Planetary Radio • May 31, 2023

The Science You’ve Enabled

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On This Episode

Jacob buffo

Jacob Buffo

Research Scientist at Dartmouth College

Palmer in the field

Andrew Palmer

Program Chair of Marine Sciences and Associate Professor of Biological Sciences at the Florida Institute of Technology

Laura Fackrell

Postdoctoral Fellow at the NASA Jet Propulsion Laboratory

Kaplan mat headshot 0114a print

Mat Kaplan

Senior Communications Adviser and former Host of Planetary Radio for The Planetary Society

Bruce betts portrait hq library

Bruce Betts

Chief Scientist / LightSail Program Manager for The Planetary Society

The Planetary Society has just announced the latest awards in its Science and Technology Enabled by the Public (STEP) Grant program. With regular host Sarah Al-Ahmed on vacation, Mat Kaplan returns to introduce the principal investigator for a project that will prepare us to grow food on the Moon and Mars. Another PI and his team plan to analyze extreme life in super salty lakes. Planetary Society Chief Scientist Bruce Betts heads the STEP Grant program. He’ll give us an overview, and a quick look at the satisfying success of the previous projects. Stick around as Mat joins Bruce for this week’s What’s Up.

NASA’s Biomass Production Chamber at the Kennedy Space Center
NASA’s Biomass Production Chamber at the Kennedy Space Center The chamber replicates the closed growing environment astronauts will use in space or on other planets to grow fresh crops. NASA scientists Bill Knott, left, and Tom Dreschel examine the growth of crops.Image: NASA
Hypersaline lake
Hypersaline lake One of several hypersaline lakes found on the Cariboo Plateau in British Columbia, Canada. As part of Planetary Society STEP grant project these lakes will be studied using a wide variety of data collected at different scales and distances: from spacecraft to drones to in-person sampling.Image: Jacob Buffo
Close view of a hypersaline lake
Close view of a hypersaline lake A close-up of one of the small, hypersaline lakes on British Columbia's Cariboo Plateau that will be extensively studied thanks to a Planetary Society STEP grant.Image: Jacob Buffo
2023 STEP grant winners
2023 STEP grant winners Dr. Jacob Buffo (left) and Dr. Andrew Palmer (right), leaders of the projects funded by the 2023 round of The Planetary Society's STEP grants.Image: Chris Carr/Georgia Tech/Florida Institute of Technology

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This Week’s Question:

According to official records, who was the first person to sleep in space?

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A beautiful James Webb Space Telescope (JWST) poster.

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Complete the contest entry form at or write to us at [email protected] no later than Wednesday, June 7 at 8am Pacific Time. Be sure to include your name and mailing address.

Question from the May 17, 2023 space trivia contest:

Where in the Solar System is there a crater named Macbeth?


Macbeth Crater is on Oberon, a moon of Uranus.

Last week's question:

What three moons of planets in our Solar System have average densities greater than or approximately equal to 3 grams/cm3?


To be revealed in next week’s show.


Mat Kaplan: Learning to farm on Mars and looking for life in the saltiest of waters, this week on Planetary Radio. Hi everyone. I'm Mat Kaplan, senior communications advisor at The Planetary Society. It's great to be back at the Plan Red Microphone while Sarah is on vacation. She'll be back next week with more of this human adventure across our solar system and beyond. The Planetary Society has just announced the two projects that have been awarded our latest STEP grants, that's Science and Technology Enabled by the Public. In other words, by you if you're one of our members or donors. Stick around as we meet the principal investigators for these exciting efforts. The society's chief scientist Bruce Betts will provide a brief overview of the program in moments. I wonder if he'll remember me. I mean, it was more than two decades that we brought you "What's up?" And we'll continue that tradition today. It all begins with selected headlines from the Downlink, our free weekly newsletter. The May 26th edition is topped by a stunning image of what may be sand dunes on Pluto, that's if you can call tiny particles of frozen methane, sand. Check out the closeup captured by New Horizons when it whizzed by in 2015. Drop down a bit closer to the sun and you'll find a polar storm on Uranus. The data were collected over several years by the giant dishes of the Very Large Array in New Mexico, which is an awfully impressive piece of radio astronomy in anyone's book. This discovery puts Uranus right in step with our solar systems' other big planets that host polar cyclones. Move over SpaceX. NASA has picked the team led by Blue Origin as the second provider of a lander that will put humans back on the moon. The Blue Moon lander is expected to be part of the Artemis V mission. We link to the NASA release and a very cool artist concept at There's something else I have to mention. Scroll a bit farther down in the May 26th newsletter and you'll see a really beautiful painting of Pluto's big companion Charon. Here's what makes this work even more interesting. The artist's name is Ken Charon. That's right, C-H-A-R-O-N. How could he resist? Hey Bruce, we got you up front here to talk a little bit more about the STEP grants. And as I've told everybody, we're going to be meeting the two principal investigators in moments. But since you run this program, I thought you might want to remind us a little bit of why this is so important to us and why we're so glad that it's been successful. I'm so impressed by these two projects.

