Planetary Radio: Space Exploration, Astronomy and Science - 2026 NASA's Innovative Advanced Concepts Symposium: Part 2 — Solar sails and breathing beyond Earth

Episode Date: October 7, 2026

In this second of two episodes from the 2026 NASA Innovative Advanced Concepts (NIAC) Symposium at Wichita State University, Sarah Al-Ahmed talks with researchers developing the propulsion and life support technologies that could open up new frontiers in deep space exploration. First, Artur Davoyan, associate professor at the University of California, Los Angeles, discusses Coilable Stacked Solar Sails, a new sail architecture that could enable fast missions to the outer planets and interstellar space. Then, James Bickford of Charles Stark Draper Laboratory introduces TFINER, the Thin Film Isotope Nuclear Engine Rocket, a project that generates thrust from the natural decay of radioactive thin films, enabling rendezvous with interstellar objects and missions to the solar gravitational focus. Finally, Alvaro Romero-Calvo, assistant professor at Georgia Tech, and Theo St. Francis, graduate researcher in Georgia Tech's Low-Gravity Science and Technology Lab, discuss their concept, Breathing Beyond Earth, a pump-free oxygen production system for long-duration space missions to Mars. Plus, Bruce Betts, chief scientist of the Planetary Society, joins Sarah for What's Up, with a look ahead to the launch of JAXA's Martian Moons Exploration mission, MMX. Discover more at: https://www.planetary.org/planetary-radio/2026-niac-symposium-part-2See omnystudio.com/listener for privacy information.

Part two of the 26 NASA Innovative Advanced Concept Symposium. This week, on Planetary Radio. I'm Sarah Al-Ahmad of the Planetary Society, with more of the human adventure across our solar system and beyond. Last week, we explored the technologies being developed to reach some of the most inaccessible places in our solar system. This week, it's more about how we get there. I'll share three more conversations from the 26th, NIAX Symposium

at Wichita State University, featuring a new solar sail architecture that could send low-cost probes to the outer planets and interstellar space, a thin film nuclear engine rocket that could catch interstellar objects, and a clever new approach to producing oxygen in microgravity for long-duration space missions. Plus, Bruce Betts, chief scientist of the Planetary Society and I, are going to look forward to the launch of the Japanese aerospace exploration agency's Martian Moon Exploration Mission, MMX. It's set to lift off in just about two weeks on a journey that's going to bring back

the first samples from the Mars system. If you love planetary radio and want to stay informed about the latest space discoveries, make sure you hit that subscribe button on your favorite podcasting platform. By subscribing, you'll never miss an episode filled with new and awe-inspiring ways to know the cosmos and our place within it.

If you caught last week's episode, you're already familiar with what the NIAC symposium is all about. If not, I'd recommend going back and listening to Part 1 where I explain the program and share three conversations with some of the NIAC fellows. We talk about exploring caves on Titan, lunar lava tubes, and exploring some of the moon's darkest craters. I've had the privilege of hosting the NIAC symposium webcast for the last four years, and this week we're going to pick up where we left off at the September 15th through 17th symposium at Wichita State University.

First up is Dr. Archer Davayan, Associate Professor at UCLA, and a returning NIAC fellow. His earlier work on extreme solar sailing went all the way to Phase 2, exploring how a close solar flyby could propel spacecraft to near relativistic speeds. But now he's back with a new Phase 1 concept called Coilable Stacked Solar Sails. For those who may not be familiar, a solar sail is exactly what it sounds like. Instead of wind, it uses the pressure of sunlight hitting a large reflective surface to push the spacecraft forward. No fuel required. It's a concept that the Planetary Society help prove with our Light Sail 2 mission. But scaling these sails up to sizes needed for deep space exploration has been one of the biggest challenges in the field.

And that's exactly the problem that Arter is trying to solve. We're about to talk about something that is near and dear to my heart with Artur, Davoian, from UCLA, the University of California, Los Angeles. Nice to see another fellow Angelino. Thank you much. Very much, Sarah. And great pleasure to be here. So I come from the Planetary Society, and something that we did a few years ago is that we created a solar sail, the Light Sail 2 mission. It was the first fully crowdfunded space mission ever, and the second solar sail to actually achieve that kind of flight, right? All the credit goes to the Japanese aerospace exploration agencies Ikaros mission. But I'm really excited to hear about what you guys have tried to accomplish with this concept, because there are some limitations, as we found out with our.

project and I think what you're proposing will solve a lot of that. But before we go into coilable stacked solar sails, I want to acknowledge your previous NIAC projects on extreme solar sailing that actually went to phase two. Can you talk about how that project has led to you getting to this moment now with your new NIAC proposal? Sure, sure, absolutely. So first of all, we are very much inspired by light sail. It's a great effort. And I want to mention that it's, although Japanese space agency did a great job and sent up interplanter spacecraft, light sail to was lighter and more capable in that sense. And it showed that you can do small, low-cost missions, which is very important,

you know, something that is new. We had several NIACs on solar sailing. So the first one was on extreme solar sailing that we were thinking of, which was to send the spacecraft very close to the sun and to do two things, either to explore the solar polar regions, like, you know, to go to very high inclination orbits, like polar orbits or, you know, more than 50 degrees, something that is not possible with any other spacecraft. Or a slingshot and then go to interstellar medium or, you know, interplanetor or interstellar medium

very fast, like, you know, much faster than Voyager 1, which is record-breaking space craft can do. So the challenge there that we were addressing was the materials issue, because once you get very close to the sun and by close, I mean like several solar radiate away from the surface of the sun. So like, you grill up everything pretty much. So the question was, can we get materials that can withstand that heat flux, that particle flux and all of that? And I think we proved that, yeah, we can do it. But to get to the orbits and destinations that we want, another challenge is structure. So you want to have large air spacecraft that is lightweight and can

be compacted into a very small spacecraft body, which is, you know, like a CubeSat type of format. And that's a challenge because you have like 100 meters by 100 meters sail, which is nobody has ever built before. The largest one that is being considered, I think, is about 40 meters by 40 meters, a solar cruiser that NASA Marshal Space Flight Center is working on. So once you get to that large area structures, then the question is, how do you make it light mass?

