Sleep, the Final Frontier

Leroy is a chemical engineer and a former NASA astronaut who's been to outer space on four separate missions, racking up two hundred and twenty nine days in space. One of the things that a lot of people find weird, and I found a little weird too, is you're not sure what to do with your your head and your neck.

You know, because you're on Earth you're used to feeling that pressure on your head against a pillow, and in space, of course, you're just kind of I mean, we actually do have like a little phone block at the top of the sleeping bag that you can act as a pillow, and there's a cloth of fabrics trap with velcrow that you can strap against your forehead if you need that pressure against the back of your head to fall asleep,

and I don't think anyone really uses that. Spending that much time in orbit means that Leroy and his fellow astronauts will definitely see the effects of that environment on their bodies, particularly when they're trying to sleep, which is even more of a challenge in space than it is on Earth. The lack of gravity effects astronauts spines, their brains, and even the amount of fluid build up in their nasal cavities, just to name a few of the challenges.

All of these things just make it even more difficult to get good rest on the final frontier. Sleep is not only important when you're really young, but it's important as a lifestyle, even as a professional, to make sure you get enough sleep so that your brain can develop to it's full capacity. And certainly, anyone in any position where you have to perform, you know that you've performed best obviously when you've had good sleep and good rest. So sleep is definitely an important thing and it and

it is a challenge in space. Beyond the expected challenges of sleeping in space, Leroy experienced a sort of jet lag as he first embarked, So we kept the laboratory running twenty four hours a day, and so that meant that four hours after launching into space for my first time, I had to go to sleep. And so imagine being so excited to be in space for the first time, looking at the air and floating. You know, we're in

this weird environment. Feeling a little weird because you know you're floating and you're in space, and they're all these physiological changes happening in your body. Anyway, the biology and functions of the human body have been shaped in part by its evolution in the gravity of Earth. So how does an astronaut's body, having escaped that gravity, adapt to life in a spacecraft speeding through the vacuum of space.

Today we're going to explore what it's like getting rest for our bodies in the ultra hostile environment of outer space, and how the absence of gravity and abundance of radiation affect the delicate mechanisms that allow our bodies and our brains to power down and recharge. On this episode of Chasing Sleep, Sleep, the final Frontier. Hi, I'm on a hut O'Connor, and this is Chasing Sleep and I heart

radio production and partnership with Mattress Firm. Sleep in space is pretty weird, you know, especially the first time to get up there. Once we launched into space, I have to say we were kind of pretty worn out by the time we did fly. And that's kind of a joke among ast or not especially those of us who fly on the Space station, which is not really a joke. It's like, you know, you're ready to go fly when you're completely exhausted, and so, you know, not necessarily the

best way to launch into space. Right, So you're high above the Earth's atmosphere in space, a million things going through your mind and all sorts of different environmental effects happening to your body. What exactly is it like to sleep up there? We had sleep stations on that flights because we were to shift operations, which meant we had

kind of little, you know, little closets if you will. Um. I hate to I hate to use this word, but they're kind of like little coffins that we could get into and slide the door shut so it would be dark, and put ear plugs in. Leroy continued to tell the story of his first time sleeping in space, getting to

the obstacle that I find most interesting zero gravity. And so I got into my little bunk after I had taken my sleeping pills, and it was dark, and had my ear plugs in, and I knew the orientation of the Space shuttle. Usually it was always the belly of the shuttle facing the Earth, so I knew the orientation of the shuttle. I knew my orientation inside of that dark sleep station. And I was laying on my back.

Although I was floating, I wasn't really laying. I was just floating in there in a sleeping bag, and I kind of felt like laying on my side, and it didn't make any sense whatsoever. But I rotated ninety degrees and in my mind I knew I was on my side relative to the Earth. Didn't make any difference because I was, you know, floating, and then I fell asleep. So just describing these sleep closets seems like an interesting place to have to squeeze into for rest, are there

multiple astronauts in each bunk? And exactly how tight is the space on a bed up there in space? It looks like a big box. Okay, So you slide the door open and you kind of get yourself inside, and then there's three other people beneath you if you're on the top right, but you're all separate. You're on your

own little box. And there's air flow, so you got plenty of ventilation, so you don't, you know, build up carbon dox and all that, and but the sleeping bags in there, and it's just kind of floating in there. There's not much room. There's room for nothing else except you, basically. So one part about being an astronaut you can't be the slightest pit claustrophobic, and that doesn't work out. But

it's not that bad. It's not uncomfortable. Maybe it's not uncomfortable, but there's a reason it takes months of training just to get used to sleeping in those quarters. And beyond the training, Leroy explained how extensively he and his fellow astronauts were monitored for sleep and for other medical conditions. So, for example, on that same first mission, I had to wear an actograph during uh my sleep period was a little thing I had to put on my wrist and

it was just monitor. It was trying to get a handle on how well I was sleeping, how restless I was, how long it took for me to stop moving around and go to sleep, and then during sleep how much I moved around? So they were collecting data like that. There are also journals that you keep that you could keep on your you know, part of that was your sleep quality. How was your sleep quality? Uh? Anecdotally for myself, it seems like I need a little less sleep in space.