Bruce Betts: And I'm very happy with it. And it is a relatively new program. This is now just the second round of STEP grant winners. And basically, we created the STEP grant program to help fill out our science and technology portfolio of things that we support, niches that we can fill, that our members as a group can support and make a difference in science and technology developments. But in this case, we are able to cast the net far and wide and invite proposals through an open international competition and therefore find things that we may not have otherwise found, which has been true. And we're very happy with the first two projects that we've talked about on the radio podcast before. Now, we're very excited about these two new winners. I'm glad you've talked to them and we'll hear about their projects.

Mat Kaplan: What was the process? How did these two rise to the top?

Bruce Betts: Well, I have a dart board. No, no. With STEP grants, we invite pre-proposals first. So, people submit a couple pages with backup information. And we assess those using experts from our organization. Those, anyone can submit. And then we invite full proposals from the top of the crop. We invited four full proposals. They were all excellent, wish we could have funded all of them. But these two rose to the top after being evaluated by numerous scientists and engineers, experts in the field, as well as The Planetary Society as a whole to figure out where we could make a difference.

Mat Kaplan: You said this is the second round, so we don't have a lot to go on, but I know that you've been staying in touch with our first round winners. What's the latest on those?

Bruce Betts: Sure. And I'll also mention, Planetary Society has done crowdfunding support of science and technology since long before the word crowdfunding was invented, going back to the beginning of the organization. But now we're opening it up and making it more of this competitive open process. And out of the first round, we had a proposal from UCLA by Jean-Luc Margot, led by him, that has been making a lot of progress on the field of SETI, Radio SETI, so Search for Extraterrestrial Intelligence, taking signals from Green Bank Telescope. But what's interesting about where our piece fit in was we funded part of the development of the public involvement as citizen scientists. One of the hardest things when you're looking for signals from aliens is to get rid of all the signals from we, human aliens, that are putting out a bunch of radio interference, at least it's interference if you're trying to get rid of it. You can actually go online and you can find out on our website how to do so if you want to participate in the project and help identify the patterns that go along with the human caused interference. And basically, that's being used to train artificial intelligence processing that will be able to make the whole process more efficient and search through more signals. So, that's one over in SETI land. And then over in Planetary Defense, defending the Earth from asteroid impact, we funded a group in Serbia, the University of Belgrade, who has been making great progress doing theoretical studies of details of extracting physical properties of near earth asteroids by using a thing called the Yarkovsky effect, where if that gets measured, that tweaks the orbit of the asteroid and they're able to then deduce something about the asteroid. Eventually, its density, its surface properties. Anyway, you can learn more on our website where we'll get more out there, we'll interview them again one of these days. But both projects have been doing great over the last year or so since they were funded.

Mat Kaplan: Makes me proud. I'm a member, and that's how all this stuff is happening, with the support from all of us members and donors. And thank you for managing this for us.

Bruce Betts: Thank you. I'm proud and happy to do so. And grateful to all the members and supporters who get involved in supporting this. And grateful to all the proposers. I wish we could fund more. And hopefully, we'll be able to in the future. We'll run another one of these competitions in another couple years or so. And meanwhile, we have another competition coming out at the end of June, we'll be telling you about our newest round of Shoemaker NEO grant winners who do planetary defense upgrade observatories. But that's for another show.

Mat Kaplan: Another very successful program though. All right. You'll be back when we get to "What's Up?" toward the end of this week's show. But we can now meet Jacob Buffo out of Dartmouth College and hear about the first of these two 2023 STEP grant awards. Jacob, great to see you again. Congratulations on being one of our brand new STEP grant winners. It's great to see you, and how wonderful it is to be able to congratulate you on this.

Jacob Buffo: Yeah, thanks so much. It's great to be back. We're super excited and pretty humbled to get the opportunity to work with The Planetary Society and with the STEP grant program.

Mat Kaplan: We are thrilled to have such a great project to support, yours along with the one from Andrew Palmer. I read the proposal. What it really made me want to do is go with you when you head to those weird lakes in British Columbia. But I was surprised to read in the proposal that there has been so little study of these so-called hypersaline lakes, these bodies of water that are often many times as salty as our oceans. Especially, as we find super salty water, or at least we suspect it, all around our solar system.

Jacob Buffo: Yeah. They're pretty inconspicuous, it kind of seems. A lot of them aren't very, very big. They'll be like an acre or two, some of them might be 5, 6, 7 acres. I got introduced to them by Alex Pontefract who's one of the co-Is on the project. I got to go up there in 2019 as a graduate student to these lakes. They're super exciting systems. And like you said, they're really salty. And one of the other exciting things is, the unique geology of the region up there is such that all of these different chemicals and salts that get leached out of the rocks by groundwater and precipitation and runoff and stuff, collect in these basins. But they're not the salts that we think about, these sodium chloride salts that are in our ocean, they're these magnesium sulfate systems and sodium carbonate systems. We think that's really exciting because some of those compositions have been seen on Mars and these ocean worlds like Europa and Enceladus. So, we want to go up there and use these as our little planetary laboratory. You can kind of drive 10 or 15 kilometers from one side to the next and get a totally different flavor of lake to work in, which is really exciting.

Mat Kaplan: I think it's terrific also that these very exotic lakes are relatively close to civilization. It's not going to be that difficult for you to reach them. It's not like you have to go up into the high Andes or something.

