Mitigating Lunar Dust for Future Missions

Yeah. Hey, it's La Lichman and you are listening to Science Friday With the Artemis missions, NASA aims to begin construction on a lunar base in late twenty twenty eight. There is a lot of tech that needs to be worked out. including What's for dinner You gotta eat to live. Remember the movie The Martian where Matt Damon Botany is the Dg out of his situation I now have four hundred healthy potato plants I dug them up, being careful to leave their plants alive The smaller ones I'll reseed larger ones are my food supply All natural organic, Martian grown potatoes And it turns out this is not just science fiction, there's real life research on growing spuds in space. So how far off are we from successful space gardening? Here to hash it out is Dr. David Handy. He's a space biologist studying how to grow potatoes in moon dirt, and he's at Oregon State University. Welcome, David Hi Thanks for having me. Thanks for being here How often do people name check the Martian with you? Oh all the time. I got my start in the space biology stuff right around the time that The Martian came out and I was actually working with plants in Martian dirt back then. and so it was perfect. I got to say, you see I' the Martian? I was on a tech school campus. So the answer was always yes. And I said that, but I'm working with lettuce Okay, so how do you go about doing these experiments? growing food in lunar dirt. Like whereere do you get the dirt, for instance? Uh so Sadly, we cannot afford to get the genuine So we work with what's called lunar regolith simimulants So it's fake mooner And there's a few places that you can get it. you know, NASA has teams that survey places around the globe for minerologically similar areas that we can then dig up, maybe add a few things to make it a little more accurate U There's also companies that specialize in making these simimulants where it's fully synthetic, they just get bulk mineral pure mineral and they grind it. and mix it into the proportions needed to simulate the moon And does it have all the nutrients you need to grow food? Like how is it different from regular soil? So the main distinction between regolith and soil is there's no biology going on in reggolith. So soil here on Earth Things are living in it, thingsings are dying in it. There's microbes. There's plants that are living and dying and decomposing and giving this biological component to the dirt Whereas Reolith is biologically sterile. There's no life going on, especially the genuine thing Do the potatoes grow differently They do, yes For one thing, they tend to grow a lot smaller And, you know, a part of that is, you know, soil texture. compaction preventing the roots from growing too well We're also looking into if there might be some issues with certain heavy metals in the soil and those can many of those can cause stunting, even the ones that are Need as micronutrients If you have much of a good thing, it can become a problem. So one thing that we're learning is that when we Do this for real on the moon, we're going to need to really tailor our fertilizer system to the soil itself So we worked with regularly from the Lunar Mare, which are the darker colored portions of the moon when you're looking at it. those are low elevation. It's called the Mare as in maritime because If the moon did have water systems, those parts would be where the ocean is because of the low elevation And then there's the lunar highighlands which are minerologically different. That's the lighter colored portion of the moon that we see That reflects all that, that bright light back at us And so what we are finding is that just between these two types, there's a lot of differences, which that's kind of to be expected, you know, here on Earth. I'm here in Oregon and the dirt between Western and easastern Oregon alone is very different. You look at that compared to the dirt back in Florida where I did my grad school Very different soil chemistry mineralogy, texture All these things are different, and all these things will impact how plants grow Is there something special about potatoes that make them a good candidate for a space garden. I mean, you also mentioned lettuce. Uh yes. so potatoes specifically are G to be our prime candidate for that caloric dense staple crop So you know, a lot of other things that NASA iss looking at. they're looking at pick andat crops like lettuces and tomatoes, things that require very little preparation so that the astronauts don't have to spend all their time. Pcessing the plants into something edible They still need calories and especially once we're on the moon and can have a large structure where we can grow a large amount of crops. Potatoes are one of the largest outputs of calories per unit area that we have So they're very calorie dense. They are also very nutritious and also they're very versatile. You can do a lot of things with them. you can Make them into chips, French fries, you can mash them. Bake one whole. So