Ep. 429: Living on Mars


When Elon Musk announced plans to send humans to Mars, he conveniently left out one important aspect. How are we supposed to survive on a place this hostile to life? Seriously, Mars sucks, and it’s going to take some impressive techniques and technologies to make it on the Red Planet.

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Show Notes

  • SpaceX’s plans for Mars
  • Climate on Mars
  • NASA Aquaponic gardening experiments
  • O’Neill Cylinders for settlement
  • O’Neill Cylinders
  • Building an O’Neill Cylinder Colony

  • Transcript

    Transcription services provided by: GMR Transcription

    Astronomy Cast Episode 429 Living on Mars. Welcome to Astronomy Cast, your weekly facts-based journey through the cosmos. We will help you understand not only what we know but HOW we know what we know.

    Fraser: My name is Fraser Cain. I’m the publisher at Universe Today and with me is Dr. Pamela Gay, the Director of Cosmo Quest. Hey, Pamela, how are you doing?

    Pamela: I’m doing well. How are you doing, Fraser?

    Fraser: Good. Another episode to continue our miniseries on the red planet. Who knows how many episodes we will do until we get bored of it and sometimes I can get bored of things very quickly and other times I can just be entertained for years.

    Pamela Gay: But it’s Mars.

    Fraser Cain: It’s Mars. Mars is awesome! Were there anymore announcements?

    Pamela Gay: So, I think this will come out before I am in San Francisco. So, on September I believe it’s the 14th, if that’s a Wednesday, there is a meetup scheduled in San Francisco at Rosamunde’s and the mission district. It’s for Cosmo Quest Astronomy cast. It’s listed on universe.com, so if you go to universe.com and search on Cosmo Quest and San Francisco it will pull up. It’s a great place with craft beer and sausage and big wooden tables. We can sit around and talk science at.

    Fraser Cain: That sounds great. Sorry, I won’t be there.

    Pamela Gay: We’ll miss you.

    Fraser Cain: All right. So, when Elon Musk announced plans to send humans to Mars, he conveniently left out one important aspect. How are we supposed to survive on a place this hostile to life? Seriously! Mars sucks and it’s going to take some impressive techniques and technologies to make it on the red planet. I’m not sure you’re aware of this, Pamela. Mars is just awful!

    Pamela Gay: Yeah, well, the whole universe is trying to kill us. So, yeah, I think it’s one of these things where Mars is more hostile than Earth. No atmosphere, no magnetosphere, but given the grand scheme of deadliness of our entire universe, it’s not that bad.

    Fraser Cain: So, Mars is just mostly awful as opposed to a death zone. It’s still a death zone. No, I think it’s – as opposed to instantaneously lethal.

    Pamela Gay: It’s a slow death zone as opposed to an instant death zone.

    Fraser Cain: Right. Okay. All right, so let’s – before we kind of get into how we’re going to actually survive on Mars, let’s sort of set the stage and just talk about how awful Mars is.

    Pamela Gay: So, first of all, it’s cold enough that dry ice freezes out of the atmosphere.

    Fraser Cain: Yeah, we mentioned this in last week’s episode that it snows carbon dioxide in the wintertime.

    Pamela Gay: So, it does occasionally get up above freezing for water but that’s only occasionally, only at special latitudes but given the fact that there is such low air pressure, any water that happened to be around would essentially boil off instantly.

    Fraser Cain: Okay, so hold on. We’re going to keep a list here somewhere. So, the temperatures go from REALLY cold to SO cold that carbon dioxide freezes right out of the air and falls like snow? And you don’t want that. That’s very bad.

    Pamela Gay: Yeah, that would be fairly accurate.

    Fraser Cain: All right. The air pressure is one percent the thickness of Earth air pressure, so if you try to breathe it you couldn’t because you couldn’t keep the air pressure in your lungs and it’s carbon dioxide, which is no good.

    Pamela Gay: And so, you’re talking about if you have exposed skin it pretty much instantly bruises. Not as instantly as in outer space but fast enough that you’re still hating everything.

