it for. If they want to use it for rocket propellant, that’s fine. They want to use it for life support consumables, that’s fine. But just having that commodity of water and being able to sell it or use it is going to be really important.

Host:Well, first, you got to make it and then you can do the other stuff.

John Gruener:You have the other stuff —

Steve Hoffman:But see, that’s a — there’s sort of a chicken-and-egg problem there, too. If you’re going to sell it, you have to have a customer for it but the customers aren’t going to show up until they know that they have this stuff there.

Host:So you’ve got to have the capability first.

Steve Hoffman:Well, it’s a chicken-and-egg problem.

Host:Yeah.

Steve Hoffman:So who now, it’s somebody has got to start. One, there’s got to be either a customer there with a demand for it and then somebody will follow and fill the demand. Or somebody’s going to demonstrate that they can do this and have that commodity ready to go or at least have the technology ready to go. So that the customers, the people who are going to generate demand will feel confident enough that they can, you know, invest whatever else they have to do to go there and use this stuff. The way we usually get around that is some, usually a government or a research field of one sort or another breaks or takes the first leap. Some organization that has enough resources that they can invest in something like this without having to answer to stockholders or other investors for a return on that investment. And demonstrate that they can do this sort of stuff. Now, so there’s a big risk but there’s a big payoff in that sort of thing. And so whoever demonstrates this first and demonstrates not only can you do it which we kind of know we can do it, but has — puts that chemical plant in place that actually takes all these dirt and other things and turns it into a bottle of water, that organization is going to get a big payoff.

Now, if it’s a government — governments usually are magnanimous about this and turn it over to somebody else to use. But there could be other people or could be other investors, people with enough resources to do this on their own, that they may just go off and do it on their own. And you know, they’ll reap the reward in doing that.

Host:Now, is the reward specifically for space travel or are there Earth applications that may be part of this investment, I guess?

John Gruener:It’s tough to make people who looked at that for a long time and it’s tough to make a case, mainly because of the transportation cost. You know, if you’re talking about — so take water as our example again. You can go down to the grocery store and buy, you know, a case of water for five bucks. If you had to pay for all the transportation cost to get water from the moon, back here, put it in bottles. It’d be a lot more than five bucks for that case of water. So that’s what I mentioned before, sort of a rule of thumb for ISRU is to use this stuff as close to where you’re producing it as possible. So you minimize, if not eliminate, that transportation cost piece of the whole equation.

Host:So he’s talking about, so when you’re talking ISRU, you’re talking about turning, getting water specifically from the moon. It’s not like you can take that same technology of creating water on the moon and bring it to Earth because the moon has — is made of different things.

John Gruener:And we don’t need to.

Host:And we don’t need to.

John Gruener:We are a water world, right?

Host:Yeah but still extracting — well, I mean, maybe not. Maybe not water in this case. You’re right, because we’re a water world. But extracting resources from there. They’re living off a land component.

John Gruener:So there are other resources people do talk about bringing back to the Earth. One of them is helium-3. Helium is also a part of the solar wind so it constantly is embedded into the lunar surface. And some day, you know, if we can ever develop fusion reactors versus our fission reactors that we have today, the people that work in that industry say that helium-3 is a great fuel for fusion reactors, right. And so that’s something that somebody like Apollo 17 astronaut Jack Schmidt, he likes to talk a lot about helium-3. The Chinese National Space Agency right now and the Russians also talk about helium-3. My time with helium-3 is when I was in college back in the ’80s, we were — they were, you know, digging a big hole at the University of Texas and they were going to put a Tokamak reactor and fusion energy wasn’t going to be solved. Well, here we are in 2018 and we’re still not close to producing fusion or you know, making fusion reactors that really work.

So helium-3 is talked a lot about. You’ll see that in the press, you know, in bringing back that to Earth. Some people talk about bringing a platinum group, metals back to the Earth primarily from asteroids and rare Earth metals that you use in the semiconductor business in batteries and things like that, you know. Because those are hard to find and precious around the Earth. So those are the kind of things people do talk about bringing back to the Earth. Not so much water.

Host:So it’s not necessarily the resource itself from — I guess, is it fair to say that there’s plenty of helium-3 to provide fuel? It’s just the technology isn’t quite there yet to actually do something with it.

John Gruener:To do something with it, that’s right. So the helium-3 is sitting there on the moon, waiting for us.

Host:Yeah.

John Gruener:Waiting for the technologies to mature. And I don’t remember, Steve, maybe you know that somebody back in the, you know, when the Shuttle was flying, they talked about a Shuttle payload bay where the helium-3 would power the United States for, I don’t know, how many days or months but it was, it was pretty incredible.

Host:Wow.

Host:So it’s —

Steve Hoffman:Probably more than that.

John Gruener:Yeah, it’s a pretty neat fuel source if we ever get that fusion reactor technology developed.

Steve Hoffman:It doesn’t take much to generate a lot of power from nuclear sources like that. So yeah, a Shuttle payload bay folder stuff would probably — it’s more like years or decades it could power.

John Gruener:So just to follow up on this water on the moon —

Host:Oh, yeah.