Jacob Buffo: Absolutely. And that's another reason why we chose to go there. It's really easy to get to them. We find Vancouver and we just drive up into the interior, and can stay at a hotel every night instead of camping on the ice like they do in Antarctica or Northern Canada or something. So, they're pretty accessible. And it's great when we're up there. All the folks in town kind of know us now and, "Oh, you're back for the lakes." And they'll have suggestions for which lakes to go to. So, we've also built a rapport with the community up there, which is really exciting too.

Mat Kaplan: That's great. I didn't realize that it was more of a community of what really amounts to an analog for some of these other places around the solar system where you're probably not going to find friendly neighbors directly into the best lake. Do we know that there is already stuff that has learned how to live in these pretty extreme environments?

Jacob Buffo: There's a few folks on our team that are just specialists in the biology side of things. And one of the big reasons that we go up there is to, one, not just figure out what these lakes look like, especially from the remote sensing perspective. If you're looking at them with satellites or drones or something like that, that's the way we do planetary science lot of times.

Mat Kaplan: This is the top-down approach. You talked about this top-down approach in the proposal, which is what you're going to emulate or use up there.

Jacob Buffo: Yeah, absolutely. We go through this, like you said, the top-down approach where we go from a probe to an orbiter to a lander to a rover. And that's how we typically do planetary exploration, but we want to be able to optimize that for select insights, whether it's for looking for life or utilizing resources for future crude missions or something like that. We want to be able to do that efficiently, so we're trying to simulate that in these environments as a dry run to practice and improve that approach so we can optimize that for future missions like Europa Clipper or Juno that just got sent out or future Mars stuff as we send more and more things there. We want to make our selections so that we're not wasting money or energy or activity. And we do that on earth, right? When I'm planning a field season up there, I go to Google Earth and I'm like, "Oh look, there's a lake just over this ridge. Maybe we should go check it out." But if we go and it's not exciting, then all we did was waste a few hours and a little bit of energy walking up over the ridge, where if you make that same mistake on Mars, you've maybe wasted a little bit more than just a bit of a hike.

Mat Kaplan: Yeah, especially if your rover took a month to get to that spot that turns out to not be interesting. Does this have relevance? I mean, sure, Mars, we hope someday Enceladus, Europa, where we might find life as we know it, in quotes. Would this have relevance maybe for more exotic places like Titan and the Dragonfly mission?

Jacob Buffo: Like you said, it's a more exotic system. The farther you go out in the solar system, it seems the weirder things get. Titan has all of these different hydrocarbons and stuff like that. But we're still hoping that there could be some direct relation. Some of the big things is in the winter these lakes freeze over, so they have ice covers. And in the ice gets trapped small amounts of biology and small amounts of chemistry and information about what's underneath. When we look at this from our top-down from the sky or drones or spectra and stuff like that, can we understand what's underneath the ice in these lakes? Can we predict the composition or how biologically rich it is by what we see in the ice? Hopefully, we can extend that to more complex systems as far as just really being able to link what we see at the surfaces to what's underneath to make good predictions for where we should go, what places we should target.

Mat Kaplan: How many trips are you and your team going to make up there? And are you going to go at different times of year?

Jacob Buffo: The plan is to be able to do four trips. There'll be two in the dry season and then two in the winter. One of the exciting things about this place, it sits right in between the Canadian Rockies and the Coast Mountains, it's this high plateau area. And so, in the summer, it gets extremely hot. It'll be 40 degrees Celsius, 100 degrees Fahrenheit. And you have this warm desiccating system where you're evaporating all of your water out and you have these salt pans. And so it's this extreme, maybe not the heat part, but at least the dryness part of dry Mars system. And then, in the winter, after you've had some snowfall and rain in the fall, it gets extremely cold, -40, -50 sometimes up there. So, you have this other extreme. We like it because there's a lot of exposure for the biology and for the geochemistry to this wide spectrum of temperatures and dryness and all this stuff. We really like to go and look at these extremophiles that live in these systems and just how these systems behave. So, we'll go up two years once in the warm part, once in the winter part. The reason for this in this top down approach, using the first year as our training data set where we'll go up and we'll get all this information, boots on the ground, in-situ, grabbing all our samples and stuff, and then comparing that to aerial and orbital scale imaging and information to link those remote sensing measurements to what we're actually getting in the ground. And then, the next year will be this simulated mission. So, we want to go to some lakes that we've never been to before and we'll basically use those remote images to predict what we think we'll see in these environments and let that drive our sampling strategy. And then, we'll go up there in that second year and see how well we did or if we've really bungled it up.

Mat Kaplan: That's a really exciting part of this project that you will be doing in this second year, that simulated mission. Hopefully, not having to wear bulky spacesuits as you do it to go that far with the simulation. Who will actually make the trip with you? And you want to say something about your co-investigators?