    Fraser Cain: Right. But if you were dropped out onto the surface of Mars, all the air would go out of your lungs pretty much instantaneously, explode them if you hadn’t breathed out before you stepped out onto Mars.

    Pamela Gay: You’d get the bends.

    Fraser Cain: Yeah, yeah, you’d get the bends and you would fall unconscious within 15 seconds, 30 seconds, and would die.

    Pamela Gay: You have longer than that. It’s actually one of these things where if you hyperventilate yourself to over-oxygenate your blood, completely exhale, and make a mad dash and you happen to be in an equatorial latitude until it’s not too bad, you’ve got until you run out of oxygen in your blood, so it’s as long as you can hold your breath under water basically.

    Fraser Cain: Well, no, because you can’t hold your breath. Right? The air is all out of your lungs. You’ve only got the air that’s in your –

    Pamela Gay: In your bloodstream.

    Fraser Cain: In your bloodstream, yeah.

    Pamela Gay: But if you think about it, if you’re trying to sink yourself under the water, a lot of times people will exhale when you’re a stupid little kid and try and stay underwater as long as you can. So, with a stupid little kid staying underwater, not the adult with the lung full of air underwater basically you’re good until your body is like I must inhale and you inhale essentially nothing.

    Fraser Cain: Okay. So, no air, cold temperatures, and then a little slower than that nasty radiation.

    Pamela Gay: Yeah, so here on Earth we have a thick atmosphere that protects us from extreme ultraviolet to everything more deadly than that and everything with a shorter wavelength and ultraviolet IS more deadly than ultraviolet, so we go from just you’re going to get skin cancer to your DNA is destroyed now. It’s not as bad as being like in the open space between Mars and Earth but it’s still going to kill you given time and cancer.

    Fraser Cain: Yeah, and now we’ll talk about ways you can mitigate this but, in general, if you’re out on the surface of Mars for long periods of time you are going to accumulate a lot of radiation and if there’s big solar storms, you are not going to enjoy your time out there. Bad radiation and then low gravity, which sounds like fun but it’s actually going to be a total pain.

    Pamela Gay: Yeah, because low gravity – we’re still coming to terms with all of the effects but it definitely causes decalcification of your bones and it seems to muck with a whole bunch of other different bodily things such that if you don’t constantly exercise you end up with muscle atrophy and it’s just bad news. So, we know that the zero gravity-ish of being on the International Space Station has consequences you HAVE to exercise a lot.

    Fraser Cain: And you’re dying while it’s happening. You exercise a lot but you’re still dying in space – in microgravity, right? Your body is wasting away. You’re putting it off but you are not preventing the destruction that is happening to your body by being in microgravity.

    Pamela Gay: And so, we’re not yet sure just how bad being on Mars will be since there IS gravity and you have more room to wander but nonetheless bad for you – bad.

    Fraser Cain: Yeah, we have no idea still – like, we know microgravity is death. We know that Earth gravity is fine and we don’t know where the dividing line is between those two numbers. At 38 percent, the force of gravity on Mars could be lethal over longer periods of time, maybe a couple of years. We don’t know if children can be gestated properly and born into that environment. These are still unknowns right now. More experiment is required.

    Pamela Gay: And there’s experiments they do up on the Space Station looking at how plants are affected, how animals born in space and gestated in space are affected but at the end of the day, human beings are not rats and the experiments we do with mice and invertebrates and other critters – a zebra danio isn’t going to totally reproduce the effects that a human being is going to have.

    Fraser Cain: Yeah. So, low temperature, low air pressure, bad radiation, bad gravity. So, these are really – and then we’ve got a few like a collection of things like the days a little longer.

    Pamela Gay: That one I don’t think we’ll try and kill. I’m GOOD with days being slightly longer.

    Fraser Cain: Yeah. The soil is made of poison.

    Pamela Gay: That’s a problem, yeah.

    Fraser Cain: Yes. Wash it. No, you just wash it.

