Although humans have never actually been to Mars, explorers have simulated many aspects of Mars missions here on Earth. There are missions under the ocean, on the tops of volcanoes, in the harsh Canadian north, and even in bed that simulate the limitations of spaceflight, and teach us many of the lessons to prepare us for the real thing.
Bed Rest FAQs (NASA)
Apollo Lunar Training (Northern Arizona University)
What is Lunar Regolith? (Universe Today)
Mars Desert Research Station (The Mars Society)
How LARP Works (How Stuff Works)
Antarctic Stations (NSF) (NASA)
Biosphere 2 (The University of Arizona)
High-tech sleeping bag could solve vision issues in space (Science Daily)
Parabolic Flight (NASA)
Transcriptions provided by GMR Transcription Services
Fraser: Astronomy Cast Episode 638: Simulating Space Missions. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know but how we know what we know. I’m Fraser Cain, publisher of the Universe Today. With me, as always, is Dr. Pamela Gay, a senior scientist for The Planetary Science Institute and the director of CosmoQuest. Hey, Pamela. How are you doing?
Dr. Gay: I am doing well. We are at that point in spring where the magnolias are in full bloom. The apple tree’s about to bloom, and that means we will have one more snowstorm.
Fraser: Yeah. We have a snowstorm right now. So, like in April. This is madness. So, I was talking to one of my patrons today. And so, one interesting thing people maybe don’t know, if you sign up as a patron for Universe Today, I do a phone call with you or a Zoom meeting with you to just get information about how you became a patron, and how you found about Universe Today, and how we can make things better and so on. And I was talking to another person who says they use our stuff for falling asleep. And, I just wanna say, “That’s okay.” We understand. We appreciate the fact that we’re able to play this really valuable role in everybody’s lives in helping them go to sleep.
Dr. Gay: It’s true. I do listen to other people’s podcasts –
Fraser: Me too. To sleep.
Dr. Gay: – to go to sleep.
Fraser: Yes. So, we understand. We do it, too. It’s totally fine. Don’t feel guilty. If we can bring that valuable role – if our soothing monotone voice can make you feel like you have to go sleep, that’s perfect.
Dr. Gay: I think it’s our soothing, not entirely monotone voices that are putting people to sleep.
Fraser: Yeah. Ties up the thinking part of the brain. Although humans have never actually been to Mars, explorers have simulated many aspects of Mars missions here on Earth. There are missions under the oceans, on the tops of volcanoes, in the harsh Canadian North, and even in bed that simulate the limitations of spaceflight and teach us many of the lessons to prepare us for the real thing. So, have you ever done one of these simulated Mars missions?
Dr. Gay: No. They require you to put the rest of your life on hold for longer than I’ve ever felt that I could get away with, given all the different things that I’m constantly doing. Basically, I like to multitask. And, if you’re doing one of these things, you have to be completely committed. And the other part is that the Mars ones they do in Hawaii. I have a severe Sulfa allergy that when –
Fraser: Mmm, the vog.
Dr. Gay: Yeah, vog makes me think that I have pneumonia, and it’s just allergies. So –
Fraser: Well, and sulfurish, sulfuric clouds going into your lungs. All right. So, about this idea – so, I guess – what are some examples of simulations that are done to help us understand space life? How does this work?
Dr. Gay: They’re trying to test lots of different things, ranging from; how does the human body respond to not having a diurnal cycle with sunrise and sunset? How does the human body respond to not being allowed to be vertical in a gravity well? How do human beings deal with being stuck in a small container they can’t escape?
And to test each of these different things, including technology tests of, how do we handle it when – as kids, we all played “the floor is lava.” Well, they instead go out into Northern Arizona and play “the air is vacuum.” And with each of these different experiments, they’re looking to understand the human psyche or the physiological response to these different “not normal” environments.
Fraser: Yeah. I mean, there’s so many communication delays. The checklist of procedures that you have to go through to go in and out of your spacecraft and so on. There’s a very rich heritage of this. The Apollo astronauts simulated their missions in the deserts here on Earth as well.
Dr. Gay: And some of it is to simulate to get used to things and to test out things. Desert RATS is building on the legacy of what the Apollo astronauts did out in the North American deserts because they are sending out astronauts who are going to be asked to collect geological samples while wearing these bulky terrible suits that have been adjusted so that they don’t weigh as much. But it’s the equivalent of what they’re going to be dealing with in terms of “my hands are stuck in gloves.”
