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Landing From Space

Season 1Jul 21, 2017

Dr. John Charles, Chief Scientist of the Human Research Program at the NASA Johnson Space Center, talks about what happens to the human body in space. NASA astronaut Shane Kimbrough gives a first hand account of landing from space. HWHAP Episode 3.

Houston, we have a podcast

Houson Podcast. Episode 3. Landing from Space

“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 3 features a conversation with Dr. John Charles, Chief Scientist of the Human Research Program at the NASA Johnson Space Center, who talks about what happens to the human body when exposed to the microgravity environment aboard the space station for long periods of time, and also what we’re learning that can be applied to a human mission to Mars. This episode features a short interview with Shane Kimbrough, a NASA astronaut, that occurred just 2 days after he landed from space after 173 days. This episode was recorded on April 19, 2017. The interview with Shane Kimbrough was recorded on April 12, 2017.


Gary Jordan (Host): Houston, we have a podcast. Welcome to the official podcast of the NASA Johnson Space Center, Episode 3, Landing from Space. I’m Gary Jordan, and I’ll be your host today. So on this podcast, we bring in the experts — NASA scientists, engineers, astronauts, pretty much all the folks that have the coolest information, the stuff you really want to know — right on the show to tell you about everything NASA, everything from extraterrestrial dirt to the unknown parts of the universe. So today, we’re talking landing from space with Dr. John Charles. He’s the chief scientist for the NASA Human Research Program here at the NASA Johnson Space Center in Houston, Texas, and we talked about the more human side of space — specifically, what happens to the human body in the microgravity environment and what that means for adjusting to life back on Earth, even on other planets, like Mars. I also had the chance to catch NASA Astronaut Shane Kimbrough just two days after landing from a 173-day mission aboard the International Space Station, and he gave a firsthand experience of what it feels like to adjust back to Earth’s environment after living in space for that long. So with no further delay, let’s go light speed and jump right ahead to our talk with Dr. John Charles and then NASA Astronaut Shane Kimbrough. Enjoy.

[ Music ]

Host: All right. Dr. Charles, welcome. Is it, should I say Dr. Charles or John?

John Charles:Call me John.

Host: John, okay. [laughs] All right. Well, John, thanks for coming on the show. We always seem to end up in the same circles first with the landing on Mars video and with speaking presentations, and, you know, you were the first person I thought of when we had this topic. But what’s cool about this one is for this particular podcast, I actually got a chance to talk to Shane Kimbrough two days after he landed, which was awesome. I mean, he was really tired, but it was pretty cool to talk to him. Not to say that you’re not a special guest, but–

John Charles:I’ll try not to be as tired as you are.

[ Laughs ]

Host: Well, we’re doing this I guess after lunchtime, so I can understand.

John Charles:Yeah, that’s possible. Yeah.

Host: It is. But what’s cool is that he was just getting adjusted to Earth. It was perspective, of such a unique perspective. He just came down, and he was still getting adjusted, and that takes weeks, right? That takes–

John Charles:Yes, it may take — well, some folks say it takes as long to respond to or adjust back to Earth as it did in flight. So there is going to be ongoing adjustments, especially in the areas of, say, the bone loss, that will take months, and months, and months before they even come back to what they were approximately before flight.

Host: Yeah. I mean, even some astronauts say they have, they still have dreams about floating. I mean, even floating and–

John Charles:Yeah.

Host: They kind of, I guess their body just doesn’t know where they are.

John Charles:That, it’s certainly, it is certainly a monumental experience, and I cannot imagine ever getting tired of it or used to it. I understand Peggy Whitson was excited to get the mission extension of three more months.

Host: Right.

John Charles:And she said she was actually interested in going back again. So I think once you’ve experienced the wonders of weightlessness, and the awesome view out the window, and all the other parts of going on a spaceflight these days, it’s not something you ever get used to, and it probably colors your dreams for many, many years to come.

Host: That’s beautifully put way.

John Charles:Thank you.

Host: A beautiful way of saying it. But that’s what I guess, you know, for, at least for Shane Kimbrough is kind of I guess happy to be home. You know, when we were interviewing him, his wife was not too far away. So he was, you know, I’m sure he’s happy to see his family.

John Charles:Sure.

Host: But I was thinking, you know, why don’t we start off with that conversation with Shane Kimbrough? Because he does talk about a lot of the human aspects, and he just says, you know, I’m dizzy and this is how I’m feeling. So I thought it would be cool if we kind of elaborated on that a little bit after. But first, let’s start with Shane Kimbrough’s interview. We do have to go back in time, so producer Alex, let’s cue the wormhole sound effect thingy.

[ Music ]

Host: So if you need to take a breather, you know, let me know because it’s just like talking, and then talking–

Shane Kimbrough:No, no. It’s—

Host: And then talking, and then talking.

Shane Kimbrough:Good. [laughs] Let’s knock it out.

Host: Oh, man. So, wow. Okay, I know it’s been a busy couple of days for you, but, you know, thanks for taking the time to actually set, you know, ten minutes aside to have this conversation. You just landed two days ago. That’s pretty crazy. [laughs] But since we only do have, like, a short period of time, I thought we’d start, and if you can just kind of take us through the journey of starting at when you were saying your final goodbyes to Peggy, and to Thomas, and Oleg, and then you just closed the hatch, and then that journey all the way to where you, bam, smacked the ground.

Shane Kimbrough:All right. Yeah, we were, you know, it was an anticipated moment when we were going to say goodbyes. We’d kind of been sitting around for about an hour waiting on the time to, when Sergey, the Soyuz commander, came and said, “It’s time to go.” So we did say our goodbyes. We gave hugs to all the other crew members we were leaving, like you said — Peggy, and Thomas, and Oleg. We spent about four-and-a-half months together with them, so we spent a lot of time together, so we got to be really good friends and crewmates. So it was great with them, but it was, you know, we were heading home, and so we had to say our goodbyes, quickly shut the hatch right after we say goodbyes, and then we started preparing our vehicle with leak checks and everything, trying to make sure we were leak tight before we departed from the Space Station.

Host: So a lot of, like, a lot of right to the procedures, right. Not a lot of reflection time.

Shane Kimbrough:Absolutely.

Host: Just right into it.

