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International Space Station

Season 1Jul 7, 2017

Dan Huot, Public Affairs Officer at NASA’s Johnson Space Center, talks about the International Space Station: what it is, how it works, what it’s made of, and why it’s there. HWHAP Episode 1.

Houston Podcast

Houston Podcast Episode 1 International Space Station

“Houston, We Have a Podcast” is the official podcast of the NASA Johnson Space Center, the home of human spaceflight, stationed in Houston, Texas. We bring space right to you! On this podcast, you’ll learn from some of the brightest minds of America’s space agency as they discuss topics in engineering, science, technology and more. You’ll hear firsthand from astronauts what it’s like to launch atop a rocket, live in space and re-enter the Earth’s atmosphere. And you’ll listen in to the more human side of space as our guests tell stories of behind-the-scenes moments never heard before.

Episode 1 features a conversation with Dan Huot, Public Affairs Officer for the International Space Station (ISS) Program at NASA’s Johnson Space Center, talking about the ISS: what it is, how it works, what it’s made of, and why it’s there. This episode was recorded on March 17, 2017.


Gary Jordan (Host): Houston, we have a Podcast. Welcome to the official podcast of the NASA Johnson Space Center, episode one, International Space Station. I’m Gary Jordan and I’ll be your host today. So, on this podcast, we’ll be bringing in the experts– NASA scientists, engineers, astronauts– pretty much all the folks that have the coolest information, stuff you really want to know, right on the show and tell you more about all things NASA. We’re talking everything from extraterrestrial dirt to the unknown parts of the universe. So, today, on the first episode ever, we’re talking International Space Station with Dan Huot. He’s the public affairs office for the space station program here at the NASA Johnson Space Center in Houston, Texas and we had a great discussion about what the International Space Station is, how it works, what it’s made of, and why it’s there. So, with no further delay, let’s go light speed and jump right ahead to our talk with Mr. Dan Huot. Enjoy.

[ Music ]

>> T minus five seconds and counting. Mark.

>> Here she goes.

>> Houston, we have a podcast.

[ Music ]

Host: That’s true. Very true. So, anyway, let’s begin. I figured you’re the perfect person to have here, being the public affairs officer of the International Space Station. You talk to scientists, astronauts, engineers constantly, so you’re very aware of what’s going on and everything about the space station. So, for those of you listening, I think this is a good opportunity to learn just everything about it. Right? So, start from the very beginning. What is it?

Dan Huot: Everything. Awesome. Well, to start, in the beginning– no. So, the space station is– it’s a giant spaceship. I mean it is– it is the largest spacecraft that humans have ever built. And we haven’t been flying in space for too long, relatively, I mean we’ve been up there for 50 or 60 years, but the space station is kind of the pinnacle for what we’ve built so far. It is massive. I mean this thing supports multiple people. It’s been up there– at least pieces of it– since 1998. So, that’s another one of those factoid alerts that we always like to tell people. If you were born after the year 1998– spacecraft’s always been up there, but if you were born after the year– after November of 2000, as long as you’ve been alive, human beings have been living and working in space.

Host: Wow.

Dan Huot: We are aliens. We are a space-faring species. We are the ones off the planet. We’ve had people up there every single day for– as of right now, over 16 years. I mean that is mind-blowing. And they’re doing stuff every single day that’s either going to impact us here on Earth or get us ready to go further out. I mean that is the purpose of the space station. That’s why it’s up there. That’s why we have this huge thing floating above us.

Host: So, you say stuff, we’re doing stuff every day. Obviously, living up there I think is like a– is a big part of it, right? We’re– like you said, we’re explorers, we’re space farers. What is the stuff that’s actually, you know, that has that impact?

Dan Huot: It’s a lot of stuff. It’s a lot of stuff. And I mean it is– it is– and it’s divided up. It is as simple as just living in space. Just everything you do in space is a little bit different than the way you do it down here on Earth. I mean it could be anything from going to the bathroom to how you eat to just how you get your water. Everything is different.

Host: So, it’s like a way to practice, really, for–

Dan Huot: It is.

Host: For things further out. Because it’s not really far up, right? It’s only 250 miles. If you think about it, we’re still in the Earth’s protection. Like, we’re still protected by the Earth’s magnetic field.

Dan Huot: Well, space is funny in that going up– it feels like it’s so far away, space, but it’s 250 miles. That’s not that far. I mean I feel like the city of Houston is 250 miles. It’s not, but I mean 250 miles in a car is a short road trip, but 250 miles straight up, that’s a rocket ride. That’s a slightly different road trip, but it is– it isn’t that far away. I mean we still kind of are right on the doorstep. There’s a really great quote in the paramount of space movies, Armageddon, where Owen Wilson says, you know, we’re not even in outer space yet. This is just like the beginning. And that’s kind of where the station is. It’s in space, it’s in what we call low Earth orbit. So, still pretty close. I mean they could get in a Soyuz spacecraft and be back on the ground inside of a couple hours. So, I mean you’re still right on the doorstep. You’re not really way out there yet, but it’s getting us ready to go way out there.