And the poor astronauts couldn’t bend at the waist. And just trying to figure out how to do anything when you know if you fall over, you’re going to be a landed turtle. You have to practice that. You have to practice the, “Okay, how does my spacewalk buddy get me back up when I fall on my back?” And all of the awkwardness of outer space. We think of the glory, the overview effect, the amazing “I get to eat that water bubble in the capsule.” We forget the – that rock is really far away because I can’t bend over problems of spaceflight.
Fraser: Yeah. Astronauts fell over several times. There’s even some hilarious video of this happening to them. So, let’s talk about some of these missions. You mentioned Desert RATS. So, give us an example of – what is Desert RATS?
Dr. Gay: So, Desert RATS is a program that has taken various concept models for lunar rovers and spacesuits and tested them out in Northern Arizona. And what’s cool is they’ve done things like – we know that moon rock is finely ground up into regolith is like wearing glass in your clothing. So, we want to do absolutely everything possible to mitigate the potential of getting space dust into the human areas. And so, they’ve been doing cool testing of things like rovers that drive along with these bodies mounted to the outside, except they’re just the spacesuits. And the astronauts slide into the spacesuits, a door gets closed onto their back, and they’re good to go.
And this is a super clever new design, but you have to figure out the logistics of can human beings handle getting in and out where you’re essentially docking your back up at the end of the spacewalk. And so, they’re testing different designs. They’re testing different, like I said, concept models for the lunar rovers. And this gives them a much cheaper place to test these prototypes and figure out the design elements that really matter if we want to have more than a couple of weeks at a time up in space.
Fraser: And you can imagine – when you think about something that you know how to do really well –I don’t know, like, get into car and drive it. And then if you really sit down and think about all of the different parts that you have to do. You have to open the door, unlock the car, open the door, get in, sit down, adjust the seat, maybe adjust the steering wheel, start the car, operate the car. And then imagine you’re wearing a spacesuit this entire time while you’re doing this. You don’t wanna be on the Moon or on Mars the first time that you’ve tried all this stuff out. You want to be incredibly comfortable. And the engineers want to have gone through every action, every motion that you’re doing to try to minimize mistakes and parts where you can accidentally press the wrong button at the wrong time.
And so, there’s a lot of design issues. And it’s through trial and error that you find this stuff, ideally in a really safe environment. All right. So, we talked about Desert RATS. And I think that’s the kind of simulation that a lot of people are very familiar with. But there is some really interesting simulations that say the Mars Society is doing, NASA is doing, where people take their simulation of Mars to the next level.
Dr. Gay: And the simulation of Mars from the next level – we have people going from rovering around in Northern Arizona to instead perching on tops of volcanoes on the big island of Hawaii and in this lava-strewn landscape, where things really are sharp. It’s not just a let’s go out and drive around for a while and test the feasibility of getting in and out. There is also the, “Okay, we’re going to have everyone live off of solar electricity in a dome, where we have airlocks that you have to deal with.” And the entire thing becomes a, “I could die,” by which I mean ejected from the simulation – up on this world. And, here, they actually do fairly regularly look for volunteers for this simulation.
Fraser: And they even – they’ll put in the time delay between Earth and Mars, the roundtrip time delay. And so, you can’t just ask for help. You can’t have a conversation with – you have to send messages, and then you have to wait 40 minutes, between 15 and 40 minutes for a reply to come back from Earth.
Dr. Gay: Yeah.
Fraser: That causes an enormous amount of complexity and difficulty because you really are on your own. I’ve talked to someone who was in one of these simulations, and they really get serious. They’re really LARPing it to the next level –
Dr. Gay: That is the right way to put it.
Fraser: – because – Yeah. Yeah, they’re LARPing, doing a mission to Mars.
Dr. Gay: Yeah.
Fraser: And, if you don’t know what a LARP is, the live-action role playing, yeah. And so, then, when things go wrong, they do their best to try to make it work. And they’ve had problems with their toilets. They’ve had problems with their water system. They ran out of water, and they had to figure out how to get water into the simulation. And that just makes things even more complicated. Well, you’re going outside. You’re putting on this stupid spacesuit, going out into the blazing sun of the volcano navigating around sharp lava rock trying to just get this work done. It’s really the closest we can get to do to actually being on Mars so far.
Dr. Gay: And the psychological side of this is something that really has to be understood. I think that prior to COVID we didn’t really have a good understanding how the regular human being would react when asked to stay in one confined space in isolation or with the exact same group of people for a long period of time. And, if nothing else, COVID has taught us that a lot of people really, really don’t deal well with spending months at a time never leaving their house. It turns out I’m one of those people who’s pretty good at it. I’m not sure what that says about me.
