How to keep Martians fed and happy

Published Nov 5, 2024, 6:00 AM

Daniel and Kelly talk about the future of food in space. Do you like lukewarm cricket tacos? 

In nineteen ninety one, eight people entered Biosphere two. You may have heard of Biosphere two. There was a polychchore movie sort of based on Biosphere in the nineties, and as a child of the nineties, I of course watched it and learned so much about the value of friendship. But Biosphere two was a three point one four acre enclosure out in the Arizona Desert that was meant to replicate Biosphere one, which is the Earth. So they had a rainforest, a marsh, an ocean with the coral reef, a desert, a savannah, agricultural fields, and human habitats. And the people who started this giant experiment had future settlements in space in mind. If you could figure out how our Earth works and you can miniaturize that, maybe you can take that out with you into space and create sustainable habitats for humans in space. But during this first run, the men lost eight teen percent of their body weight and the women lost ten percent. They just were not able to create enough food to keep themselves going. And this was despite the fact that they were spending an average of eight to ten hours a day five and a half hours a week doing this kind of stuff. And that doesn't even include the other kinds of things that you would have to do if you were, you know, trying to make a living on Mars, like running a power plant. Biosphere too was running off of the grid, so on Mars there'd be all this extra stuff like crewing the solar panels that you'd have to worry about. But we need more experiments like these. Probably it would be better to start on a smaller scale and then sort of scale up so we can understand the systems better. But we need these kinds of experiments where you're in a closed environment. The amount of plants that you're growing determine how much oxygen you get and how much carbon dioxide is extracted from the atmosphere. We need to prove to ourselves that we can live in these systems while growing sustainable amounts of food. These experiments take time because they happen at the pace of ecology, which is slow. So today we're going to talk about what we've learned from these kind of closed loop systems so far and what other kinds of challenges we might have as we attempt to grow food to keep ourselves alive on Mars. So welcome to episode two of our series on food in space and Welcome to Daniel and Kelly's Extraordinary Universe. Hi.

I'm Daniel. I'm a particle physicist and a professor at UC Irvine, and I would never ever ever go into biosphere too voluntarily.

I am Kelly Wienersmith. I study parasites. I have been dying to visit biosphere too. Like I'm thinking of going to a conference in Arizona so that I'll be close enough to visit biosphere too. Why don't you want to go in the same reason.

I get the chills when I visit Alcatraz and they ask you to step into the cells, and I'm like, oo, feels like you will asking to get trapped.

Huh. So I am claustrophobic, and I went into a cave on with family and was like, I have to get out of here. But I think three point one four acres is big enough that I don't feel trapped. But anyway we can differ.

Well, let me ask you another question about that kind of scenario. Imagine you're living on the surface of Mars, struggling to survive. Is there some kind of food that's so gross you'd rather starve than eat it and survive.

Oh man, Okay, Well, so first, I just finished re listening to the story of Adolphus Greeley's trip to the Arctic, and I think that what you learn from a book like that is that when you're hungry enough, you will eat anything.

Did he like boil his shoelaces and make tea or something?

He did? Yeah, they were eating their shoes at the end there.

Oh no, that was a joke.

Yeah, no, it gets bleak. They were also accused of cannibalism, but there's no solid evidence, but a lot of them didn't make it. So I'm sure that if I got to that point, I also be eating my shoes. But I can say that most of the food that I've read about as it pertains to life in space are not things that I think would be delicious. Like I happen to come from a culture that doesn't eat a lot of insects, and that seems to be a major recommended protein source in space. And you can find recipes for how to like hide insects by like grinding them and like mixing it up with wheat, so you can have like cricket bread that doesn't taste so crickety, but I don't know what about you. Are you more adventurous.

I'm pretty adventurous, and I think it's hard to predict how you'd react in those situations. But I've thought about the cannibalism question, like would I rather starve or eat people? Oh boy, I'm very happy to not be in that situation because I don't know how I would react. Probably i'd be eating people.

I mean, I think if I was gonna die before the rest of my crew, I would want them to eat me because I wouldn't want them to die. If they could like stretch it out and increase the probability that they.

Live, wouldn't matter who though.

I mean, I guess if I had a death wish for someone, I feel differently. But uh, and you probably reading about how these like closed loop systems work. Often the crews end up hating each other, like in biospheric, you know, they were spitting on each other. So maybe I'd be like, you know, Jane can eat me, but Brian cannot, and that is my dying wish.

Yeah, or especially if you're on a colony you might be related to some of these people. You're like, all right, my kids can eat me, but don't share me with the Millers over there, because you know they've been jerks.

Yeah, Oh, let's get space gets weird fast.

I know exactly. And that's why space is so fascinating, because we know it's gonna be tough. We know it's going to be difficult, we know we're gonna have to push the limits of human ingenuity but also probably the limits of human experience and culture and what we think is appropriate.

Yeah. I think that there's some things that you can learn by looking at like Arctic expeditions, and I think we should have an episode on that in the future. But you know, you see that people will do so I think two lessons there. One, people will do extraordinary things to survive, but two, they still treat each other really well at the end in most situations like there, you know, as the Greeley expedition members were starving to death, they were like spoon feeding each other and holding each other and like they were it was very well sweet, I don't know sweet sweets the right word, but their humanity was maintained even in the case of this, this horrible situation. It gives you a bit of hope for humanity.

Well, maybe they were just exceptionally nice people, because I'm not sure everybody would end up babing so well, yeah, fair.

And then the question is are humans nutritionally complete? I don't know if they are, so you also, you know, there's a lot to think about when you're eating in Mars.

Do you need to add beans to your meal to get all your proteins? Yes? Great question. Yes, And these are just a sampling of the questions we're gonna be talking about today as we explore how humans can feed themselves in Space episode Part two.

