EPISODE 144: MINING THE MOON WITH NASA’S IPEX ROBOT

Transcript

Andres Almeida (Host): Welcome to Small Steps, Giant Leaps, the podcast from NASA’s Academy of Program/Project and Engineering Leadership or APPEL. In each episode, we explore the lessons learned and experiences of NASA’s technical workforce. I’m your host, Andres Almeida. Today we’re taking a close look at a robotic explorer that could pave the way for sustainable human presence on the Moon. It’s called the ISRU pilot excavator, or IPEx for short. 

It’s a game changer, and it functions as both an excavator and a dump truck engineered to extract oxygen from lunar regolith, or soil. This is important, not only because we use oxygen for breathing, but also because oxygen is a key ingredient in rocket fuel. By producing it directly on the Moon’s surface, IPEx could help reduce the need to transport heavy consumables from Earth, making lunar missions more efficient and opening the door to long-term exploration and settlement. We’re joined by Jason Schuler, IPEx project manager, and Andrew Smith, lead controls engineer. 

Hey, Jason and Drew, thanks for joining us today. 

Jason Schuler and Andrew Nick: Thanks for having us. Yeah.

Host: So, walk us through the development of IPEx. How and when did the idea come up? 

Schuler: Sure. We came up with the idea in 2010 after the cancelation of the Constellation Program, which was supposed to take us back to the Moon as well. And we have been doing work under Constellation with what was known as the Space Exploration Vehicle, which is like their version of the rover that was going to drive the astronauts around the Moon. 

And so, we were doing excavation attachments for that vehicle. So, a large grater blade – we had some designs to do some excavators and things like that. And when that program got canceled, we started thinking, “Well, how are we going to do excavation? We don’t have a large vehicle like this anymore.” And so there come some real challenges of how to do excavation when you have a small platform, like a little robot.

And so, you know, we saw the near term being these robotic missions, right? And so, the question came, “Well, how do you do excavation with a robot that’s small and that lands on the Moon that has 1/6 Earth’s gravity?” so it has almost no weight, and weight is what we use on Earth to do excavation, right? The more steel we put on an excavator, the more traction it has, and it stays still when it goes to dig the dirt. And so, that was kind of the fundamental problem we tried to address. 

I remember we had a whiteboard session in 2010 and came with all these different ideas, and then there’s this aha moment of, well, what if we balance forces, right? What if we have excavators on both ends of the robot, and so one excavator is reacting off of the other excavator, and so you’re no longer relying on the robot being heavy? You just balance forces. And so that was kind of our eureka moment. 

Host: So, what design features and technology make IPEC suitable for surface missions to the Moon and Mars? Drew, I’ll let you take that one.

Smith: A lot of it is when you get to the surface of either one, either Moon or Mars, you have the dirt, the dirt and the dust. And with an excavator, you’re going to be in the dirt, right? You know, like excavators here on Earth, you know, they’re covered in dirt all the time. Or there’s a ton of dust flying around. So, the challenges with that is on the Moon, there’s no air, right? So, cooling your vehicle on Earth, you do it through radiators and those sort of things that the wind blows through them, or you have a cooling path and fans, just like you do in your cars.  

But on the Moon, you don’t have that luxury. So you have to be able to take the heat that’s being generated from your vehicle and expel it out to space through radiators, and if you get dirt and dust onto your radiator surfaces, then it kind of reduces that efficiency of how well you can reject all this heat that you’re generating while you’re digging and operating your vehicle. So, we had to come up with some innovative solutions of how to protect those surfaces, so that when we’re down in the dirt digging, getting really dusty and dirty, we can protect those radiators. And when we protect those radiators, and when we need to expel that heat back into space, we can open up a cover and have a pristine radiator that’s still there that’s able to radiate to the black body of space and cool our vehicle back down. 

One of the other challenges that we have is to be able to excavate for a longer period of time, we have to store the heat that we’re also generating while that cover is closed. 

So, we use what’s called a phase change material. It’s essentially a wax pack that is storing all of this heat energy from all the actuators and the computers and batteries and everything that are on board. And then when that wax pack gets fully saturated, we can then go to like a safe place, we can open up our radiator cover that exposes the radiator itself to the black body of space.  