I don't know why. It just seems like maybe I need about an hour or less in space, or I would wake up maybe an hour earlier than I might here on the Earth and sleep was okay. The struggle to get good sleep and outer space may not be easy, but Leroy told me about plenty of moments that made all the hard work well worth it. Yeah. I think the most uh wow moment of my space flights was on my third flight. We were on the second major

assembly mission of Space Station program. And during that time I was doing a spacewalk, one of the spacewalks, and then my my boots were attached to the robotic arm of the Space Shuttle and I was being moved from

one work side to another. And during that transition of several minutes, during a good part of it, I was faced down towards the Earth, and I couldn't see the space station or the space shuttle out of my peripheral vision, and so I was looking straight down at the Earth, watching the clouds and the continents roll by, and I felt like a satellite flying over the Earth. So that was probably the most amazing, you know, a few minutes

of my career. We'll be right back after a brief message from our partners at Mattress Firm, and now back to chasing sleep. The moment the human body enters space a place we've definitely not evolved to be, our bodies inter mechanisms start to change. We evolved here on Earth, so life generally likes where it evolved, and so humans. There are a number of biomedical things that happened to

us in space, and none of them are good. A lot of people have a little bit of congestion because in space is a fluid shift where you're no longer have gravity pulling fluids down into your legs, so you have a fluid shift, and even though your body tries to calibrate that, in fact, the average person loses about two leads of water in space. You know, you you carry about two leaders less water in space when you're floating around. So imagine one of those big soda bottles.

That's how much less water is in the average person. And but nonetheless you still feel a little bit full headed, a little bit like you're laying on an inclined head down, and so that can make you feel a little bit congested. And so you know, that was something I was aware of, uh, during my sleep, is that I couldn't breathe. This is easily through my nose, you know, and sometimes that would

wake me up or something. Leroy has amazing firsthand insight into the challenges that astronaut's face and the techniques to overcome them. So to better understand the technicalities behind how space is affecting our bodies and brains, I sat down with Dr Matthias Bosner, a professor of psychiatry. I joined the German Aerospace Center actually the Flight Physiology division, and was actually hired to investigate the effects of aircraft noise on sleep. Was the largest study ever that was done

at the time at the German Aerospace Center. Stayed at the German aerospacent the footage years, studied a lot of sleep, then came to the United States and did a lot of work in space flight and an astronauts. Dr Matthias Parsner broke down exactly what's going on in and around the bodies of astronauts that makes it so hard for them to sleep. We also see some volume shifts in the brain and the volumes that carry the cerebral spinal

fluid they actually extend during long duration space flight. And then there's a radiation which is not a super big deal on the I S because it's still in it's a low Earth orbit and it's within Earth magnetic shield. But once we venture out of a low Earth orbit, you know, back to the Moon or two Mars, radiation

becomes a major issue. And we actually generated predictive models for a mass so looking at all the different environmental stressors on the I S, and radiation was one that was consistently showing up and that it was affecting cognit performance even the oh they're still you know, in that protective environment magnetically. But then there's also the nutrition is different.

On the is s. You have oftentimes elevated carbon dioxide levels that can affect performance sometimes you know, lower oxygen levels. You have just the psychological stress related to living in an isolated, confined, an extreme environment with the threat to life component. These changes on your body can be very jarring for first time astronauts, but with enough time, incredibly the human body begins to adapt, including changes to how

our brain functions. There is a lot of adaptation going on, both physiologically but also from a brain perspective, because you know that gravity vector is gone, and you know your your brain kind of has to rewire itself or or reweight the different neural connections to make sense of this. You know, for example, the visual input becomes much more important now because you know, our vestibulous system that tells us how we are oriented in space is no longer working.

Basically it switched off, right, So there's a lot of brain placidity going on. But also you know, because of that, nausea is a big problem during the first you know, one or two weeks, and you know there's a medication for that as well. Or back pain is another is another big issue. You know, astronauts spines are actually extending because you know, we don't have that gravity vector, and you know the spine is not compressed when we're walking around.