That's a big problem. Even light sail, too, although it's very small and compact and nice. It's still the, quote-unquote, density of it is not what we want to have. We want to have like 10 times lighter system of the similar area size. So that's where we came up with an idea of, okay, how do we solve deployment issue, very large area sale, how do we solve the mass issue, how do we solve the acceleration issue? And we came up with idea of segmenting kind of the structure, a large area structure, into deck of sales, smaller sails that are not deployed.

They are already unfurled, so they kind of stay as they are in the fairing of the rocket. And then we just use a boom or truss, single truss, that is unfolding all of them. I love this idea. This is really, really clever. I mean, so we used ripstop mylar in order to make our solar sail. So efficient for what we were doing, still pretty heavy. But the spacecraft lasted several years longer than we expected. And ultimately, we had issues with one of the booms kind of buckling over time. So it's interesting to hear that perhaps we don't have to make it one monolithic,

structure, we can create smaller segments that then scale out. Looking at the images, it almost looks kind of like a staircase. Can you describe what this looks like? It is a staircase. It is indeed like a staircase. And actually, the buckling of the boom on live cell, too. And then similar issue was on ACS3 recently. So both of them lead to the non-uniformity of the square sale. So you really get, instead of a square sale, you get some weird shape that is very hard to control later on. and the radiation pressure and so on, is very difficult to compute and then to understand what to do with the spacecraft. So that's where we also thought about it,

that our system of sails is kind of less sensitive to the issues of the boom deployments. Sure, you need to tension it, but we're kind of resolving it in a different way. Now, it's indeed like a staircase, and there isn't like a staircase, because we want each and every sail that we have to be illuminated fully by the sun. So the sunlight has to be incident on each and every one of them. To do that, what we need to do, we need to push them a little bit apart from each other so that they all get eliminated. That's where the staircase comes into play. And now there is a lot of kind of optimization going on in terms of what is the angle of that staircase,

at which angle you want to eliminate the sunlight, and at which angle you want to run the boom. And so we figured out that there is certain sweet spot of parameters that gives you good performance. What made you come up with this idea? Because I imagine there are several different ways that you could go about creating a solace. solar sale that's made out of smaller solar sales. That's an interesting one. So it's actually the story of that is that I thought that, you know, for me in the university environment, it's very hard to build a hundred meters by

hundred meters sail. There's no way I can do it. And not only for me, it's even in a large NASA center, for example, you really need a bay that would be that large and then how do you test it, how they deploy. So that was a problem. And I said to my students, maybe we can, you know, build smaller sales and then put them on top of each other. And the way I thought about it is that we're going to have

booms on each and every sale. And then if you do math on that, then the booms, they don't scale really well. So a few of my students came back and said, oh, you know, we don't need booms. We can do this thing. I said, right, yeah, let's do it. So we thought that, you know, we can do this. We did some math. We ran some simulations. We did some estimates. And we see that performance is pretty good. Now we're trying to build it. So we're prototyping. How do you actually make this thing deploy? Icaros did the thing where it spun out the solar sails. We did the thing where we deployed along the booms.

But how do you actually make this thing turn into a staircase? So we keep all of the sails much like a deck of cards on top of each other. So they're layered on top of which. They're going to be like about 100 sales. But in fact, you can build a spacecraft that is smaller than that, like maybe 10 sails. So we have 100 sails that are sitting on top of each other. And we use a, in the center of it, we use a must or trust. that is coilable truss that can be expanded.

This is known technology that has been used on other spacecraft as well, usually like in people deploy magnetometers, for example, with it. So that trust starts expanding, and as it expands, it sort of pushes these sails apart from each other. And as it pushes apart from each other, the entire big, one large structure is kind of appearing with this entire surface eliminated. Of course, it's going to be long. It's also not small.

It's like, you know, the length of this trust is going to be more than 500 meters. to support the areas that we want to have. But we are kind of solving issues with the deployment asymmetry. We are solving issues with the masts and we are solving issues with the sale stowing. So we do have other problems to solve, but we are minimizing those risks. Once the entire thing is deployed, if all things go as planned, what kind of area are we actually talking about on the solar sale in total? It depends on the level of tier of the mission that you want to do.

So we think that we can start with 10 sails. Each of them is going to be about, to fit into under the faring of the rock, there's going to be about 5 by 20 meters. So it's 100 meters square sail, 10 of them is going to be 1,000 square meters. So that's the starting point that you can start doing some missions. That's not going to be a capable mission, but there's going to be a mission, similar to the ones that are flown right now.

But if you want to do really capable mission, then you're going to go with about 10,000 square meters. so it's like 100 meters by 100 meters effectively, right? And that one is going to give you really great performance. So you can go to destinations that are not possible today. You're going to go to orbits that are not possible today. So not possible, I mean not with solar sails, not possible in general with chemical engines or iron engines. So like polar orbits around the sun or, you know, interplanetary, fast slingshots, interstellar medium,

out of the plane of the ecliptic or solar gravity lens that, everybody's dream, so we can get there. That's so exciting. I mean, there are so many places that we really can't get to. And in this case, we would be able to do it without the normal propellant that we need to do these missions. So that enables a lot. But of course, your acceleration on the spacecraft is going to depend on how close you are

to your light source. So assuming that we're somewhere around like one astronomical unit, the distance from the Earth to the sun, what kind of acceleration can we achieve with, you know, your optimal area? here? It depends on sets of missions that you want to do with the solar sail. So in certain types of solar sail missions, you really need to target acceleration, which is, for example, going to outer planets or, you know, like doing inclination clamp and so on. So that's where you want to talk about characteristic acceleration. You want to get numbers that are more than 0.5 millimeters per second square or, you know, it's probably more than 1 millimeter per second

square. Not only that, it is important. Once you get to the lightweight structures, you can also do missions that don't really require high delta-tv, so to speak. It can be like hello orbits, like pole sitters, for example, that you can have a sort of like kind of affected like a geostationary orbit that is outside of the equatorial plane. So you can sit on top of the pole

of the earth and do observations there continuously looking down and, you know, that's very interesting. Or on the moon. So you can do this type of things. So this becomes enabling technology for different sets of missions that are possible with the solar sails. Like inclination climbs that require

extremely high delta v, like going to the sun and climbing up. Slingshot missions, and then there's Pulse Cedar missions, artificial Lagrange points, artificial orbits, like non-caplinarian orbits, there is a whole family of them. So you can access all of that. And the lighter is your spacecraft, area to monster ratio, the better it is. Or, you know, if you are talking about the accelerations, the more than 0.5 millimeters per second, you're already getting to do to these nice things. Yeah, I don't know how many people think about the fact that there are some orbits that we just can't really achieve with normal technology.