So, Daniel, I'm wondering if any of the people that you talked to on the street brought cannibalism up in the conversation as quickly as we did when you ask them about food on Mars.

Let's find out. I walked around the campus if you see Irvine, and I asked people what they thought was going to be the biggest challenge to feeding people in a colony on Mars. If you would like to contribute to these audience participation segments in the future, please don't be shy. Write to us two questions at danieland Kelly dot org. We'd love to have your voice on the podcast. So think about it for a minute. What do you think is the greatest challenge to feeding astronauts on Mars? And is it finding the right marinade recipe for human thoughts?

Oh?

No, too much, this whole episode I might dump.

I'm just slowly trying to change your opinion about cannibalism, because really it's just a cultural thing.

You know, there's a culture that was really into it, and they got this protein disease called kubru, and so I think there's good disease related reasons to not eat your family.

All right, pull your biologists credentials there.

Fine, But I do have an expert on cannibalism that we could talk to in a future episode because I know all the best people.

That sounds great as long as it's not over dinner. Let's get back to our audience participation segment. Here to folks around the uc Irvine had to say about challenges of living on Mars. The astronauts could make sprouts and stuff like that, so on Mars a few ways to do that too.

I mean, we all saw The Martian.

The Martian was not a documentary, but the process felt feasible, Like they need water there first, to supply it, and the climate.

I guess how cold it is. Nutrients in the soil, so you have to bring like nitrogen, and I think we basically have to find ways to make local fertilizer possible. I mean also, I think at some point, like there's this the bare minimum to keep people alive. It keeps you alive, but it's horrific and nobody's gonna want to come to Mars, so there's kind of a marketing inside of this.

Well, so far we have not established an a sort of colony on Mars there we could even grow any food.

So it's a bit of a premature question, to be honest.

I guess he did it in that movie The Martian and not supposed to be accurate.

Not a documentary.

Not a documentary. No, that's right, But I guess you'd have to do it someday. And you've got some frozen water in the ice caps, so people always talk about terraforming it and getting that liquid water, so maybe it's possible.

Well, no one brought up cannibalism, which is a little disappointing, but you know, I'm glad they focused on the more immediate challenges. Yes, water came up a few times. One of the great things about Mars actually is that there's kind of a lot of water. So there's water at the poles and just about anywhere you go. If you dig down far enough, you're gonna hit frozen water. We're gonna talk a little later in the show about some of the problems with that water, and it's going to be hard to get, but there's water, whereas on the Moon there's a lot less than it's even harder to get.

One thing I've found fascinating is how many people refer to The Martian, and it's very entertaining, but it's also amazing how much science people seem to have learned from that movie.

Yes, so I like The Martian because it got a lot of things right. So, like, Mars has one percent of Earth's atmosphere, so you do get dust storms that kick up like or that can engulf the entire planet. But because you only have one percent of the atmosphere, those winds are not probably strong enough to like knock over a rocket. And as you correctly noted in these interviews, it is not a documentary, and so it wasn't one hundred percent correct, but it was very well researched, and you know, I think it's fine for fiction to take some scientific license.

Something I found fascinating is how many people saw the movie and didn't understand that it was a made up story. A bunch of people came out of theater and thought, oh, this is a true story about something that really happened to somebody on Mars.

No.

Really, a lot of people googling like is The Martian a true story after they saw the movie, which is like maybe a testament to the apparent realism of it. But yeah, you're right, there's definitely some science issues with that movie.

And again, I don't think that's a problem in my mind. That's the only thing that matters is that you create a world and then you stay consistent with the rules you made for that world. And I think The Martian was incredible, not complaining, but yeah, also not a documentary. Also, when I was researching a city on Mars, I was surprised by how many people in the literature on settlements would be like, well, could such and such happen well in the expanse, And I'm like, dudes, that's fiction too, And like, I know the author, he's a great guy, but He's like, he hasn't been there. None of us have the author's quarrel, right, because there's two of them.

The expanse not a textbook, you.

Say, yes, that's right, very well thought out, great character development. Not a textbook.

Well, I've written a lot of science papers and have never cited science fiction in those papers. So maybe that's something I should try. That sounds like a lot of fun. But today we're not talking about science fiction. We are talking about science, and I'm very excited to hear about the science. I'm growing food on Mars whether we do need to be pooping in our own gardens. But first, Kelly, you were going to tell us about experiences here on Earth that are sort of simulations for what life might be like on Mars. Where do we start with that.

Well, let's start back in the nineteen sixties in the Soviet Union, so while the space race was heating up the Soviets, we're interested in figuring out like, okay, not just how do you grow food on Mars, but how do you make that food work for you in a lot of different ways. So if you are in a sealed environment, every time you breathe out that carbon dioxide it just builds up and it could suffocate you. And you know, people complain about headaches way before the suffocation happens. So you could have chemicals and devices that remove the carbon dioxide, but you could also just let the plants do that work for you. And so they try to come up with systems where the plants pull out the carbon dioxide. The plants also produce the oxygen that you breathe, and then you can like recycle the plant material, maybe by feeding something else with it. And so just trying to be as efficient and good at recycling as possible.

So making a system which is enclosed and self sufficient and where things support each other so you don't need to be injecting supplies from the outside. That makes sense.

Yeah, it's so expensive to ship stuff from Earth to space, and the stuff that you have you want to get the most use out of. So you know, anything that you can stretch the use of in space like you want to do. And you know, every once in a while it feels like this goes in cycles. But people will get really excited about algae and so, you know, algae grows fast. It you know, takes up carbon dioxide, releases oxygen, it like you can grow it in a vat, so you can get a lot of it in a small area. And so the first experiment was called bios that we're focusing on growing algae, an attempt to like do a bunch of this stuff. And it worked pretty well actually, but a major complaint was that algae sucks to eat, and like.