Jacob Buffo: Yeah, absolutely. I think that's one of the other really special parts about the STEP grant opportunity here. Typically, with some of these bigger NASA and NSF grants, the teams are typically made up of professors, researchers, stuff like that. And while you might have graduate students or younger folks working on these projects, they aren't necessarily writing these proposals and leading these research components. Whereas our team is basically... There's going to be seven people on the team in total, half of the co-Is are graduate students or have just recently received their PhD. There's Emma Brown from Arizona State. She's a graduate student there who does geochemistry in extreme environments. Emmy Hughes is at Georgia Tech. She's also a graduate student and has been going up with me to do spectroscopy in these systems. She focuses on the salts in these environments and their applicability to Mars. Floyd Nichols just got his PhD from Northwestern, and he's a bio-geochemist who's been working at these lakes as well. So, he knows his way around them and looking at these biological markers that get left in these systems. That's a whole side that has an opportunity to drive this whole project. They help write the proposal, they'll be leading the sampling for their specialties in this environment. And then, there's Alexander Pontefract who was the person who took me up there the first time. She's a research scientist at Georgetown. And then, there's Mitch Barklage who will do subsurface imaging stuff. He'll use electromagnetic induction technique to basically look at the groundwater flow underneath these lakes, which is really exciting for how would we figure out where the water is on Mars. And then, Maggie Osburn, who's also at Northwestern and is a bio-geochemist as well.

Mat Kaplan: Very diverse team. And what a wonderful opportunity for some of these younger researchers. Great experience early in their careers.

Jacob Buffo: We couldn't do the project without them. They're truly leading their own subsections. They're specialists in those fields, so they're kind of holding the reins for that. And I'm just super thankful that they agreed to be part of it and work together on this. It is really a takes a village project just because planetary science is so diverse. So, to do this comprehensive dataset gathering for these lakes, I could absolutely not do it on my own. So, it's really great to have this community of folks that's willing to go up and work together, work at these lakes, characterize these lakes, and do this simulated mission approach.

Mat Kaplan: What is the STEP grant going to support? We're very proud of it and we're a small organization, but one of the priorities in this grant program was to leverage existing resources. Is that happening in your case?

Jacob Buffo: Yeah, absolutely. Most of the time as a scientist, we spend at our institutions doing our day-to-day life and things. So, a lot of these folks have grants already, the graduate students are working on different projects. All of their work is very tangential to what we want to do at these lake systems, but those specific projects might not have dedicated funding to go and work at these lakes just because it's working on a slightly different, kind of a tangential, similar problem. So, we have all these laboratories and equipment and things that are just ideal for going and exploring and working at these lakes, but we don't necessarily have the funding built-in all the time just to go and do these data grabs and in the field stuff. So, there's a bunch of different NASA proposals that I work on and that a lot of the co-Is work on that's doing similar things for maybe slightly different systems. Emma, I know, works in Yellowstone on some extreme systems. People are all over doing all these different things, but we don't have that funding as a group. This kind of island of misfit toys of folks, we don't have that funding to get together and all go up and go to Canada at the same time to work as this conglomerate team. So, the STEP grant is giving us the opportunity for everybody to come up together and do these big field seasons together to get all this data and information.

Mat Kaplan: That's great. Exactly, of course, what we were after with the STEP grants. I got to come back to biology for a second before we wrap up. I've said before on Planetary Radio that outside of quite a few mammals, including my family, my favorite organisms on earth are the pup fish that live seasonally in the waters that are found in Death Valley. The biology in these hypersaline lakes, are we talking just tiny microorganisms or is there any bigger multicellular stuff that swims around up there now and then?

Jacob Buffo: Typically, we're most interested in the little guys, the little bacterial small-scale stuff, but there's actually also a ton of brine shrimp in many of these lights.

Mat Kaplan: Oh, no kick, that's great.

Jacob Buffo: Yeah. They have a really unique cellular structure, these lakes. If you think of this big, wide salt flat, they're usually not very deep. They're usually, I don't know, 10 to 50 centimeters thick, pretty shallow lakes. But they form this really weird pattern ground where you have these sub-pools within the lake. They're really, really cool. You'll like walk up to one of these pools and it'll just be full of brine shrimp swimming around in it. And you're like, "How is this even possible for this organism that's a bit bigger to be in these systems that are completely saturated?" A lot of times the floors of these lakes have salts on them because the liquid has gotten so concentrated that the salt can't dissolve anymore, it just crashes out. So, these are 20 to 30% salt in the solution, and these little shrimp are just swimming around and they're super happy. Looking at the chemistries of these systems to figure out what is limiting in these environments to life is just another aspect of that. Why is magnesium sulfate maybe not as toxic as sodium sulfate or something like that? And picking apart what really controls habitability here so that we can extend that to other systems. And how can we measure that remotely and link that to what we're seeing in these brines or underneath these pools?

Mat Kaplan: This is so cool. I was only half joking when I said I want to join you up there. I saw the hotel is not very expensive, and I suppose I could drive to Vancouver. I promise not to step in anybody's research or on the brine shrimp. I would love to think I could make it up there someday and watch the work as it goes on. I am also sure that when this work is farther along and you have some things to report back on, Sarah, or maybe I, will want to bring you back on the show if that's okay.

Jacob Buffo: Yeah, absolutely.

Mat Kaplan: Have a great time up there. Stay safe. And can't wait to hear the results of your STEP grant. Thank you so much.

Jacob Buffo: Thanks so much for having me on.