John Gruener:You know, the reason we like the pole so much is because water is already there in the form of ice, all right. So we had a spacecraft called LCROSS. It flew out to the moon with Lunar Reconnaissance over the back in 2009. And LCROSS was a really fun little mission where people over at Ames Research Center, they had two spacecraft and they basically smashed one into a permanent shadowed, you know, permanently dark area of the moon where we’re pretty sure there was water ice. A plume of all sorts of volatiles escaped into space because of that high-energy crash. Another spacecraft threw through the plume. It measured what was in it. And the most abundant compound was water, right. So we have ground truth that there is water ice at the poles of the moon. And the neat thing about that is we only have to heat the dirt up a few hundred degrees to volatilize or you know, get that water, melt it, vaporize it and collect it.

Earlier, we were talking about using the rocks and minerals and breaking chemical bonds. That requires thousands of degrees of energy, huge amounts of kilowatts of power. So the promise of the water ice at the moon is it’s already there. We can get to it with small amounts of energy versus the large amounts where you’re breaking chemical bonds. But the moon, the environment there in the polar regions very extreme.

Host:Yes.

John Gruener:I mean, in the — so on the Earth, we have, you know, our axis of rotation is tilted and we have seasons. And so, unfortunately, here in Texas, we’re moving into summer because we’re pointing at the sun.

Host:Oh, feeling it already.

John Gruener:Yeah, well so the moon’s axis of rotation’s almost perpendicular, straight up and down to the big ecliptic plane. That plane where all the planets orbit the sun, right? And so, you could imagine the moon at the equator, the energy from the sun, the sunlight is just coming straight overhead. It’s really intense. But as you go up in the ladder to these are the North Pole or the South Pole, now the energy from the sun is more of a glancing blow. And now you get to the very poles of the moon and now the energy of the sun is going parallel right across the surface. I don’t know if you remember your geometry class in high school? But when the intersection of a curve and a line —

Host:Tangent?

John Gruener:The tangent, there you go.

Host:Oh, I remember.

John Gruener:That little bitty point, right? So imagine you’re sitting in a hole at the poles of the moon, a crater, if you will. Well, that sunlight’s going to cross parallel to the surface. It’s never going to get into your hole.

Host:Yeah.

John Gruener:And for about two-and-a-half billion years now, we think there are these craters in the polar regions have been permanently shadowed, very, very cold. I mean, colder than Pluto cold, you know. People are always thinking Pluto is the coldest thing in the solar system because it’s way out there. But Pluto’s actually receiving sunlight and reflecting that sunlight. And that’s why we can see Pluto. These craters never get sunlight so we’re talking, you know, 25, 30 Kelvin.

Host:Oh.

John Gruener:That’s just barely over absolute zero.

Host:Yeah.

John Gruener:All right. So the challenge is from the engineering standpoint. Great, we have water ice in these permanently dark, very, very cold places. Now, build me a robot that can work in that environment, you know.

Host:So this is probably freezes that [inaudible].

John Gruener:Yeah, yeah.

Steve Hoffman:But these metals will just crystallize and you, they’ll just shatter like a piece of glass.

Host:Wow.

Steve Hoffman:I mean, so those cold temperatures are part of the biggest deterrent from doing what can be as simple as heating up the soil and just collecting the vapor that comes off it. So the technology of gathering that water is very simple but the materials that you need to survive in that environment are something that they’re very challenging from what we can get out of it.

John Gruener:Yeah, folks out of the Jet Propulsion Lab are working on something called bulk metallic glass instead of metal so you can build gears and structural components out of this stuff and it can better withstand these really, really cold temperatures. So scientifically, we know the stuff’s there. And we kind of have an idea of where to go. Now, we don’t really know how deep it goes into the subsurface. All of our remote sensing instruments can only get down, you know, less than a meter. The LCROSS impact probably went down only three to five meters. So understanding the subsurface amount so in the mining world, they call it grade and tonnage, you know. How pure is it and how much of it is there?

Host:Right.

John Gruener:Because a lot of it is going to have to be there to be economically feasible or if we’re really going to use it for rocket propellants. You know, if you have one cup of water out in the middle of the desert, that’s not going to last you that long. But if you have a whole oases out in the desert, that’ll last you quite a while.

Host:Yeah, because if you’re talking about a surface mission, let’s say, you’re bringing humans down to the surface, maybe near the poles. I don’t know if that would be feasible or if it would be too cold there. But not necessarily in the crater where it’s 30 Kelvin but if you’re near the source of where you can produce the water, is there enough to get something out of it, to create enough oxygen, to create enough water and to create the propellant that we need?

John Gruener:That’s what we have to find out and so, in the economic, you know, the mineral world of mining companies, you know, that phase is called prospecting. And so, we have a lot of data sets from orbit from our remote sensing but we have to get robots down to the surface to do ground prospecting so we can get a better idea of the grade and tonnage of this stuff to see if it really even makes sense to pursue it. But so you know, you talked about people landing. I mentioned, you know, these holes, these craters at the polar regions that are permanently dark, permanently cold. Well, so think just the opposite, so now I’m at that tangent point between the line of the circle and I’m not in the hole anymore. But now, I’m on a mountain peak. And what are you going to see? You’re going to see the sun just about all of the time, okay. So there are a handful of locations both at the North and the South Pole that sees the sunlight almost 90% of the time. So most places on the moon like all the places we visited with Apollo, you wind up with two weeks’ worth of daylight followed by two weeks’ worth of darkness, right.

