Speaker 1: Three two.
Speaker 2: Space flight definitely changed me.
Speaker 3: I think it has definitely has an effect on everyone
Speaker 3: who goes up there, even for a short mission. So,
Speaker 3: you know, just looking down at the Earth, I mean,
Speaker 3: it's just so beautiful and colorful and looks extremely peaceful.
Speaker 2: Right you're.
Speaker 3: Eighty million kid two point eight.
Speaker 4: Very few people have viewed Earth the way Leroy Choo has,
Speaker 4: from over four hundred kilometers above the planet's surface and
Speaker 4: cruising at an unimaginable seventeen thousand miles per hour. Leroy
Speaker 4: is a chemical engineer and a former NASA astronaut who's
Speaker 4: been to outer space on four separate missions, racking up
Speaker 4: two hundred and twenty nine days in space.
Speaker 3: One of the things that a lot of people find weird,
Speaker 3: and I found a little weird too, is you're not
Speaker 3: sure what to do with your head and your neck.
Speaker 3: You know, because you're on Earth you're used to feeling
Speaker 3: that pressure on your head against a pillow, and in space,
Speaker 3: of course, you're just kind of I mean, we actually
Speaker 3: do have like a little foam block at the top
Speaker 3: of the sleeping bag that you can act as a pillow,
Speaker 3: and there's a cloth a fabric strap with velcro that
Speaker 3: you can strap against your forehead if you need that
Speaker 3: pressure against the back of your head to fall asleep,
Speaker 3: and I don't think anyone really uses that.
Speaker 4: Spending that much time in orbit means that Leroy and
Speaker 4: his fellow astronauts will definitely see the effects of that
Speaker 4: environment on their bodies, particularly when they're trying to sleep,
Speaker 4: which is even more of a challenge in space than
Speaker 4: it is on Earth. The lack of gravity effects astronauts spines,
Speaker 4: their brains, and even the amount of fluid build up
Speaker 4: in their nasal cavities, just to name a few of
Speaker 4: the challenges. All of these things just make it even
Speaker 4: more difficult to get good rest on the final frontier.
Speaker 3: Sleep is not only important when you're really young, but
Speaker 3: it's important as a lifestyle, even as a professional to
Speaker 3: make sure you get enough sleep so that your brain
Speaker 3: can develop to its full capacity. And certainly, anyone in
Speaker 3: any position where you have to perform, you know that
Speaker 3: you performed best obviously when you've had good sleep and
Speaker 3: good rest. So sleep is definitely an important thing, and
Speaker 3: it is a challenge in space.
Speaker 4: Beyond the expected challenges of sleeping in space, Leroy experienced
Speaker 4: a sort of jet lag as he first embarked.
Speaker 3: So we kept the laboratory running twenty four hours a day,
Speaker 3: and so that meant that four hours after launching into
Speaker 3: space for my first time, I had to go to sleep.
Speaker 3: And so imagine being so excited to be in space
Speaker 3: for the first time, looking at the air floating. You know,
Speaker 3: we're in this weird environment. Feeling a little weird because
Speaker 3: you know you're floating and you're in space, and there
Speaker 3: are all these physiological changes happening in your body.
Speaker 4: Anyway, the biology and functions of the human body have
Speaker 4: been shaped in part by its evolution in the gravity
Speaker 4: of Earth. So how does an astronaut's body, having escaped
Speaker 4: that gravity, adapt to life in a spacecraft speeding through
Speaker 4: the vacuum of space. Today we're going to explore what
Speaker 4: it's like getting rest for our bodies in the ultra
Speaker 4: hostile environment of outer space, and how the absence of
Speaker 4: gravity and abundance of radiation affect the delicate mechanisms that
Speaker 4: allow our bodies and our brains to power down and recharge.
Speaker 4: On this episode of Chasing Sleep, Sleep, the Final Frontier. Hi,
Speaker 4: I'm Anahad O'Connor, and this is Chasing Sleep and iHeartRadio
Speaker 4: production and partnership with Mattress Firm.