Does it taste as bad as it smells, because it don't smell great.

No, it smells awful. I hate that smell actually, And I actually lived with two roommates who studied algae, and they smelled great, but like they did not enjoy talking to me about algae because I would always tell them how bad it smells.

But you know, also, like blue cheese doesn't smell great, and if you smell blue cheese for the first time, you're like gross. So I wonder if algae is just like an acquired taste, maybe in a thousand years people will be like, oh my gosh, have you had this algae vintage? It's incredibly complex.

Well, I can at least tell you that the Soviets in this experiment did not come to that conclusion, and so in the second iteration they added another wing where they grew plants that were not algae, and then in the third iteration, they were like, look, it's not worth having any algae because none of us want to eat this stuff. And so then they had two wings that were just growing more traditional plants.

So do you think if it came down to it, they'd be like, I'd rather starve than eat more algae, Like, really, I'm just not going to do it.

I think the answer to this question is always going to be when it comes between death and eating something else, we become way less picky. Do you disagree?

I don't know. I feel kind of picky, but also I know the human drive to survive is very, very powerful, and people do basically anything in that situation. But based on my knowledge of the documentary The Martian, it makes me wonder in an enclosed environment like that, what happens to the people's poop? Like are they pooping in their garden? Is that for real?

That is for real in a lot of these systems. I don't think they were doing that in these bios systems, But when we move on to some of the other systems we're going to talk about, yes they are, and in space I think absolutely you're going to need those microbes, you're going to need those nutrients, and you're just going to have to be really careful to make sure that you're not transmitting any diseases, so you can like screen for stuff ahead of time. I think using human waste on fields that's called like night soil or something like that.

That's a good name for it.

Well, yeah, it sounds way less, way more appealing when you call it that, but you do get diseases transmitted that way, so you have to be really careful about how you do that. And I think that's why we don't tend to do that in a lot of areas where we're able to avoid it.

That reminds me of a dinner I had once in France at some fancy restaurant where my wife ordered a particular kind of dish she'd never seen before, and the waiter warned her that the dish had quote a barnyard aroma. She ordered it anyway, and yes, when it came it smell like poop. What was it? It was some kind of horrible sausage. I tried it also, I was like, I just cannot eat that. Oh my gosh. You know, the French they're very creative with their meat dishes, and they eat a lot of things that a lot of other people would be like, yeah, that's not food.

People will sometimes say that goat milk has a barnyard after taste, and it does, but that's just the taste of hay, which is way better than the taste of feces or the smell of feces. So I guess there's a variety of barnyard tastes out there.

So but back to BIOS three, they didn't have goats, they didn't have barnyards. When is this all happening? Is this like in the middle of the space race?

Yeah, so it's before So sixty five was the first one, so before we landed on the Moon in sixty nine. Oh, and then they kept it going so like they I think BIOS three was in nineteen seventy two, and then the Soviet Union started running out of money and so they kind of stopped. But like they so for a while they were spending like twenty percent of their time just like sort of tinkering with the system. So it was very time intensive and they never achieved complete closure. Like, for example, they weren't growing meat, they didn't have cows in there, but quote Siberians must have their meat was a quote I found in one of the papers. So they were like doing meat deliveries regularly. And actually talked to a guy who was born in Siberia and I was like, Oh, it's so funny, and he's like, you don't understand. In Siberia you need meat to stay alive. And I'm like, I'm not sure that scientifically sound, but I'm going to stop pushing you on the meat question.

Well, what's interesting If you're going for a closed loop system and then you're like importing meat and you're exporting human poop, it feels like you're not really close to a closed loop system. Are you still learning something because you're doing some closed loop stuff people haven't done before.

I think you're still learning something. So like you're getting a handle on how long it takes to maintain these systems, and you know, maybe a little bit about the psychology of living in these systems, a little bit of information about food production, but you know, so biosphere too. One of the exciting things about that was that their goal was nothing, no food comes in, and there were some rumors that maybe like liquor snuck in at some point, but like, I mean they lost the men lost eighteen percent of their weight, the women lost ten, and so like they were really they were sticking to it. But they had the benefit of being on the grid, so they didn't have to like worry about power or you know, like cleaning solar panels or anything like that. And they had these giant lungs that equilibrated the pressure, so like on warm days, you know, like the air would expand and so and the lungs would sort of adjust to make sure that, you know, like the panels didn't burst and break and fall in on them. So like they did a good job of closing things, but there were still things that they were able to, you know, benefit from because they were on the Earth.

And so do we have like a linear progression from the earliest efforts that are less closed loop to the later efforts that are more closed loop or like making progress or are we making progress? Or is it sort of like a random assortment of Hey, let's try this, let's try that.

You know, one of the most frustrating things about space settlement related research is that it does seem to be a grab bag of someone who's like, oh, I have the right knowledge that to answer this question. And I've got the right knowledge that to answer this question, and there's no like funding for like. This is the like step wise path we're going to take to get to the answer. It's a bit more of a hodgepodge. Lunar palace is one of the more recent ones.

So what is lunar palace?

So that is a facility in China. The palace part is actually an acronym the permanent astro based life support artificial closed ecosystem.

Yeah, do they have an acronym generating facility within their experiment in case they need new acronyms so they don't have to import them from the outside.

I mean they should, they should. And you know, if there's a space race heating up between China and the US, we should at least worry about China's acronym game because they're rocking it.

Oh really, well, they're winning the acronym racey.