Also, we are a battery – IPEx is a battery-powered excavator. So, another challenge is, how do you recharge your batteries? Because the same similar situation with wanting to protect our radiator surface from the dust, it would be really hard to protect solar panels that traditional space vehicles use to continuously have power. So, we made a decision early on in the project that we would have a power system on the like the mothership or lander that we would deploy from they would either have a battery bank or solar panels, and we would actually go back to that lander to recharge. So, we had to come up with a solution of how to have a dust tolerant way of charging our batteries. We did this partnering with another group for a wireless charging system. So, the same thing that you can wirelessly charge your cell phone on, like a desktop wireless charger, we can essentially drive back to the lander and connect (wirelessly connect) and transfer power from the lander or mothership to the back to the excavator to recharge the batteries. 

Host: Why is lunar regolith so challenging to excavate? 

Schuler: It is a really fine material. It’s been broken up over millions and millions of years, and so it has this really fine particle size, and so that allows it to stick to a lot of things. And the fact that there’s no atmosphere on the Moon allows the regolith material to charge up and have really no way of dissipating the charges as well as you do in an atmosphere here on Earth. And so, the particles will stick to everything. 

We saw this in the Apollo missions, where the astronauts came back into the lander and their EVA [extravehicular activity] suits were just covered with regolith. And some of the outputs of those missions where, you know, we weren’t sure how much longer we could have stayed right there about three-day missions on the surface, but because of the dust, things are starting to get into seals and bearings and cause challenges. And so that is one of our biggest technical hurdles moving forward with a sustainable presence on the Moon, is how to deal with dust in a long-term way keeping it out of those mechanisms and joints. It’s really abrasive and sharp and so it will scratch up things like lenses, camera lenses, or visors for EVA suits. So, we need to make sure that we have all these technical solutions to survive and operate amongst that harsh regolith. 

Host: And so, what are we trying to get regolith for? 

Schuler: That’s a great question. We’re going after materials, in this case, oxygen, so that we don’t have to bring it from Earth, right? Now, all of NASA’s missions have the consumables brought from Earth, right? And if you think about our future trip to Mars, if we keep with that architecture, that means everything that we need we have to launch from our initial take off here on Earth, so all of the fuel to take back off of the surface of Mars and come back home, we would have to launch with the initial mission. And I liken that to taking a road trip across the country, and you’re having to tow a trailer behind your car full of gasoline, right? It would be extremely inefficient, but that’s the only way that we have right now. And so, the goal, one of the goals of doing excavation, is that you can then extract resources from the regolith, that surface material at your destination. And in the case of the Moon, one of those resources is oxygen. 

There’s 40 percent oxygen in the regolith on the surface of the Moon. No matter where you go, every sample we brought back and all the orbital data shows that same 40 percent number, and that oxygen, if you heat the regolith up, you can break the chemical bonds between the oxygen and the minerals that it’s chemically bound to, and you can then store that oxygen and use it as propellant for your rocket. And it’s a huge percentage. Oxygen makes up 80 percent of your rocket fuel. 

So, if you’re able to capture that from the Moon, you have basically a gas station on the Moon and then eventually Mars. 

So that’s what IPEx is doing. We’re excavating the regolith so that we can bring it to a chemical plant that would then heat it up, break that oxygen – break those bonds – and recover the oxygen so that we can refuel rockets.  

Host: Drew, a question for you. What, to you, has been the biggest technical hurdle in developing IPEx and how has the team worked to address it?  

Smith: Like Jason said, the astronauts, you know, they came home from doing their EVAs on the Moon, and their spacecrafts were basically filled with this regolith dust just kind of all over the place. They had problems with the joints on the seals for their helmets and their gloves. So, trying to keep the dust out of those mechanisms is like, by far, one of the biggest challenges that we’ve had to come up with. But kind of going back to the very beginning of trying to come up with a way to excavate it on the Moon itself. The type of excavators that we have on this robot, we call them bucket drums, and they’re essentially like a hollow drum that has tiny scoops on the outside of them, and like Jason was mentioning at the beginning, where we put one of these drums on both sides of the robot itself. So, when we’re digging on one side, we can cancel those excavation forces with the other side, when we can be able to drive and dig at the same time. 