    Pamela Gay: Well, it’s basically a giant superfund site, so –

    Fraser Cain: Whole planet, yeah.

    Pamela Gay: Whole planet. So, if you think about all the stuff that HAS to take place to clear up a superfund site to clean the dirt, test the dirt, clean the dirt some more, test the dirt, how deep do you have to dig, how deep do you have to clean, yeah, and it’s death. I’m just going to keep saying that this episode.

    Fraser Cain: Yeah, yeah, it’s death. So, I think we’ve set the stage here that, you know, if you want a place that’s a thousand times easier to live at, go on and head to Antarctica. Feel free to set up your tent on Antarctica and you are living in an absolute paradise compared to Mars, BUT the adventure of colonizing in other planets is pretty exciting. So, what can we do to compensate and deal with all of these issues?

    Pamela Gay: So, one of the things that deeply amuse me is at the end of the day it all seems to come down to fish tanks and tilapia, so we would need to have a steady food source that is diverse. We would need to have oxygenation, all of those sorts of things going on. So, you need a system than can produce in a complete closed ecosystem. It won’t be perfect. There will be losses. You will have to replenish water. You have to come with starter food but to get that ecosystem going you essentially start with water plankton, add tilapia, tilapia eats plankton, tilapia eats any invertebrates that you end up in the water.

    Invertebrates are good in general. Throw in some snails. They’ll reproduce madly. That’s what snails do. Then set up a vertical water system that has all of the fish poopy water flowing over the roots of plants and now you can start growing vegetables. You eat the invertebrates, you eat the tilapia, you eat the plants, and now you start producing your own waste and your own waste can start going to – well, if you watched Mars you know. You clean the dirt, you clean the dirt, you clean the dirt, you then add poop to the dirt. This is also going to be a very poopy episode it turns out.

    Fraser Cain: Right. As usual.

    Pamela Gay: But the whole goal is to build and expand an ecosystem that produces food, produces oxygen, and purifies water as it goes.

    Fraser Cain: But this, I mean, this problem and solving this challenge is going to be the same wherever we go across the whole solar system.

    Pamela Gay: Yes.

    Fraser Cain: You and I are both quite partial to the idea of O’Neill cylinders and hollowing out metal asteroids and spitting them up and living on the inside of those but it’s going to be the same challenge, which is that you need water, you need tilapia, you need fighter plankton, and you just need to keep building up your ecosystem to larger and larger animals depending on how much sunlight you are able to do. So, the good news is you do have gravity on Mars that can generate that you can use to keep your water down and have your plants grow up.

    Pamela Gay: Yes.

    Fraser Cain: And chances are that should work okay in the Martian gravity.

    Pamela Gay: And the crazy thing is we can’t actually just use sunlight. You have to actually – now, here’s where the next challenge comes. I start with don’t starve, probably because it’s a good place to start, and it’s U.S. Thanksgiving so there’s a turkey cooking in the crockpot in the background making me think of food.

    Fraser Cain: Yeah, someone was mentioning the chat, mmm, Thanksgiving tilapia.

    Pamela Gay: We don’t do tilapia in this house after an unfortunate tilapia incident that shall not be spoken of, but it’s one of these things. So, you figure out the food. You’re not going to start but then there’s this whole electricity thing going on that you need and you figure you start with a good radiothermal generator – something powered through nuclear isotopes going through half-lives, generating heat, powering your power source. That gets you started and you get grow lights going but that’s not a scalable system unless you happen to start mining radio isotopes on Mars, which that’s a whole lot of effort.

    So, now you start putting out solar panels. Now the sunlight on Mars is different than the sunlight on Earth and that whole radiation thing isn’t going to be stopped by the roof of a greenhouse, so you actually need grow lights. We are looking to learn from every pot grower who ever grew pot in their momma’s basement.

    Fraser Cain: Right.

    Pamela Gay: They have the skills.

    Fraser Cain: Marijuana growers, YOU are the future of staying alive in space.