Mat Kaplan: Jacob Buffo is a research scientist at Dartmouth College and the principal investigator for one of The Planetary Society's 2023 STEP grant funded projects. After the break, our other PI, Andrew Palmer, will tell us how he'll use his STEP grant to learn how we'll grow crops on the moon and the red planet. This is Planetary Radio.

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Mat Kaplan: A trip to Mars and back is likely to take two years or even more. Keeping astronauts healthy, fit, and happy on that long journey is turning out to be at least as big a challenge as building the spaceships that will get them there and back. Radiation, microgravity, isolation, and food. Someday when humans are living on Mars, where their next meal will come from, and the next, and the next, is a question we're not yet ready to answer. Andrew Palmer's STEP grant project may become a big step toward a solution or more likely solutions. Andrew is associate professor of biological sciences at the Florida Institute of Technology. His impressive project is titled Evaluation of Food Production Systems for Lunar and Martian Agriculture. He and one of his collaborators recently joined me for an online conversation. Andrew or Drew, which is I guess how you prefer to go by, thank you so much for joining us on Planetary Radio. And congratulations on being one of our two STEP grant awardees this year.

Andrew Palmer: Thank you very much. It's a great honor. Myself and the rest of the team are really excited to be able to work with The Planetary Society on this research.

Mat Kaplan: Now, your co-I, your co-investigator, Rafael, was unable to join us today. But would you introduce Laura who is with us right now?

Andrew Palmer: Sure. It's my pleasure to introduce Dr. Laura Fackrell who's a postdoctoral fellow at JPL and is one of our partners on the geology and the metagenomics of this project.

Mat Kaplan: Welcome Laura, and congratulations to you as well.

Laura Fackrell: Thank you. Good to be here.

Mat Kaplan: Drew, we've talked before on this show about why growing at least some of your food is going to be so important on a long, long trip and stay on Mars, and maybe even closer to home on the moon. But I wonder if you could talk a little bit more about that. Remind us. Why is it going to be important to do some agriculture on these other worlds?

Andrew Palmer: Sure. There's a variety of reasons why it's really important. One of the most vital reasons is crew morale and support and nutrition. And I guess that's more than one thing, but as it turns out, a lot of fresh ingredients will not survive the journey to the moon, especially not to Mars. And so, you need fresh produce and fresh vegetables in order to provide nutrients, but it's also taste and flavor, morale. There's a connection between human beings and our environment, plants are very much a part of that. So, I think there's a component for both food security and food safety of having plants that are grown in soil where you are, in the terrain where you are, not just hydroponically. But there's also a component to this psychologically that will be beneficial.

Mat Kaplan: Nobody has to convince me about the importance of fresh food. We have seen in Andy Weir's The Martian, both the book and the movie of course. That was almost certainly most people's first exposure to growing food on another world. And Mark Watney, the Martian, managed to do it in Martian regolith with the healthy addition of some astronaut poop. I'm sure you know. What did you think when you read that in the book or saw it in the movie, somebody doing what this project is actually all about?

Laura Fackrell: Several years ago, I had actually designed a project to look at growing plants on Mars, and it was before I'd ever read The Martian or seen the movie. I watched the movie with that perspective of like, "Oh, I'm actually doing this." But I think it was interesting to see that. And I think it provides a really useful excitement.

Mat Kaplan: Definitely. Drew?

Andrew Palmer: I read that long before I was ever involved in any of this kind of projects. In the back of my mind I was like, "Oh, that's interesting. I wonder how you would do something like that. That's not what I work on." And then, as I came here to Florida Tech, my lab sort of migrated from one area of research that we worked on into space agriculture. I really began to look at that as like, "Well, if it's good enough for Matt Damon, then it's got to be good enough." I use it actually as a really good educational tool because I can say, "Okay, so you've seen him do this. It's not that simple." But it's a powerful image in the movie and in the book, and I think it shows how strong of a connection we have for the concept of growing food. We want to grow it in the dirt. There's certainly benefits to hydroponics. And I think one of the major points of this project is to not be dismissive of hydroponics, it's to try and find the right balance of what we need. You're not going to want to put all of your eggs in one basket and rely on one way to grow food when you're six months away from Earth. You're going to want to have multiple ways that the people there can get food. And so, I think it's a great image.

Mat Kaplan: And this is obviously at the core of your proposal and the work that you're going to be doing, partly thanks to the award of this STEP grant. In your proposal, which I recommend everybody read, it's fascinating, you actually have a hypothesis about this balance between hydroponics and what you call RBA. Do I have it right? Regolith-based Agriculture? What is that hypothesis?

Andrew Palmer: Fundamentally, we believe that there's not going to be a right answer for hydroponics or regolith. It's going to depend on the type of crop that you're trying to grow. So, we think things that grow very, very quickly like a lot of microgreens that have been very popular in choices for space agriculture, those will probably be settled very easily by hydroponics. They grow quickly, very easily in those systems. But we think as you transition to foods that may take a little longer to grow, tomatoes, which is where I have a lot of experience in regolith stimulants, and some of these other plants, that there'll be a trade-off where long term it'll become easier to grow these things in regolith as you condition this material, which is not very friendly, not very hospitable for plant growth. But as you condition it over time, the benefits, they're going to outweigh the use of trying to grow it hydroponically. And then, we have a efficiency specialist looking with us to look long term, what we call, the cradle to grave relationship. If you factor in resupply missions to bring in new equipment for hydroponics versus fertilizer inputs for terrestrial agriculture, or I guess in this regolith based agriculture, where does that point break? And we think that's really what's going to come out, an understanding of the trade-off.