Shane Kimbrough:We didn’t have any time to mess around [laughs] because you, we do a leak check, then we get in our space suits, and then we get in the descent module, close the hatch to the other module, and then we depart pretty quickly. So all had to happen, you know, by the procedure. If we had any hiccup in that, then we wouldn’t have been leaving that day. So it was pretty pressure packed trying to get to the undocking time. And so we undock, and then we actually, after you undock, you have about an hour and a half, which is an entire revolution around the Earth, to really not do much. So we took a little nap [laughs] because we were–

Host: Well deserved.

Shane Kimbrough:Really tired. I mean, they had us on a crazy sleep shift on the last day. And so we were pretty worn out. So we took a little nap and then got ready after that for the deorbit burn, which is a pretty big emotional event when the big engine fires off–

Host: Yeah.

Shane Kimbrough:And puts you on a trajectory to enter the Earth’s atmosphere at the correct angle so that you actually make the landing site and make sure the vehicle’s pointed in the right direction so you don’t burn up when you’re coming through the atmosphere. So that’s obviously a plus.

Host: So you didn’t really feel the deorbit burn, right? You mainly felt the reentry? Is that what–

Shane Kimbrough:You do feel the deorbit burn–

Host: Oh.

Shane Kimbrough:Because the engine kicks in and it’s, you know, it’s kind of like a kick in the pants, and you’re thrown back in your seat.

Host: Oh, wow.

Shane Kimbrough:And it, you know, lasts I think about a couple minutes. So, you know, it’s a sustained kind of pulse, and–

Host: You feel it that whole time, right?

Shane Kimbrough:Yeah, you’re feeling it. I mean, initially, you feel it a little more, and then you get used to it.

Host: Right, right.

Shane Kimbrough:And so then you’re kind of getting ready to come back through the atmosphere, then separation of our descent module in the [inaudible], the habitation compartment happens. That’s kind of like just an explosion, right. [laughs] So you feel it. You hear it. You see things flying by the windows from the other module that just came apart. So that’s pretty interesting.

Host: Yeah, not a boring ride.

Shane Kimbrough:No, [laughs] not a boring ride. And then, we’re kind of getting ready for the next big event. There’s always, I mean, four or five big events along the way. The next one was parachute opening. Of course, after you started pulling, you’re feeling the effects of gravity, all right. So we were pulling and we ended up pulling them 4.3 g’s I think. So we felt like 4.3 times your body weight.

Host: Wow.

Shane Kimbrough:Which, after microgravity, felt like about 20 times your body weight.

Host: Yeah.

Shane Kimbrough:And so that built up, and we kind of just felt it building. We’re watching the meter go up, and, man, I was like, wow, that’s a lot. And then, right after that, the parachute, you know, started coming out, and that was really an emotional event because it’s really dynamic, [laughs] I guess is the best word. And it kind of throws you around really drastically four or five times, and, you know, it’s completely normal. But until you go through it the first time, which is my first experience, I was like, there’s no way this can be normal.

Host: Yeah. [laughs]

Shane Kimbrough:But it is, and that’s the way they do it, and it’s just the parachute coming out and getting set up and the risers getting in the right position. And then, once that’s done and then it’s kind of a peaceful ride until you crush into the ground.

Host: Yeah, yeah. [laughter] Okay, so the swinging back and forth, how would you compare that? Is it — I’m thinking of an amusement park ride, right. It’s got to be more intense than that, right?

Shane Kimbrough:It is, but, you know, I don’t know if there’s one out there that just really slams you to the right [laughs] and slams you to the left, and you do that five or six times, you know, in a — you know, I can’t think of one that does that, but that’s what it was like. I couldn’t believe it.

Shane Kimbrough:Yeah.

Host: I guess that’s why they, you know, they kind of strap you into that thing real tight, right, because you’re–

Shane Kimbrough:Right.

Host: Getting bounced and kicked in, like, all–

Shane Kimbrough:Exactly, yeah.

Host: Directions.

Shane Kimbrough:So as we come in, you start, the advice I got was as soon as you start feeling the g-force, start pulling on your straps as much as you can to really get you down into that seat–

Host: Yeah.

Shane Kimbrough:So that you’re not just secured but, you know, getting ready for the impact of the landing as well.

Host: So is it fair to say that that landing was the hardest impact, probably?

Shane Kimbrough:Oh, yeah. [laughs] Yeah. No doubt.

Host: How did that feel?

Shane Kimbrough:it was, you know, I’ve heard it called like, it’s like a really bad car crash, and now I can confirm that that is accurate.

Host: Wow.

Shane Kimbrough:So you hit just really hard. And in our case, we hit twice really hard, so.

Host: Oh. [laughs] And then, you roll around, right?

Shane Kimbrough:And then, we rolled some more too just for added effect, so.

Host: And then, you said, I remember you saying, because we did it in like a bunch of other events before this, but you said, like, you were in a position where you were just kind of dangling a little bit, right?

Shane Kimbrough:Yeah, so I was kind of on–

Host: You were–

Shane Kimbrough:Top looking down at the ground, but–

Host: Yeah.

Shane Kimbrough:In that case, I was hanging from my straps.

Host: Wow.

Shane Kimbrough:Really uncomfortable feeling for about five minutes, five to ten minutes until they could get there and roll the vehicle kind of to the normal position.

Host: Oh, that’s it. Just five to ten minutes, and then they were there.

Shane Kimbrough:Yeah. It was very likely we had perfect weather that day. The search and rescue forces saw us the whole time. And really, right after the parachute opened, they tracked us all the way to the ground, so they were right there–

Host: Wow.

Shane Kimbrough:In about ten minutes and got us out pretty quickly.

Host: So when that door opened and they pulled you out, what was that feeling? Was it relief or was it just more of the, you know, just here’s the next step kind of thing? Or, like, describe those emotions.

Shane Kimbrough:Yeah, so the hatch, they opened the hatch, the search and rescue forces. And they’re familiar faces from our training in Star City, Russia. I mean, they’re Russian–

Host: Yeah.

Shane Kimbrough:Folks. But it was nice to see their smiling faces. And then, I saw my flight sergeant from NASA and the Chief Astronaut Cassidy right there as well. So, you know, we were all smiles and waving. We all felt great at the time. And getting out is very challenging because it is so small, like we were talking about earlier.