And that’s your typical lunar day on the moon, if you like. And that’s all because of the orbit of the moon around the Earth. But again, when you get to the poles and you have that perpendicular axis of rotation, that whole two weeks of darkness and two weeks of sunlight goes right out the window and now it’s all based on topography. So on the high points, you’ll get a lot of sunlight. The low points, you’ll get a lot of darkness. So the idea is for people to land and work and live in the high points where there’s sunlight. And now, we can use solar rays, just you know, like on the space station, we have these really tall rectangular solar rays. You put something like that on the surface of the moon at the poles and you know, you jack it up into the sky. Now you can receive sunlight 100% of the time.

Host:Yeah.

John Gruener:So the people are living in the sunlight, getting energy from the sun with solar rays. So that’s very low tech. You know, we don’t need nuclear reactors for that. And then you’re sending your robots into the dark to harvest the water ice. That’s kind of the grand picture someday. But first, we have to do the prospecting to find the stuff in useful quantities. We got to do the technology development.

Host:Right.

John Gruener:To see if your machines can even operate in those very cold temperatures. And then we have to have the human systems as well.

Host:So where are we now? You hinted at the beginning that we have been looking at ISRUs since the ’80s. But how about technology? Have we sent anything into space? Have we tested stuff from the ground?

John Gruener:Just we have one experiment. I’ll let Steve talk about this, getting ready to go to Mars on Mars 2020 called Moxie, right. And it’s all about making oxygen out of the atmosphere at Mars. So you tell it.

Steve Hoffman:[Inaudible] well, to back up one step though. The technologies that we’re talking about using for many of these concepts, whether it’s heating up or breaking up chemical bonds or just heating up the ground and capturing the water, a lot of that stuff is technology that’s been used on Earth for, you know, decades, centuries —

John Gruener:Centuries.

Steve Hoffman:In some cases.

Host:Oh wow.

Steve Hoffman:So the —

John Gruener:But in space, nothing. So we haven’t done any of these demonstrations in space yet. Moxie will be our first.

Steve Hoffman:So on Earth, we can afford to have giant chemical plants and when something breaks, it’s very easy to go fix it. When you send something into space, right now we don’t, it’s usually a robotic device without any people around. And so if it breaks, you’re done. So we have to — we have to — and launching stuff off the surface of the Earth and getting it to some other destination requires a rocket of some size, usually quite large compared to the payload. So when you talk about taking those technologies that have been used on Earth for centuries in some cases, and sending it somewhere else, now we’re talking about the engineering to make that thing very small, very light and very reliable so that you can operate it for very long periods of time without — with the expectation that it’s not going to break.

John Gruener:And when I talk to school kids and I say, you know, we have hundreds of thousands of equations at NASA. And fortunately, I’ve forgotten most of them. Because I’m 57, I’m, you know, I’m going to be in this another five, six, 10 years maybe. But the most simplest equation and the most simplest concept to remember is mass equals money, right. If you want to send a lot of mass into space, you better have to have a lot of money, because you need this big rocket that Steve was talking about, right. We never have a lot of money so we try to minimize our mass as much as possible. So you’re not going to see big front-end loaders like you know, you go to a construction site here on the Earth and you see these huge vehicles. Big massive vehicles with big rippers and front-end loaders and drag lines. We can’t do that on the planets because we don’t, we can’t get all that mass to the planets in the first place.

Host:Right.

John Gruener:Way too expensive. So our robots are going to be smaller, nimble, more agile, right. And you’re just going to have to accept a slower pace of accumulating the resources than we do here on Earth where we have these big monster vehicles that can, you know, dig up a whole baseball field in one big scoop. We’re just — we don’t have the — you know, where the tyranny of the rocket equation. We just don’t have the money to afford a huge rocket to send big tractors and bulldozers to the planets.

Host:How nice it would be though to have a moon bulldozer. That would be pretty nice.

John Gruener:That would be cool.

Steve Hoffman:All right, so he mentioned something called Moxie.

Host:Right, yeah.

Steve Hoffman:What are things on Mars that we have — that’s on Mars that we don’t have on the moon is an atmosphere. And that atmosphere is very thin compared to here on Earth. It’s — to find a similar pressure and density here on Earth, you’d have to go out to an altitude of about 100,000 feet. So it’s very, very thin. But it’s there. So that makes it something that we can use. It’s mostly carbon dioxide, about 95% carbon dioxide. Most of the rest is nitrogen and then there’s traces of other stuff. So when we talked about using water for rocket propellant, we’re also looking using that atmosphere to make at least part of rocket propellant for a human mission. We can all see but you could also use that for robotic missions. We’d like to do a sample return from Mars, for example. So the rockets don’t care if the payload on board is a rock or a human being.

It’s just its mass that the rocket is moving around.

Host:Right.

Steve Hoffman:They both use rocket propellant. Moxie is a way to get oxygen out of that carbon dioxide and with the idea that that would be half of the two kinds of rocket propellant that you need to get something off the surface.

John Gruener:And so for rocket propellants, you have a fuel and you have an oxidizer. So here on the Earth, you know, we talked about earlier that Earth’s a water world. Well, here on Earth, we have oxygen in our atmosphere. So the good old, you know, internal combustion engines in our cars and in our lawn mowers and everything else uses the oxygen in the atmosphere as an oxidizer to get that fuel oxidizer combination going. And you get, you know, energy out of that. But we don’t have —

Host:But you can pull it straight from the atmosphere.