The other thing was, you know, typically here on Earth, when you, when you dig with an excavator, you also take that, all that dirt, and you put it in a dump truck, right, and then it gets hauled off somewhere to be used. We actually designed these bucket drums to be able to collect and fill inside of the drum itself. So now we have an excavator and a dump truck all in one. So, like, our efficiency of rovers and things like that, we can reduce those down to just one vehicle to be able to do both of those operations. 

Host: So, NASA has the Game Changing Development [GCD] Program that selects projects so they can go from lab concept to full-fledged prototype. What contributed to IPEx getting chosen? 

Schuler: So, we had a previous prototype for this excavator. We called it RASSOR in the past. And so, there’s actually two generations that we’ve developed over the years, prior to proposing to the GCD, the Game Changing Development Program. And so, I think that really helped, having advanced the technology to a stage where we were seeing, kind of the fundamental elements of this force-balancing excavation technique proven. 

We had videos that we could show people and really easily communicate the benefit of this technology. So, I think that was a big contributor. And also, the proposal that we put in right this is a big leap in the state of the state of the art in terms of doing excavation in this type of environment, right? We’ve only done spoonfuls or cupful scoops of sampling to this point. We’ve never done excavation at scale. And so, we were able to put a proposal together that allows us to really advance the state of the art in a very kind of tangible way with a really discrete mission that is achievable with the technology we have now and the CLPS [Commercial Lunar Payload Services] missions, the commercial lander missions going to the Moon. 

Host: So, what is the next milestone for IPEx development? 

Schuler: So, we have our critical design review in September. So that is about the 90 percent level of our design. And so, our project started at Technology Readiness Level [TRL] 4. So, NASA has the scale going from one to nine. You know, one being like a brand-new concept. Maybe you’ll do a paper study on it. Nine is a technology that has flown in space and has been qualified in that environment and can go support some critical mission, right? We came in at 4, which is like a lab prototype, not suited for, you know, operation on the Moon, but you’ve proved the basic concept with hardware in the lab. 

And right now, we’re at TRL 5, so we’ve built a lot of the components that will enable us to operate in that lunar environment. We’ve tested them in chambers, and we’ve kind of tested each of those as subsystems. And our final step is to get to TRL 6. That’s where our project will end. And with TRL 6, we, you know, assemble the full robot qualified to do a technology demonstration, which means that there’s no larger mission that’s counting on this technology. It’s not, you know, in the critical path for some human mission. It is kind of a standalone demonstration. So, that’s our goal. 

And at the end of September, we’ll present a design that’s 90% complete for that version of the robot. And then in the first half of 2027, we’ll have built that version of the robot ready to fly to the Moon, and just looking for looking for a flight to actually demonstrate it. 

Host: And that’s not really all that far away. 

Schuler: No, it goes fast. And, you know, considering how long ago we whiteboarded the idea in 2010, right, we’re kind of in the home stretch. 

Host: What sort of simulations or tests are being conducted on Earth to ensure the excavator will function the way you want it to on the Moon. 

Smith: Right, yeah, so one of the big milestones that we actually just completed was we did a mock mission with this TRL 5 excavator that we have already built. And with this mock mission, we had several things that we were looking for to get out of this mission, several of them being like, how does the rover drive? How do people operate it? What level of autonomy do we really need? There’s a seven second delay in communications from the Earth to the Moon, so driving this excavator with the joystick would be nearly impossible to do for a continuous mission. 

This demo basically proved out that we’re able to perform all of our mission during with the correct characteristics that we’re expecting to see on the Moon, such as communication delay, bandwidth delays, recharging our batteries, practicing how we would do the thermal resets or the phase change material, and also just the durability of the robot, at least for our Earth mission, or Earth environment-type mission. 

And that tells us a lot about how the performance of the actuators and a lot of the other mechanisms would be able to perform on the Moon as well. So that was a big one that we hit that we just finished – to do a higher fidelity testing of the excavation system and the designs of the wheels and the bucket drum excavators themselves. We have a regolith bin in the Granular Mechanics and Regolith Operations Lab here at Kennedy Space Center that it’s full of 120 tons of regolith simulant. BP-1 is the name of the simulant that we use. It’s a good mechanical simulant for testing those sort of things. So we use that regolith bin to test out how well the robot is able to actually dig through the dirt and the forces that it takes and the efficiency of which it can collect the regolith itself, as well as how well the vehicle is able to drive on a simulant that is mechanically similar to what we’re expecting to see on the lunar surface. 