Host: Right.

Shane Kimbrough:But they have to help you out. You can’t get out on your own for gravity for one, and then it’s just too tight and too small. You can’t even really get to unstrap yourself. They have to get in there. It’s that tight.

Host: Wow.

Shane Kimbrough:Like, you can’t move your hands enough to unstrap most of your straps, so they get in there and help you out doing that as well as pulling you out of the vehicle.

Host: Yeah. So okay, when you first, you know, you’re pulled out of the capsule. You have fresh air, familiar faces. Obviously, that’s a great moment, but so now you’re kind of, you’re back on Earth. You can feel it, right? What’s, how are you feeling — do you feel sick? Do you feel, is it mostly happy? Is there overwhelming feelings? What’s going on?

Shane Kimbrough:I think people have felt all those things you’ve mentioned. [laughs] I really felt great. I love smelling that fresh desert air. It was kind of like a 60-degree day in Kazakhstan. Feels beautiful. The wind was blowing. It was just awesome to have that sensation of nature again for me. And then, just seeing friendly faces and knowing I was going to get to talk to my family pretty soon after that was pretty special.

Host: Yeah, that’s amazing. What was the, so what was the main thing you noticed about the way your body was adjusting to life back on Earth?

Shane Kimbrough:Well, to not move your head around is great advice, I guess. [laughs] Yeah, because that really provokes some folks to get sick, so–

Host: Okay.

Shane Kimbrough:I really try to keep my head focused straight ahead. If anybody was talking to me, I would make them come right in front of me so I didn’t have to kind of, because the natural tendency is to just look at them, right, but that really gets your–

Host: Yeah.

Shane Kimbrough:Inner ear spinning up pretty well and–

Host: It must’ve been hard because there’s a lot happening, right? People are–

Shane Kimbrough:There is.

Host: All over. Yeah. [laughs] Yeah.

Shane Kimbrough:So I heard people to my side, and I was, I just told them, “Hey, come right in front of me so I can see you [laughter] because I’m not going to turn my head.”

Host: Yeah, exactly. So–

Shane Kimbrough:And it seemed to pay off, so.

Host: Yeah. Well, okay, so besides feeling sick, were you weak, like are, can you move around, or what was the–

Shane Kimbrough:You can move around a little bit.

Host: Okay.

Shane Kimbrough:They were carrying us. You know, I wasn’t walking anywhere at the time, and they had people that carried us to where we were sitting there for a while. And then, after that, they carried us to the medical tent. But once we got in there, then it was a bunch of testing, and walking, and with your eyes closed and open, and just crazy things. And, [laughs] you know, just trying to–

Host: You just don’t get a break.

Shane Kimbrough:See where you’re at. [laughter]

Host: You just don’t get a break. And then, they throw you–

Shane Kimbrough:Yeah.

Host: On, what is it? To get a helicopter, and then the helicopter–

Shane Kimbrough:Yeah.

Host: To a plane.

Shane Kimbrough:Right.

Host: You’re off to Houston.

Shane Kimbrough:Exactly.

Host: Did you — I’m guessing you slept on the plane, right?

Shane Kimbrough:I did. I slept–

Host: Yeah.

Shane Kimbrough:Really well on the plane, so it was good. [laughter]

Host: I probably should’ve start off this — I just realized — but how are you feeling now?

Shane Kimbrough:I’m feeling, yeah, I’m feeling really well compared to what I thought I’d be feeling at this point. It’s only two days after I landed, like you mentioned earlier, and I really feel great. I had a great workout today, which I think really made me feel better.

Host: Oh, wow. You’re right back into it.

Shane Kimbrough:Yeah, so we got about a 45-day program of working out and getting you rehabilitated, back to your full strength.

Host: Okay.

Shane Kimbrough:But it should only take maybe a week or so to get there, and then from there, we’ll just build on whatever strength I have.

Host: All right. All right, well, one more question, then I’ll let you go. What was the first thing you ate when you got back here?

Shane Kimbrough:[laughs] A lot of people are asking me that, and [laughs] it’s a really boring answer, but it was a banana–

Host: Oh.

Shane Kimbrough:Because that’s something [laughs] I hadn’t had in–

Host: A banana.

Shane Kimbrough:A while. I was really wanting some fruit, and–

Host: That’s true. It’s not, yeah.

Shane Kimbrough:I had a banana and an apple and had a bunch of those on the plane. [laughs]

Host: Okay, so once you’re — how about this? — once you’re well enough, what’s the first thing you’re–

Shane Kimbrough:Yeah.

Host: Going to eat?

Shane Kimbrough:I think we’re going to do some Italian tonight, which I’ve been thinking about.

Host: Oh.

Shane Kimbrough:So that’s good. And then, Mexican probably here in the next few days as well, so.

Host: All right. All right.

>> It’ll be good.

Host: Definitely two good ones. Well, Shane, thank you for spending these couple minutes with me.

Shane Kimbrough:My pleasure.

Host: Thanks.

Shane Kimbrough:Thanks, Gary.

Host: Cool.

[ Music ]

Host: All right. Producer Alex, we’re going to have to work on that wormhole sound effect. Come on. That was quite a ride. I mean, I was, [laughs] I honestly felt sick just listening to the way that he was going down. But there was a lot going on for every step of the way, so, I mean, first off, you know, what are those changes that he was talking about that makes him feel so, you know, so off when he lands on the ground?

John Charles:The human body goes through many changes in weightlessness and the rest of spaceflight. I’m always interested most in weightlessness. I don’t like the term microgravity. I think that’s unnecessarily accurate.

Host: There’s a lot of synonyms, or syllables.

John Charles:It’s, yeah, a lot of syllables too. [laughs] But the weightlessness has profound effects, and I like to say that it’s evolutionarily unanticipated. There’s nothing that has ever happened to us in our lives and in all of the lives of everybody that lived before us, all the way back to as far as you want to go, that is weightlessness. Now, even floating in water is not weightlessness because you’re still subject to gravity. The parts of your body that are denser go to the bottom and the parts of your body that are lighter float to the top, and that’s true even in the vestibular system. The organs of balance he was talking about. Being dizzy. Those are not weightless, even underwater. The only time they’re weightless is if you fall off a cliff, and then the effect is very short lived.