Host: Well, that’s the whole– so, NASA describes it as Earth-reliant, right? So, I kind of like the way they section it off, right, Earth-reliant means exactly what you said. Right? So, if something goes wrong, you can just hop in a spacecraft and be home in three hours and it’s easy to get stuff there because it’s only a– I mean some Soyuz rides have been as little as six hours, right?

Dan Huot: Relatively easy.

Host: Relative–

Dan Huot: Going to space is, yeah–

Host: It’s only rocket science.

Dan Huot: Don’t want to trivialize it. It’s still– and even– that’s– I even have to admonish myself. It’s still not easy to go to space. It’s still– I mean it is rocket science. It’s literal rocket science, which is hugely complex and there’s always inherent risk and all these other things, but when you start comparing it to, you know, going to Mars or our far-flung aspirations of spreading throughout the solar system and the galaxy and everything, when you compare it to that, it’s, you know, doing hand quotes, easy. But it’s still a monumental undertaking.

Host: Yeah. And that’s why– so, we’re doing that– just like you said, in the future we want to go farther. Right? So, we want to go to Mars, we want to really just expand our presence in the solar system. So, the International Space Station is a great way to practice that. It’s a good– like you have a good understanding of what it takes to live in space, to operate in space, you could do a ton of science and learn how things interact and then, if you learn how things interact, you can design better systems to make them work better. I think one of the ones– I think– capillary action I think was a great one. Like the way that fluids move in space is kind of cool because they sort of like create a ball and there’s no down, so if you’re trying to design like a system that– like a rocket system in order to propel fuel, you need to– the fuel isn’t going to go down, right, it kind of needs to have that sort of capillary action and a path to get there. Like little– those little tiny things are things that make the huge difference in being able to kind of explore the solar system.

Dan Huot: Well, it all comes to– down to gravity and that’s kind of the ultimate differentiator between why everything we do in outer space is different from the way we do it on Earth.

Host: Totally.

Dan Huot: Some of the stuff you touch on is very apt. I mean just moving fluids where, you know, here on Earth we almost take it for granted that everything settles towards the bottom. So, in plumbing systems and everything you can use that to your advantage. In space, you don’t have that and that affects everything from moving rocket fuel to, you know, I’m an astronaut and I need to get a drink of water. Well, that system has to be specifically designed to work in the absence of gravity.

Host: Yeah.

Dan Huot: And we’ve had a lot of practice, you know, since we’ve been flying in space, since the 60’s, but the station is really the first place you’ve had on this scale– there have been space stations in the past, both from the U.S. and Russia, but the space station is really the modern cutting-edge test bed for just doing and learning everything about living in space. And so you have all of these different technologies that, like I said earlier, everything you do in space is different from the way you do it on planet Earth where, you know, you have oxygen, thanks to natural cycles. And you have trees scrubbing carbon dioxide from your atmosphere and producing oxygen back for you. You have water and lakes, reservoirs coming– literally raining down on you from the sky, where in space none of that exists.

Host: You have to create it.

Dan Huot: You either have to bring it with you or find a way to create it.

Host: Yeah.

Dan Huot: And that’s something that we’re doing on the station right now, where you’re trying to– and that’s one of those key– we always talk about the different technologies that you need and technology is a really broad term, but one of the ones that is a lot probably easier to understand is how we get those things. How you get the water, how you get the air, just for the crew members. And one of the things you’ve got to remember is, again, so we’re close to Earth right now, so we can launch water. We can launch air. We can launch all of these things to these crew members, but when they go to Mars, there’s no resupply ship. There’s no, you know, hey, the water tank’s getting low, let’s, you know, stop off here and tap it off. You can’t do that. So, you’ve got to bring everything with you and everything is heavy. So, the more stuff you bring with you, the more fuel you need, the more expensive your mission, and then it just kind of compounds on and on and on and on and on. I’m going to ramble here for a while because I love this subject.

Host: OK. Well, I’ll kind of– I’m not going to stop you, I’m going to kind of, like, redivert you. So, one of the things on the International Space Station they’re doing now to do exactly that, so you said things are heavy, right, water. Water especially is very heavy.

Dan Huot: Yes.

Host: I forget the cost per pound to order– in order to launch water.

Dan Huot: Always varies.

Host: Oh, it always– OK, that’s good to know. But I know the– like, one way they’re actually doing– like, helping that out for long-duration missions is recycling. And the recycling system is just top notch. So good that they actually brought the technology back down to Earth and it actually is helping out third world countries with, you know, not access to any kind of clean drinking water. It’s– like the filtration system is that good. They drink their own urine and they capture sweat and stuff like that, right?

Dan Huot: They do. And that’s always a fun ew [phonetic] moment for little kids and stuff when you tell them that, but– and there’s the famous astronaut saying that yesterday’s coffee is tomorrow’s coffee. To where– that’s what you have to do when you have these weight limits and you’re in this environment where, you know, outside your four metal walls is just a vacuum of nothingness. You have to find ways to conserve all of those things and we know very well here on planet Earth that conservation is a very important facet of life. They try to do it through recycling and any number of things. It’s 10 times more important when you’re in space and there is no, you know, corner store that you can run to and, you know, pick up some water.