Fraser: Not me. Yeah, not me. Yeah, you’re clearly –
Dr. Gay: So, I’d be fine going to Mars. But the interpersonal reactions. Kim Stanley Robinson and his Red Mars series makes the fascinating point that the number of human interactions within a group goes up as an exclamation mark, which is that mathematical thing that means –
Fraser: In factorial.
Dr. Gay: Yeah, which means factorial. And it means that it’s – say you have four people, the number of interactions is 1 x 2 x 3 x 4. And that’s a lot of human interactions. And, if even just one of those doesn’t work, it can destroy all of those interactions.
Fraser: Yes. Yeah, yeah. And we definitely have lots of experience. There’s missions down in Antarctica. There are submarine missions where people are under pressure. And they – and fairly enclosed places. I think Antarctica is probably the best practical simulation of this that we have because, for six months of the year, they are inaccessible. It’s almost impossible to deliver them any supplies, to rescue people if there’s some kind of medical emergency. They are on their own for half of the year. And yet people are there all year long. And just imagine all of the ways that things could go wrong, not to mention people getting on each other’s nerves, which they can do. Yeah.
Dr. Gay: Yeah. And we’ve learned a lot about the way humans interact, but in all of the examples that we’ve talked about now and I think we’d be remised if we didn’t mention the Biosphere 1 and 2 experiments.
Fraser: So, let’s talk about that, yeah.
Dr. Gay: So, in this case, there was an attempt made, again, in the Arizona desert, to build a fully enclosed biosystem that would be receiving no air from the outside and folks would be required to do all of their own gardening, all of their own everything. There were some technological problems that they ran into, specifically – and this is the most ridiculous “huh” that I have come across. It turns out that cement interacts with atmosphere while it is curing. And while your cement may be solid, that doesn’t mean it’s fully cured. And they ran into problems with just their building materials destroying their atmosphere on them.
Fraser: It was releasing carbon dioxide, excess carbon dioxide that they hadn’t accounted for in their simulations, yeah. Yeah. So, Biosphere 1 is Earth. Biosphere 2 is the simulated habitat. I’m obsessed about Biosphere 2. I cannot describe how much of an amazing idea that was, and they got a ton – a ton of flack about what they were doing. People were eye-rolling. People were making fun of it.
But it allowed them to essentially create a completely enclosed environment and then sort out every single one of the variables that human – you figure out which things human beings run out of. Did we run out of water? Do we have too much carbon dioxide? Are we – various nutrients? And, if they were able to continue running the simulation, we would’ve learned more and more. And it just shows you how much the Earth is doing naturally for us year after year after year, completely self-regulating that we just take completely for granted.
Dr. Gay: Yes.
Fraser: I can’t believe that Biosphere 2 wasn’t restored immediately and isn’t ongoing. Apparently, it might be coming back. But, right now, it’s just kind of a tourist attraction.
Dr. Gay: It’s an educational facility. It gets lots of grant money to do educational stuff.
Fraser: Yeah. Restart Biosphere 2. Make it happen. We can’t have a colony on Mars until Biosphere can run for decades safely and successfully.
Dr. Gay: Yeah, I agree with that.
Fraser: So, if you’re into space exploration. All right. Man, I just – I am on such a soapbox here. All right. That’s talk about this idea of bed rest.
Dr. Gay: Oh, this is wild. So, all the experiments we’ve talked about so far are ones where you still have gravity, you still have a day/night cycle. And it turns out that gravity and a day/night cycle are things that really matter. And one of things that they’ve had to figure out is: what is the physiological issue with never having gravity draining the fluid out of face and things like that?
And so, they will look for volunteers periodically to hang out at Johnson Space Center laying in bed for weeks or months. And they’re required while maintaining a horizontal position to go through various things like exercising and there’s – I couldn’t find a picture that I could readily share, but there have been posts before of people like precariously figuring out how to roll over just right so they can put food into their mouth without wearing it. It’s apparently a combination of remarkably difficult to actually keep yourself horizontal all the time and you have to.
Fraser: Yeah. You can’t get up and go to the bathroom. Just think about that for a little while. You have to eat, entertainment, everything, in this prone position for weeks or months at a time.
Dr. Gay: People can come visit you.
Dr. Gay: But it starts out as a, “I’m just gonna catch up on all my reading and playing video games and watching television, and it will be great.” Exercising on this particular schedule while having to stay laying down while exercising is a bad thing. And so, apparently, everyone eventually falls prey to the boredom and tedium, but they got the medical data they need.