Laura Fackrell: And I think a big part of that too is considering the microbiome that the plants have. And that microbiome is really made to grow in a soil environment that they're all supposed to evolve to be in. And it changes. And actually, certain types of microbiome relationships struggle in hydroponic setting. So, depending on the plants and how important certain microbial relationships are, for example, legumes are a big one for that. Peas and peanuts and different things that can participate with nitrogen fixation, that could be a big one that is important. That's really difficult to do hydroponically. And so, it's trying to figure out how the healthy microbiome and how to balance that, and which crops and diversifying your system so it's more sustainable.

Mat Kaplan: Laura, I'm really glad that you brought this up because the microbiome, it's a big part of this project. But haven't we realized, actually in fairly recent years, that there's so much going on in the soil or wherever plants are growing and that it really is a symbiotic relationship. So much of what we grow for food depends on these tiny little critters that make up the microbiome.

Laura Fackrell: Yeah. It's a huge question and one that we're just really scratching the surface on even in terrestrial agriculture. Not only the root microbiome, but also the above-ground microbiome, basically the leaves and the stems, and how that interacts with the plants, how that changes if you fertilize settings and how that alters what relationships that has, what nutrients it's allowed each uptake, how it helps to defend against pathogenic infection, lots of different mechanisms that microbes can use to relate to plants depending on what you're doing to help grow those plants can affect so many different parts.

Andrew Palmer: One of the things that I think is important when we distinguish between hydroponics and RBA is, hydroponics you have fewer of those interactions that occur. In some ways, you have more control over the environment in a hydroponic system, I'd argue, than you do in a regolith based system. Regolith-based agriculture is going to be just traditional farming, you're going to have to tease out a little bit more about what's going on. But these microbial associations are so critical and they can play a really big role in also helping us create a more sustainable ecosystem on these settlements. How are we going to help process waste? These microbes can be a participant in that process.

Laura Fackrell: Drew said something important about you can technically more tightly control the hydroponics, but we also have to more heavily control the hydroponics because if it goes out of that range, you lose half your crop or even all your crop. But there's a trade-off between you can't control the regolith maybe as much, but there are advantages to that. So, it's just finding that balance between two.

Mat Kaplan: We love to say space is hard. Maybe farming out there is even harder in some cases. I was so impressed, Drew, when I was reading the proposal by the experimental process that you describe and the type controls and the comprehensive data gathering that you've laid out. It's pretty awesome.

Andrew Palmer: That's a real testament to Laura and Rafael's contributions as well. We've been working together as a team now for about two years on various projects. This is the first real research project we've been doing, but we've been intellectually consulting and working together. This is a great opportunity for us.

Mat Kaplan: I think you mentioned microgreens, lettuce, tomatoes. And I know that by microgreens, you're also talking about radishes. I have to say that if I was living on the moon or Mars and had to live on radishes, I'd probably go outside and take my helmet off, I'm not a big fan of radishes. But lettuce and tomatoes sounds just fine. You sort of addressed this, but why those three choices? Why will these be your crops?

Andrew Palmer: A lot of this is because it's what we have seen before. If we're going to do a comparative study looking side by side, we want to use some of the most established crops possible. For instance, the outredgeous lettuce is what's been grown in the veggie system on the International Space Station. And it's a lettuce that has gone all over the world now. It's so highly grown just because those visual images are so powerful. But we also have a lot of information on how to grow it. So, we've been growing it in my lab for three, four years now. So, we really have a feel for how it's going in the regolith and whether or not we're about to lose a plant, we're about to get lettuce we can eat. And then, the same is true on Rafael's experience working with the microgreens is he's got a lot of experience working with those microgreens in lunar stimulant. And so, he has a good sense for the same thing. And so, when we compare these hydroponics, we'll have an understanding of what we're looking for. And then, on my end, I have a lot of experience with the tomatoes. And the other reason for bringing in the tomatoes is that both lettuce and microgreens are what we'd refer to as short-term crops. If you think of an index of edible biomass versus inedible biomass, the most of those plants can be eaten. The microgreen, you can eat everything. The lettuce, you can eat almost everything. With the tomato, there's a high amount of inedible biomass, amount large enough that you can't eat and you're going to have to compost or recycle in some other way when you're on a lunar settlement or on a martian settlement. And so, that's really what we want to get at is, when you start to have these inputs into the system that are going to have long-term impacts on waste management, how well do those regolith hydroponic rules and trade-offs, how well do they hold up? Because you have to start thinking about the fact that you're sinking carbon into these plants, parts of these plants you're not going to eat in a while, and nitrogen. That has potential to skew how you gear your life support set up. And so, we want to think about that. Also, I like tomatoes a lot, so. I want us to have some other plants also. I think if I had to live on just lettuce and radish, microgreens, I wouldn't be so happy either.