Host: The only things you have are the things you bring with you.

Dan Huot: And so to recycle the water, they actually– and they do, they collect water from all different sources, whether it’s the astronauts’ urine, which is a major source, their sweat, condensation in the cabin, any kind of wastewater gets fed through a treatment system which, you know, purifies the water and then puts it back out on the other side for them to continue to reuse. And the percentages seem to vary, but I mean we’re reclaiming at least 85% of the astronauts’ urine back into potable water. So, drinkable water. I mean that’s incredible. And, as you alluded to, we’ve actually taken that water recycling technology and made it available and it’s been used in disadvantaged areas of the world that don’t have access to clean drinking water and so that’s just a great example of here’s a technology that we need for outer space, you know, we’re trying to solve a problem off this world where we have the problem, and then we find a completely different use for this technology that it wasn’t necessarily designed for. I mean our scientist didn’t set out to develop a water filtration system for places without clean drinking water on Earth.

Host: Right.

Dan Huot: But it ended up having a use there and that’s– we call them spinoffs and that’s– you know, there’s a lot of famous ones throughout NASA’s history. That’s just an example of one that came about with all the work being done on the space station.

Host: Oh, yeah. You’ve heard of– there’s a lot of them, right? There’s like– memory foam is another one and like insulation for your house. Stuff like that. Like that– all that stuff–

Dan Huot: There’s a lot and we produce something called Spinoffs Magazine where– I mean it goes through just about every spinoff– every technological spinoff that’s come from space-based research that’s used here on Earth. And that’s just a symptom of doing research and development of this kind of funded research and development. People can find novel uses for technologies that were designed for one thing in a completely different field.

Host: Totally. OK. So, let’s take a step back and so we’re talking about like all the experiments and like the reason that we’re up there. Who’s up there right now? So, you said like, you know, if you’re 16-and-a-half, right, I think is the number– if you’re 16-and-a-half or younger, you’ve never lived in a time where people haven’t been in space. How many people are in space right now?

Dan Huot: Six.

Host: Six. And it– it’s international, right? So, we got– we have two Americans, right?

Dan Huot: Yeah, so international is the first word in the name of the station.

Host: Sure.

Dan Huot:It’s the International Space Station, so there’s always an international crew up there. Right now, there’s two Americans, Peggy Whitson and Shane Kimbrough, one French astronaut, Thomas Pesquet, and three Russian cosmonauts. And so you have crew members– we’ve had crew members from– and I’d have to look up the exact number, but I mean countries all over the glob have flown crew members on board the space station.

Host: Oh, yeah. I want to say 18 I think is the number.

Dan Huot: I think 18 is the latest and you’ve had well over 200 individuals travel to the space station and it is this global effort. You have 15 countries that are considered the main partnership, so these are the countries that signed all the papers and did everything back in the 90’s to form this partnership and you have five main agencies. You have NASA here in the U.S., the Canadian Space Agency right to our north, European Space Agency, which actually incorporates a lot of different space agencies from all over Europe into one larger conglomeration. The Russian space agency, Roscosmos, and the Japanese space agency called JAXA, the Japan Aerospace Exploration Agency.

Host: Right.

Dan Huot: And so lots of agencies, but all of this alphabet soup comes together to make the station possible and so everything that gets done just about is done in this big collaboration. So, you have these countries with drastic language barriers, cultural differences, sometimes governmental differences all working together on this massive multibillion-dollar piece, science research project.

Host: I think it’s fair to say that space exploration is really a global interest, right? I mean– exploring the cosmos, it’s not just a U.S. unique thing. It is really an international effort to make that possible.

Dan Huot: It’s something that will– as it does now and will certainly in the future involve the human race, not just one country. I mean especially as we continue to expand upon what we’ve done on the International Space Station and we’ve even recognized that future missions, there’s a lot of reasons to increase international collaboration, whether it’s drawing on other countries’ expertise, you know, one country’s much better at doing one type of engineering than we are and vice versa or they have some kind of novel science. There’s also the pooling of resources, which is– can a lot of times be a major driver. Going to Mars, going to other places is going to be very expensive.

Host: Yeah.

Dan Huot: And so it makes a lot more sense to shoulder that burden across several countries who all have this kind of shared interest will probably have different main goals, which is true. It’s even true on board the space station. Different agencies have different priorities for their research, but we all have that common goal of exploring space, improving the situation for people back here on Earth, and trying to push out further into the cosmos, into the galaxy, into, you know– making Star Wars a reality. That kind of thing.

Host: Well, Star Trek.

Dan Huot: Or Star Trek, yeah. Star– yeah, Star Trek is probably–

Host: Star Wars, we don’t need to fight.

Dan Huot: Yeah.