It's pretty interesting how studying something that might seem as foreign as an astronaut sleeping in space gives us great insight into how our bodies work down here on Earth. I asked Matthias what other info he was able to discover for us Earth links while studying the sleep of astronauts. We did the study in twenty for astronauts, measured their perform moments and we asked them questions about their sleep

and how they felt, etcetera. But at the time we didn't have the environmental data from the International Space Station. It was actually very interesting to see which variables were you know, showing up. And I already mentioned the radiation that's not that relevant on Earth, but CEO two, for example,

is one of the factors that plays a role. And we just did another study here on on Earth in bedroom of participants who were wearing like an active graph which is a fitbit like device for fourteen consecutive nights or twenty four our periods, and we measured you know, air pollution PM two point five levels in the bedroom, CEO two levels, temperature, humidity and noise and low and behold, we get significant effects on sleep of air pollution CEO

two temperature, and noise always in the sense that higher levels are worse for sleep. So in that sense, I think a lot of the things that we observed on the I S S translate back nicely to situations on Earth. Matthias's job is to study all the physiological effects of outer space so we can avoid any surprises on the adventurers that are heading up there, but dealing with an environment as new as that, there will always be something unexpected.

I found the challenge regarding noise particularly surprising. My assumption would have been that up in space that you're probably dealing with less noise than you are on the ground. Well, you know, outside the space station it's incredibly quiet because you have a vacuum and days there's you know, sounds are not transported at all. But inside the space station you have you know, lots of pumps and devices and alarms,

so there's a constant background noise level. But there's also you know, intermittent noise events that can grab your attention and also affect your sleep. Yeah, So how does that kind of noise a factor sleep? What does it do? Well? You know, one thing is that our auditory system has kind of a watchman function it's it's like always online,

it's constantly monitoring our environment for potential threats. So we have to have some sensory inputs that we're still monitoring while we're sleeping, and if everything dangerous comes up, you know, we're woken up and so that we can actually run away and and get away from that threat. So the auditory system is monitoring the environment while we're sleeping, and

not only for sound levels, but actually for content. There were studies as earliest in the nineteen sixties where they would play back names and whenever your own name was played back, you would wake up with a much higher probability than when it was just another name that didn't have a meaning for you. So it's both sound levels

and content that do matter. So in that sense, you know if you have an alarm, I mean alarm, alarm is actually meant to grab your attention and to arouse you, like an alarm clock, right or baby crying that those are those sounds have properties that that make you wake up. So if there's an alarm of the isis obviously you know the intent is to wake you up. But oftentimes there are like alarms that are not that important that

void you up. Nevertheless, so there is you know, a pump running every time there's a change in the noise levels that is very meaningful to humans and more likely to wake you up. So this is, you know, when it's a noisy on the International Space Station that may

actually affect the astronauts sleep as well. The mechanism in our brains that can determine which noises are normal and which are important, all while we're basically shut off has got to be one of evolution's most useful and coolest achievements, the testament to our species ability to explore even places we were explicitly never meant to go. The thing that surprised me is how quickly, just how adaptable the human body is. Like you get up there, it's one of

the weirdest environments. You can suddenly find yourself in your floating You feel weird, you're you're dizzy. For the first couple of days, You've you've got this fluid shift going on, so you feel like you're standing on your head. But then after a few days, even the people that have trouble a little trouble adapting, even they will adapt. And then you know, surprisingly even after short shuttle mission of

one or two weeks. When you come back, your body has already forgotten what it's like to be on Earth, and so you've got to adapt to being back on Earth where you're dizzy again. You can't walk a straight line save your life. Um, you feel might feel a little nauseous, you might feel fatigued and low on energy. But after a few days after a shuttle mission, you bounce back pretty well. So the human body can adapt to these different environments. Uh. Surprisingly, Well, that's all for

this episode. Join me again next week when we learn about people who live at the top of the world, where the sun stays in the sky for months at a time, and how the perpetual daytime affects their sleeping patterns. Of Winter is so much easier just because it's dock all the time. But in the summer we have to like just close all the windows, all the cones, put like cobboard on to block out the light. At like ten pm, just run around the house play operation nighttime.

We want to hear from you. Leave a rating or review for our show on your podcast player of choice. You can find me on Twitter at on a hot O'Connor. Until next time, hoping you're living your best while sleeping your best. Chasing Sleep is a production of I Heart Radio in partnership with Mattress Firm. Our executive producer is Molly Sosha. Our EP of Post is James Foster. Our supervising producer is Kia Swinton. Our producer is Sierra Kaiser.

Our researcher and writer is Eric Lesia. This show is hosted by me On a Hot O'Connor