John Gruener:That’s right.

Host:Yeah.

John Gruener:That’s right. So we, you know, we don’t need oxidizers here on the surface of the Earth.

Host:Right.

John Gruener:But we do out there on the planets and Steve, what’s that gear ratio usually between oxidizer and propellant? Like seven-to-one or six-to-one usually?

Steve Hoffman:It depends upon which combination you’re using. But it’s mostly in the — for the combinations that we want to use on Mars is mostly oxygen. So it’s to our benefit to be able to make oxygen there.

John Gruener:And even if you can’t make the fuel there, you make the oxygen, you just satisfy the bulk of your propellant needs.

Steve Hoffman:And in this case, it’s on, it’s in the 70% to 80% range of the total mass that you need for a rocket to get off the ground. So I can bring the 20% of fuel and in our case, what we’re looking at now is methane. But we’ll make the oxygen while we’re there. We know where the atmosphere is. It’s everywhere. So it doesn’t restrict us to where we can land. John was talking about these ice fields being at the poles. So that constrains us to land at one of the pole on the moon if we want to use [inaudible] — excuse me, if we want to use water. On Mars, at least for the oxygen part, we can land wherever we want to. And we can use a device similar to Moxie to pull that oxygen or pull the atmosphere into the device. You separate out all the dust and the nitrogen and the other stuff that you don’t want. And you take that carbon dioxide and then you use processes that we understand well from doing the same thing on Earth.

Separate it into carbon monoxide and oxygen and keep the oxygen part. And you’ll let the other rest of it go. So Moxie is the first. We know how that technology works. We haven’t demonstrated that we know how to do it from a practical point of view in an environment like Mars. So Moxie is being flown on Rover that’s going to be launched in 2020. It’s job will be to do that actual demonstration that says, “Okay, in this real environment with real dust and impurities and other things and temperatures, all that sort of stuff that goes into actually making this thing work for real will be there and we’ll run Moxie to demonstrate that we can at least do that part of collecting the atmosphere, filtering out the stuff we don’t want and then getting the oxygen out the back end that we can use.

Host:Is there a storing component? You would grab the oxygen and then kind of put it into a tank?

Steve Hoffman:Eventually.

Host:Okay.

Steve Hoffman:I don’t — I think Moxie and now I’m trying to remember where Moxie — I do not think will store that but eventually, we’ll have to store it somewhere.

Host:Yeah.

John Gruener:So at the very beginning, you know, we mentioned the prospecting part of finding resources. The other part, the technology part is demonstrations.

Host:Yes.

John Gruener:So for the next decade, you know, that’s kind of where we are in the world of resource utilization and understanding what resources are available on the moon or Mars. It’s all about prospecting and demonstrations and mostly robots. You know, we won’t have people on the moon for quite a while. We won’t have people on Mars even longer. So it’s going to be a lot of robotic technology demonstrations at sites where certain resources are where you know you can turn those resources into certain products. You know, it’s all about getting to the useful product eventually.

Steve Hoffman:But there — so there’s another example though of things that are going on, on Earth that will eventually adapt in some form for these other planets. A lot of the mines, the big mines that you see on Earth are becoming more and more automated. The trucks are driving around on their own. There’s no driver on board. Some of the machinery that’s digging things out of the ground are just supervisors. Nobody in there pulling levers or steering the machine anymore. It’s somebody watching on the screen to make sure that it’s digging in the right spot and hasn’t gone off somewhere else where it’s not supposed to be. We can take that same kind of technology that we’re learning how to do and working all the bugs out here on Earth, and then miniaturize it and improve its reliability. And then we can send it off to the moon or Mars and have those robots do a lot of the work that used to take people here on Earth to do in a more intensive fashion.

Intensive in the sense that they had to have a lot more people to make this thing work. Now I don’t have to have a lot of people anymore. And in fact, I’ve got the people here sitting on the Earth and instead of watching a mine that might be in Arizona somewhere which they can do, now I’m sitting on Earth and I’m watching a mine that’s on the surface of the moon. Or I’m sitting on Earth and I’m watching a mine that’s working on the surface of Mars. And until there’s something that the robots themselves can’t handle and we have to send people to correct that situation where there is something broke or something unexpected happened, we can sit here on Earth and we can have our minds working on these other planets, making these commodities that — that will then be available when people actually do go there for whatever reason they’re going there for.

Host:Right, so robotically, we would sort of develop the infrastructure to eventually support a human mission. Assuming that if we do send humans to, let’s just say, Mars in this example. If we send humans to Mars to live, we can expect that the mining operations will have been tested, demonstrated and you have these tanks of oxygen and water and rocket propellant and everything.

Steve Hoffman:Well, we’d like to hope so. But just like Moxie, the Mars environment is not the Earth environment. So we’ll have to do, as John said, we’ll have to do demonstrations to convince ourselves that we know what we’re talking about or we know we can do what we say we can do. Then it’s a question — we’re back to that chicken-and-egg kind of question. When do you, when do I start building a mine because that’s going to require a lot of investment to be able to do that, if there’s nobody there? I mean, if there’s no — if there’s no demand on the moon or on Mars for this whatever you’re making in this mine, why are you building the mine?