Host: See, when– I think one of my favorite things really when you think about like global participation is the way that the modules were designed. So, like each of them were just given like specifications this is how it needs to be built and they built them all over the world and then launched them up into space and connected them for the first time in space. Really, everyone had to be working together constantly to make sure that actually happened. And then you have to launch into space, then you have to connect it in space, make sure it works, make sure all the systems are integrated. That’s crazy.

Dan Huot: It is. And, again, that comes back to you have these countries with, I mean, language barriers and just completely different ways of engineering and everything, but we built the station piece by piece in outer space. Like you just said, none of these things were connected on the ground the first time, so you better make sure that when you send it up to space it’s going to– like you didn’t build a square peg for a round hole kind of thing.

Host: Yeah.

Dan Huot: So we had– we– there are definitely ways to share that knowledge, to share the technology, to make sure that all of your, you know, you can agree on standards, essentially, to make sure everything talks to each other, all the different electronics or all the different structural systems, all these different things. But it was still monumental to build this piece by piece. I mean it was literally done piece by piece. You had elements launched on either Russian proton rockets or carried up in the space shuttle where it would arrive, a big robotic arm would reach in and grab it out of the shuttle payload bay and then they’d attach it and you might have to do space walks and I mean unfurling solar arrays and all of these, you know, gigantic tasks. And it was done piece by piece by people talking and working together all over the planet. And there’s really not another engineering project or even big project like that that exists.

Host: I think it’s– it has been described as one of the greatest engineering feats in human history.

Dan Huot: Not to toot our own horn, but we would certainly– I would certainly argue that building a football-sized million-pound spacecraft in space is definitely up there.

Host: Yeah. That is– I– yeah, I would rank it number one, but yeah, who am I to say, right?

Dan Huot: We’re biased.

Host: A little bit biased.

Dan Huot: We’re a little biased.

Host: So, OK, let’s kind of think about like what it looks like, right, and how it operates. So, we talked about how you don’t have access to– you can’t just walk outside or you can’t drill for more resources. Everything has to be there, so it’s got to have power, it’s got to have air, it’s got to have water, have all these things. So, let’s– power. Where does it get its main power?

Dan Huot: The sun.

Host: The sun.

Dan Huot: Everything comes from the sun. It’s incredible. And a lot of spacecraft do this because you have the sun. I mean the sun is– we have solar energy here on Earth, but in outer space you can have even more direct access to the sun.

Host: It’s a very readily-available energy source in space.

Dan Huot: That we know how to harness.

Host: True.

Dan Huot: We know how to make solar arrays and we have gigantic ones on board the station. So, every– all the power on station is generated through solar energy. And we had talked about– they see 16 sunrises and sunsets a day. So, about half the time, they’re in complete darkness, so there is no sun. So, what you have is you have these great big solar arrays that are generating power and then there’s a bunch of batteries on board and the solar arrays are just charging up those batteries for every time they slip behind the Earth again and they’re in nighttime. Those batteries are just supplying power to everything, but it’s 100% solar, renewable, clean sun energy.

Host: Very true.

Dan Huot: it’s all solar energy.

Host: And they’re massive, right? Is it– I think it’s– they actually– they’re so big and they produce so much power that actually they do have to like kind of get rid of some of that power because it’s kind– it’s a little bit redundant, right? Just in case one of them breaks, like you still have enough power to power the whole thing.

Dan Huot: You do have redundancy built in. Redundancy is one of our favorite words. Redundancy is a fancy word for back-up plan and at NASA we always– you have back-up plans for your back-up plans. So, yeah, even if you lose– we call them power channels– if you lose one, you lose two, you can still power the majority of all of your systems on board. And even going beyond that, if you lose, you know, a much larger amount of power, you can still power your key systems and everything. You might just power down other things temporarily while you fix the problem. But it– they generate pretty much a comparable amount to keep everything that we want on board and that’s all the life support, that’s keeping the lights on, that’s running all of the experiments on board, all of the different hardware, just keeping the station, you know, oriented in the right attitude and flying it and any time– I mean everything. Everything, everything, everything is powered by the solar arrays and it– I mean it doesn’t generate an overwhelming excess of energy by any means, because, again, you are spending a lot of time in darkness, so those batteries are getting used pretty much constantly.

Host: Oh, yeah.

Dan Huot: We’re in the process of swapping the batteries. We’re upgrading.

Host: Yeah.

Dan Huot: We’ve already upgraded one-fourth of them.

Host: We switched out nickel hydrogen for lithium ion, right?

Dan Huot: That is correct.

Host: That’s right. Lithium ion. They’re way more efficient, right?

Dan Huot: Yeah. But that– I mean that’s the power story. It’s all solar energy through those big– and they are very large and we come back to the football field, the American football field and now that–

Host: We haven’t clarified yet, have we?

Dan Huot: That the solar arrays are basically– each solar array is the size of an end zone and there are eight of those. Yes. That are the size of an end– or–

Host: Think like a pair of four of them, right?

Dan Huot: Pair of four, so–

Host: Yeah.