This opens up a lot. I was recently listening to a talk by an astronaut who went on the first commercial polar orbit and talking about that experience of seeing something with human eyes and from spacecraft that almost no one has seen of the poles blew my mind. What would it mean to you to be able to enable something like that? Oh, it's just opening up a door to entire new science, I would say. because you can do all sorts of planetary science missions, all sorts of heliophysics missions, all sorts of Earth observation missions that you can't do today. Like, for example, you can place a spacecraft and look down.

So it goes back to Cold War days, right? So we, like in the United States is sort of covered by this geostation in orbits. You place a spacecraft there, and you easily kind of have a geostation spacecraft that is monitoring the surface of the Earth and is pointing down to a single point. Russia didn't have that. That's why they had to invent this malnian thunder orbits that, you know, yeah, sure, you go to this very high apopsis point and you spend some time there, but it doesn't continuously look down over and over that spot for 24 hours and so on. So with the solar sails, you can do it, and you can do it much closer to the surface of the Earth, you just sitting around the poles or, you know, or whatever destinations that you want.

On Earth, on Mars, Venus, Mercury, so this becomes enabling technology for a range of missions, so you can do. planetary observations, you can do remote sensing, you can do like chemical analysis maybe if it's upper atmosphere layers. So that's great. Well, you already worked on the materials necessary in order to do this. I know you're passionate about meta materials, but you're going to be doing something completely different with this NIAC project. So what are you hoping to accomplish within phase one? Within phase one, we want to show the feasibility of deploying this type of system because we kind of sketched it as a cartoon, we ran the numbers, but we don't know whether it is really working or not. So our prototyping so far shows that we are on the right path, and we want to show that we

are on the right path by the end of phase one, which means like a small structure that we deploy, we show that it works with a trust with set of sales, maybe five, ten of them. So that's our goal, like to show the structural implementation of that. And we are bringing up the materials issue. So we're thinking of this as two parallel efforts, this extreme solar sailing that I was mentioning, so we were doing the materials part, we're doing structures part, so we want to do demonstrations on both of them. And at some point, we're going to merge them. So that we're going to have an extremely lightweight system that can go to very close to

the sun and do things that are not possible today, and just beyond beyond the reach. Well, you don't necessarily have to have the really special materials in order to establish that you can actually make this thing deploy. Are you going to be building it with less optimal materials? No, no, it's going to be the actual materials that are used on current spacecraft, like CP1, for example, polymer film, which is 2.5 microns thick, maybe a little thicker than that, you know. So these are regular materials for the sail membrane, and for the truss is just also regular materials. This is carbon fiber, like, you know, elements of the truss that you need to coil and so on.

There is a little bit of engineering involved, but the materials, they're standard regular materials. So we're not making new materials in that sense. One of the issues with using something like a solar sail is that you can accelerate it up, but getting to a target and actually decelerating becomes a bit of a challenge there. How are you thinking about actually going into orbit in these locations using this technology? Some orbits, they don't require decelerating. Like, for example, placing a spacecraft on a solar polar orbit, you just orbit there, or you throw out a sail and your spacecraft starts orbiting there.

Or hello orbits around the polar regions, you just continuously thrust in that sense, like all this non-Caplarian orbits. But you're right, like interplanetary missions or interstellar missions, you can't really slow down in a reasonable way, let's say like this. So in those type of missions, you just do fly-by or you do aerobraking or you do different type of tricks. But I think even fly-by missions, they're great. So if you can have a – that's again going back to Light Sail 2. Light Sail 2, I think was the total cost $7 million for the mission. So if you can do an interplanetary mission that costs maybe $20 million.

or $30 million and you can develop it in one or two years, build it, package it, and send different suitable instruments to, say, Titan or, you know, and beyond Neptune. Yeah, fly by, but several of them and explore that. I think that's great, you know, it's low cost, gives us ideas in terms of what to do with major flagship missions. So it's more like kind of cube sets for deep space. Yeah, it was really amazing seeing the effort that it took to put light sail up there.

but 50,000 people came together to crowd fund this thing, and we managed to pull it off without backing from any major space agency. So it's conceivable that you could get the money in order to go and do these fly-by missions. And we need them so desperately because some of the worlds out there we have not seen since the Voyager days. And now those missions, at least Voyager 2, is about to be at one light day in a few months. So it's been quite a while since we've been out there. What would you love to see in this concept? What worlds would you like to fly by? Oh, several of them. So the very first one, I think I want to fly by through the plumes of Europa, for example,

just to see, like, are there plumes with signatures of life forms? So do we have all of that? And maybe there is something in there. But certainly getting ideas in terms of atmosphere of Uranus, for example, and that would be interesting. Because that one has some uncertainty in terms of how it's structured and why it behaves that way, because if it's like so far away from the sun, but it's still very active. Well, clearly I'm excited about this,

and I really hope that you guys have a lot of luck in this phase one, because this could be the technology that takes us out of our solar system into entirely different systems. Next up is Jim Bickford from Charles Stark Draper Laboratory. His phase two concept, T. Finer, tackles a question that has haunted space scientists since 2017. If another interstellar object like Oumuuma passes through our solar system, How do we actually catch it?