I mean it's close, it's neck and neck.

All right, I want to hear about this amazing acronym facility, but first let's take a quick break. All right, we're back and we are importing ideas into your mind and exporting night soil. You know what that means. And we're hearing about early efforts to try to learn how to grow food on alien planets by practicing enclosed environments here on Earth. And you were telling us about the Chinese Lunar Palace. So this is neither a palace, nor is it on the Moon.

I'm guessing that's right, but it is preparing for settlements on the Moon eventually. And in my mind, this is the most impressive closed loop system that's been set up so far. So Biosphere two was like huge, but it's so complicated that if something goes wrong, it's kind of hard to tinker with the system to figure out, like what would you would do differently if you are on Mars. So Lunar Palace started a little smaller. They had two wings where they were growing plants, and then they had an area where like humans could live, and there was a meeting space, and then they had a bathroom and a waste treatment area. So they were trying to like reuse the water from the urine. I think they were using the feces for fertilizer, but actually I'm forgetting if they did that for sure, but they did a great job at capturing the water that they breathed out, that they used for showers, that they urinated, and I think eventually they made it to one hundred percent like water recycling.

Kind of like they do in Dune, that other documentary.

Oh, there's so many space documentaries. Yes, so impressive. I watched the more recent version of that documentary just the other day.

And for anybody out there who's not getting the joke, obviously Dune, he's not a documentary. Don't write us emails about how Dune exact right fiction? But you're saying that they did actually achieve some amount of recycling all of their water like they do induce.

Yes, and there is a worm connection. So Dune there were those giant worms. There are not giant worms in the Lunar Palace. And I'm going to stretch this to make the connection. But so they one of the things that they did that was unique in this facility is that they took meal worms.

Oh no, are we about to eat worms?

We're about to eat worms? Yeah, So meal worms they've got like an exoskeleton, so they're not like the worms in your garden. They like become beetles eventually, so they were feeding the meal worms on the wasst the plant waste, and so any part of the plant that wasn't digestible by the people was being turned into protein by the worms. And they created a meal plan, and the meal plan they were able to grow seventy eight percent of the food by weight for this meal plan, and they included the worms for like a protein source. They did bring in things like different kinds of spices.

So they're saying they're using the meal worm to turn the plant waste in the proteins, and then they're just directly eating the worms.

Yes, they would season them to make them more palatable, and they'd like fry them up and stuff, and so they had a couple different like recipes for preparing them. But yes, they were being incredibly efficient. And so while this makes a lot of Westerners like you and I not hungry, you know that's not true. And other places in the world, other places in the world are way more comfortable with eating insects than we are.

So you're saying these Chinese lunar palasin knots or whoever whatever you call these folks living there were totally cool with this meal worm based diet. They were like yum yum yum, put some soy sauce on it, and it's good.

There was a survey and they raided the food favorably, And I mean it could be because, like if a lot of the people who do analogs are people who are hoping that eventually this their nation Space Agency will send them to space. So maybe they were like, I am just such a good sport about everything. These meal worm tacos are just the best thing I've ever eaten. But they did report that they liked it.

Well, I have a science question for you, which is I get how turning that plant matter into protein is useful, but can't we have another layer there, Like, can't you have something that we'd like to eat, eat the meal worms, you know, feed the meal worms to talapia or something. Have a fish farm, then yeah, you get to eat fish and the fish get to eat mealworms and everybody's happy. Do you lose a lot of efficiency there because you're like one step up the pyramid? Or is that pretty efficient?

So this is a great question. Almost every plan that I read for settlements on Mars stopped at insects. So every time an animal eats another animal, you lose a lot of energy as it like converts what it ate into its own like muscle mass. A lot of that gets like lost as heat. So every time you add a step in the food chain, you're losing some of the calories that you could have produced.

So the way, like it takes a huge amount of corn to support one cow, So you could replace a burger with like a huge amount of corn, eat a lot more food if you eat the corn directly exactly.

Yeah, So I think there's zero chance of us bringing cows to space and then your term, because they like take up a lot of space and they fart a lot. You're gonna need to like clean the air a lot. I wasn't even seeing chickens like listed as something that we could handle bringing with us to space right now. I mean, they make a huge mess and they're just not efficient. I feel like eventually we're going to have to have that kind of stuff. So when I was talking to people about like what we're going to do so some you know, one person pointed out that a lot of people who start as vegetarians are vegans, something like eighty four percent of them can't stick with it, at least in Western diets, and I personally was a vegetarian for two years and then I had a craving for Arby's beef and cheddar sandwiches that I just could not. My husband is like that. So my husband's been a vegetarian for twenty five years and he's like that is just so depressing that that's what threw you off.

Is it a pregnancy related thing? Was it when you were pregnant?

Yeah, No, wasn't pregnant. I was an undergrad.

You can't even blame it on the fetus.

No, maybe it was a hangover related thing, which anyway, Arby's, if you want to advertise on our show, where we're open for that. But so they were trying to figure out, like, well, what do you do if you know that the people in your facility are going to be sad on Mars if they're not eating meat, And so their proposals were it's called so based meats. But the ideas you like, take cells from cows, for example, and you feed them all the nutrients that those cells need to divide, and you grow them and essentially like a nutrient filled vat and then all you need is the cells and so you don't need the whole animal. There's a lot of waste that way, and you don't have to worry about like humane treatment of those animals, and so you can still get the cells. That science is like it's coming along pretty well. But like you know, when you bite into a steak or something, there's actually a lot of different cell types that are in that steak that contribute to the taste. And so I think trying to create a taste that is similar to actually eating cow if you're someone who eats cow, is difficult. But maybe bringing these cell based solutions with us will be a way to make it happen.