Host: Right.

John Charles:You don’t get a chance to enjoy it very much.

Host: Right.

John Charles:So this is a real opportunity to, for the body to experience something that it’s never experienced before ever, and not surprisingly, there are changes that occur in the body, and the changes might be summarized by the concept that the body economizes its metabolic energy. It doesn’t waste energy supporting metabolic processes it doesn’t think it needs. And nobody, you can’t tell your body, hang on to that because you’re going to need it eventually. The body doesn’t talk to you in that sense. The body responds — and by this, I mean the autonomic processes, the physiological processes — respond to the environment that they have seen recently and are seeing at the moment. So as far as the body is concerned, gravity went away and it’s never coming back. And so what do I need to do to be more effective metabolically in the environment that I will see forever?

Host: It’s just the body adapting to a new environment.

John Charles:It’s to a new environment. And luckily, the body adapts nicely to the weightless environment–

Host: Right.

John Charles:Because it really is sort of a step down. It’s less hard to do almost everything metabolically in weightlessness, and the body doesn’t know that you’re going back to Earth with gravity, so you have to fool the body to get back to, to get ready to go back to Earth. So you go through the changes of weightlessness, and these metabolic efficiencies I’m talking about include not maintaining bone strength. You don’t need bone strength in weightlessness, and the body says, great, I’m not going to spend metabolic energy on that anymore. I’m going to dedicate it to something else.

Host: Right.

John Charles:You don’t need muscle strength. You don’t need cardiovascular strength so much. You don’t need all of the intricate understanding of how to respond to gravity. You don’t need to keep track of where all your joints are, your limbs, and all that kind of stuff.

Host: Because all of that is gone in the weightless environment.

John Charles:That’s right.

Host: It’s just, you don’t need your bones because you’re not pressed up against anything.

John Charles:You’re not–

Host: You’re just floating.

John Charles:You’re not supporting yourself anymore.

Host: Right.

John Charles:There is a residual bone strength, a residual bone volume or density that you will probably plateau at. If you stay in space forever, you will never become like the guys were in WALL-E when they had no bones.

Host: [laughs] Yeah.

John Charles:Just the big blobs of jelly.

Host: That’s right.

John Charles:That would never happen. You probably, based on other studies and clinical experience, you’d probably lose up to 40% of your bone mass eventually. That is after years, and years, and years.

Host: Wow.

John Charles:So you, I mean, even so–

Host: Is this saying that you’re not working out during those years?

John Charles:Yeah, assuming you’re just weightless.

Host: Assuming you’re just weightless.

John Charles:Assuming you’re just weightless and not working out, that’s right.

Host: Okay.

John Charles:Which would be I think my preferred lifestyle. [laughs] I’d like to be weightless and not working out. But that, see, Gary, that’s the answer, though, is the way we fool the body or don’t fool the body. We just change the conditions is by working out. So the astronauts work out two hours a day every day, including resistive exercise, my favorite. I call that weight lifting in weightlessness.

Host: Right.

John Charles:And that’s all done with hydraulics and computers. And then, or aerobic training — exercising on treadmills, and bicycles, and maybe a rowing machine someday. And what that does is put a load on the bones, and the muscles, and the cardiovascular system, not the vestibular system, not the organs of balance, but all the other systems mimicking the absence or the effect of gravity, which is then absent in that environment.

Host: So that’s, so they’re doing those you said aerobic and resistive. So that’s the, I guess like you said, though, in space, the weight-lifting machine–

John Charles:Right.

Host: Sort of with hydraulics–

John Charles:Right.

Host: And that simulates weight lifting. And then, you also have aerobic exercise, which is the treadmill and the bicycle.

John Charles:The bicycle.

Host: So you have to do this I believe two and a half hours every single day–

John Charles:Yeah.

Host: In order to maintain everything?

John Charles:Right. And that’s a total of two plus hours a day. That includes breakdown, and setup, and changing your clothes, and all that stuff. So you do–

Host: Oh, yeah.

John Charles:You know, multiple tens of minutes at each.

Host: I see.

John Charles:And different exercises on different days. And I think one day is actually a free form. You can do whatever you want. But, you know, the other days are fairly prescribed. But what that does is put a load on the bones, and the muscles, and the cardiovascular system, and other organs as if they were doing something against gravity. It’s not the same, but it’s close.

Host: So that’s the way that you’re saying you’re tricking your body–

John Charles:You’re tricking your body.

Host: Into thinking that, you know, you don’t need, you still need to maintain the muscles. Hold on.

John Charles:Right.

Host: Stop. You know.

John Charles:You’re maintaining them for something else. You’re maintaining them for exercise and not for fighting against gravity.

Host: Right.

John Charles:But it has the beneficial effect in many cases of being appropriate for gravity. And in fact, the resistive exercises that we’re doing now seem to minimize the loss of bone structure that occurs in weightlessness that has been seen on previous missions. So the Advanced Resistive Exercise Device, the ARED, may well be the way that we protect bones and muscles in the future on Mars missions.

Host: Oh.

John Charles:It may be that we’re able to go on really long missions without losing much calcium and without changing the structure very much of the bones. And it’s not the loss of calcium per se that’s the problem. It’s where the calcium comes out of. The bones are developed in everybody whilst you’re growing up.

Host: Right.

John Charles:You’re, when you’re growing up, you know, you’re, first, you’re born with a skeleton, and then you spend the first 18 years of your life banging yourself around, and jumping up in trees and off of hillsides, and falling, and jumping, and running, and pulling, and lifting. And all that stuff shapes your body.

Host: Yeah, and that’s in childhood.

John Charles:Right, and that, [laughs] well, I saw people do it. [laughs] Like I said, see previous comment.

Host: Right, right.

John Charles:But that shapes your body and gives you the structure you need to keep doing that for the rest of your life. And then, at some point, that, those structures, those facets are completed, and you can then go and do useful things with the body that you’ve built up over the first 18 plus years of your life.

Host: Right.