His answer involves nuclear physics, a sheet of material thinner than a piece of paper, and speeds that could get you from Boston to Washington, D.C. in just about six seconds. So I'm here with Jim Beckford from the Charles Stark Draper Laboratory Incorporated with a project called T. Finer. So this is a thin film isotope nuclear engine rocket, right? But if you look at the images of this thing, it doesn't look anything like a classical rocket.

So can you explain what exactly this is? Yeah, sure. Thanks, sir. So basically you think of a rocket, usually. It's on a launch pad. It has fire coming out of the end, a payload on the top. Our rocket looks completely different. It's not really a traditional rocket.

It's a thin layer of material, in particular in nuclear fuel. You operate it in space, and it has a very high energy density. So it has a high exhaust velocity and allows you to go very fast. Now, there's some unique things about doing it as a thin film, a nuclear rocket. And that in our case, in some of the implementations, our payload is actually in the exhaust. So it sort of like turns the whole idea of a rocket on its head, literally. The trick is by using this nuclear fuel, our energy density is probably a million times higher than what a chemical fuel would be. So that's what allows us to go much faster and be more effective and go to destinations that you couldn't with traditional technology.

Can you describe what it actually looks like for people who haven't seen an image of this thing? Yeah, sure. So there are a few implementations. The primary one, which we call the baseline, is basically a thin film of about 10 micron thick nuclear material. These are alpha radioisotopes, so they emit alpha particles at about 5% of the speed of light. And they all flow out in one direction on one side. And what we have is a payload that's separated from that. So the first part that kind of sheet looks like, almost like a solar sail, but a little bit thicker.

Still thinner than a piece of paper, though. And it's held by tensioners to tension it and push it out so it's stiff and doesn't fold over it on itself. And then there are tethers that carry over to a payload module that basically gets pulled behind. And that payload module has a telescope in it so you can do science, but you also can use it for laser communications to communicate back to Earth. And you can have other things in there, other types of sensors, whatever payload you want to take to deep space. One of the really cool applications of this technology that I was reading about is this. potential that maybe we could use this to check out interstellar objects. We've only had three of these that we've found so far.

There was one eye Oumuuma, two eye borosov, and then most recently three eye Atlas. We haven't seen a lot of them, but with the new Vera Rubin telescope and the survey is going to be taking, we might be seeing a lot more of these. But currently, it is really hard to intercept something like this. So how could T. Finer help us go explore these objects that are literally coming at us from outside of our solar system? All right. I think, so I love that question because

Umuua was the original inspiration for this project. How can you go fast enough to catch it? The challenge with all these inter-solar objects, whether the past ones or any future ones, is they're going much faster than everything else in the solar system. So if you want to go rendezvous with it, you have to go much faster to overcome it, rendezvous, slow up, and basically do whatever signs you want to look at it.

Umu-u-u-u-uh-uh-uh-is a particularly hard target because it flew by in 2017 and it's been exiting the solar system. It's basically outside our solar system already. And it's going very fast, faster than any really object that a traditional spacecraft would go rendezvous with. So we have to fly fast enough that we can not only catch up to it, but then we have to slow down and basically rendezvous with it. And actually before you rendezvous with it, you have to find it because it was only a point of light. It was basically, even with the most powerful telescopes on Earth, it was just a dot of light that we tracked for a few months in 2017-2018.

So there's uncertainty where it is, and it's growing with time. It's getting bigger and bigger. And it's sort of mysterious on its own, which makes it a very enticing target. Like, what could it be? It's the first interstellar object we ever detected. So if we have to go there, you have to fly to it, slow up after you've overcome it, rendezvous, and then kind of do a local search for what's there. I remember being so excited when we found this thing.

I actually took the numbers, sat down at my computer, tried to model out the shape of that thing, because what a wild idea that we can actually be at this phase in our technology to find them. But you're right. Getting there means that you have to get really fast, essentially. And with T. Finer, you can get a change in velocity somewhere between 100 and 150 kilometers per second. So can you put that in perspective for people, why that is different from everything else that we've used before? Yeah, so it's much faster than what any traditional spacecraft to flies at. you know, like Earth orbit is less than 10 kilometers a second.

So we're well over an order of magnitude faster than that. And to give you some insight, like just to give you a feel for how fast that is, a flight from Boston, which is where my company, Draper, is based out of, to Washington, D.C., and it takes about six seconds to fly there. So super, super fast. And, you know, it's just exciting to go, you know, this quickly. And to put it in perspective, if you used a conventional rocket, if you wanted to go that velocity, I said, okay, well, let's use like, you.

if you think of a space shuttle engine or a raptor rocket, how much fuel would you need to go that fast? And there's a rocket equation that describes this exponential of how much fuel you need, and it doesn't look good. You actually, I calculated, I said, well, if you want to go that fast, and it's the mass of human civilization. So obviously, completely impractical,

which is why you have to go to this different technology and use nuclear fuels and other things that will allow you to go faster. And one of the unique things about our technology is that, for instance, solar sails, you can fly in close to the sun, but what we can do is when we're away from the sun, we continue to be able to thrust and propel, which is what allows us to do these things in deep space, like rendezvous or for other types of missions,

continue to move around for whatever you want to do. But the way that this works is basically you've got nuclear decay happening on a thin film, but a thin film has two sides to it. So how do you bias the direction of this thing's velocity? So if you just had this radioisotope that's emitting alpha particles about 5% of the speed of light, it just goes off in every direction. So you're not going to actually be able to get any thrust out of it because it's omnidirectional. But what we're going to do is we're going to make that film very thin, about 10 microns,

so the alpha particles can escape from it. But on one side, we're going to add a substrate that's tens of microns, 30, 40, 50 microns thick, just enough so it can stop those high energy alpha particles. So now on one side you have a film that's stopping all of the alpha particles in the other direction. They're flying away at about 5% of the speed of light. So you basically have a rocket exhaust traveling at 5% of the speed of light, give or take. And this is where we have our payload out behind it. And fortunately, because the alpha particles don't penetrate too far,

it does shield a lot of radiation. But a lot of the design tricks we have to do is like how we manage all of the radiation effects and so forth in that payload. And speaking of radiation effects, this makes me think of the ways that you can test this thing safely. And first off, congratulations on making it to phase two. I hear that you guys are working at Yale right now to actually implement some testing of this thing. I know very safely. Can you tell us a little bit about what that process is like? Yeah, sure.