Host:Yeah.

John Gruener:So there has, they’re going to probably evolve or expand or get in place more or less together. I mean, they’ll probably be a little mine, a little group of people that get, turns into a bigger mine and a bigger group of people. And they’ll just kind of grow together as demand grows and the suppliers will have to grow with them and vice-versa.

Host:John, I wanted to ask you about the simulants that you’re working on because —

John Gruener:You’re right, I was just going to jump in here because —

Host:There you go.

John Gruener:— we’re talking about all these technology demonstrations in space. And of course, when you’re building hardware, you want to understand what’s going to happen when it gets all dusty. Are the hinges going to work?

Host:Right.

John Gruener:Or are the shock absorbers, things that move in and out, are they going to work? And you know, though we brought back about 840 pounds of rocks and soil from the moon, we’ve never brought anything back from Mars. Now, Mother Nature always done that for us through meteorites, right, so we have an idea of maybe what some of that stuff’s like on Mars. We also have our robots on Mars making those measurements. But we don’t just have planetary materials to give out to the technology world to help them with their machines in developing their robots. So what we do in the planetary science world here in the Astromaterials Division at JSC, we look at what we found on the moon and Mars. And we look at the chemistry and the mineralogy. And then we look around the Earth, mainly the United States because that’s where we are and we find rocks and minerals and soils that are similar in composition, similar in mineralogy and then we’ll go and collect those in the fields.

We’ll grind them up into you know, very, very tiny particles so that they mimic the particle size that are on the moon or Mars. And now, we have a bucket of fake moon dirt or fake Mars dirt that we can give to our technologist to test their systems and to see how it’s really going to work. So you know, the challenge of that is you can’t just go to the store and buy one bucket of moon simulant because the moon’s a very diverse planetary body, just like Mars is. And so, there are numerous different simulants you could design and you know, recipes, if you will, for certain processes. You know, so like right now, we’re working on a Mars simulant that simulates a very specific windblown deposit on Mars called Rocknest. You know, our Curiosity Rover’s on Mars. It measured this dune-like looking thing that was called Rocknest. They put it in an oven. They cooked it and they wound up with about one to three weight percent water.

Host:All right.

John Gruener:So they said, “Oh, cool. There’s water right there in the sand dunes of Mars, you know.” Now, of course, there’s also water ice all over Mars. So you know, water’s going to be a lot easier on Mars than the moon. That’s for sure.

Host:Nice.

John Gruener:But the ISRU guys, the technologists wanted to design something where they could easily dig into a sand dune, cook it and boil the water out. So we, you know, just recently were working on a simulant that will produce one to three weight percent water out of the same chemistry and mineralogy of Rocknest on Mars, right. So that’s a very specific simulant. You look back at the moon in the night sky. You see the dark areas. You see those bright areas. All those dark areas are just basaltic lava flows. I mean, the same stuff that on the news right now coming out of the ground in Hawaii?

Host:Right.

John Gruener:Yeah, same stuff as that’s those dark areas on the moon, all right. And so, a lot of iron. A lot of magnesium on the moon, something called titanium and a mineral called ilmenite. So you know, everybody knows about titanium. You know, that stuff’s strong. You see it advertised on TV. Well, if you want to do a process to mine the dark areas of the moon or the Maria regions so its lava flows. Now you’re going to need a different simulant than you would, say, for the polar regions where now you’re talking about the bright areas of the moon. So you know, you look at the bright areas of the moon and that’s not lava at all. That’s a feldspathic mineral called anorthosite. So a lot of calcium and aluminum whereas the basalts were mostly, you know, iron and magnesium and things like that. So the simulant business is kind of tricky because sometimes, NASA is really interested in the moon for a while. And so we’ll think about moon simulants. And then sometimes, NASA is interested in Mars for a while and so we had to come up with Mars simulants, right.

And there’s not just one simulant for the moon and one simulant for Mars. There’s all sorts of simulants for all sorts of processes. So that’s one of the things we do at the Astromaterials, you know. We have the Mars scientists that are actually doing the experiments right now on Curiosity right in our building. And so I work with them to find out, well, what is the chemistry and what is the mineralogy? How can we find stuff like that here in the United States and make it available to our technologists? So it’s a pretty fun project. It’s a great mix of science and engineering.

Host:Yeah and you would think, you know, looking at the moon. I mean, if you didn’t know the intricate details of the moon like the mountains and the different regions, you would just think, “Oh, any kind of — any kind of technology you produced to grab water out of the moon is going to work universally around.” But it doesn’t seem like that at all. It seems like wherever you put it, you’re going to need a different piece of technology because you’re dealing with a different dirt, I guess.

John Gruener:That’s right, yeah. Different geologic deposits.

Host:Yeah. So besides — so going to the moon for just a second, talking about all of these different areas, we talk about water being one of the main things you would want to pull from the dirt. You pulled the oxygen from the dirt and then the hydrogen, like you said, from the solar winds. So you’re getting a little bit of that. What else could you pull from the dirt of the moon to make useful for something else?

John Gruener:So for a lot of years, people have talked about using those silicate minerals, you know, so like I said, most of the moon is silicate minerals, using the silica and those silicate minerals to make solar rays.

Host:Oh.