Speaker 3: Sleep in space is pretty weird, you know, especially the
Speaker 3: first time to get up there. Once we launched into space,
Speaker 3: I have to say we were kind of pretty worn
Speaker 3: out by the time we did fly. And that's kind
Speaker 3: of a joke among us, or not especially those of
Speaker 3: us who fly on the Space station, which is not
Speaker 3: really a joke. It's like, you know, you're ready to
Speaker 3: go fly when you're completely exhausted, and so, you know,
Speaker 3: not necessarily the best way to launch into space.
Speaker 4: Right, So you're high above the Earth's atmosphere in space,
Speaker 4: a million things going through your mind and all sorts
Speaker 4: of different environmental effects happening to your body. What exactly
Speaker 4: is it like to sleep up there?
Speaker 3: We had sleep stations on that flight because we were
Speaker 3: two shift operations, which meant we had kind of little,
Speaker 3: you know, little closets, if you will, hate to use
Speaker 3: this word, but they were kind of like little coffins
Speaker 3: that we could get into and slide the door shut
Speaker 3: so it would be dark, and put ear plugs in.
Speaker 4: Leroy continued to tell the story of his first time
Speaker 4: sleeping in space, getting to the obstacle that I find
Speaker 4: most interesting zero gravity.
Speaker 3: And so I got into my little bunk after I'd
Speaker 3: taken my sleeping pills, and it was dark and had
Speaker 3: my ear plugs in, and I knew the orientation of
Speaker 3: the Space Shuttle. Usually it was always the belly of
Speaker 3: the shuttle facing the Earth, so I knew the orientation
Speaker 3: of the shuttle. I knew my orientation inside of that
Speaker 3: dark sleep station, and I was laying on my back.
Speaker 3: Although I was floating, I wasn't really laying. I was
Speaker 3: just floating in there in a sleeping bag, and I
Speaker 3: kind of felt like laying on my side, and it
Speaker 3: didn't make any sense whatsoever. But I rotated ninety degrees,
Speaker 3: and in my mind I knew I was on my
Speaker 3: side relative to the Earth. Didn't make any difference because
Speaker 3: I was floating. And then I fell asleep.
Speaker 4: So just describing these sleep closets seems like an interesting
Speaker 4: place to have to squeeze into. For rest, are there
Speaker 4: multiple astronauts in each bunk? And exactly how tight is
Speaker 4: the space on a bed up there in space?
Speaker 2: It looks like a big box.
Speaker 3: Okay, So you slide the door open and you kind
Speaker 3: of get yourself inside, and then there's three other people
Speaker 3: beneath you if you're on the top right, but you're
Speaker 3: all separate.
Speaker 2: You're on your own little box.
Speaker 3: And there's airflow, so you got plenty of ventilation, so
Speaker 3: you don't, you know, build up carbon dox and all that.
Speaker 3: But the sleeping bag's in there, and it's just kind
Speaker 3: of floating in there. There's not much room. There's room
Speaker 3: for nothing else except you, basically. So one part about
Speaker 3: being an astronaut you can't be the slightest bit claustrophobic,
Speaker 3: and that doesn't work out.
Speaker 2: But it's not that bad. It's not uncomfortable.
Speaker 4: Maybe it's not uncomfortable, but there's a reason it takes
Speaker 4: months of training just to get used to sleeping in
Speaker 4: those quarters. And beyond the training, Leroy explained how extensively
Speaker 4: he and his fellow astronauts were monitored for sleep and
Speaker 4: for other medical conditions.
Speaker 3: So, for example, on that same first mission, I had
Speaker 3: to wear an actigraph during my sleep period. It was
Speaker 3: a little thing I had to put on my wrist
Speaker 3: and it was just monitor. It was trying to get
Speaker 3: a handle on how well I was sleeping, how restless
Speaker 3: I was, how long it took for me to stop
Speaker 3: moving around and go to sleep, and then during sleep
Speaker 3: how much I moved around? So they were collecting data
Speaker 3: like that. There are also journals that you that you
Speaker 3: could keep on your part of that was your sleep quality?
Speaker 3: How was your sleep quality? Anecdotally for myself, it seems
Speaker 3: like I need a little less sleep in space.
Speaker 2: I don't know why.
Speaker 3: It just seems like maybe I need about an hour
Speaker 3: less in space, or I would wake up maybe an
Speaker 3: hour earlier than I might hear on the Earth and
Speaker 3: sleep was okay.