John Charles:So when you go into weightlessness, you start eating away at that in the absence of gravity, and if you come back to the Earth, you restore some of that, but you don’t restore it the way it was originally. You restore it to the way it needs to be now, which means you don’t go back inside the bones and reestablish the framework, the structure. And the bones actually have structure inside of them. The outside is called the cortex, and it’s a thick layer. And then, on the inside are the trabeculae, and the trabeculae are like a framework. Think of a lattice work inside of your bones. And those, that lattice work is genetically engineered by you as you grow up to respond to the forces you’re putting on bones. So it puts down calcium where the forces are the greatest and it doesn’t put down calcium where the forces are not the greatest. But that’s the structure you take with you for the remainder of your active life, unless you go into weightlessness. In which case, that obviously gets eroded gradually but persistently over the time in weightlessness. So your bones actually do lose calcium, do lose mass, bone mass, and you lose strength of the bones. Not, so far, not enough to cause you to fracture when you come back to the ground. There have been a couple of astronauts who have fractured bones in the post-flight period, and we have analyzed those, and they would’ve fractured their bones if they had never flown in space. They just caused an impact that broke bones, and that’s just what happens.

Host: They were trying to run up and down trees like their childhood days, right?

John Charles:Well, they, yeah, nothing quite so [laughs] glamorous. One guy fell off of a stage after a public affairs presentation. He just–

Host: Oh no.

John Charles:He didn’t fall off. He tripped because there was something on the edge of the stage, so–

Host: Oh.

John Charles:It was unavoidable whether he was an astronaut or not and whether he’d flown in space or not.

Host: Right.

John Charles:So we don’t see bone-breaking episodes in astronauts that would not have broken their bones beforehand, but there’s the risk that with even longer flights, longer than six months like Shane was on and longer than one year like Scott Kelly and Mikhail Kornienko were on, and perhaps, you know, two-and-a-half year Mars missions might be getting close to the threshold where you might start seeing a slight possibility, increased possibility of breaking bones under normal circumstances. Not during the mission, but after the mission when you’re back on the Earth. You know, that’s sort of, after 30 months, that’s when you start getting close to that threshold.

Host: So it has to do with the time that you’re in the weightless environment?

John Charles:It seems to be an ongoing process. And like I say, though, that process seems to be interrupted by the heavy resistive exercise.

Host: Right.

John Charles:So that sort of stretches that period out. So you’re not at risk if you keep doing your heavy resistive exercise. But that’s an interesting question too, and you haven’t asked me that one yet, but I’ll go ahead and answer it because–

Host: [laughs] You were just reading my mind.

John Charles:Yeah. That is, are we going to do resistive exercise on the Mars missions? And the answer is I hope so.

Host: Right.

John Charles:But we probably will not be using the ARED. The ARED is a very large device that takes up an entire module on the–

Host: Right.

John Charles:Space Station. It’s a node, which is, that’s a module. And we don’t have, probably will not have that kind of real estate, that kind of volume available for that kind of device. So right now, what the Human Research Program is doing is trying to understand which of the exercises on the ARED are the most effective in protecting which of the bone facets that are important to protect. And then, building a smaller device that’ll just do those. A tailored, specialized device. So this is maybe an important point to make, and that is astronauts will go on missions and will suffer deficits — deficits that we know how to protect against because we can’t afford to protect against them within the limited constraints of a spaceship. So we will give them a device that gives them certain exercise capabilities to protect them against deficits that we think are the most important. But we may be allowing the rest of other aspects of the, say, the other aspects of the skeleton to go ahead and atrophy just because we don’t have the flexibility and the resources to protect them against that. We don’t think that’s going to put them at an increased risk because they’re not going to be doing things that will need those aspects on the skeleton, for example.

Host: Right, so you’ve prioritized and you–

John Charles:We had to prioritize lots and lots of things when we start talking about a Mars mission.

Host: Right. Yeah. No–

John Charles:I knew we wanted to talk about a Mars mission [laughs] because that’s the only thing you talk to me about ever.

Host: [laughs] Well, we were getting there.

John Charles:Yeah.

Host: I was taking baby steps.

John Charles:Yeah.

Host: And you just jump right there.

John Charles:I did. I did.

Host: [laughs] I guess, so how would the exercises, since we are on Mars now, how would the exercise work on Mars, you know, if you’re talking about landing on — would you kind of use sort of the same thing, or can you afford a different type of exercise?

John Charles:Well, it’s going to have to be tailored for the Mars environment, and for the Mars environment means both exercising at one-third of a g, or 38% of Earth’s normal gravity — we call that a third of a g — on Mars. And also, being appropriate for the spacecraft that will land on Mars. And you raised a very important question. I hope you realized you raised it because it’s an important question.

Host: [inaudible] intentional.

John Charles:And that is, that’s, it’s a matter of economics to get to Mars. First, you got to build a spaceship, and then you got to send it there with fuel. And fuel is the coin of the realm in space. It takes lots, and lots, and lots, and lots of fuel to get any place. And if you get there, then it takes even more fuel to slow you down and land safely. So everything on the surface of Mars will be mass constrained and volume constrained because mass, volume requires mass. You know, if you build a small room, it’s got less mass than a big room. So we are going to be focusing on not only what we can put into the Mars transit vehicle, which will be constrained by the volume of the vehicle, but also what we can land on Mars, which will be constrained by the volume of the lander and the mass capable of landing. So it may well be that we figure out, we hope we figure out a way to use that one-third of a g on Mars as a way to supplement some of the exercise that they would normally be doing in their mini-gym inside the Mars lander or the Mars habitat.

Host: Right, so when you’re thinking about a Mars mission, it kind of goes back to that idea of prioritizing, right. So just as you’re going to prioritize which parts of the body are the most sensitive–

John Charles:Right.

Host: The most important for you to maintain, when you’re sending stuff to Mars, you got to prioritize which things are the most important things to bring, to send, and make sure they’re really small, and light, and don’t take up a lot of space.

John Charles:Small, and light, and don’t take up a lot of space, and don’t take a lot of energy, don’t take a lot of mass, power, volume, which are the–

Host: Right.

John Charles:Important constraints of a spaceship. And just think, we started talking about this because I was trying to make the point that Shane’s body is not back to normal yet still. It’s, his bones are going to take months to get back to normal. But other organ systems may respond more quickly.

Host: But they will get back to normal? His, is the months?

John Charles:See, here’s a metaphysical question — what does normal mean in a case like this? Because your bone changes normally over the course of your lifetime, including over every six months. You know, he was gone for six months. His bone was going to be atrophying a little bit anyhow.