So we have some great university partners that we've been working with. And my understanding is early on they had tried to develop fundamental physics experiments that looked at like violations and momentum, My understanding is they didn't find anything, but what they did do is develop a very high precision way of measuring forces and torques. In particular, the recoil from like individual atomic decays, in our case like an alpha particle. So they're building up a structure that would allow the alpha particle torque or the forces from these emissions to be measured. And it's basically a levitated film that we have like a little mini version of our sail, like a few millimeters at most maybe a centimeter on a side. with easier-to-manage isotope that they could have at the university,

and it will allow us to validate our performance models of how well we expect and how much force and thrust we're going to get out of it. But there's another really interesting piece and some uncertainty that came up in an earlier NIAC program of, well, what charge do you end up with on your sheet? Because you're emitting alpha particles. They're at a positive charge, so you expect your sheet to be negatively charged over time and build up,

which could impact performance. But their experiment also allows you to look at what the charge change is over time. And it turns out it's a little more complex than that first thought I had. And it actually, like, you'll knock off electrons as well. And it had a very different charge distribution. So I think there's more news to come in the future. There's more work to do. But it's exciting to see the first version of this little thin film,

Icedoak nuclear engine rocket that's going to be in the lab and kind of pave the way towards something that will be in space. I'm going to put you on the spot here because I had a question about just the materials that you're using here, you know, radioactive materials have a half-life. Conceivably, how long could the fuel last on a craft like this? Yeah, so it really, what you do is you pick your isotope based on the mission duration and where you're trying to go. And really what we want to do is even pick multiple isotopes. What we call multiple stages, like a normal rocket stage of the first stage and the second stage. In our case, the first stage would include both. isotopes that would have let's say a short half-life which will give you a quick push

and then the longer one which will allow you to operate over decades if you wanted to. So you play with the different isotopes to match to the mission and then for the shorter ones after you've consumed all the fuel after it's decayed due to its nuclear half-life you would discard that type of material so you reduce your weight and that's why it's like a traditional stage in a rocket and that enhances performance. I know in any case where we use nuclear materials on spacecraft say the plutonium 238 that we use, it's really difficult to source that material.

But in this case, I thought it was really interesting. You're looking for dual use cases where you can collaborate with other organizations. And specifically, you were looking at facilities that create materials for proton beam cancer treatment. Can you talk a little bit about that and how you guys can work together in order to not only help people with cancer,

but facilitate space exploration? Yeah, sure. So one of the challenges is with the preferred fuels, the ones that have the highest energy that give us all the decay chains that we want that would give us the best system performance is that it's really hard to make these isotopes. And the way you make them is you put them in a particle accelerator

and you shoot high-energy protons at like a thorium, natural thorium target. And eventually, slowly you produce these materials. Now, there are different approaches. You could have a really big particle accelerator like the CERN that people mentioned yesterday. But there's also an alternative that we've been looking at, which is to focus on smaller distributed systems.

that overlap with dual use. So it turns out that proton beam therapy, which is a relatively new, advanced approach for treating cancers because you can deposit all the energy of these protons right at the tumor and it's much more effective. It doesn't produce as much radiation damage to the surrounding tissue.

But there are relatively small number of these sort of facilities available through the United States. So one thought was, it would be a real challenge because you have to deal with the FDA, and approvals from another side. But if you're going to build a whole large number of accelerators, could you consider a dual use case where during the night or between patients,

since the treatment time is relatively short, you have a large amount of time, if you could be producing isotopes, and then you allow the patients to get treated, and you have the symbionotic relationship between the two. And this would be a huge win for NASA, right? So if you think about, like, a billion-dollar mission, a significant amount of that's going to go towards building,

or manufacturing our fuel in these systems. So if at the same time you can build, let's say, 500 facilities to do this cancer therapy, that's superior to what's out there now. It's going to be a long haul and there are a lot of regulatory issues. But if he can overcome that, it's a win for both the medical community, the patients, as well as NASA and our mission goals. That's such a wonderful use. And honestly, there are so many ways that NASA interfaces with our health infrastructure

that I don't think people are very aware of. and that would be a beautiful one. And shout out to all the people who are inventing technologies like this that can help our cancer patients. My partner is a cancer survivor. So this kind of thing is near and dear to my heart. But there are so many applications for this. You know, we've talked a little bit about interstellar objects,

but another one that I want to bring up, because this is like pie in the sky, awesome science, is this idea of the solar gravitational lens focus. We've heard some people talk a little bit about this over the last day, but can you describe what that is? Yeah, the solar gravitational lens is, if you think back to Einstein, who said mass bends light,

so the sun will bend the ray of light going around from a distance star, and it focuses out at a distance of around 550 astronomical units and beyond. So 550 times the distance between the Earth and the sun, very far. For instance, the Voyager spacecraft have been traveled in my entire lifetime,

just say about a half century, and they've only gone 170 astronomical units. So if you have to go a minimum of call it 600 when you include real effects, that's a tremendous lifetime, or actually more than a lifetime of a researcher. So it would really not be practical with current technology. So you want to get there quickly,

and that's what our approach can do. And basically what you do is a telescope, it's angular resolution, and what can see is dependent upon the aperture, how big it is. We've heard a lot about that in different projects today. In this case, the solar gravitational lens, that aperture is the size of the sun. The sun itself is the lens.

So you could measure and look at distant exoplanets with a resolution of like 10 to 20 kilometers that some prior NIAC projects like Phase 3 projects have evaluated. So what we would do is deliver a telescope to that location very quickly compared to any conventional approach. And one of the big bonuses of our nuclear fuel is that. if we use one of these long half-life materials, they continue to provide thrust and propulsion over decades, if you pick the right one.

So you could fly, and it might take 30 years to get out there, which is long, but not impossible if you think of the length of some of the missions that have flown today. But then you could look at one target, which is on just the opposite side of the sun. So you've spent three decades looking at one target.