Dan Huot: Four. It’s tough because like one pair is actually two array blankets and– but they’re very large.

Host: Yes. Yeah. OK. So, that’s power, right? So, we already talked about water because you need to recycle water and make sure you have enough and water is very expensive to launch and if you recycle it it’s a lot more efficient and it’s very, very clean. So, what about air, right? We– that’s one thing– you know, you think about like what a human needs– shelter, water, food– you don’t really think about air because– but it’s something you definitely need in space.

Dan Huot: That’s– again, that’s something we kind of take for granted that air is just– it’s air. It’s everywhere down here, but up there you’re in a sealed environment. You’re basically in a big sealed tin can and you need to fill that with air. So, they– we can launch air, just like we can launch water. You can launch a tank of super pressurized air, usually in its liquid form, and then feed it into the atmosphere, but the main way we get it is from water. We use a system called the oxygen generation system that actually takes water, splits the atom– not splits the atom, but splits the– a water molecule into oxygen and hydrogen and then we can take that oxygen and pump it into the atmosphere. And they aren’t in a pure oxygen atmosphere, so there’s other stuff in there. There’s a lot of nitrogen, so–

Host: Very similar to Earth’s atmosphere, right?

Dan Huot: Yeah, they’re basically in the exact same composition atmosphere that we have on Earth. And actually the same pressure too. So, there’s no big difference there. That feeds into some of the stuff they have to do for space walks, but that’s a completely different tangent I can go on. But– so, we split the water molecules so then you have your oxygen which you can just feed directly back into the cabin and then you have hydrogen which you can vent overboard if you just build up a bunch of excess hydrogen or there’s a process in a payload up there. It’s used as more of a technology demonstration, so it’s not really in the critical path, so it’s not a critical piece that we have to have running at all times, but it’s called the Sabatier. It uses the Sabatier process where you can take that hydrogen that you had left over from your water and then you can take the carbon dioxide that gets scrubbed out of the atmosphere by a different device, you split that carbon dioxide, you now have oxygen and then you have your leftover hydrogen. You combine those two and you’ve got more water.

Host: Boom.

Dan Huot: And so you can kind of build– the ideal is to build– we call it a closed loop. So, everything that gets put into this life support loop– it’s a big circle– just constantly gets recycled. You’ve got your water, you drank your water, you recycle your water, you take some of that water and you turn it into air and oxygen, you take that excess hydrogen and you combine it with CO2 that the astronauts are breathing out and you make more water. And so it’s all just kind of constantly going around in a circle and that way you get the absolute most out of everything you send up there.

Host:That’s crazy. You actually have to create an atmosphere, right, up there?

Dan Huot: Yes.

Host: It’s not like Earth where it kind of does it for us. You actually have to make it work. That’s crazy. I like the Sabatier system. That’s cool. You said it was a technology demonstration. I thought it was like part of the whole thing because I know they called it a partially closed loop because, like you said, you can eject the hydrogen if you have too much, right, so it’s– but yeah, same– kind of the same concept. So, OK, so they have air, they have water, they have power, they have all kinds of stuff. So, let’s talk about like I– the– some of the experiments. I know one of the biggest one is the experiment on themselves, right? So, you– in order to actually function beyond low Earth orbit and actually function in space, you have to learn how the human body reacts in space and what happens. So, I think the biggest thing– maybe it’s not the biggest thing, but it’s definitely very important is bone loss and muscle degradation. Right? So, that is if you’re in space for too long and you’re just kind of floating around, your bones start to exhibit symptoms of osteoporosis and your muscles start to degrade. So, how do they counter that?

Dan Huot: Yeah. Well, when we talk research, there’s really– there’s kind of two different camps. There’s the research that we’re doing on board the station to get us ready to, you know, go on to Mars, explore the solar system, all of those other things, which is a lot of what you were just talking about, and then there’s the research that has direct applications on Earth and we can dive into that too. That’s research flown by commercial companies, by, you know, academia, taking advantage of this microgravity environment because we’ve seen there’s a lot you can learn by taking gravity out of the equation. But, to the first camp, to the, you know, studying the people, the astronauts are guinea pigs kind of thing. The human body is an incredible machine and it’s incredible at adapting to different environments. I mean that’s both a gift and a curse because when you go into outer space– I mean your vestibular system, so your sense of up is down, down is up, your balance, all of that goes all out of whack, but within about a day or two, most astronauts don’t have the nausea anymore, their body is used to it already and they’re able to live and work, which that’s incredible. That’s a great advantage to just getting into a new environment and hitting the ground running. The problem with that is when you get to an environment where you have gravity again, hitting the ground running can be very problematic because your body, when it’s not– when gravity is not pulling down on you– so, you and I right now, I mean gravity is pushing down on you at all times and that builds up muscles in your hips and bones in your hips and that’s why your legs are strong enough to just hold you upright because they’re constantly fighting against that force. On places like the space station, that force disappears and so your body says, hmm, well, I don’t need these muscles anymore, so it stops feeding nutrients to those and so you can actually– astronauts will dispel– so, in their urine they’ll get raised levels of calcium because their bones aren’t needing it as much because their bones aren’t, you know, getting that much force just by existing.