So you're saying, we can't bring cows, but we could grow real meat sort of in the lab without having the whole animal, just by growing the cells. I think I've seen people do that here, Like they even just ban that in Florida because people were worried about the effect on the industry or something.

Oh that's a bummer. So, like, I'm excited about this idea because it seems less environmentally damaging and far more humane. So I'm excited about this technology personally, but I can see how, yes, lobbyists would not be happy to have cattle farms replaced by vats, and it does feel kind of dystopiing it's.

Sort of weird indeed, bad grown meat. But is it a lot more efficient or does it require as much or just different resources like energy, etc.

I am not an expert. My sense is that it is more efficient, but I don't know that for sure. It's possible that those factories have some complicated extra stuff that makes it less efficient.

Well. Also, just in terms of satisfying the Siberians, plant based products that taste like meat have come a long way, right, A lot of people happily eat impossible burgers or beyond burgers or whatever.

Yeah. Yeah, So my husband has tried a bunch of those kinds of like fake meat. I call them feet and he doesn't appreciate that. But every once in a while, Who'll be like, oh, man, try this hot dog. It tastes just like a hot dog. And I was like, you haven't had I eat in twenty five years. It does not taste like a hot dog. Actually, I like eating a lot of those foods, but in my head, I never think, oh, I'm eating a hot dog. I think like, oh, I'm eating something different. This is like protein something different. I don't classify it as meat in my head.

I was a vegetarian for a long time, and when I was I wasn't into the whole like meat replacement things. I was like, I'm a vegetarian. I'm into vegetables. I like vegetables. Let's make an eggplant, let's roasta cauliflower, Like, let's eat the vegetables as vegetables and not force them to pretend to be meat. But it brings up an interesting question about these colonies, Like you have to think not just about the initial colonists who just want to survive and will be able to choke down meal worms, but you want to build a self sustaining population that lives and has quality of life and joy and can have barbecues and whatever. And so you're right, you need to build up this technology to have like different kinds of foods and actually tasty foods, not just Shackleton styles scraping by.

Yeah, but like even I Shackleton Expedition, they got to like kill penguins and have fresh meat.

All right, So we'll talk more about growing food on Mars and the science of that, But you're telling us about the lunar Palace is that's sort of the epitome of examples of growing things in a self sustained colony on Earth.

Yeah, there's some companies who are trying to do stuff like this on the small scale, but in my mind, Lunar Palace is the facility that has managed to close the most things while doing the best recycling. But there's still a lot to learn. So like, they had a run where it was three guys in there, and the carbon dioxide levels were like fluctuating up and down. They were getting too high and then dropping down again, and so they took two of the bigger men out and replace them with two smaller women, and then then the carbon dioxide levels were okay. And so like if that happened on Mars, like that's like that could have just been death for everybody. And so like right now we're at the stage where like we're swapping out sizes of humans to try to make things work, and so like the papers from the Lunar Palace group have like many pages of storychometric equations where they're trying to like figure out where all of the different like atoms and molecules went. There's still a lot we have to figure out it's complicated.

So are we sending short people to Mars? Is that what we learned from this experiment?

So women are slightly more metabolically efficient, and on average we're smaller. I've heard people argue that we should be sending just women to space, or and then my exac likes to joke that we should send just jockeys to space. But it's worth considering. But at least initially, you know your cargo will stretch for longer if the people are smaller.

What about amputees. We could have amputees in space, right, I mean, do you really need your legs anyway? Right? Why support all that leg tissue?

Yeah? Yeah, I mean Mars has partial gravity, and so there's still some benefit to having having to But maybe it would be way more comfortable to have a prosthetic on Mars if there was less gravity pulling you down and creating like friction and pain at the interface between the prosthetic and the human body. So I don't really know the answer to your question.

Somebody's going to type amputees in space into Google and see some really really weird stuff.

There's lots of weird space stuff. Yeah, yeah, So Lunar Palace did well. There's a ESA, the European Space Agency is working on this system. Their acronym is Melissa, and I don't remember exactly what it stands for. But they are doing some experiments with algae. Again, algae's back, and they don't have humans in this system, but they're they're trying to figure out these equations for like, you know, how many for if you have like one hundred cells of algae, how much carbon dioxide can that extract from the air, and how much oxygen does it give you back? And it does it depend on like what you're feeding them. And I'm just sort of making things up here, but like the point is they're trying to like start at the bottom and work out all of these little equations that you're gonna want to have sort of figured it out before you go to Mars. And so there's there's groups sort of tackling this from different angles. But we're I would say, we're definitely not there yet. All right, Well, we have been having too much fun. I've lost of time, and it is time for us to take a little break and we'll be back to talk more about food and space in just a second.

So this is great practice and we're learning a lot, and we're tweaking our systems, and we're learning to love algae and meal worms because apparently it's the future of Michelin starred restaurants on Mars. But what do we know about, like the long term plan for growing food on Mars, because as you said, we can't like shift food from Earth for a long time. And you know, the whole plan I think is let's make humans multiplanetary. That's only useful if we're actually independent. Right, if we have colony on Mars and it's totally dependent on Earth and then Earth gets hit by an asteroid and it goes capute, then the colony, if it's dependent on Earth, it's going to die out anyway. So what do we know about like making a actually independent so you can survive on its own.

Well, we know it's going to be even more complicated than doing it on Earth. So one of the reasons it's going to be complicated. So in our prior episode on why it's going to be so hard to work on the Moon, we talked about how regolith is a huge pain in the rear end. So like the dust on the Moon and Mars. It's jagged. You don't want to breathe it in That jaggedness we think also makes it hard to grow plants in it. So there were these samples from the Apollo mission that folks tried to grow a Rabbitopsis thaliana in and the plants grew, and it wasn't just lunar regolith. It was like lunar regolith plus fertilizer and nutrients and water, like there was a lot of stuff done to like put lipstick on the pig, that is lunar regolith.