Speaker 4: The struggle to get good sleep and outer space may
Speaker 4: not be easy, but Leroy told me about plenty of
Speaker 4: moments that made all the hard work well worth it.
Speaker 2: Yeah.
Speaker 3: I think the most wow moment of my space flights
Speaker 3: was on my third flight. We were on the second
Speaker 3: major assembly mission of the Space station program, and during
Speaker 3: that time I was doing a spacewalk, one of the spacewalks,
Speaker 3: and my boots were attached to the robotic arm of
Speaker 3: the Space Shuttle and I was being moved from one
Speaker 3: work site to another, and during that transition of several minutes,
Speaker 3: during a good part of it, I was face down
Speaker 3: towards the Earth and I couldn't see the space station
Speaker 3: or the space shuttle out of my peripheral vision, and
Speaker 3: so I was looking straight down at the Earth, watching
Speaker 3: the clouds and the continents roll by, and I felt
Speaker 3: like a satellite flying over the Earth was probably the
Speaker 3: most amazing, you know, few minutes of my career.
Speaker 4: We'll be right back after a brief message from our
Speaker 4: partners at Mattress Firm, and now back to chasing sleep.
Speaker 4: The moment the human body enters space, a place we've
Speaker 4: definitely not evolved to be, our bodies inner mechanisms start
Speaker 4: to change.
Speaker 3: We evolved here on Earth, so life generally likes where
Speaker 3: it evolved, and so humans there are a number of
Speaker 3: biomedical things that happened to us in space, and none
Speaker 3: of them are good. A lot of people have a
Speaker 3: little bit of congestion because in space there's a fluid
Speaker 3: shift where you're no longer have gravity pulling fluids down
Speaker 3: into your legs, so you have a fluid shift, and
Speaker 3: even though your body tries to equilibrate that, in fact,
Speaker 3: the average person loses about two liters of water in space.
Speaker 3: You know, you carry about two leaders less water in
Speaker 3: space when you're floating around, So imagine one of those
Speaker 3: big soda bottles. That's how much less water is in
Speaker 3: the average person. But nonetheless you still feel a little
Speaker 3: bit full headed, a little bit like you're laying on
Speaker 3: an inclined head down, and so that can make you
Speaker 3: feel a little bit congested. And so, you know, that
Speaker 3: was something I was aware of during my sleep, is
Speaker 3: that I couldn't breathe as easily through my nose, you know,
Speaker 3: and sometimes that would wake me up or something.
Speaker 4: Leroy has amazing firsthand insight into the challenges that astronauts
Speaker 4: face and the techniques to overcome them. So to better
Speaker 4: understand the technicalities behind how space is affecting our bodies
Speaker 4: and brains, I sat down with doctor Mattias Bosner, a
Speaker 4: professor of psychiatry.
Speaker 5: I joined the German Aerospace Center actually the Flight Physiology division,
Speaker 5: and was actually hired to investigate the effects of aircraft
Speaker 5: noise on sleep. Was the largest study ever that was
Speaker 5: done at the time at the German Aerospace Center. Stayed
Speaker 5: at the German Aerospace Center for te years, studied a
Speaker 5: lot of sleep, then came to the United States and
Speaker 5: did a lot of work in spaceflight and in astronauts.
Speaker 4: Doctor Mattias Bosner broke down exactly what's going on in
Speaker 4: and around the bodies of astronauts that makes it so
Speaker 4: hard for them to sleep.
Speaker 5: We also see some volume shifts in the brain and
Speaker 5: the volumes that carry the cerebrospinal fluid they actually extend
Speaker 5: doing long duration spaceflight. And then there's the radiation, which
Speaker 5: is not a super big deal on the ISS because
Speaker 5: it's still in a low Earth orbit and it's within
Speaker 5: earth magnetic shield. But once we venture out of our
Speaker 5: lower Earth orbit, you know, back to the Moon or
Speaker 5: to Mars, radiation becomes a major issue. And we actually
Speaker 5: generated predictive models for NASA looking at all the different
Speaker 5: environmental stressors on the ISS, and radiation was one that
Speaker 5: was consistently showing up and that it was affecting cognitive performance. Oh,
Speaker 5: they're still you know, in that protective environment magnetically, but
Speaker 5: then there's also the nutrition is different. On the ISS.