    Pamela Gay: So, you start your solar farm outside. You start your veg and tilapia and plankton and invertebrate farm on the inside and the problem is you now need an inside that doesn’t kill you due to radiations. So, I mean, it’s kind of – we didn’t do an episode on HOW you get to Mars because there’s a lot of problems so totally not solved that that would be a whole lot of speculative fiction going on.

    Fraser Cain: Well, next week we’re talking about getting back from Mars. Maybe we could include getting TO Mars.

    Pamela Gay: Right.

    Fraser Cain: Let’s talk about getting to and from Mars.

    Pamela Gay: So, the problem that – I’m just going to assume SOMEBODY has solved is how to build that habitat you lived in to get to Mars so that it is radiation proof. So, you start out in this hab but it’s probably small because it didn’t want to weigh that much if you were trying to use energy, use fuel to get it all the way to Mars. Now, you want to expand beyond your initial food source. You want to expand beyond your initial safe habitat and how you have to become the moleman of Mars because it turns out dirt is really good at protecting you from radiation.

    So, that whole living in the basement idea – it’s more like living in a cave, living in a lava tube, living underground with that dirt protecting you from radiation. And here the cool idea comes where we know there’s a lot of subsurface ice on Mars so maybe you dig yourself a nice hole, extract the water from the soil, and then blow up an inflatable habitat inside and now you have a nice friendly walled, not dirt-walled containment vessel for you, your tilapia, your plants, and your electronics, and hopefully a few other humans.

    Fraser Cain: Right. So, Martians are going to be tilapia farmers and they’re going to be, as you say, moleman. They’re going to be digging into the ground. They’re going to be taking the Martian regolith; they’re going to be turning it into concrete. They’re going to be building interesting and more exotic buildings and they’re going to be digging down. Ideally, if there are lava tubes, they are going to be able to use those lava tubes as a way to kind of get a head start, less excavation required, but they’re going to want a lot of excavation machinery, backhoes, things like that to be able to move around on the surface of Mars and just, you know, push it all around. Minecraft that place!

    Pamela Gay: This is where you really have to send a whole lot of stuff ahead of time to the Martian surface. You need to go land – well, your fleet of robotic backhoes essentially. So, take curiosity and give that thing a much bigger claw and let it start digging holes big enough for itself. I mean, ideally what you actually need is one of those spinning, chomping things that looks like a worm from dune that they used to build the tunnel and other giant underground tunnels around the world but we have to land those successfully, get the process started remotely and then have the humans follow behind.

    Fraser Cain: It’s interesting in some of the follow-up questions, like when Elon Musk was announcing his plans to just end the Mars transportation system to send the BFR to Mars and send groups of 100 colonists at a time, eventually hundreds of thousands every Mars window. He figured once Mars gets to about a million people; it should be a self-sustained, self-contained habitat that’s completely separate from Planet Earth. It doesn’t NEED Earth anymore. But until then, what are the Martians going to need from Earth?

    Pamela Gay: This is where we’re not sure how well that food ecosystem – will it be completely self-contained? Are we going to have to worry about that plankton doesn’t do so well under the artificial sunlight or we don’t have enough plankton growing to support the invertebrates and to support the tilapia? Do we need fish food delivered on a regular basis essentially? Can we in a successful manner have enough solar panels or do we need regular reinforcements of solar panels and the batteries that hold the charge?

    These are still technologies that we’re working on. Anyone who has had an iPhone they refuse to replace or an Android they refuse to replace, you know, eventually you hit the point where your phone is just like, dude; I’m not going to hold my charge any longer – replace me. It’s that battery issue that we are going to have to worry about. We’re still learning what’s the maximum lifespan that a solar panel works at a high enough operational level.

    Then there’s tech. They’re not going to have circuit boards getting built. They’re not going to have all the manufacturing going on. Where is cloth going to come from? There’s a lot of people that talk about the next step past tilapia for protein that isn’t a veg is goats because goats produce fur, goats produce milk, and you can eat them, so goat is kind of the perfect critter other than being very smart and very grumpy. But how long does it take to get to the point that you have the cloth, you have the manufacturing, you have all the things that we totally take for granted. Just the fact that I’m sitting at a wooden desk, you’re clearly going to be printing the bejesus out of everything so you need the stuff for your 3D printer.