one thing that space biologists consider is menu fatigue And you know, if you're eating the same thing over and over again, you get sick of it. you will want to eat less of it and if it's the only thing you have to eat You're not going to want to eat it They're versatile. Yeah, of course. Yeah. I mean, it's the idea that astronauts would be relying on this lunar garden to survive What about all this freeze dried stuff So the freeze dried stuff will be useful at first. you know, all these systems will need time to be built And become established and start, you know, cycling. uh and recycling Eventually, you know, even the freeze dried stuff, it has mas and it costs money to ship mass into space. And as we have more and more people up there, that's just going to be more and more food that we need to ship if we're relying on the freeze dried Stuff from Earth I mean, there's been a lot of attention on the moon recently, obviously with these Artemis missions and this talk about a future moon base Has your work felt more urgent? Is your phone ringing more than it has been in the past U the work does feel more more urgent I wish my phone were ringing more U You know, I'm a I'm currently a postdoc and our funding runs out in July. So I'm hoping to lan somewhere preferably at a university or maybe even with NASA themselves, if any positions are open for me to keep doing this kind of work Good luck Thank you. Dr. David Handy, space biologist at Oregon State. Thankk you for being here After the break, it's not all fun and gardening, mond dust is actually a big de problem for NASA to navigate. We'll hear about it. Stay with us Imagine this. You're an astronaut, you've landed on the moon, and as you're taking one small step for mankind, You kick up a bunch of lunar dirt. It's on your space suit. It's sticking to the spacecraft. It's getting in the machinery It turns out that mooon dust is a huge pain in the butt for NASA. Here to tell us why is Dr. Erica Jowin. She's a planetary geologist at the National Air and Space Museum in DC, and she's also a participating scientist on NASA's Artemis science team. Erica, thanks for being here Oh thanks so much for having me Is moon dirt somehow more annoying than regular dirt Um I would say it's much more of a problem than dust that we have on Earth. The technical term that we use for the ground up layer of rock on the surface of planetary bodies is reggulus So it's regulous on the moon, it's regulous on Mercury or Mars And Earth, if we didn't have life here, would also have reggolith. And yeah, it's actually kind of a big problem. Hm. I mean, we have all these grand plans for a lunar base, with these Artemis missions. How big of a problem is the Regolith So when you talk about things like building and living on the surface of the moon, The reggulith itself is a little bit tricky because it's this potentially deep, maybe tens of centimeters thick layer of ground up rock But specifically what we're talking about here is the very, very finest fraction of the regolith, specifically what we call dust So the size of lunar dust is anything smaller than twenty microns in diameter So for reference, a single human hair is around fifty microns So at the very largest size, lunar dust is like half as thick as a single human hair. But in general terms, dust can be about fifty times smaller than a single hair So really, really tiny pieces of rock and glass And the critical thing that's The reason that lunar dust is so dangerous is that it's tiny particles of angular jagged rock and glass So on Earth, We have life, of course, but we also have geological processes like wind and rain And these active geologic processes can actually round particles, including tiny particles of dust. so that they're not that sharp But because the moon has no atmosphere It doesn't have active wind or water flowing across the surface. Th particles get broken into shards and they stay really sharp And so what happens is if you kick up dust off of the surface is sharpened so it can actually stick into things, whether that's Your space suit If it gets lofted in the habitat, you can breathe it in And it's very irritating It's like like tiny needles. It's like tiny little jagged shards. So physically, it's quite abrasive But there's actually a second part to it that because the Mon doesn't have an atmosphere or a global magnetic field to protect the surface from radiation, The surface of the mooon is constantly being bombarded by radiation from the sun and from from space in general. And so this dust actually gets electrostatically charged. So not only is it tiny and jagged, but it actually can loft off the surface and get attracted to things because of static electricity, basically. So it will stick to things because of static, but also because it's sharp and jagged. And then even a third thing is that the Mon is smaller than the Earth and it has less gravity So these tiny particles of dust, once they're lofted, they'll actually stay lofted for longer than they would