Host: Right.

John Charles:So we’re not going to get him back to what he was before flight. And why would we? Because he wouldn’t be at that condition now after his landing if he’d just been walking around the Earth for six months. Our goal is to get him back to where they need to be to live a full, happy, functional life here on Earth. But it’s, you can’t, you know, you can’t go home again. You can’t go back to your old skeleton again. It just, this is, things are different [laughs] with time in life, and that’s doubly true for time spent in space.

Host: Yeah. It doesn’t matter. You’re always going to, just going to get older. Time’s–

>> You’re going to get older.

Host: Just going to go forward.

John Charles:That’s right.

Host: But you, I guess, you know, bones are not the only thing you have to think about, right? You have to–

John Charles:That’s correct.

Host: Think about a lot of other things. Shane mentioned, you know, when he landed and they pulled him out, he couldn’t even turn his head. He was extremely dizzy.

John Charles:And see, I think this is the other extreme. The bones are the, some of the slowest to respond in spaceflight and some of the slowest to respond post flight during the recovery back on Earth, but the vestibular system is probably the fastest responder. The vestibular system is the organ system of balance, and it allows us to stay upright. We are constantly making adjustments in our bones and our muscles and the way they’re lining our, lining us up. I mean, the old illustration is imagine balancing a broomstick. Remember broomsticks? We used to have brooms and broomsticks. And imagine balancing a broomstick upright on your, on the palm of your hand and all the adjustments you have to make to keep that upright.

Host: Right.

John Charles:That’s how it is when you’re walking. When you’re walking and standing on one foot or even standing on two feet, your body is constantly adjusting its center of balance and its center of mass to stay over the center of pressure of the feet so you can stay upright. And that all requires sensors in the skin, sensors in the soles of the feet, sensors that detect the angles between the ankle, and the shinbone, and all the other bones, and the organs of balance inside the inner ear. And Gary, even though we’re on a podcast, I am automatically pointing at my ears because the organs of balance are behind the inner ears.

Host: I can see.

John Charles:Yeah.

Host: [laughs] But I guess no one else can.

John Charles:Nobody else can. [laughs] But this organ system is exquisitely tuned to respond to motion and to respond to gravity. There are parts of it that detect how you move your head, and now I’m twisting my head left and right because that causes a sensation in my inner ear, which then is, at a most simple case, is translated to my eyeballs. So my eyes counteract the motion on my head so I can keep continuing to look at you while we’re talking. But there are other organs that detect my tilting my head left and right, and those are the balance. So those are the otoliths. The other ones are the semicircular canals. But the otoliths, the otolith is ear stone, oto-lith.

Host: Okay.

John Charles:And those are little stones inside little sacs of fluid inside your head which detect which way down is. And those are the ones that are the most immediately affected by spaceflight and weightlessness because if your whole existence is predicated on detecting down and somebody takes away down, then what do you do? And that’s sort of how the vestibular system responds to weightlessness is it spends a lot of time the first several hours or several days saying, oh my God. Oh my God. Oh my God. My only job is to detect down and there is no down. What do I do now? Now, I’m built, you know, the organs of balance are built to detect motion and to detect directions of acceleration, so they may get more sensitive. In fact, the little otoliths in your ears might become bigger. They might accrete more of the mineral that they’re made of because they, they’re sure there’s a down there someplace and that if they could only get heavier, they might be able to detect it again.

Host: And this is over the first couple days of the spaceflight?

John Charles:Over the, it’s over the course of the spaceflight.

Host: Oh, over the — wow.

John Charles:Over the course of the spaceflight. Over the course of the first few days — thank you for bringing me back to the point at hand — [laughs] over the course of the first few days, essentially the brain says, you know what? You guys are just making gibberish. You’re not making any sense anymore. I’m going to start ignoring you. Now, the brain doesn’t actually use words. It just sort of economizes the metabolic energy. It says, I’m not going to put so much metabolic energy into the nerves that come from the vestibular system because–

Host: Right.

John Charles:I’m just getting gibberish from there and it just, it makes my, the stomach part of me sick. Let’s just not pay attention so much to that anymore. And in fact, on Skylab, the American space station in the 1970’s, when there was a rotating chair onboard specifically to see how often we could make astronauts sick in spaceflight — rotating chairs are good ways to make people sick. If you rotate them and ask them to move their heads while they’re rotating, that’s a great way to be sick.

Host: Oh, yeah. I remember those chairs.

John Charles:Turns out after a few days in weightlessness, astronauts couldn’t be made sick anymore by moving their heads while they were rotating because the–

Host: Yeah.

John Charles:Organs of balance had adapted and also because the stimuli were different.

Host: I’ve seen that video of Tim Peake, where I think it was Tim Peake and Tim Kopra, when they were both on the International Space Station–

John Charles:Yeah.

Host: Kopra took Peake and just spun him around really, really, really fast–

John Charles:Yep.

Host: And then stopped him suddenly. And Peake had like one moment where he stopped suddenly where, I mean, the whole time he was spinning, he didn’t feel a thing.

John Charles:Yeah.

Host: And then, he stopped suddenly. He’s like, “Okay, I’m dizzy for a second.” And now he’s good.

John Charles:It’s gone.

Host: Yeah.

John Charles:So there are quick responses, but as I say, you know, the organs of balance, vestibular system continue to, like I say, try to find gravity. And so they may actually increase the mass of the little stones inside your inner ears. And that’s kind of an interesting novelty that nobody’s figured out yet whether, what the functional — operational, I should say — significance — functionally, we know what it means — but operationally, what does it mean in terms of your ability to stand upright after you land on Mars? Or things like that. So there’s lots of more, lots of research on, some topics for research that we can do in that domain. But the point I was trying to make originally is that this is a quick-responding organ system. Then, slightly slower will be the organs of your cardiovascular system. And those are all fluid based in the sense that they, you’re a big, pressurized bag of fluid. Nothing personal, but all of us are. [laughs] And our goal is to stay pressurized by the function of our heart so that the blood can then perfuse the brain and also the blood pressure we carry around with us, 120/80, when the doctor does your blood pressure, tells you, yes, 120/80.

Host: That’s a good one.