    Fraser Cain: Yeah, yeah, Earth is still ideally going to still be here. The worst-case scenario hasn’t happened and Earth is still a place and the discoveries that get made on Earth – the plans can be sent to Mars and they can 3D print them. So, in theory, if the manufacturing gets good enough and the iPhone 12 gets released on Earth and the plans, the specs, are sent to Mars and they 3D print their version of the iPhone 12 and they’ve got iPhone 12s as well.

    But as you said, the circuit boards, like the 3D printing, which is currently just kind of a hobby – the future really will depend and rely on us being able to manufacture things remotely this way. Then the same thing as well – whatever we’re missing, we can put in cargos chips and send them to Mars. It only takes a couple of years and so if they’ll build a big shopping list like we need more goats, we need more whatever, and every two years another shipment will come and we’ll replenish and they’ll learn over time the things that they’re missing to be able to be a lot more self-sustaining.

    Pamela Gay: And it’s really only six months to get there, so you can imagine setting up a system where you have this set of constantly moving vehicles that you dock with and undock with going, again, back to the movie The Martian where you don’t have the power loss of matching speeds with Mars. You don’t have the power loss of matching speeds with Earth. You just have this ship that you dock and undock, fill it up at Earth, empty it out at Mars and keep doing the circuit every six months.
    Fraser Cain: We’ve talked about ways to mitigate everything but there’s really one problem that is going to be really difficult that we can’t dig, we can’t resupply, which is this is low gravity, so IF it turns out that 30 percent gravity IS lethal to human beings over long periods of time, what can we do about that?

    Pamela Gay: So, this is where I’m going to go back to one of my favorite sci-fi authors, Kim Stanley Robinson, and in one of his more recent books he put forth the idea that every couple of years the human beings HAVE to come back to Earth for a period of time to let their body get back to equilibrium and that without that constant return to Earth it may just be that human beings can’t quite make it. And there’s stock out measures.

    There’s the idea of sleeping in essentially rolling compartments where you can imagine everyone lined up along the walls at essentially a carnival ride getting spun up, sleeping like that and then it spins back down when it’s time to get up.

    Fraser Cain: One idea on PBS Space Time – they were talking about this a couple of months ago, about having some kind of huge train that just goes around and around and around and the train is at a bit of an angle so you take the centripetal force that you’re going to feel from the train – or is it centrifugal force that you get with the train and you match that with the partial gravity from Mars to equal out to 100. So, you’re going to be on the sort of curved track and it’s just going to go around and round but just imagine the scale of engineering of that. Irony is that space just, you know, a few hundred kilometers above your head in some kind of orbital facility like Phobos, or whatever, if it’s turning and is able to generate that artificial gravity, that’s going to be a place you could replenish, so you could come back to Earth, as you said. Or maybe you go up to Phobos, spend a year or a month or whatever in the full gravity of the rotating Phobos.

    Pamela Gay: But, again, spinning up something that is a rubble pile may be a bad idea, but –

    Fraser Cain: Sure, the 16 –

    Pamela Gay: We can just build a space station. Just build a space station.

    Fraser Cain: Is it 16 Psyche the metallic asteroids in the asteroid belt? You move that so that it’s going around Mars and then that becomes a place that you can go and rest and recuperate. That’s the part that’s, you know, if we can’t solve this problem it’s going to make living on Mars really, really difficult and there’s no way to fix the lack of gravity on Mars.

    Pamela Gay: And we really don’t know if this is the kind of thing that has some weird alternative biochemical solution where we’re going to find ourselves using CRISPR editor genes to add in things that change how we process, lose, and replenish calcium. We don’t know if there’s some magical hormone combination that’s going to be discovered. The solutions to these kinds of things could take any form and here is where occasionally you’re waiting for that next genius to have that breathtaking idea that changes the paradigm and it may be that slow incremental advancement that’s not going to get there and we need a giant paradigm shift.