You decide, oh, I want to go look at something else. We can go repoint the telescope, which means all you're doing is changing the vector, looking back towards the sun at another target. And we could maneuver to probably about a degree, so a relatively small amount of the sky. But there are a lot of stars in one degree and potential targets versus spending 30 years flying there and then realizing, oh, that's not that interested in a target. We'll improve the odds and the science return a huge amount by offering this capability in deep space. We'll be right back with the rest of the 2026 NIAC symposium after this short break. What if a salty frozen lake in British Columbia holds the key to searching for life in other worlds?

That's just one of the questions Dr. Jacob Buffo and his team have been working to answer. Thanks to generous supporters like you. Dr. Buffo is a recipient of the Planetary Society's step grants. That's our science and technology empowered by the public program, which funds groundbreaking research driven by your support. They've been studying salty lakes with chemistry like ancient Mars, chemistry that may still exist in the hidden oceans of distant icy moons. Now it's time for the next phase.

With your help, the team will build artificial intelligence tools that let future spacecraft help find the most promising places to look for signs of past or present life and be able to do it all on their own as needed, even without waiting for instructions from Earth. They'll test it right here on Earth at Mono Lake in California and the Great Salt Lake in Utah. Since 1980, the Planetary Society's members and donors have supported science and technology projects crucial to future space exploration. Visit planetary.org slash step. That's S-T-E-P today. Your support will help fund the next phase of Dr. Buffo and his team's work.

Thank you. Our final conversation brings us back to a team that I spoke to last year. Dr. Alvaro Romero Calvo is an assistant professor at Georgia Tech, and Theo St. Francis is a graduate researcher in his low-gravity science and technology lab. Their phase two project called Breathing Beyond Earth tackles a challenge that sounds deceptively simple. How do you reliably produce oxygen for astronauts when there's no gravity to help separate gas bubbles from liquid? Now, we're going to be talking about another one that I'm excited to talk about because I got to see you guys last year during phase one.

This is Alvaro Romero Calvo and Theo St. Francis from the Georgia Tech Research Corporation. And we're going to be talking about a project called Breathing Beyond Earth. What is the larger problem that you're trying to solve here? Well, it is interesting, right, because we take some things for granted like breathing, but in a space when you are millions of miles away from Earth, it is not as simple. We're essentially trying to develop a system that can make astronauts breathe easy. We're developing an oxygen generation assembly that is going to be, or we hope it is going to be more reliable and easier to maintain and easier to build than the state of the earth. Well, Theo, I know that you kind of specialize in what happens to liquids in space. What is the challenge with trying to use electrolysis to do something like this in low gravity or even in orbit?

the way we make oxygen for astronauts is by turning water into hydrogen and oxygen. The challenge there is you're taking a liquid and you're turning it into gases. And when you don't have the buoyant force of density difference as we do on Earth with gravity, there's no automatic mechanism by which those gases escape the liquids. So right now, the way we do that works, but it comes with reliability concerns, for example, with rotating equipment, with pumps, centrifuges, these things take a beating when they get launched. Storing them for a long time can be challenging. And so our high-level goal is can we come up with a way to get those gases out of the liquid without needing so many spare components? So that's a challenge. Now you've got to think about how you're going to use magneto hydrodynamics to do this kind of thing. Can you explain how this project uses these forces to actually accomplish your goal? So the idea came out when We were talking yesterday about the influence of movies and fiction in science and the retro-inmentation loop that happens there, right?

This idea came up after watching a movie that made familiar to our viewers. San Conner is the Hand for Red of Tower. It's a Soviet spy movie that talks about how magneto-hydrodynamic drives can potentially propel submarines. So I was at home. It was very, very close to my defense. At that time, I was thinking, well, the idea doesn't, really work on the sea because it is very inefficient, but in a space because of the lack of

buoyancy, we have this ability to control fluids in microgravity and potentially the magneto-hydro-animic force, which is a concept we all study as the Lorenz force in high school, it can become interesting for this. So I started thinking, built a small prototype in my kitchen, and then put everything together and thought, well, if we change the geometry of this device, we can potentially achieve phase separation in microgravity, which is the goal that Theo, was referring to before. And there is one important reason why this can be so impassful. I challenge everyone to think of all the times

you have gone to Home Depot this past year or to Amazon to repair something that broke up at home, right? I can tell you I have done maybe 20 trips to Home Depot in the past year, right? Well, try to go to Home Depot when you are millions of miles away from Earth. And that is the situation that astronauts finds. You cannot really repair anything in your spacecraft If you don't have spare components and the more spare components you bring with you, the harder it is to fly something to space.

So reliability and little details that, as I mentioned before, we take for granted are very, very important in human spaceflight. We are trying to develop something that doesn't require 20 trips to Home Depot every year. But that's an interesting thing, right? If there are no moving parts to this, what is the benefit there, not just the fact that we don't have to go down to Earth, but what is the benefit to our astronauts? So not having moving parts means that there are simply fewer things to break. That has to do with very simply launch loads. There's a lot of vibration when you have to get something into orbit. And so generally any rotating machinery, any deployable structures take a lot of loading in that environment.

But also just the fact that to break a magnet, you can overheat it. So it demagnetizes. But other than that, there isn't a long. you can do to make the magnets no longer work. And so for us to be able to separate the gas and liquid without having the two rotating pieces of machinery that we currently have on the space station in that oxygen generation system could end up leading to dramatic gains and reliability, which would mean that astronauts don't have to do repairs. They don't have to get out their toolkits disrupt their scientific agenda and that could lead to mission benefits overall aside

just besides simply the mass benefit of needing fewer parts. Right now, the only place that we have humans in space are on our space stations, right? But we're looking forward to a future where potentially we're going to have humans on the moon, humans on Mars. Where are you envisioning using this technology? The mission profile that we have set up as the primary target is a trans. to Mars. Our technology works in a condition called micro-ravity in the absence of buoyancy. So any transfer vehicle that has to bring humans to the moon, Mars, or beyond is our natural

field of application. I love the idea of using this to help people actually get there. Many other problems we have to solve along the way as well, but breathing is kind of a fundamental one. Another benefit here is that potentially you could use these systems to allow oxygen production that can be dormant for a while. How does that work? Yes. So in the Mars mission architecture, Alvara just outlined, the expectation is that there would be several months of transit. The astronauts would leave the spacecraft in orbit. They would descend to the surface. They would be there for a certain period of time and then they would return to orbit again and they would come home. In that period where there are no astronauts on the station, it's advantageous to

not require a lot of power and certainly not require any maintenance because there's nobody in that spacecraft when it's orbiting Mars when the astronauts are on the Mars surface. And so the current technology that we're employing now in the U.S. segment on the space station works very well when we have the ability to maintain it, when we have an environment where the temperatures don't swing so much because there are humans right nearby the system. When we have a period of weeks or months where no one is around, we'd like to be able to safe that system so that it sort of just stays where it is. Nothing happens, nothing grows, nothing freezes, nothing breaks.