Mat Kaplan: Yeah, okay. So, we're together on that. Laura, part of what you bring to this project is just fascinating. First of all, you have those great resources in your lab there at JPL, which I guess partly addresses how the STEP grant from The Planetary Society will leverage these other great resources. So, thank you to NASA and others for making this an even greater project. I think of the tools that you're going to use to examine what's happening at the smallest level, really at the level of the genome of these plants, right? DNA?

Laura Fackrell: Yeah. That's the part that really fascinates me. My current project that's related to this and how I'm connecting in is looking at nitrogen and how we can recover that from plant waste and different things like that, like Drew was talking about. I'm already looking at legume and rhizobia which is that nitrogen relationship that we talked about, where we have nitrogen fixation happening. And now we can add on some of these other plants and see what they're doing and what is the microbiome that's happening and get a bigger picture for what is really big, complex questions. That's going to be really fascinating.

Mat Kaplan: Drew, what exactly will the funding from the STEP grant do? How is it enabling this? What's it going to pay for?

Andrew Palmer: One of the great things is actually, it wedges nicely into a bigger piece of all of our research, both Laura, mine, and Rafael's. In my case, we're working with another group from Arizona State University, where we're looking at the removal of toxic perchlorates from martian regolith. Probably most of your listeners are aware, but the surface of Mars has a really high concentration of perchlorates. And we've shown in our group that that basically kills almost every plant that you try to grow in it. And so, that's been something that we've been working on with them through an NSF grant to fund that. And so, what we have is a great capacity for evaluating the nutritional quality and growth factors that associate with the plant. And where this funding fits in is it gives us an opportunity to help fund a student who will do a lot of this work and travel between my lab and Rafael's lab and actually work on both ends at these institutions and bring these resources together so that we can analyze the plants. They'll isolate plant material so that they can send it to Laura for extraction. We'll be looking at what we call metabolomics, which is a large-scale examination of all of the different small molecules, sugars, lipids, and small factors that are being made by the plant in order to understand how it's growing differently between regolith and growing in hydroponics. It's a really great wedge into all of our work that fits nicely.

Mat Kaplan: Maybe the most exciting thing to me about this project is what it says about how close we are to actually putting humans maybe on the moon to live there, but also sending them to Mars, that we are considering what's going to be necessary, and it's going to be hard to make this successful, to let those people thrive and do the work that we need them to do in these places. Do you ever sit back from your data for a minute or two and think, "Wow, we're really part of this effort to put humans on another world."

Andrew Palmer: Yeah. I just took a bunch of undergrads to a regional plant biology conference in Arkansas. And we were working on all their posters. And we've got mushrooms growing in regolith and all these different things that we're working on. And they're so excited and it's infectious. So yeah, it's a fantastic line of work. Just to sit back and think about how the discussions we're having are not like, can we survive there? It's more about, are we going to grow hydroponically or are we going to grow in the dirt? And which is the right one to do? The very fact that we're actually having a calculated discussion and study into the optimization of what you're going to grow means we're past the stage of, can we grow there? We know we can. We know that we're going to be able to, the question is what's going to be the most efficient and the best opportunity for the settlers on those missions?

Laura Fackrell: I think it's also a topic that people easily relate to. Sometimes when you talk about your science and you get deep, people are like, "I have no idea." But this is a really easy topic. You can just say, "My project works on growing plants in the moon or on Mars." And they're like, "Oh, that's cool." They can just instantly connect with that. And so, it's really exciting just to be able to talk to people about it. And it's also just really exciting to inspire people to get excited about science, especially students in high school who are like, "Science is too hard." And you're like, "It can be hard, that's true. But look what you can do with it." And it's a really easy topic to help students become excited, and that's a really cool thing.

Andrew Palmer: It's been a great educational tool for just engaging students and teaching them basics of... I have students who come through my lab, they're like, "I'm not interested in plants." And I'm like, "Just wait." And by the time we're done, they're converted. They care about plants, they care about environmental science and soils and erosion, and they understand better the world. Again, it's showing us how we can use what, kind of piggybacking off of what Laura said, that we can use these tools to educate a next generation of people who are not only interested in space, but also in how this world works and the challenges that we're facing here. So, they understand better when they see, "God, it's going to be so hard to grow there because of nitrogen issues and fertilizer." And we say, "Well, why don't you go look down the street, at the farm there, and see the challenges that they're facing." It shows them how biology is biology wherever you're going to go. These fundamental rule is what we're teaching.

Mat Kaplan: You have proven with even just this last point, these collateral benefits of this project, why this project, evaluation of food production systems for lunar and martian agriculture, was such a great choice. Congratulations once again on becoming only the second year recipient of a STEP grant from The Planetary Society. I only wish that I could be around in 50 or 60 years to hear the arguments between hydroponic farmers and regolith farmers on Mars about who has the superior way of growing food for the martian colony. Great to talk to both of you, and I think you can count on us asking you to be back when the project is farther along to give us a little report here on Planetary Radio. But thanks so much and congrats again.

Laura Fackrell: Thank you.

Andrew Palmer: Thank you.