Host: Could the technologies or approaches used in IPEx be adapted for commercial space or even Earth-based mining resource collection? 

Schuler: Yeah, absolutely. That’s one of the big focuses of our GCD project is to do this work in a way that we can transition it to commercial space, right? There’s a lot of interest in doing mining and excavation and resource gathering on the Moon with commercial space so you can do this refueling operation that we talked about. We’d love for industry to be able to do that. 

So, this project hopes to enable that by showing that this is possible to do, and here’s a solution to actually do this excavation at scale, so then you can go extract those resources. So, we are leaning hard into that. 

We’re creating publications all the time. We have a public-facing website, and all of our technical reports are on there, videos, animations, and we’re gearing up to release a whole data package that goes into detail on the design of this excavator, our TRL 5 version of it, so that companies or universities/organizations that want to build their own or learn how we built this one will have the resources They need to go look at that. And then for Earth applications, I do think there’s possibilities of taking this approach to terrestrial excavators, because what we’ve effectively created is a very efficient way to do excavation, right in terms of the amount of energy spent per kilogram of material you collect, IPEx is one of the best in the world. It’s extremely efficient, and that’s again, because we have that counteracting excavation technique, no longer relying on this massive, heavy vehicle that every time you move, it uses a lot of energy, right? And so, I hope that one day, we can demonstrate this for terrestrial applications, and decrease the amount of energy we’re spending every day to do these mining operations. 

Host: And Drew to continue: Can you tell me about a mentor who’s been influential in your career? How do you think mentorship shapes professional development? 

Smith: Jason and I both take mentorship really seriously in our careers at this point right now, where we’re actually the mentors for a lot of up and coming engineers and our and the type of environment that we work in, we have lots of interns and Pathways students every year come through our lab, and you know, we try to give them the best experience that we can, you know, we don’t just stick a book in front of them and say, Hey, read all this stuff, and then, you know, report back to me later. We actually try to give them a lot of hands-on type work to do something that they can use some critical thinking skills, be able to get something out of their internship with us and mentor them along the way. 

And that kind of goes from how, you know, we were brought up when we first got hired on into NASA. 

One of the mentors that comes to the top of my head is Robert Mueller. He’s here at Kennedy Space Center. I remember when I first did my did an internship back in 2018 Rob was kind of like my high level mentor, where he had a vision for his group, and he gave, kind of each one of his new hire interns and employees, a vision of what he was hoping that his group would turn into, and where NASA should go in the future. And just that little bit of having that vision was very inspiring and then also when I got hired on, Rob was able to bring me into his group still with the same vision, and basically just task me and several other members of his team with a project, right? And that project – he basically kind of just gave us the high-level requirements of what we needed to accomplish and let us just kind of run with all the ideas. He expressed to us, this idea of a helical design process that he believed in through a systems engineering approach of how to complete projects, especially technology projects, in an efficient and timely manner, so we could be able to design, build and test things rapidly. 

And we always feel, especially in our group, that if you’re able to get hands on build something that you actually designed yourself, and then test it, you’re going to learn a whole lot faster than just sitting behind a computer and designing something for a long period of time without actually getting hands on with the hardware that you’re designing to learn. And that was always kind of my passion growing up and everything you know, I always loved building things and breaking them and those sort of things. So that kind of fit right in with me. But yeah, I would say for one of my mentors, you know, bringing up, bringing us up through this would be, would be Rob Mueller. 

We have the saying, and I think it’s probably, you know, a lot of people say it in the type of research industry, but “Fail fast forward.” So, fail often, fail fast, and learn from your mistakes. So, you can, you know, iterate and move on to a better design that’s, you know, not going to fail eventually in the end. 

Host: And how about you, Jason? Has anyone come to mind? 