So, but for people who haven't heard that episode or don't remember, you're saying, basically, there's no soil on the Moon and no soil on Mars, and that the dirt we grow our plants in has a lot of useful stuff and that stuff is just missing from Mars and from the Moon. Yeah, And what is a Rabbitopsis thaliana For the of us who are not biologists.

A rabbit ops Ofstheliana is a plant. It's also known as sale criss and it's a workhorse for biologists. So tons of experiments have been done on this kind of stuff. We know, like if you grow it under soil with toxins in it. We know what genes turned on to tell us that the plant is stressed out, for example.

So it's like a well understood plant here on Earth. Is it something that you could eat or is it just like, hey, let's start with something we know how to grow.

I think it's can you just start with something that we know how to grow. It's edible, edible, by.

The way, I like to describe my food source. What are we having for dinner tonight? It's edible. Don't worry, right right, Yeah, I feel now I'm worried.

I feel like foragers like to tell you that food is edible a lot like I feel like what you're telling me is that artificial selection has made food good, but nature provides edible anyway. Okay, it is edible.

So you're saying, they tried growing this thing in lunar regolis, right.

And they added all of this stuff to make it more like Earth's soil, and the plants that grew showed signs of stress based on their coloration and what their genes were doing. And one of the hypotheses was that all of those jagged lunar bits were like making it hard for the plant to put out roots, and maybe nutrients and water were leaking out because it kept getting poked. We don't really know. But the point is, even if you like supplement a lot, it's hard to grow in this stuff.

So you're saying they basically grew it in earth soil, but with lunar regolith mixed in, and that was bad enough to make the plants stressed out.

Yeah, that's right, and Mars is going to be worse.

Now they're really testing the Mark Watney experiments, right. Basically, human poop plus regolith is not a great place for plants to grow.

Yeah, so they didn't actually use human poop. They used other fertilizers, but if they had wanted to be more realistic for Martian settlements, they could have used human poop.

So what do we need to add to regolith on Mars to actually make it soily enough that we could grow plants on it?

So you might need to supplement with nitrogen and potassium. So I think those things are both available on Mars, but maybe not in the form that plants use, So we might need to bring some of that with us. We almost certainly need to bring boron and we understand Martian soil in some areas where it's been studied well, but I don't think we have a good handle on variability and what Martian soil is like. But some of the areas we've sampled have perchlorates, which are endocrine disrupting hormones.

That sounds bad.

Yeah, that's bad right, so for developing fetuses. So like if a pregnant woman was consuming food that had been grown in regulus with these perchlorates, the perchlorates get taken up in the food. We know that plants take it up and it messes with nervous system development, so bad for the baby, and it also messes with maternal metabolism, so bad for the mom.

So edible but poisonous.

So when I talk to folks who are pro space settlement, they always say, ugh, pah, it's water soluble. You just gotta like rinse it and it's gonna go away. But then I talked to a friend of mine who's a geologist and his lab works with perchlorates, and I was like, is it that easy? Do you just like rinse it and it goes away? And he's like, we work with that in fume hoods, only, Like, it's not that easy, and he's and it's a big deal if you miss it. And also like if you imagine, you know, so Zach and I bought some farmland and we wanted we have like a garden. If someone was to say like, hey, it's cheap, it's got like these endocrine disrupting hormones in the soil, but like, just rinse it first before you grow your plants. It's cool. Like I wouldn't be like, oh great, I'm fine with that.

And you have to rinse the plant, so you have to rinse the soil. Rise every rinse.

The soil to get the perchlorates out. But then now you've got the perchlorates in the water. So basically, like the more you talk about the regolith, like it's jagged, it's filled with chemicals. I think it also has toxic amounts of aluminum. Maybe that's on the moon, but like it's gonna need to get cleaned up so it's not toxic first. So a lot of folks say like, look, this is all too much work. Let's just do hydroponics. And so the idea with hydroponics is you plant the plants directly into water, like you give them something to hold on to, but they're just in water, and into that water you add nutrients and everything else that they need, and then that way you don't need the soil at all.

Everybody who like carved an apple before listening to this episode knows what you're talking about when it comes to hydro.

Don't understand I have a I have apple trees growing in my head.

Was a bong reference.

Oh I thought this was a family friendly show.

That's why I was making a subtle reference.

Oh well, it goes right over my right over my head. Can't be too subtle with Killy on the show.

Well, that tells me something about your college experience. First, I want to go back to something you said about importing this stuff, Like you said bringing nitrogen and boron. I've heard of nitrogen as something we need for plants to grow, but what is boron and why do we need it for plants?

Well, I'm not a botanist, so I'm not one hundred percent sure, but so like just you know, our bodies, we were mostly made out of what knops I think carbon, hydrogen, oxygen, phosphor a sulfur. Those the main things that are in our body, but we also need other things and like trace amounts, and so something that plants need some of but not loads of, includes boron, and I think that's something that we just haven't found a lot of on Mars, so it's something we'd need to bring with us. The list of things that you need to bring for the Moon is much longer, and you know, Mars has things like there's carbon in the atmosphere in the form of carbon dioxide, and so you can get that carbon, whereas the Moon has very little carbon and it's hard to acquire. So, like Mars has a lot of good stuff, but you're still going to need to bring some and recycle others.

So we're going to need to pull some of the things we want out of the Martian environment and bring a bunch of stuff in order to create an environment where plants can be healthy and grow in a way that they produce food we want to like feed our children.