John Charles:That’s the pressure that you need to get through the muscles when you’re exercising. The, when your muscles are exercising, they’re constricting and contracting. They’re squeezing down the blood vessels. It takes a certain amount of blood pressure to push through there to deliver the nutrients that the muscles need to continue exercising. That’s where your 120/80 comes from. And you have to continue building that pressure up. But in weightlessness, you’re not exercising so much anymore. You’re floating freely. You’re relaxing, and your blood vessels are dilating, and your pressure, you’d actually lose blood volume in space. You may lose about a liter of blood in space.

Host: Wow.

John Charles:You may actually lose, that’s about a blood donation, about the same amount as they take out of you when you donate blood, half a liter or a liter.

Host: Huh.

John Charles:Yeah, that’s because the body’s, the fluid distribution builds into it an assumption that a lot of your fluid is going to be down in your lower limbs because of gravity, and your lower limbs have a lot of veins, which are very floppy and good places to sequester extra fluid that you don’t need, extra blood you don’t need. And in weightlessness, that fluid is all shifted into the upper direction, and it’s–

Host: Oh.

John Charles:There’s not a lot of extra venous volume in the upper part of the body, and so the body says, aha, I’ve got a, I’ve got too much fluid onboard. I know what to do in a case like this. Decrease thirst, increase urination, you know, eliminate fluid elsewhere, shift it into other parts of the body, which has the effect of causing your body to lose blood volume over the course of the first few weeks in spaceflight.

Host: That was going to be my question.

John Charles:Yeah.

Host: Where does that liter go? Okay.

John Charles:Liter goes out, becomes tomorrow’s coffee.

Host: Yeah. [laughs]

John Charles:You remember the old analogy about the water recycling system.

Host: That’s right.

John Charles:So that fluid volume is appropriate for your time in weightlessness. And again, one of those tricks that you pull on your body is that you come back to the Earth after your time in weightlessness and suddenly that fluid drains back down to the lower part of the body. And then, suddenly, the upper part of the body is volume deprived, and that’s when you may feel a little bit light headed, a little bit weak. Astronauts wear compression garments in the lower body — in the legs, especially — to squeeze to make sure the fluid stays up in the upper part of the body and not pooling in the lower part of the body. Shane was wearing those compression garments that are called Cantaver [phonetic] garments. That’s the Russian name for Cantaver. [laughs] And it–

Host: Nice translation.

John Charles:Yeah. I’m good at that. But that, those are very effective techniques, and we are, we have other capabilities like that as well. But the point is during, while he wasn’t being sensitive to emotion by not turning his head very much, he was also, his body was functioning to keep the blood flowing to the upper part of his body through his brain so he could continue to function normally. That’s all part of the early re-adaptation process as well.

Host: That’s right.

John Charles:So the vestibular system is quick responding. The cardiovascular system is slightly slower. Along the way, you lose muscle mass because you’re not hefting your body mass around, and they have to rebuild that when you come back. And then, out there at the, sort of the tail end is your skeleton. What we haven’t talked about before, yet, though, are things like your radiation tolerance, or radiation exposure, I should say.

Host: That’s right.

John Charles:That doesn’t plateau. That doesn’t decrease. That doesn’t accommodate because you keep getting exposed to radiation, and radiation has a cumulative effect. The more you–

Host: As long as you’re in space–

John Charles:As long as you’re in spaceflight. So that’s an ongoing issue, and that’s something we will have to deal with going to Mars because you’re exposed to even more radiation when you leave Earth’s magnetic field and are–

Host: Right.

John Charles:Exposed to the deep-space radiation. And then, the other aspects, of course, are the psychological aspects of spaceflight. And if you think what I’ve described to you before is complicated, you ain’t seen nothing yet because the psychology [laughs] is one of the most self-regulating and self-protecting let’s call it organ system that we have until it’s not anymore. And so you adapt, you accommodate, you adjust. All those A words are the way that your [laughs] psychological aspects function in normal, everyday life and especially in spaceflight.

Host: Yeah.

John Charles:But you’re exposed to stresses that are the most unique that anybody’s ever been exposed to in spaceflight. And if we’re talking about a Mars mission, we’re talking about let’s call it two and a half years just you and three other people face to face in the volume of a couple of Space Station modules maybe with the pressure and the eyes of the world on you to make sure you, to wonder if you succeed. So there’s no pressure, obviously. And the, nobody can help you when you’re on your way to Mars. At least, they can’t help you immediately. There’s going to be, when you get to Mars, you may be eight minutes away from Earth by radio.

Host: Right.

John Charles:At the midpoint of your stay on Mars, you might be 40 minutes away, 20 minutes away one way by radio.

Host: Yeah.

John Charles:So if you have a problem and it takes longer than, it takes less time than 20 minutes to fully express itself, and you don’t know what you’re doing, then you’ve got a big problem.

Host: That was one thing Shane said. He said, five minute, he landed. Five minutes, and everyone was, you know, taking him out of the capsule.

John Charles:That’s right.

Host: And you’re right. You’re not going to have any–

John Charles:That’s right.

Host: Not only no help, but it’s going to be a while until actually someone talks to you.

John Charles:I like to paint a picture for people, and that is if you’re the first person on Mars, you’re climbing down the ladder, and you stumble and fall face first into the Mars dust, [laughs] the bad news is that everybody on Earth will see it because they’re all going to be watching the live stream.

Host: Of course.

John Charles:But the good news is it’ll be 20 minutes before they see it. [laughs] So you’ve got a few minutes of relief before you have to explain to the entire universe how you stumbled your, for your first step on Mars.

Host: [laughs] That would be pretty cool if that was the actual video of–

John Charles:Yeah.

Host: The first person stepping on Mars. [laughs] So obviously, you know, you have to be thinking about, you know, this is, obviously, you are thinking about, you know, this is kind of what that’s going to look like if someone’s going to land on Mars. You know, what are we doing to sort of get them ready for that? One of the things I think, I’m pretty sure Shane mentioned was they sat him in the seat and, for a while, and then they took him right to a tent and started doing some field tests on him.