    Fraser Cain: Yeah, and there was a great book on – I don’t even remember who did it but maybe it was an azimuth book story but anyway it was this idea that – I’m sure someone in the chattel will remember it, that as you said we don’t try to change Mars; we change ourselves. We meet Mars halfway, yet that we can, as you say, really genetically engineer a different race of human beings in life that IS equipped to deal in that kind of lower gravity and you can imagine this far, far future where we are genetically different from the other kinds of humans that are around in the solar system, that there are the people who live on Earth.

    There’s the people who live in space. There’s the people that live on different worlds depending on their gravity and they have different genetic structure adapted for that environment.

    Pamela Gay: And you can imagine as a starting point, again stealing ruthlessly from Kim Stanley Robinson. Everyone needs to go read everything he has ever written. He puts forward the idea that perhaps you start by finding like and adjust it to extraordinarily high altitudes and see if you can adjust it to living on Mars. Now, here we are sort of admitting to the idea of completely destroying all potential microbial or other life on Mars, but life adapts. Life finds a way and it is potential that life as we know it would die horribly on the surface of Mars, but perhaps we can get to having life as we don’t currently know it, that’s perfectly happy to be radiated.

    Fraser Cain: Yeah, if I understand the likings that come from Antarctica and such, they would still die and suffer horribly on the surface of Mars but it’s not THAT far. It wouldn’t require a ton of modifications to be able to handle the drier habitat. As long as you give them water you could handle that drier habitat and be able to survive on Mars, so we actually could be very close to be able to make this happen.

    Pamela Gay: It’s just that whole lie that we aren’t alive currently that is always the sticking point because each of us want to do it rather than imagining the edited humans that might do it in the future.

    Fraser Cain: Or of course if we end up merging with our robots, then they don’t care, so when we join with our robots then our robot bodies will be able to survive out on the surface of Mars with no problem, which is just another reason to, you know, merge with our robots.

    Pamela Gay: And now I want to go watch Battlestar Galactica again.

    Fraser Cain: Right. All right. Well, thanks, Pamela. Next week we’re going to talk about getting from and maybe to Mars.

    Pamela Gay: Sounds great, Fraser.

    Fraser Cain: Alright, see you next week.

    Pamela Gay: Bye-bye.

    Thank you for listening to Astronomy Cast, a nonprofit resource provided by Astrosphere New Media Association, Fraser Cain, and Dr. Pamela Gay. You can find show notes and transcripts for every episode at astronomycast.com. You can email us at info@astronomycast.com, tweet us at @astronomycast, like us on Facebook, or circle us on GooglePlus. We record the show live on YouTube every Friday at 1:30 p.m. Pacific, 4:30 p.m. Eastern, or 2030 GMT. If you miss the live event, you can always catch up over at cosmoquest.org or our YouTube page. To subscribe to the show, point your podcatching software at astronomycast.com/podcast.xml or subscribe directly from iTunes. Our music is provided by Travis Earl and the show was edited by Chad Weber.

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    Duration: 30 minutes

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    2 Responses to Ep. 429: Living on Mars

    1. Audrey November 25, 2016 at 10:45 am #

      Hey Pamela, I know you weren’t intending to be hurtful or exclusionary, but I do nonetheless feel like I should remind you that “lame” is ableist language, and that when you say “consenting men and women” you’re using binarist language. One hopes that a genderqueer or two-spirits astronaut would be able to consent to sexual activity in space. Love the show otherwise and again, I know these are just slips of the tongue but being reminded about how our use of language affects others is important.

      • susie December 7, 2016 at 6:28 pm #

        Thank you Audrey for your response. You are correct – we should be very mindful of our use of language, and do not wish to hurt or make anyone feel excluded. We will work hard in the future to not use these types of terms and make sure we’re using inclusionary language. Space is very large – there is room for everyone out there, and we encourage all humans to explore and enjoy the wonder of space and it’s mysteries!
        -Producer Susie

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