Host: They’re getting rid of the calcium because you’re right, it doesn’t– the body is saying you don’t need this anymore.

Dan Huot: And so understanding a lot of those processes is important because– I mean if the astronauts were just going to stay in microgravity forever, not that big of a deal because their body just adapts and I mean they become space people. But astronauts come back to Earth. Astronauts will walk on Mars where there is gravity– less gravity, but still gravity and you’re going to need to walk around in a pretty heavy space suit and things like that. So, finding ways to counteract– we call them countermeasures– for all the ways the body adapts is– it’s something that we’ve been doing pretty much as long as we’ve been doing spaceflight, but we’ve really aggressively pursued it on board the space station. So, for example, bone loss and muscle loss. We’ve actually pretty much reversed for the most part all of the bone loss and muscle loss. You’ll still see changes in bone density in some of the crew members, but a lot of them aren’t losing that bone mass, that muscle mass that was such a problem in early long-duration spaceflight. And we do that through exercise. That is– that is the main driver. There’s exercise and there’s nutrition, but exercise, the crew members are working out about two hours every single day. I don’t know about you, but I don’t work out two hours every single day.

Host: Thirty minutes, I’m pretty much done.

Dan Huot: Yeah. Even that can be hard for some people to find, but the crew members, two hours every single day and that’s exercise both cardio and resistance. So, they have a number of devices up there. They have a treadmill, which, again, you need to remember everything– and this is the running theme– everything we do in microgravity is different. So, you can’t just hop on a treadmill. You’ll just float away and you’ll just be pumping your legs in microgravity and that does nothing for you. So, the treadmill actually has a harness with basically bungee cables that pulls them down towards the treadmill so that way you’re getting the force on your legs, you’re actually exerting more force, and you can– you can run. It’s the closest you can get to just running in space. And I mean we’ve had astronauts run marathons on the treadmill and that’s one of their key devices. They also have something called the advance resistive exercise device. I’ve stayed away from acronyms as much as possible–

Host: You’re doing a great job.

Dan Huot:So far. But they inevitably come up. We call it ARED and it is– it’s their– it’s basically their home gym on board the station. Now, again, you can’t just pick up a heavy weight and do some curls and, you know, get a workout.

Host: Weight lifting makes no sense in microgravity, yeah.

Dan Huot: There’s microgravity– so I mean they can– they literally move several-hundred-pound modules and pieces of hardware all the time. And so, to help simulate weight lifting, it actually uses a series of pneumatic tubes to simulate force and they can actually simulate up to 600 pounds of force.

Host: Nice.

Dan Huot: Which some of the astronauts, their squat– their squat number goes up when they’re up there and it’s slightly misleading because they’re not squatting their own body weight like they are here on Earth.

Host: Right. It’s still 600 pounds. I don’t think I could–

Dan Huot: Well, I don’t think any of them do 600 pounds, but they have the option if we ever get some powerlifters.

Host: One day.

Dan Huot: Up on board the station. And then they also have a stationary bicycle and then there’s another treadmill. So, there’s actually– well, there’s two treadmills on board the station, but– I mean they use all of those two hours a day just– and that’s just to maintain that bone and muscle. And there’s also ways you can help that process through nutrition. We’re constantly looking is there a better way for them to work out, should they do– I mean there is something– there are research projects like Sprint where does it make sense for them to work out, you know, a lot harder but for shorter amount of time.

Host: Like high intensity interval? Yeah.

Dan Huot: Because two hours is a long time every single day.

Host: Right.

Dan Huot: That’s a lot to ask. But, so–

Host: And crew time is very valuable, right? Because they– I mean you’re talking about, like you said, 200– I think it’s 200 experiments per increment, right? And astronauts–

Dan Huot: Two-hundred-and-fifty is the usual– is the usual number. In like a six-month span, 250 experiments will happen on board the station.

Host: That’s crazy. So, yeah, crew time is very valuable and that’s two hours gone every day from experiment time just to maintain bone and muscle mass.

Dan Huot: Yeah.

Host: Wow.

Dan Huot: But I mean that’s just one part of what changes when you’re in microgravity.

Host: Oh, yeah.

Dan Huot: I mean there are– they– we– your body actually has less blood in it by the time you come home. Your heart can change sizes because it doesn’t work as hard to pump the blood. And then one of the big outstanding ones that we’re still addressing is vision changes. And that’s something that we knew about, but was never really considered a huge deal– not a huge deal, but never really considered a major impact until within the last couple of years when we had a significant amount of astronauts returning from these really long stays in space and reporting that their vision was worse. And it’s normal to come back to Earth and have a couple of changes that linger for a little while, but for these crew members, the vision never got better.

Host: Wow.

Dan Huot:Dan Huot: And that’s a concern. If you send somebody to Mars and in the nine months or however long it ends up taking to get there, all of the sudden they go from 20/20 to needing glasses to needing even stronger glasses that they don’t have available and they land on Mars and they can’t see, that’s a big issue.