Speaker 5: You have oftentimes elevated carbon dioxide levels that can affect performance.
Speaker 5: Sometimes you know, lower oxygen levels. You have just the
Speaker 5: psychological stress related to living in an isolated, confined, and
Speaker 5: extreme environment with a threat to life component.
Speaker 4: These changes on your body can be very jarring. For
Speaker 4: first time astronauts. But with enough time, incredibly the human
Speaker 4: body begins to adapt, including changes to how our brain functions.
Speaker 5: There is a lot of adaptation going on, both physiologically
Speaker 5: but also from a brain perspective, because you know that
Speaker 5: gravity vector is gone, and you know your brain kind
Speaker 5: of has to rewire itself or reweight the different neural
Speaker 5: connections to make sense of this.
Speaker 2: You know, for example, the visual.
Speaker 5: Input becomes much more important now because you know, our
Speaker 5: vestibular system that tells us how we are oriented in
Speaker 5: space is no longer working. Basically it's switched off, right,
Speaker 5: So there's a lot of brain plascicity going on. But
Speaker 5: also you know, because of that, nausea is a big
Speaker 5: problem during the first you know, one or two weeks,
Speaker 5: and you know there's a medication for that as well.
Speaker 5: Or back pain is another big issue. You know, astronauts
Speaker 5: spines are actually extending because you know, we don't have
Speaker 5: that gravity vector, and you know the spine is not
Speaker 5: compressed when we're walking around.
Speaker 4: It's pretty interesting how studying something that might seem as
Speaker 4: foreign as an astronaut sleeping in space gives us great
Speaker 4: insight into how our bodies work down here on Earth.
Speaker 4: I asked Mattias what other info he was able to
Speaker 4: discover for US earthlings while studying the sleep of astronauts.
Speaker 5: We did this study in twenty four astronauts measured their
Speaker 5: perform moments and we asked them questions about their sleep
Speaker 5: and how they felt, etc. But at the time we
Speaker 5: didn't have the environmental data from the International Space Station.
Speaker 5: It was actually very interesting to see which variables were,
Speaker 5: you know, showing up. And I already mentioned the radiation
Speaker 5: that's not that relevant on Earth, but CO two, for example,
Speaker 5: is one of the factors that plays a role. And
Speaker 5: we just did another study here on Earth in bedroom
Speaker 5: of participants who were wearing like an actigraph which is
Speaker 5: a fitbit like device, for fourteen consecutive nights or twenty
Speaker 5: four periods, and we measured you know, air pollution PM
Speaker 5: two point five levels in the bedroom CO two levels, temperature, humidity,
Speaker 5: and noise and lo and behold, we get significant effects
Speaker 5: on sleep of air pollution, CO two, temperature, and noise,
Speaker 5: always in the sense that higher levels are worse for sleep.
Speaker 5: So in that sense, I think a lot of the
Speaker 5: things that we observe on the ISS translate back nicely
Speaker 5: to situations on Earth.
Speaker 4: Matthias's job is to study all the physiological effects of
Speaker 4: outer space so we can avoid any surprises on the
Speaker 4: adventurers that are heading up there. But dealing with an
Speaker 4: environment as new as that, there will always be something unexpected.
Speaker 4: I found the challenge regarding noise particularly surprising. My assumption
Speaker 4: would have been that up in space that you're probably
Speaker 4: dealing with less noise than you are on the ground.
Speaker 5: Well, you know, outside the space station it's incredibly quiet
Speaker 5: because you have a vacuum and there's you know, sounds
Speaker 5: are not transported at all. But inside the space station
Speaker 5: you have you know, lots of pumps and devices and alarms,
Speaker 5: so there's a constant background noise level. But there's also
Speaker 5: you know, intermittent noise events that can grab your attention
Speaker 5: and also affect your sleep.
Speaker 4: Yeah, so how does that kind of noise affect or sleep?
Speaker 4: What does it do?
Speaker 2: Well?