John Gruener:So you process the moon soil. You make your solar rays and now, you’re generating electricity with these solar rays that you made out of lunar materials, right. So the silica could be used for that. The iron that we were just talking about in the lava flows, of course, is the structural thing. The titanium in those lava flows is a structural thing. And the bright areas of the moon, the highlands, you have a lot of aluminum so again, there’s a big structural thing. There’s something I’m just learning about as we’re trying to find sources of simulant materials to represent the highlands of the moon. There’s something in the world called E-glass. Steve, I don’t know if you’re familiar with E-glass. But it’s a structural thing. So you know, we think of skyscrapers being made out of steel girders or we see aluminum panels on the side of barns and such. E-glass made out of the highland materials of the moon may be a structural component someday. So structural things like that, volatile things like the water and the oxygen.

And one thing we haven’t talked about and one thing I spent a lot of my life in the 1990s doing was growing plants in simulants of planetary soil. Because if we’re ever going to have people there, we got to feed them, right?

Host:Oh, yes.

Steve Hoffman:That’s the beauty of robots. You don’t have to feed them. You don’t have to water them. You don’t have to bring them home to their families. But we do all of those things where there are the astronauts, right?

Host:Right.

Steve Hoffman:And so —

Steve Hoffman:But one of the things that the moon is deficient at is carbon. And carbon is going to become an important constituent if we’re going to go down that path. So I mean, that — there’s an example of something where we’re going to have to import a critically needed material to be able to pull off some of these kind of debt — the crop growth, the animal growth, the feeding the human beings that are there kind of situation.

Host:At least, for a moon mission though. On the Mars, I think you’ll have more carbon.

Steve Hoffman:On Mars, we’ll probably have all the constituents we need. Although John can — John the moon farmer and Mars farmer can tell you that that we can’t just — you can’t just take a shovelful of dirt and put it in a bucket and grow things like was done on the [Inaudible]. You do have to remediate that soil. You do have to take out some other things.

John Gruener:Take out the bad stuff.

Steve Hoffman:The bad stuff before you put your plants in it. The best stuff that could either harm the plants or harm you, if you eat it because the plants take it up and then you consume it. So ISRU is not a universal catchall. There isn’t everything everywhere that we need it. There are still some things that we are going to have to bring with us to make supporting human beings for long periods of time and so plants make that possible.

John Gruener:Yeah, so in the geology world and in the Astromaterials Division where I work, when we were growing the plants, we were trying to come up with a substrate that would incorporate either the soil on the moon or Mars. And so we had to work with the plant people, right. So find plants that can grow in the types of soils and maybe do better with some nutrients. So I had to learn all about biology, you know. So my first degree was Aerospace Engineering because I thought, “Oh, well I want to work in NASA. Well, I better be an aerospace engineer.” That sounds very NASA, right?

Host:Right.

John Gruener:But after about six years or so and working with Steve way back in the late ’80s and early ’90s, part of my job was to go talk to the scientists and find out what they want to do on the moon so we can provide those systems for them, right? And as I started talking more and more to the planetary scientists, I thought, “Wow this is really cool stuff.”

Host:Oh, yeah.

John Gruener:And so I went to night school to get my Planetary Science degree. But it was all geology and so now I had to learn biology all of a sudden because now I’m working with the plant people and growing stuff in the soil on the moon or Mars. And so, then I had to learn about, you know, so I learned chemistry. We all learned chemistry, right? But the 17 plant essential nutrients, do you happen to know what those are?

Host:Oh no. I couldn’t list them for you.

John Gruener:It turns out plants only need like 17 different chemical elements and they’ll do pretty well, right.

Host:All right.

John Gruener:And we had those broken down between macronutrients and micronutrients. And Steve mentioned carbon so that’s one of the macronutrients. So hydrogen, oxygen, carbon. You know, those things we don’t worry about in our fertilizers here in our soil because it’s in the air and the water, right? Hydrogen and oxygen, that’s our water. And then we all learned about photosynthesis and how plants take in CO2, right? So as long as you have CO2 on Mars or you have astronauts on the moon exhaling CO2, we’re going to get the carbon we need from the astronauts, right, through that CO2.

Host:Nice.

John Gruener:So just by the fact of having people on the moon or Mars, we’re going to get our hydrogen, oxygen and carbon through the air and the water. Now, the other things is where the soils come in, right. So if you ever looked at a bag of fertilizer, there’s three big numbers like 15-5-10 or 13-13-13. Those are nitrogen, phosphorus and potassium, right. We know those things are on Mars. There’s the problem with the nitrogen on the moon. But again, we have those astronauts there. And when we go to the bathroom, there’s lots of nitrogen in what we put out of our bodies, right?

Host:All right.

John Gruener:Our water systems in our regenerative life support world will take some of that dirty water, what we would, you know, consider dirty water. We couldn’t drink the stuff because it’s full of ammonium. Well, ammonium, NH4 — great, there’s nitrogen. So again, if astronauts are there and they’re doing their usual human things, they’re going to supply us nitrogen through the waste products, right? And so now, we have the nitrogen from the humans. The phosphorus, potassium — they’re on the planets. The other macronutrients, calcium, magnesium, sulfur are on the planets. And then you get into the micronutrients, the irons, the zincs, the coppers, the molybdenums, the borons. All those things we have measured both on the moon and Mars. So are all those chemical elements, those plant essential nutrients that we need, are on the moon. They’re on Mars. But not everywhere. So you want to go to your best places. So on Mars, I don’t know if you’ve ever seen pictures from Curiosity or some of those but there’s these very dark-looking sand dune looking things, right.