Schuler: I was only a couple of year, years in, and Drew was my intern maybe even a year in, and Drew became my, one of my interns. So, we basically had a very similar experience. So, Rob as well. I, you know, just like Drew said that, that approach of, you know, helical design, of iterating quickly, that was instilled through Rob, and I think one of the most impactful things that we’re trying to pass on to the people that are coming into our group now is you’re not going to sit at a computer and design this thing perfectly the first time. No matter how long and how much money you spend, you need to build it, and you’re going to have missed something, and that’s okay. Or you’re going to learn something that you just didn’t, a question you didn’t even think to ask. 

And so, we want to answer those questions as early as we can, so that we can build that knowledge into the next iteration of whatever we’re designing. And so, I think that’s just fundamental to what Rob instilled in us and to the work that we’re doing here at Swamp Works at Kennedy Space Center. 

Host: And one more for you both: What is your giant leap so far?   

Schuler: I think getting this GCD project is I see as kind of the giant leap, right? We’ve worked all kinds of technology development projects all related to. Regolith and how to move it, how to have it in different systems, how to, you know, use it as a construction material. Then they’re all kind of lower technology readiness levels, right? Usually, you know, maybe some starting at one, maybe getting up to four, maybe five. 

But this was one of the first ones that we had a chance to cross what’s called the “Valley of Death,” the “TRL valley of death” where you get an idea far enough along that you kind of need to have enough budget and support to take the leap to get it ready to actually do a demonstration, either in space or on the Moon. And so, getting this project and actually be able to take our excavator design, to that stage really feels like a big leap. 

It was a stressful time, actually, during the proposal phase. It was right during COVID. And I vividly remember actually being in the hospital with my wife, who had just given birth to our son. And so, I was pitching the idea to the GCD program office from the hospital room with my wife, my son, you know, like a day old. And so I’ll always remember how long we’ve been working on this project, because my son is exactly the same age. And how about you, Drew? 

Smith: Yeah, so I don’t have the same baby story that Jason does, but I think it’s a similar kind of situation where, you know, we, we came up with this idea back in 2010 and, you know, we made several prototypes. We made sure the technology idea was feasible. We built the prototypes to actually test it, and our regolith bin and reduced gravity to make sure, just like everything was, you know, all the things that we thought were going to be the hardest parts to overcome, we were able to overcome those. And we probably proposed this project for probably three or four years before we actually were able to win this proposal through GCD. 

And that was that was a ton of work and sometimes discouraging to basically say, hear people say all the time that it’s a really cool thing, but, you know, just not right now. We’re not ready for it. And we did that, and we presented at conferences the technology, and just kept, kept pushing and pushing along, because we knew that we had something special and something that we could or that NASA could use to advance space exploration. So, we were persistent. 

And when that finally came along, and GCD basically was just like, “Okay, we’re ready for it. Now, NASA is ready for this,” and then Jason being able to present that in the hospital room and everything like that, it was just really cool just to be able to finally get this project and get started on it since we knew that the technology was what NASA was going to want. 

Schuler: Drew was actually at a conference presenting this, this idea. And like Drew said, we had presented this multiple times before, and, you know, there was support behind it, but this one, we said, “You know what, we’re just going to go with a bunch of videos.” And so, we prepared a bunch of videos showing it doing different operations with our prototype robot RASSOR. 

And when Drew presented that you could almost hear the light bulbs flick on for everybody in the audience. It was like an a-ha moment. Like, we knew it, because we’ve been working it every day, but we just weren’t communicating in a way that people were kind of getting the vision, and so when they saw that, that really kind of turned things around. And that was a lesson, I think, for us, was, you know, you really have to communicate it in a way that people can see the vision, right? And sometimes a bunch of videos could be your best presentation. 

Host: We could probably do a whole episode on communication. 

[Laughter] 

Worth exploring. 

Jason, Drew, thank you so much for your time today. Good luck to IPEx. 

Schuler and Smith: Thanks very much. Thanks for having us. 

Host: That’s it for this episode of Small Steps, Giant Leaps. For more on Jason and Drew and the topic we discussed today, visit our resource page at appel.nasa.gov. That’s A-P-P-E-L dot nasa dot gov. We’ll be taking a holiday break, but will return in January. In the meantime, you can catch up on previous episodes, and listen to our other NASA podcasts like Houston, We Have a Podcast, Curious Universe, and Universo Curioso, NASA’s first Spanish-language podcast. On behalf of NASA APPEL Knowledge Services, happy holidays.