Mat Kaplan: Andrew Palmer, principal investigator for one of the two 2023 STEP grant projects just funded by The Planetary Society, his colleague and collaborator, Laura Fackrell is a post-doctoral fellow at the Jet Propulsion Lab in California. Congratulations again to both of our STEP grant teams. It's time to welcome back, Bruce and "what's up?" Hey, Bruce, welcome back. I'm going to tell you a cute fact that Jacob Buffo mentioned to me after we stopped recording because he talked about in the interview how he had made previous trips up to those salty lakes in British Columbia. And they worked hard when they collected samples, not to pick up any critters. But one time they accidentally picked up a little brine shrimp. And they brought it back to the lab and gave it a name. He became Jeffrey, the brine shrimp, who was the mascot of the lab. He lived for another two or three years.

Bruce Betts: Oh my gosh.

Mat Kaplan: Probably longer than he would've made it in that salty lake.

Bruce Betts: Yeah, I'm guessing, all those brine shrimp predators.

Mat Kaplan: Listen, that's what's passed. What's up?

Bruce Betts: What's up is Venus, Matt. Venus, right around its highest point in the sky this time around. In its appearance, super bright, brightest starlike object over in the west after sunset. Easy, easy, easy to see. And it's a good time. But you can also look a little bit higher, and there's a much, much, much dimmer, reddish Mars. It will be growing closer to Venus over the next few weeks, and I'll update you on that. And you can also check out in the pre-dawn, we've got Saturn now, yellowish, high up in the east before dawn. And Jupiter is actually getting much easier to see, low down to the horizon in the east, looking super bright. Mercury is near Jupiter. If you can pick it up soon, it's below Jupiter. But it'll be getting lower over the next few days. So, a lot of good planet action pre-dawn or evening. And during the middle of the day, you can look down between your feet and see the earth. All right, let's go on to what was and what shall be and what still is, which is This Week in Space History. And in this week in space history, 1966, surveyor one landed on the moon, soft lander, robotic lander from the US. And in 2003, which I think is strangely 20 years ago, Mars Express launched European Space Agency's Mars orbiter, and it's still doing its thing at Mars. Very impressive. That's this week's profound space fact. But let me give you a less profound little space fact.

Mat Kaplan: Ah, I've missed that.

Bruce Betts: Apollo 11, they just tried to sleep for a little bit on flat surfaces on the floor, essentially the lunar module. Apparently, both of them pretty much failed to get any sleep. They tried hammocks in the later Apollos, and there was some more success, but still found it tricky, just sleeping with the, you're still in gravity but you're in a little tiny space and all sorts of other issues. Now, of course, on the International Space Station, they just kick back and relax in sleeping bags and float around and have crazy, crazy, crazy dreams.

Mat Kaplan: Yeah. Someday, I want to give it a shot. I'll sleep on a hard metal floor. I'll give that a shot, especially at one-sixth gravity. Just get me up there, I'll sleep like a baby.

Bruce Betts: Your willingness as a guinea pig is something I've always, let's say admired, let's use the word admired.

Mat Kaplan: That's good, I like that.

Bruce Betts: All right, so we move on to... We played Where in the Solar System? And I asked you, "Where in the solar system is there a crater named Macbeth?" How'd we do, Matt?

Mat Kaplan: I don't get the entries anymore, and all I have is our winner. So, apologies to any of you out there, and I'm sure there were many, who made very clever answers to this and probably emulated the bard himself. But all I've got is our winner, Linda Yarborough from Anchorage, Alaska. She said, Macbeth crater is on Oberon, a moon of Uranus. Out, damn crater. The prize, Linda, that you're going to get is a Goodnight Oppy 12 ounce thermal mug. I've seen these, they're swell. Use it in good health as you listen to Planetary Radio. So, congratulations.

Bruce Betts: Congratulations. And I guess we'll go on and we'll go back to the topic of sleep. According to official records, who was the first person to sleep in space? Was it Mat Kaplan? Was it someone else? Go to

Mat Kaplan: Cool. All right. I'll try and stay awake for this. You have until June 7, Wednesday, June 7 at 8:00 AM Pacific Time to get us the answer to this one. And Sarah let me know that she has exactly one JWST poster left. The really, really cool James Webb Space Telescope posters, that I think she's given away a couple of at least, could be yours if you get it right and you're chosen. So, get us those entries. And you'll hear the answer from Bruce and Sarah in a couple of weeks.

Bruce Betts: Hey Matt, great to have you back. Keep guesting, keep checking out, keep hanging out, keep on trucking. In the meantime, everybody go out there, look up the night sky and think about [inaudible 00:49:44].

Mat Kaplan: Sarah will return next week. Her guest, Sarafina Nance, has written Starstruck, a science packed memoir about how this Egyptian-American astrophysicist and analog astronaut overcame obstacles in her reach for the sky. This has been great fun. I hope you'll hear from me again soon. In the meantime, I'll see those of you who are Planetary Society members in our online community where I host the book club. Planetary Radio is produced by The Planetary Society in Pasadena, California, and is made possible by our members who make the STEP grants and so much more happen. You can step up at Mark Hilverda and Rae Paoletta are our associate producers. Andrew Lucas is the audio editor. Josh Doyle composed our theme, which is arranged and performed by Pieter Schlosser. Ad astra.