Yeah, exactly. And the stuff that you pull out of the Martian environment, it's probably going to be a pain in the rear end to pull it out. So, like previously, we're talking about how regolith is super jagged and how that makes it hard to run equipment because it's abrasive and it gets it clogs up the equipment and wears it down pretty quickly. And so anytime you're like extracting something from the regolith, for example, you're going to want to recycle. It is probably easier to recycle it than it is to extract it additionally, and so so these recycled systems are going to be super important.

And all of these things sound like they're going to be very energy intensive, Like you're extracting things from Mars and you're separating them and doing all these complicated processes on them. I guess this is going to all run on solar power.

Yeah, so solar panels on Mars. We use them for our rovers for example, and so it's like a proven technology. But that one percent atmosphere that Mars has, as we mentioned, is enough to support dust storms that can encircle the whole planet for like weeks at a time sometimes, so they can last for a long time. They're not super predictable, and you can have battery packs to help you get through those periods. But most of the folks that I talked to say, we're going to need to bring portable nuclear reactors with us as well and plant them sort of far away from our habitats, so they're not, you know, irradiating the crew members. So we're probably going to be relying on both of those. You might be able to get a little geo thermal energy from Mars, but that's like a comple caid engineering project that I don't think we'll be ready to tackle for a while. And there's no flowing water, so hydropowers out and unless there's big surprises on Mars, there's not going to be any fossil fuels, so probably it's going to be solar and nuclear.

We've talked before about nuclear power in terms of spaceflight, and one of the big questions is like, how do you safely get the nuclear materials up there, because we mind them here on Earth and then we're going to send them to Mars or send them to the Moon. Something we haven't talked about it, and I'm wondering if you know anything about it, is extracting nuclear materials on Mars. Like Mars has uranium, right, why not send the technology to Mars to extract uranium from Marsian soil itself, because then we don't have to launch uranium in the Earth's atmosphere.

So I believe that those materials are available on Mars, but just like on Earth, it's not just a matter of acquiring those materials. So, for example, if you're using plutonium to power your power plant, you need to like centrifuge it to get certain kinds of plutonium and it requires like massive facilities to do that. And so I think, you know, eventually, if Mars is going to be self sustaining, they will need to collect and process their own nuclear fuel for their power plants. But I think we're not going to start that way.

Probably all these conversations have like two modes, like how do you get there and get started? And then how do you become self sufficient? And it's incredible, like the list of things you're going to need to run a society, you know, to grow all this food and to supply the power, and then all the people to run these facilities, and then the schools to teach those people's children, and then the factory to make the pencils for those children to do their homework. And it's just like the tensils of the complexity of the society are incredible.

Our global supply chains are so incredible, Like there's so much that we benefit from. We tried to find numbers on how many people you would need to create a self sustaining society, so like how many people would need to be there before the Earth could explode and Mars could survive without us? And I think we don't really know the answer to that, But like I think Cuba and North Korea, which are countries that maybe get the closest to running without interacting with other countries, they've got like, what is it thirty million, like probably tens of millions, but neither one of those countries are places where most of us would be like totally, I want to live there, right, So they're like and I think a lot of them would rather not be so closed or you know, maybe not the leaders in those countries, but the average citizen. So it's going to take a lot. I've seen a lot of estimates, but I think if you're going to live, well, like there's something like one hundred thousand different kinds of medical specialists, you don't necessarily need all of them, but I'm glad they all exist and that they're available to me on this planet. So it's going to take I think generations before Mars is completely self sustaining.

And do you think that answer changes if we only send jockeys to Mars, Like can we get there faster with just jockeys? Is it like a volume of humanity question or like a number of heads?

I think it's numbers of heads and hands. But uh ok, I haven't done all the equations.

So you didn't say feet. So then like my amputee only colony on Mars, you know, maybe that could succeed. Yeah, but speaking of bringing life to Mars, you were talking about importing all these materials to grow food on Mars. I was wondering about the little critters, like our life here on Earth also relies on micro organisms in the soil. Are we bringing sterile stuff to Mars to grow or are we bringing like Earth based microorganisms for our farms on Mars.

Yeah, so this is tough. So for space stuff, you try to bring as few microbes as possible typically, but we're going to need to bring those microbes with us because bacteria and fungi are like very important collaborators with the plants that we like to eat, so they need to come. And you probably can speak to this better because your wife works on questions like this, But yeah, those are going to have to come. But so then the hard thing is just bringing the organisms that you want and keeping out the organisms you don't want. So at the introduction we talked about how Biosphere two had problems with plant pests and pathogens that they clearly had not plans to bring with them, but they got in. And Biosphere two also had scorpions that got in that they didn't mean to have in there, and they're the only lethal scorpions in the United States and they managed to get in.

Wow. Do they make good tacos? I bet there's a pretty spicy.

Yeah. They did not try eating them in Biosphere too. They were not hungry enough. Eighteen percent body mass loss was not enough to get them to eat the scorpions.

At some point, you're eating scorpion tacos. But I guess they weren't there yet.

No, maybe they'll get there all right.

It's fascinating though, how we have these competing interests, Like on one hand, as you said, you don't want to bring microbes to Mars because you still want to know the answer to the question like are there already microbes on Mars that either grew independently or through some sort of like pan spermian thing got to Mars from Earth or maybe originally evolved on Mars and then got knocked off the planet and landed here on Earth and seated life on Earth? Like are we space cousins with the Martians? So you're right, we want to answer those questions, which means we shouldn't be bringing those microbes. On the other hand, we can't really go to Mars long term without bringing microbes. And so do we try to like set up some sterile barrier, I mean, the whole thing seems totally impractical. Or do we just have to wait until we've answered the science question before we can begin colonizing.