Host: That’s a big one.

Dan Huot:Dan Huot:Dan Huot:Dan Huot:Dan Huot:>Dan Huot: And so we’re trying to figure out exactly why this happens. There’s a number of good ideas, good hypotheses. We think we know, but we’re still doing a lot of tests to figure out exactly why it happens. And, just like the bone and muscle, how do we stop that from happening?

Host: Hmm. So, you’ve got to find those countermeasures to make that happen. Wow, that’s really intense. I mean imagine get– like landing on Mars and you can’t see anything.

Dan Huot: It’d be kind of a buzzkill. Travel 60 million miles and get out and everything’s blurry.

Host: Yeah.

Dan Huot: That wouldn’t make me happy.

Host: So, I know like when– here’s another thing. When astronauts– so astronauts– now they’re doing– on the International Space Station, pretty regularly they’re doing long-duration increments, right? So, they’re doing six months at a time.

Dan Huot: Yes.

Host: So, this is longer than any of the shuttle missions, a lot of the missions before it, and it’s all to practice for missions beyond low Earth orbit. But when they come back to Earth, right, they generally– right now they come back in a Soyuz, land in Kazakhstan and then we have recovery teams that go out and get them. But they have a hard time walking, right? When they first– when they first get out.

Dan Huot: Some do. And so that’s part of, again, the human body reacting to the different environments. When astronauts first get into space, some will have nausea, some will have some adverse reactions to being in microgravity. The same is true when you’re in microgravity for a really long time and you come back down to Earth. All of the sudden there’s this huge weight pressing down on you that hasn’t been there for the last six months or for however long you were in there. There’s– your inner ear goes crazy and like, oh, all the fluids pulling down again. Where am I? There used to be no up and down, but now all the sudden there’s definitely a down and so it can be tough just to– just to walk. I mean we– we will– we have teams that pretty much carry the astronauts out of the spacecraft and then on to a medical tent. So, we try to minimize any of that real discomfort and things like that for these crew members, but they are still test subjects and so we still do stuff to them.

Host: Right.

Dan Huot: And part of that is when– let’s say you’re the first person to go to Mars. When you land, there’s not going to be anybody there to pull you out of your capsule or help you set up camp.

Host: Right.

Dan Huot: Or anything like that.

Host: I’m on my own.

Dan Huot: You’re on your own. And so we need to make sure before we send somebody how much can they do on their own. And we have these crew members coming back from extended periods in space and we have ability to test them. And now every astronaut is an incredibly gracious person because not– a lot of this testing isn’t glamorous and it can be–

Host: You used the word guinea pig.

Dan Huot: Uncomfortable– they are guinea pigs in almost every sense of the word where they are subjecting themselves to pokes, prods, blood samples, all these different things–

Host: For science.

Dan Huot: For science.

Host: Right.

Dan Huot: For science! Yeah. But one of the things that we do– and we started doing this in the last couple years– is called the field test.

Host: Right.

Dan Huot: So, they’ll come home. They’ll land in the middle of Kazakhstan, pull them out of the capsule, and then we subject them to a series of– they sound really simple, but it’s just functional tests and it’s things like walking a straight line, sitting down and standing up, laying down and standing up. Standing up and having somebody push you a little bit. It’s all these things that, you know, that sounds– that sounds really easy. Like, can I stand up? I can be an astronaut. Well, after spending six months in space, can be a little jarring. It can be a little difficult. And all of that feeds back into the research of, OK, I’m a Mars astronaut, I’ve been in space for, you know, six to nine months on this trip. I’m now in a gravity environment. You need to design the spacecraft, the habitat, everything to understand that, hey, for the first couple hours, this person might have to just sit in their chair and do nothing or, no, we can reasonably expect them to pop up and, you know, do these simple things. They might not be able to get out of their spacesuit for a couple of hours– all of these different things have to be figured out before you just shove people into a spacecraft, kick them off the planet and send them somewhere else. But we’re doing that. We’re doing that right now.

Host:Yeah. Man, their job is not done when they hit the ground.

Dan Huot: Oh, no.

Host: You’re finally– you know, after six months being away from home, you hit the ground and you’re like ah, finally done, and then they make you stand up, sit down, do all kinds of crazy stuff.

Dan Huot: And it doesn’t stop there.

Host: Oh, that’s right.

Dan Huot: And it’s– and, again, when I say they are truly gracious people, they have to sacrifice a lot for this. I mean, you know, obviously they get the great view and they’re in outer space and that’s amazing, but I mean just training for these missions is usually about two years. So, that’s two years of you in intensive training, a lot of travel to all the other partner countries where they train you on different things, six months, so, you know, off the planet with you and just, you know, five of your closest friends, but away from all of your family, everything else happening in your life down here on Earth. You can’t– beyond a phone call and an email, you can’t really interact with it. And then when they come home, we shove them in a tent and push them around and make them stand up and do all these other things and then fly them back and then the testing continues. I mean they keep giving samples. They keep doing eye exams. Scott Kelly landed in his one-year mission a little over a year ago. He was just here doing more tests.