on Earth So it's really, it's just a big mess. This iss so annoying. everything about it seems very annoying. I mean, did the Apollo astronauts have lunar dust issues? Okay. So yes, the Apollo astronauts definitely had issues with dust And so if you think about This issue is not complepletely alien on Earth There are definite risks of exposure from fine grained minerals If anyone's worked in construction or worked with really fine grain rocks like pumice There's a very known risk of things like silicosis. If you inhale that in, it can do a lot of damage to your lungs Y this is the countertop issue too, right? Yeah, exactly. It's like like quite common on Earth. You don't want to be breathing in rock dust anywhere, right So this was an issue that the Apollo astronauts also had to contend with And starting with Apollo eleven, every Apollo astronaut noted some sort of irritation from lunar dust And this irritation included things like irritated eyes, maybe scratchy throats. was like a cough U Jack Schmidt on Apollo seventeen actually called it Lunar hay fever. You're just irritated and itchy. and it's from these tiny jagged shards of rock that's getting into your eyeballs, into your lungs And the good news from Apollo is that it seemed like these symptoms were pretty short lived. Most of those those lunar hay fever symptoms cleared up after about a day So the later missions tried to mitigate this and reduce the dust contamination inside the habitat from things like using brushes and vacuums But it was still a problem. This dust gets into everything, even if it's only on your outer suit, it works its way in and it got into the habitat and it's just got everywhere I mean, we've gotten better at purification and masks, right? I imagine COVID has helped with that Yessolute abbsolutely, whichich is kind of crazy to think about that something like COVID could help to make us safer living on the moon But think about how we treat personal protective equipment using masks. Think about the improvements in air filtration technologies So the ways to approach dust mitigation for humuman exploration on the surface of the moon has changed fundamentally in the last, you know five or ten years. How does lunar dust affect spacecraft and robots and machinery So it's kind of the same process with any sort of equipment or rovers or any sort of electronics you have on the surface of the moon Any movable parts, any hinges, joints, gaskets, the dust is going to get into those parts and it's going to cause irritation. So physical abrasion, it can wear down parts, it can break vacuum seals And then this additional component of this electrostatic charging could potentially pose a risk if you have very delicate electronics. It could cause shorts or interference, just noise So it's a factor that really needs to be considered if we're going to do very detailed analyses on the lunar surface. How do we mitigate this? Is it just like Bring the vacuums I mean, we certainly can bring some vacuums. We saw from Apollo that it's not that easy, right? You can vacuum up what you can see, but it's tiny dust and it's everywhere So There's certain aspects that are being designed for currently. So if you can make something like a spac suit out of a different textured material, maybe it would be a little bit more resistant to having the dust stick into the fabric. And then there actually was a really cool instrument that was flown to the moon recently. So this is a technique for dust shielding called the electrodynamic dust shhield And this was just recently tested on the lunar surface from the Blue Ghost mission So this used electrodynamic forces to lift and remove dust off of surfaces after it was deposited, and it was tested out and totally works So this is a really promising technology that could be adapted and better deployed in the future to remove dust and maybe repel it from accumulating in the first place Okay, what do we need to do between now and twenty twenty eight? to be ready to build a moon base So one of the big open questions for long term human habitation on the moon is the long term health impacts of dust on the human body. And these studies have been going on for years now. And as I mentioned They the Apollo astronauts didn't have any long term symptoms from dust interactions, but using lunar samples and lunar simulants, there have been more longitudinal studies of the impacts of dust on human health. And those studies are ongoing, and those are going to be the really foundational studies to see how humans can live on the surface of the moon and stay healthy for a long time. Keep us posted. Sure will doror Erica Jowan is a planetary geologist at the National Air and Space Museum in DC. Thanks again for coming on the show Thanks so much. That's it for today's show. This episode was produced by Kathleen Davis, and if you want more episodes about space gardening and our future on the Mon, give us a call, eight seven seven four sci Fy. We'll catch you next time. I'm Flora Lichtmann.