Having no moving parts is advantageous there. Having an electrolyte, the salty water, which conducts the electricity between the electrodes, which is by its very nature hostile to biofilm growth, which is a huge challenge on the space station. We heard Dr. Mae Jemison yesterday talk about that. That is an advantage that's inherent in the alkaline electrolysis architecture. So those are just some of the complications with leaving an oxygen generator on its own in Mars orbit. Well, I want to say congratulations that you guys made it to Phase 2. I was reading through some of the results from this, and it's actually kind of remarkable.

Can you tell us some of the statistics about what this provides if we take this tactic? What kind of percentage changes have we seen in either mass reduction or maybe astronaut time actually trying to fix things? So that is a very interesting question because at the beginning of this program, we were thinking of mass power and astronaut maintenance time as the key drivers or the key advantages of this architecture. As Theo mentioned before, the elimination of moving components, the elimination of complexity leads to an overall reduction in this matrix, which is something that we like, right?

But that reduction at this stage of development is of the order of 30%. So we are thinking about something that is 30% lighter. Now, in space engineering, when you are developing a system that has to be flown five, 10 years down the road, the metrics that you compute today tend to grow because there are many things

that you don't consider in the design of your system. So right now we are foreseen a 30% reduction in mass, but as you start adding wires, as you start adding fixtures, as you fix things that break when you build the system, this margin narrows and narrows. In reality, the main competitive advantage of our technology, which is, as you mentioned before, salty water, right?

It is something that was considered before in the shuttle era, but was discarded for other reasons. So the main competitive advantage of this approach is not really the mass power or astronaut crew time. It is the robustness of it. We have been able to build a real scale electrolyzer in our lab in a few months, and we are about to test it and you saw the video yesterday but we're about to test it for multiple months at a time

right and we didn't need complex equipment or we didn't need a huge capital purchase in order to do this it is a very simple system since the origins of electricity alkaline electrolys have been with us right so it is a system we know very well and it's very simple to operate now of course it comes with challenges that we can discuss in a second but the point here is that it is not so much a matter of mass it is a matter of developing something that is easy to be built on the ground, easy to maintain in orbit, and can persist long periods of dormancy and long periods in space. That is the key competitive advantage. What has it been actually testing these things out in the lab? Like, you know, you've had a year now during phase one

to play around with the toys. How has it been? Yeah, it's been a lot of fun. As Alvaro described, we're going to run this group of phase two articles. Some of them focused on analyzing the bubbles and their trajectories, some of them focused on the overall system balance. So what are the thermal characteristics? What are the gas streams? How do they need to be treated? So these systems, in order to run on the ground, when the device itself is designed for microgravity, require a certain strategy in order to use the same shape of device,

simply because gravity keeps pushing the liquid down. And in microgravity, it's going to end up on the outside, because, of the magnohydrodynamic swirling effect, which Alvaro described. So we built a turntable, which will spin the device at five times a second, which has been very fun to develop. We are colloquially naming the device, the spinning death trap, because it's fairly large. It's, you know, it's about waist high. It'll be mounted in a fume hood, so, you know, there will be protections.

but you need to make sure that you, you know, don't put your hand near that thing. You don't also want to put your hand near the salty water because it's so salty it'll burn you. And also we need to make sure we do our electrical checks properly because, you know, you just want to make sure that when you're developing a new device, you've crossed all your T's and dotted all your eyes. So once we have those things figured out, it's actually, it's good to go. As Alver described, we don't need a clean room. We don't need, you know, very fancy catalysts.

You know, we don't have immediate poisoning whenever a little bit of iron contacts are electrodes. The proton exchange membrane architecture is incredibly efficient in some ways, but it's very, very delicate. And so for us, we're not a massive research institution dedicated to electrochemical testing and for us to be able to develop a real flight architecture layout of a device, sort of demonstrates that once you answer those critical needs, it's a fairly robust system. See, it's lucky I'm no longer in the lab because the things I would use that to do would be absolutely destructive and everyone would hate it. But you have some really exciting tests that are actually coming up. In order to do something in the lab, you've got to spin it.

But I understand that you guys are about to be doing tests in Bremen, Germany at Zarm. Can you tell us how that's going to go down? Absolutely. But before I get there, I have to mention that these ground preparations have been done by an army of undergrad and graduate students with support from Gienerlaas, which is our industry partner in this project. The ground test that the ground test that is a microgravity test. Now, the Drought Tower in Bremen is the largest ground-based microgravity facility in the world. It is pretty much an equivalent of NASA glens, a 5.2 second shaft, only that the Zandrower in Bremen catapults of 500-kilogram capsule 120 meters up.

So you can imagine basically a block of metal going up for 10 seconds and then down. And during these free-fall conditions, we're experiencing micro-gravity, right? So a similar dynamic environment that you experience at the International Space Station. What we're going to do is take the ground prototype that Theo described, put it in there, And surely for 10 seconds, give or take, depending on the final configuration, to assess the dynamic behavior of our bubbles, which are the key component we are trying to study when we enter microgravity conditions. Now, it is very fun, it is very challenging because the time window is very small. It's only 10 seconds, so we need to make the most out of them, right? But it allows us to take a look at this problem that has barely been studied before in a very, very quiescent environment.