Speaker 5: You know, one thing is that our auditory system has
Speaker 5: kind of a watchmen function. It's like always online, it's
Speaker 5: constantly monitoring our environment for potential threats. So we have
Speaker 5: to have some sensory inputs that we're still monitoring while
Speaker 5: we're sleeping. And if everything dangerous comes up, you know,
Speaker 5: we're woken up and so that we can actually run
Speaker 5: away and get away from that threat. So the auditory
Speaker 5: system is monitoring the environment while we're sleeping, and not
Speaker 5: only for sound levels, but actually for content. There were
Speaker 5: studies as early as in the nineteen sixties where they
Speaker 5: would playback names, and whenever your own name was played back,
Speaker 5: you would wake up with a much higher probability than
Speaker 5: when it was just another name that didn't have a
Speaker 5: meaning for you. So it's both sound levels and content
Speaker 5: that do matter. So in that sense, you know, if
Speaker 5: you have an alarm, I mean alarm, alarms actually meant
Speaker 5: to grab your attention and to arouse you, like an
Speaker 5: alarm clock right or baby crying that those sounds have
Speaker 5: properties that make you wake up. So if there's an
Speaker 5: alarm on the iss, obviously you know the intent is
Speaker 5: to wake you up. But oftentimes there are like alarms
Speaker 5: that are not that important that wake you up. Nevertheless,
Speaker 5: so there is you know, a pump running every time
Speaker 5: there's a change in the noise levels that is very
Speaker 5: meaningful to humans and more likely to wake you up.
Speaker 5: So this is you know, when it's a noisy on
Speaker 5: the International Space Station that may actually affect the astronauts
Speaker 5: sleep as well.
Speaker 4: The mechanism in our brains that can determine which noises
Speaker 4: are normal and which are important, all while we're basically
Speaker 4: shut off has got to be one of evolution's most
Speaker 4: useful and coolest achievements, a testament to our species' ability
Speaker 4: to explore even places we were explicitly never meant to go.
Speaker 3: The thing that surprised me is how quickly, just how
Speaker 3: adaptable the human body is. Like you get up there,
Speaker 3: it's one of the weirdest environments. You can suddenly find
Speaker 3: yourself and you're floating. You feel weird, you're dizzy. For
Speaker 3: the first couple of days, you've got this fluid shift
Speaker 3: going on, so you feel like you're standing on your head.
Speaker 3: But then after a few days, even the people that
Speaker 3: have trouble a little trouble adapting, even they will adapt.
Speaker 3: And then you know, surprisingly, even after a short shuttle
Speaker 3: mission of one or two weeks, when you come back,
Speaker 3: your body's already forgotten what it's like to be on Earth,
Speaker 3: and so you've got to adapt to being back on Earth,
Speaker 3: where you're dizzy again. You can't walk a straight line,
Speaker 3: save your life. You might feel a little nauseous, you
Speaker 3: might feel fatigued and low on energy, but after a
Speaker 3: few days after shuttle mission, you bounce back pretty well.
Speaker 3: So the human body can adapt to these different environments
Speaker 3: surprisingly well.
Speaker 4: That's all for this episode. Join me again next week
Speaker 4: when we learn about people who live at the top
Speaker 4: of the world, where the sun stays in the sky
Speaker 4: for months at a time, and how the perpetual daytime
Speaker 4: affects their sleeping patterns.
Speaker 1: Winter is so much easier just because it's stock all
Speaker 1: the time. But in the summer we have to like
Speaker 1: just close all the windows, all the cuns, put like
Speaker 1: codboard on to block out the light. At like ten pm,
Speaker 1: just run around the house play operation nighttime.
Speaker 4: We want to hear from you. Leave a rating a
Speaker 4: review for our show on your podcast player of choice.
Speaker 4: You can find me on Twitter at Anahad O'Connor. Until
Speaker 4: next time, hoping you're living your best while sleeping your best.
Speaker 4: Chasing Sleep is a production of iHeartRadio in partnership with
Speaker 4: Mattress Firm. Our executive producer is Molly Sosha, Our EP
Speaker 4: of post is James Foster. Our supervising producer is Keia Swinton.
Speaker 4: Our producer is Sierra Kaiser. Our researcher and writer is
Speaker 4: Eric Leijia. This show is hosted by me Anahad O'Connor