And those are basically basaltic sands that have weathered out of basaltic rocks. And the reason they’re dark is they have not had many of their chemical elements leached out of them. So we have that problem on Mars going for us, that we have acidic leaching of some of the chemical elements, right. But those dark basaltic sands, what a great substrate for growing plants, you know. The moon, we can get by. We have what we need on the moon. But probably not as good as Mars. So you know, this whole idea of simulants and using the soils for plants, for our resource utilization, it’s really, really a big picture, you know, [inaudible] in your mind. Sometimes, it makes your head explode. And there are so many different disciplines and you know, and technologies working in this area both on the science side and on the engineering side.

Host:Yeah, because I think one of the more interesting parts of when you’re starting to describe these things is it’s not as universal as you would probably assume. If you’re talking about Mars dirt, Mars is a planet. Planets are big. So there’s different things happening in different areas. Maybe in the polar regions of the moon, you have more water. In the darker regions, there’s a different makeup than maybe in some of the lighter regions. So it’s a more diverse way of approaching when you’re thinking about another planet and it’s interesting because you’re going to have to have the technology to have things work whenever you get there.

John Gruener:I’m sure. I mean, very much like here on Earth. My wife’s from Wisconsin. Her family’s a dairy farming family. They have beautiful soil up there. You live here in the Houston area where we got this heavy gumbo clay. And if you’re a home gardener, you got to fight this gumbo all the time.

Host:Oh, yeah.

John Gruener:So it’s this really where you are on the planet, that’s where, you know, drive the benefits from the local resources.

Steve Hoffman:And that’s one of the benefits of these robots that we’ve been talking about was Lunar Reconnaissance Orbiter or Curiosity or other robots that are on Mars. They’re doing part of this prospecting job for us right now. They’re doing the very basics of telling us what it is. If we just saw this dark sand dune in the picture, we wouldn’t know if that was basalt or if it was something else. Now we know what it is and we know, we can kind of break down the chemicals that are in it. And these robots are also telling us that over here, you got a real high concentration of what looks like a high — we’ll pick one of these chemicals. You’re going to find a concentration of it somewhere on one part of the planet but not in the other parts. And these robots are helping us make those maps to tell us that it’s — there’s a real valuable resource over here. But if you go over somewhere else, not so much anymore. So you want to, you can kind of pick your — you can start to look at those maps and decide where it’s more beneficial for you to try and set up one of these bases than not.

John Gruener:Just like the realtors tell you here on Earth. Location, location, location [laughter].

Host:So I kind of wanted to bounce off of that to sort of wrap up this talk is at the theme here is robots are pretty easy. You don’t really have to worry about that but we’re going to have to think about a lot of different ways to support human exploration of the moon and Mars. And ISRU is just one component of the many things.

John Gruener:It’s a huge component.

Host:One huge component of making this work. And so, I kind of wanted to end with why — why explore? Why do we send humans to do this? And why are we putting the effort into ISRU in the first place to make it a possibility and to put human boots on the moon and Mars?

John Gruener:Well, you know, we get that question a lot. And Steve’s jumping at the microphone so I’m going to let him go first.

Steve Hoffman:I was hoping you would [laughter]. Well, the — the robots that we’re sending to these other planets are extensions of ourselves. People have this internal need or drive to understand what’s going on around them, what’s over the next hill, what can — can I go and live there? You know, a lot of us are in the United States because you go far enough back in our ancestry that somebody came from a different part of this world and settled here. They didn’t have to. They could have remained exactly where they were. But they moved. That same kind of drive is going on now. And eventually, that will extend to other planets. So the difference, a big difference between that example of coming from another part of the Earth to the United States is that these other planets are not like the United States or any place else on Earth for that matter.

You can’t just grow there and chop down a few trees or go there, chop a few trees, plant a garden and expect to live there. You have — there’s going to be more work, considerably more work involved in being able to stay there for the rest of your life, if that’s what you choose to do. So we’re making progress along those lines. ISRU is going to be a big part of that. You know, there’s a permanent presence at the South Pole. But no one’s growing — there aren’t acres and acres of cornfields or cattle grazing or —

John Gruener:He’s talking about McMurdo Station at our South Pole [laughter].

Steve Hoffman:Our South Pole, I’m sorry. Actually, I’m talking about the geographic South Pole. There’s a huge station there with a permanent presence but everything has to be brought there. Literally, everything has to be brought there. So that’s not some place where you’re going to see a real estate agent setting up shop to sell you, you know, the four-bedroom family house or something along those lines.

John Gruener:Well, there is that UN Treaty that kind of gets in the way of the real estate agent.

Steve Hoffman:Okay, but my point is that humans know how to live and work in a lot of different places, a lot of hostile environments. So if we’re going to be there permanently, we’re making progress along those lines. Robots are helping us do that now. There’s going to be — to get back to your original question, I think there’s going to be no end of the desire or the drive by somebody or somebodies on Earth to go live on these other planets and live there permanently. We’ve had no end of volunteers that says, “You know, send me. I’ll go on a one-way trip.” So that drive is going to be there and what we’re doing now is working on understanding what that environment’s like so we can tell people what technologies they’re going to need to be able to live and work and to enjoy themselves when they get there. And you know, eventually spend the rest of their lives there.