So we are really looking forward to that. Well, now you guys are moving into phase two. What are the things that you're most looking forward to proving with this next phase of the project? So in the first year, it has been lab work to build the prototype and build a system we can test for many, many days, months at a time, right? To understand things like how humid is the hydrogen and oxygen we get out of the cell, or what is the residual contamination we have in our system at the end of the day. So those things are going to be evaluating in the coming months. But this next year is really about once we understand our system, what can we say about the architecture? How much mass do we actually say, based on the performance we are measuring?

How does this translate to a mission? What are the real impacts of this, right? But what can we say about how the final system is going to look like? That is going to be our second year of this phase two. We're very excited about it. All the work we have been doing for the previous year to build the prototype is now going to be applied to the future architecture that we hopefully will send to space. sooner rather than later. Every breakthrough in space science is built on a foundation of proven science and engineering.

The researchers doing the work day in and day out are the backbone of everything that NASA accomplishes. But every once in a while, someone looks at a problem that doesn't have a good answer yet and imagines a new way through it. That's what NIAC is all about, planting the seeds for what comes next. We'll leave a link for the full NIAC symposium webcast in the show notes for this episode, along with other resources to help you learn more. Now, let's check in with Dr. Bruce Betts, our chief scientist at the Planetaria Society for What's Up.

Hey, Bruce. Hey there, Sarah. Well, we've talked about a lot of really cool projects at NIAC over the last two weeks, but I want to talk about something that isn't NIAC for a second because we're just two weeks away from the launch of MMX, and I am so excited for this mission. Yeah, it's super cool.

Japanese-led MMX mission headed off to orbit Mars, land on Phobos, sample Phobos, the moon of Mars, go by Demos and Phobos, both these two small moons. It's super cool. In fact, let's talk about those groovy little moons. So they're both small as moons go, very small. Phobos is about 22 kilometers of 14 miles and it looks like a potato like most things in space that are rocky. and demos looks like a different shape potato and is even smaller maybe half that. Phobos is intriguing in part because it orbits closer to its planet than any other moon in the solar system. And it actually, there are a lot of weird implications of that. Even though it orbits prograde, so the same direction as Mars,

Mars takes a little over 24 hours to rotate once, whereas Phobos's orbit is only about eight hours. So it actually rises in the west and sets in the east. east. It books it across the sky. And its orbit will degrade over time and a few tens of millions of years from now. It will first get ripped apart and form some kind of rocky ring probably and then it all burn up into Mars atmosphere crash into Mars. So that's the Fobos story. And Demos, there's been less close imaging of Demos, but again, this similar rocky beast. And the question which various spacecraft and sets of data have tried to answer the mystery of these moons is where they come from and are they captured asteroids they look kind of like asteroids i mean

rocky stuff or were they made from mars kind of like our moon with a giant impact kicking rock out into space that then coalesce together it's still unclear so that's the main focus of this mission is to get lots of up-close imaging and spectroscopy of both objects, as well as other types of data, and then actually do sampling of the surface of Phobos with two different sampling devices, one kind of robotic arm and the other, Planet FAC, which was a rapid system for collecting samples that the Planetary Society stepped in a couple of times when they needed help, and our members and donors helped us get them to the next step. they've flown to the moon and collected successfully sucked up dirt from the moon,

and now they'll do the same at Phobos. And so this way they've got a couple different samples with different techniques. So we're excited about it. We're excited to find out what the deal is with these asteroid-like items that are around Mars. Part of what they'll look for is the evidence of water and organics entrained or otherwise in in the rock of the Phobos and Demos because it's more likely to be associated with an asteroid

that's been captured rather than something that's kicked off Mars. Probably when it gets kicked off Mars, that heat is going to vaporize the water damage to the organics and you're going to end up with something that seems different. So it'll be cool. They launch right away. They get there in 2027, they being the spacecraft and all of its components

and little instruments of fun. and then it'll take a little bit to get the orbit nicely circularized and approach phobos of image demos. But then they'll do the sampling and the samples will come back in 2031. So that's the round-trip time, including sampling. And so it's cool. It's cool. We're excited. Are you excited? Oh, yeah. I mean, come on. We're going to actually have samples from Mars that aren't just Martian meteorites. And I guess it's the Martian moons and not Mars itself, but still. And I'm really curious. man. Part of what confuses

Phobos is some of the surface is probably littered with Mars dust from other impacts that do things. So we'll probably get some Mars as well as some Phobos. That'll be confusing. But you know, I just, after going to Honeybee Robotics

and seeing Planet Vacan action, although it was with nerds candy instead of with, you know, Martian fake regolith or something, but I don't know, it's going to be really cool to think about the fact that this technology that we've helped enable is actually going to be landing on a moon of another world.

We put some cool stuff on Mars, but putting it on a moon, other than Earth's moon, that's pretty sweet. Speaking of facts, let's go on to a random space fact. If you're on the moon and you're oriented so that you're, well, first of all, you're going to be chilly because you need to be on the night side of the moon, when you see full Earth, like full moon, completely illuminated. Full Earth is about 50 times brighter than full moon as seen from Earth, because Earth is bigger by a lot and brighter. Oh, man. I just like imagine that. I don't know if you need like sunglasses in the middle of the night to stare at the

earth from from the moon. That's just so startlingly bright. It's startlingly, but it'd be startling to be on the moon and, you know, just doing that. Yeah. All right, everybody. Go out there, look up the night sky and think about sampling another world with your hand. Thank you and good night. We've reached the end of this week's episode of Planetary Radio, but we'll be back next week with more space science and exploration.

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Or if you're a planetary society member, leave a comment in the planetary radio space in our online member community app. Planetary Radio is produced by the Planetary Society in Pasadena, California, and has made possible by our members all over the world. You can join us, as we dream about the future space exploration at planetary.org slash join. Ray Powelletta is our producer. Kate Howells and Mark Hilverta are our associate producers. Casey Dreyer is the host of our monthly space policy edition, and Matt Kaplan hosts our monthly book club edition. Andrew Lucas is our audio producer.

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