Fraser: Yeah. Yeah, and a lot of this stuff that we’ve learned about spaceflight, again, came from these bed rest experiments done in the past. They do them in Europe as well.
Dr. Gay: Yes.
Fraser: And it’s been invaluable. And then you can map. And then you see what happens in spaceflight, and you can see how it’s a perfect analog. And it helps us try different treatments to see if anything, as you say, exercise – there’s these potential negative pressure sleeping bags they’re considering to solve this problem. So, it’s so much easier to try experiments, take blood tests here on Earth than out in space. And so, whenever we can simulate this stuff here on the planet, they do. So, it’s one last simulation that I’d like to talk about, and this is more short term if you’re willing to simulate spaceflight for about 30 seconds at a time. And these are these parabolic flights.
Dr. Gay: Oh, yeah.
Fraser: The vomit comet.
Dr. Gay: Yeah, yeah. So, we’ve talked about this before. I have to admit I didn’t even think about them for this episode. I had two other things to bring up.
Dr. Gay: With these, you have an airplane. It climbs, climbs, climbs, and then it puts itself through free fall. And during the free fall point, you are experiencing – basically, you are falling at the same rate that gravity is pulling, and it is a simulation of a zero-gravity experience. And astronauts can practice, and students and tourists can practice various different things that they’d want to do in zero-g. And this has included various dancers trying to figure out how you can do new forms of dance in zero gravity. It’s really quite fascinating. But, again, it’s 30 seconds at a time. You puke a lot and move on with your day.
Fraser: Yeah, yeah. There are various chemical processes that have been tested. You can do tests of how various mechanical systems are gonna work in zero gravity, etc. So, it does work briefly. You said you had a couple of other things that we hadn’t –
Dr. Gay: I did. One of my favorite sets of experiments that I’ve been tracking kind of since high school. There have been over the decades experiments, where they lock people in caves for prolonged periods of time. And, in many of the experiments, they don’t give them any time devices. And they see how human beings deal with having absolutely no day/night cycle that is externally enforced on them. More recently, there was a French experiment where they put 40 people in a cave together for 90 days.
Fraser: In total darkness?
Dr. Gay: In total – it was – well, it was darkness when – it had artificial light and that was it.
Fraser: Right. But they didn’t know when it was day and when it was night?
Dr. Gay: Yeah.
Fraser: And they can totally mess with their perception of time.
Dr. Gay: And it turns out that a lot of people, not all people but a lot of people, will cycle to having a shorter day/night cycle. I know I am one, as I learned as an observational astronomer, will cycle to a longer day/night cycle. But understanding that there is no one way that people react to lack of diurnal cycle and seeing how it affects mental health. It’s fascinating. And then you see these poor humans coming out of having lived in only smaller bits of artificial light for 90 days and they’re all, like, sunglasses and looking up. It’s like out of a movie where people are emerging from the nuclear shelters. And it’s cool work.
And along similar lines, but on a little bit harder to rescue folks, if you have a panic attack on a cave, you just shove them out the cave. But there is also the NASA NEEMO session, submersible, where they do long duration, “Let’s stick astronauts in this habitat under water, allow them to go on EVAs and scuba suits that feel like space suits.” And so, that’s another way of simulating missions where you don’t have that external day/night cycle.
Fraser: Yeah, yeah. I mentioned that in the introduction. But that’s exactly it, that under water is a surprisingly good way to test out the complexities of doing EVAs, of going outside your space – spacewalking. And these underwater facilities allow them to do that. So, it is kind of amazing that how much of the various concepts in spaceflight have already been tested out, whether it’s in Antarctica, whether it’s under the ocean, whether it’s on these Mars simulations, in beds, etc., etc. – in zero-g flights. Every aspect that we can simulate, we do and really should. And it will only be until we’ve mastered all the parts that we can before we go to try and live on the Moon or Mars. And then we’ll find out the stuff that missed on our simulations. Absolutely fascinating stuff, Pamela.
Dr. Gay: So, thank you, Fraser. And thank you so much to everyone out there who makes this show possible. Your patronage of our patreon.com/astronomycast allows us to pay all the people who organize the two of us. Nancy, who has been there forever as our cat herder. Rich and Ally who do editing. And all the other humans who I’m sure I’m forgetting at this particular moment in time. This week, I would like to thank by name just a few of our Patreon followers.
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Fraser: Thank you, everyone. Thanks, Pamela. And we’ll see you all next week.
Dr. Gay: Goodbye everyone.
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