John Gruener:And so, you know, why we explore it? That’s a very hard question to answer. And a lot of times, it’s the kindergarteners that ask that kind of question because it’s a huge question and it sounds so simple. And I don’t have a real simple answer to that, right.

Host:Right.

John Gruener:But there is no simple answer to that so the past two days, I was at NASA’s Glenn Research Center working on a little project. That’s why we had to delay this little talk. And flying home, there was this woman with her little 18-month-old girl, right. And I was sitting next to the window but boy, that little girl wanted to look out the window. She just [inaudible], you know. She couldn’t say any words but you could just look at her eyes and look at her face and she was amazed at what she was seeing. And that’s just this innate quality in humans, right. We’re curious about stuff. We want to know about things. We want to see new things. We want to experience new things. And that’s what, you know, a part of what exploration is about, learning new things, experiencing new things.

Host:Okay.

John Gruener:But then that practical side that we were talking a little bit, you know, earlier about maybe, you know, platinum metals in space or helium-3 or whatever resources out there that we might be able to use here on the Earth. You know, that drive to try to make life better here on Earth, to supplement what we have here on Earth, so you know, we can keep going is critical, I think, to our species because you know, this is a great planet we’re living on but sooner or later, we will run of our resources. You know, as population gets bigger and bigger. So what are those resources out in space and how can they help us live? And maybe you do have to go live on the moon to utilize those resources or to Mars or you know, like on the TV shows, out at the asteroid belt. Who knows? But you know, that’s hundreds of years from now but we have to start somewhere. And that’s kind of where we are right now. We’re kind of have to start in all of that, you know.

It probably would have been fun to go back in your way-back machine and land in the 13 colonies of the United States and you’re at the start of a country. And way back then, they had no idea what we would eventually evolve to, right? And so, when it comes to space and space resources and people getting out there and living and working for long periods of time, we’re at the very beginning. And it’s really hard to say where it’s all going to go but we know resource utilization is going to be a big part of it.

Host:Exactly. You don’t, you can’t really predict the future but you know that something good’s going to come out of it. And so you just sort of truck on. And that’s why you cross the Atlantic and start colonizing and then you realize that, oh, maybe the, you know, there’s more to this than just the coast. And so you expand west. You know, there’s this — you just do it and eventually good things kind of come from it. Kind of bouncing off your first point, I think one of the biggest things you said was experience. And that I think though, you know, we can send robots. Robots give us a lot of data about what we sent them there to do but in terms of experience, that’s a very human thing. And I think that’s something that is really important whenever you’re actually going out and to other planets and to the moon. You know, like we sent stuff to the moon before humans landed there but it was not until humans landed there that really people latched on and were inspired. I mean, I know a lot of people here were inspired to work here specifically because of in terms of that.

John Gruener:That’s why Steve and I are here.

Host:Yeah, yeah. It’s that —

John Gruener:I’m guessing you weren’t even born during Apollo [laughter].

Host:No, that was a little — that was a little bit long, a little bit ago. But yeah, so it just — it still inspires me though. I mean, I wasn’t alive but it’s something that really drove me to work here and to put my life’s work into it.

John Gruener:Yeah, one of the things we just, you know, throw around cliches always. But you know, you’ve never seen a ticker tape parade for a robot, right? The Apollo astronauts got huge ticker tape parades. They just had a big royal wedding over in England and of course, that was a huge parade, right?

Host:Yeah.

John Gruener:You don’t see that for robots.

Host:Right.

John Gruener:But they’re great tools for us but they’re not humans.

Host:Exactly. Well, John and Steve, thank you so much for coming on and talking a little bit about in-situ resource utilization for us today.

John Gruener:Sure, my pleasure.

Steve Hoffman:You’re welcome.

[ Music ]

Host:Hey, thanks for sticking around. So today, we talked with John Gruener and Steve Hoffman about in-situ resource utilization. I hope you really liked this talk. You can find more episodes on — we’ve actually talked with a lot of folks from ARES. We’ve talked Astromaterials. We’ve talked moon rocks. We’ve talked meteorites. A lot of these talks can be found on Houston, We Have a Podcast so you can check out any of our episodes. Don’t need to listen to them in any particular order but check them out there. Otherwise, you can listen to some of our other NASA podcasts that we have, Gravity Assist, Rocket Ranch, and NASA in Silicon Valley. Go to nasa.gov to find the latest updates on deep space exploration. You can go to ares.jsc.nasa.gov to find out specifically what they’re doing. Otherwise, follow us on social media. We’re the NASA Johnson Space Center on Facebook, Twitter, and Instagram. You can use the hashtag #asknasa on any one of those platforms, submit an idea, ask a question and we’ll bring it right here on the show. Just make sure to mention it’s for Houston, We Have a Podcast. This episode was recorded on May 23, 2018. Thanks to Alex Perryman, Pat Ryan, Bill Stafford, Kelly Humphries, Jenny Knots, Tracey Calhoun, and Thalia Patrinos.

And thanks again to John Gruener and Dr. Steve Hoffman for coming on the show. We’ll be back next week.