Well, I think have to wait is a tough way to put it, Like you don't have to wait for anything, should you wait? I would like to see us have the answer to that question before humans go there, because even if you're not like you know, so, the first mission of Mars is probably not going to be trying to like grow their own food. They're probably going to pack stuff that's shelf stable. But they're humans, so they're gonna come with their microbiome and like we're lousy with microbes, and so I think we'll contaminate the surface, you know, just by like touching our space suits before we put them on for EVAs, So I think before humans go at all, if that's a question that we think is important to answer, we should probably try to answer it with the machines we send out there, which probably also brings some microbes, but hopefully fewer.

Well. People are planning to visit Mars, you know, in the next decade or so, I can't imagine we're gonna have an answer, definitive answer to the question about life on Mars in that deck. So we're most likely we're going to spoil Mars for this question scientifically.

Musk has just announced that in twenty twenty eight he's going to send people to Mars. I wouldn't hold my breath. I don't think that's going to happen that fast unless some so the United States government, I guess, would probably have to say no, you can't do that until we have the answer to this question, because I don't know who else would have the power to stop him.

Does the US government have the power to stop him?

So, according to the Outer Space Treaty of nineteen sixty seven, some country is responsible for what Musk does out there. So Musk could decide, well, I'm not going to launch from the US, I'm going to launch from some other country, and then that country becomes responsible. But given his current infrastructure, in his current nationality, he would probably be the United States's responsibility. So they're the ones who would be issuing the launch license, so they're the ones who would have to put their stamp on the mission plan. So I mean, the international community could like make a fuss and the US could feel pressured, but I'm not seeing that happening.

Another possibility I suppose is that we try to build colonies on Mars that are more separate from like what's going on on the surface. And I talked about living underground on the Moon. What about living underground on Mars also as a way to protect yourself from all the cosmic radiation the death from the Martian skies.

Yeah, so we will probably live underground on Mars as well. So Mars, like the one percent atmosphere that Mars has isn't really sufficient to save you from all of this space radiation. And unlike Earth, Mars doesn't have a planet wide strong magnetic field, so you're going to get exposed to space radiation. So most of the proposals I've seen do involve habitats either in like lava tubes or just buried underneath regolith. So first I'll say that burying yourself underground doesn't necessarily mean you're not going to contaminate the Martian surface, I think, because you're probably still going to be going on some EVAs.

And also it could be that there are microbes under the ground, right.

Yeah, right, and that might be the place we're most likely to find them because they're not exposed to you know, the radiation from space. Like maybe the most likely place we are to find these microbes could be in you know, lava tubes or caves underground. But this also this opposes problems related to growing plants because you're not going to get any sunlight. And already you were getting less sunlight than you would on Earth because Mars is farther from the sun, which is also going to be a problem for your solar panels. But now you're also underground, so you're going to need to be using a lot of energy to create artificial lights, or you're gonna have to pipe the sunlight in somehow. So it's it's going to be complicated. But yeah, I don't think being underground necessarily protects the microbes, but it adds some complications when it comes to growing plants.

Well, what about future technology. All this stuff assumes we're going to be growing earth like plants and bringing earth like chickens. What if we genetically engineered, you know, chickens that were good at growing on Mars, or plants that were good in nine environment, or like loved Martian regularithic could like filter out these toxins. Is that just a pipe dream? Should I expect Andy Weird to write a novel about that next?

Well, I'll read anything Andy wear rights. But so, I hear a lot of folks pushing genetic engineering, and often they're talking about genetic engineer in humans, which I think has its whole a whole other range of ethical questions that maybe we don't want to dive into today. But you know, genetic engineering can improve crops in some ways, but I think there are a lot of problems that are really complicated, and we don't understand which genes you would need to tinker with in which way to solve those problems. Yet, So I think that eventually it could help us with a variety of problems, maybe like genes for radiation resistance or something like that. I don't know, although if you're underground that'll be less of a problem. But I would be surprised if right now we knew what kind of genes we needed to tinker with in a way that would actually be effective. And I know there's people who disagree with me, so I guess we'll have to see.

Well, I guess we'll just have to see which plants and which people survive in that Martian colony. And that's just sort of like a form of genetic engineering, right, that is.

A form of natural selection, you know, So everyone should purchase a city on Mars and hear all about my opinions on this, But my opinion is that we need a lot more research ahead of time so that we're not said people out there and saying, like, all right, we're going to see what happens. Natural selection is going to select the best of you, and we'll see what happens there, like I would rather. I think there's a lot of engineering solutions to this stuff, you know, like burying your habitat under regoliths probably helps. There might be certain like material science problems that could be solved for like types of habitats that do better at absorbing radiation. There's a lot of work that can get done ahead of time to figure out the equations for you know, how much human poop do you need to fertilize your plants take up this much carbon dioxide to make this muss oxygen. Like, there's a lot of work that can be done ahead of time so that you can reduce the number of people who need to die. And I think we need to do that stuff first, so that we're not relying on natural selection to hone the people for space.

So you're saying we shouldn't just send a bunch of people up there and see who lives and see who dies. We should prepare for that and try to minimize the number of deaths, right.

Or we should send delicious people so that everybody can at least have some good meals while the end closes in.

Well, I want all of those jobs to have nice tasty meals from all their dead co colonists.

All right, Well, we have come full circle to the forbidden meal. So I think that's probably good for this week. And I'm going to probably not eat for a few hours because I think you've put me off of food. But I will enjoy the wonderful variety of foods that are available on Earth when I'm prepared to eat again.

Well, I hope at least that this episode was food for thought, even if it didn't inspire an appetite in anybody.

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