Host: Right.

Dan Huot: I mean it is a real commitment on behalf of these astronauts to do these flights in space. But, again, what they’re doing is going to help future astronauts, it’s going to help future explorers, I mean everybody down the line will benefit from the work that they’re doing.

Host: That’s right. You have a diverse crew of– or astronaut class, I guess. All the astronauts, they– you’ve got all kinds of different people and they all do the same thing. So, you– so the more that you do, the more you really have an understanding of what’s going to happen– in general, like on average– I mean it’s like a big sample size. Right? So, when you’re doing an experiment, you just keep doing the experiments and big sample size and you can learn a lot.

Dan Huot: Yeah. And any researcher will tell you that you need more subjects. You need as many subjects as you can. They always want more people. The more the better, the better the results you can get and it’s a good point when you say, like, they’re diverse. They are– where if you think the early days of astronauts, it was, you know, all male test pilots. That’s all– that’s all it was.


Dan Huot: Now you still have, you know, a lot of military astronauts, but it’s a much more heterogeneous mixture. There’s a lot of different parts in there where you have a lot more scientists, you have teachers, you have engineers, you have– I mean we have an astronaut who was up there last year who’s a biomedical scientist who has done research on, you know, AIDS in Africa– like all– they come from all of these different walks of life.

Host: Yeah.

Dan Huot: And because a lot of the work that they’re doing on station right now, it’s not like it used to be. I mean you’re not flying a space shuttle anymore. You are essentially a researcher or a research subject for six months while you’re up there. So, they’re coming from all walks of life now and that’s going to continue and just expand more as more and more types of people and more and more people gain access to space, which is the ultimate goal. I mean, ultimately, we want everybody– if they want– to be able to go to outer space.

Host: Right.

Dan Huot: I mean I want to go to outer space.

Host: I think– I want to say we all do, but I know there’s– I know there’s people who don’t. They’re like oh, I’m fine on the Earth. Yeah.

Dan Huot: Again, it’s– so, there’s always the inherent risk in everything and there are people who, you know– there’s always somebody who doesn’t like something. That’ll never change, but I mean–

Host: Well, regardless, that’s what the International Space Station is hoping is to accomplish. It’s really helping us to understand that so that that can actually be a possibility later. And the more we do it, the more we learn, the more it can actually become a reality. The fact that it’s a reality now is pretty awesome that we can actually do this. Well, Dan, thank you so much for coming on the show. I think that’s about all of the time we have today.

Dan Huot: I feel like I just got started.

Host: I know.

Dan Huot: I’ve left out so many things that people are going to yell at me about.

Host: Well, I have like a bunch of questions in front of me, I don’t think I– I think I asked one. I think we just kind of talked afterwards, but thanks again for coming on. Probably have to do another podcast just on the International Space Station, right?

Dan Huot: Oh, we’re going to have to do–

Host: That was just like skimming the surface.

Dan Huot: Dozens.

Host: International Space Station one, two, three– yeah, 12, 13.

Dan Huot: Let’s make it an anthology.

Host: That’ll be awesome. Dan, thanks again and stay tuned for– after the credits or music here to learn where you can submit your ideas and all that kind of stuff.

[ Music ]

>> Houston, go ahead.

>> Space shuttle.

>> Roger, zero-G and I feel fine.

>> Shuttle has cleared the tower.

>> The [inaudible] for all mankind.

>> It’s actually a huge honor to break a record like this.

>> Not because they are easy, but because they are hard.

>> Houston, welcome to space.

Host: Hey, thanks for sticking around. So, today we talked a lot about the International Space Station, but really just kind of skimmed the surface. If you really want to dive deep into some of the topics that we talked about today and maybe some things we didn’t talk about, just go to That’s our homepage. That’s where all the latest scientific experiments and updates and findings and everything going on with the International Space Station, launches, landings, it’s all updated regularly. We have a blog that we like to maintain on that page, as well as all the astronauts that you can follow, the ones both on space station and not on the space station. On social media, we’re very active. On Facebook, it’s International Space Station, Twitter at space underscore station, and on Instagram it’s at ISS. Go to any one of those platforms and we update those regularly. You can even use the hashtag AskNASA on your favorite platform to submit an idea or maybe a question that you have for this podcast. Just make sure to mention that it’s for Houston, we have a Podcast or maybe HWHAP I guess would be the acronym for that. Probably have to fix that, but just mention us and we’ll try to address your question in one of the later podcasts. This podcast was recorded on March 17th, 2017. Thanks to Alex Perryman [assumed spelling] and John Stohl [assumed spelling] for helping record the episode and, of course, thanks to Dan Huot for coming on the show. So, this show is intended to be weekly and we have a few episodes kind of sitting in the bank, so it may be a few episodes before we get to your question on social media, but please keep them coming. And thanks for listening. So, until next week.