John Charles:Yes, they’re, exactly, and that’s exactly what we called it. We call it the field test. It is, it’s one of our Human Research Program investigations. It’s a joint investigation by the U.S. and the Russians. The U.S. and Russian investigators Millard Reschke and Inessa Kozlovskaya are very longtime investigators, and they both have been anxious to do this kind of research on the adjustments of the sensorimotor system and the neurovestibular system to gravity after a long-duration spaceflight. We started doing this a few years ago. Chris Cassidy I think was the, actually the first guy to do it on his Soyuz landing.

Host: Oh.

John Charles:And we’ve been doing it pretty consistently since then to try and build up a database of responses so we know what an average, and, you know, what the statistical mean is, and what the variation is.

Host: Nice sample size.

John Charles:Nice sample size.

Host: Right.

John Charles:And it’s also very dramatic, and it’s also, it’s a, an important set of things to do. But what it does briefly is after they’re extracted from their Soyuz — and you heard Shane talk about how they got out of the Soyuz with a lot of assistance. Nobody going to help you on Mars. Your vehicle has to be designed appropriately for you to get out on your own. Then, they set him in a chaise lounge for a little bit and have a brief public affairs event there on the steps of Kazakhstan, and that’s a good chance for them to catch their breath. And then, they’re carried, not walked, but they’re carried into the medical tent. And inside the medical tent, in privacy because of human research concerns–

Host: Right, makes sense.

John Charles:They are unsuited — that is, their space suits are taken off — and then, then if they volunteered for this investigation, they go through a stylized set of motions. And they start off with being seated in a chair and just being asked to stand upright and stand quietly for 30 seconds or so.

Host: And that must be hard, though, right?

John Charles:That’s a substantial stress, a substantial [inaudible].

Host: Yeah.

John Charles:Sonny Carter back on STS-33 I think it was said — and that was after a five-day flight — said the hardest thing he had to do on his spaceflight was stand up for the first time after a spaceflight out of the chair in the shuttle.

Host: Wow.

John Charles:So that was after just a few days. Now, this is after six months or so of weightlessness.

Host: Right.

John Charles:So that’s the stress. We’re watching their blood pressure, their heart rate, as well as their balance. And then, sort of to add insult to injury, one of the early things we do then is to lay them on the floor in the face down, in a prone position, and then ask them to stand up again. And it’s, to mimic, it’s called recovery from a fall. So the idea is that they have stumbled on Mars or they’ve stumbled on the Earth and they find themselves face down in the red dust on Mars like I’ve mentioned before. How long does it take to get back up again? And that we can quantify how long it takes them to stand up, to go through all the complicated motions of getting up on your hands, and getting up on your knees, and then finding a way to balance yourself and get back up. That’s a very integrated physiological and, or musculoskeletal activity, and it’s, it can be quantified. And then, once they’ve got them standing up again, and I always haste to add that no astronauts are actually pushed over. They’re asked to lay down gently and then stand up.

Host: [laughs] That’s funny because that would be very rude.

John Charles:That would be another good video. [laughs] But then, we make them walk an obstacle course to see if they can do it. And the obstacle course is actually, as Shane described, walking in a straight line with your eyes closed, or with your eyes open and then with your eyes closed. And sometimes, you know, eyes closed, you veer because you’re using the, your visual system is your dominant way to orient yourself in the absence of a functional vestibular system and in the absence of a fairly relaxed set of somatosensory sensors. Those are the sensors that detect pressure on the bottom of your feet and at the angles of the joints, you know — your ankle angles, and your elbow angles, and things like that. So walking with eyes open is always a challenge. Walking with eyes closed is almost always impossible because you veer immediately left or right because you just can’t orient yourself in the absence of any inputs. And the inputs you’re receiving are those that your brain has decided six months ago to ignore, and inputs that it wanted us, wanted to keep you’ve now deprived yourself of because your eyes are closed. So there’s a little bit of a stressor there. And then, there are other things that we ask them to do as they sort of gradually move through this set of activities — moving heavy masses back and forth as if they were unpacking a Mars lander and getting things set up on the surface of Mars, and, you know, just a bunch of generalized things like that involving motions, bending, twisting, standing still, you know, things like that. So–

Host: So how long does that usually take?

John Charles:It’s about 45 minutes–

Host: Wow.

John Charles:In the tent, and that’s only a subset. When they get back to Houston, there’s a much longer set of measure, of activities they go through, and that’ll be 24 hours after landing.

Host: Right.

John Charles:But we also test them in the airport in Karaganda, which is where the helicopter takes them after they land.

Host: Right.

John Charles:Or we test them in the airport either in Norway or in Scotland, depending on where the jet lands to refuel on the way–

Host: Their layover, right.

John Charles:On the way back. Their layover.

Host: Yeah.

John Charles:So that gives us, you know, minutes, and hours, and then a day of adaptation. And then, we watch them for several days post flight up to potentially even several weeks post flight to track their full recovery back to normal. And this is specifically to quantify the responses, the re-accommodation and re-adaptation back to gravity so engineers can design habitats and landers for Mars missions, and they’ll know what capabilities astronauts will have to design around.

Host: Right.

John Charles:Now, smart fellow that you are, you’re going to say, but John, you already said that Mars has only one-third of a g, and here we are making them do all this stuff at one g.

Host: Again, you’re reading my mind. [laughs]

John Charles:We’ve worked together so much, I can anticipate your, almost your next thought. But the deal is, yes, we are making them do it at one g when normally on Mars they’d be at one-third of a g. All we’ve got is one g, and this is the closest we can get to that situation, so we have to–

Host: Right.

John Charles:Make the appropriate adjustments, if we think it’s necessary, to compensate for the fractional gravity. But right now, in answer to your next question, we don’t have any information on what fractional gravity does. And so we just have to assume that it will be as unpleasant, uncomfortable, difficult as one g is. And then, once we get experience at fractional gravity, like if we go to the Moon and get one-sixth of a g experience or if we land on Mars, and do it a few times, and say, you know what? That was not as hard as we said it was going to be. It’s going to be easier here at one-third of a g. We can make the appropriate adjustments.

Host: Right. There’s a lot deeper of a story here, I can tell.

John Charles:Yeah. [laughs]

Host: There’s a lot of different directions we can go, but I’m going to ask one more question, and then we’re going to let you go. So, you know, you have all these field tests, and you’re kind of preparing for what, you know, what we have to do in order to make a Mars mission work. So I do have one, like, theoretical question for you: In a perfect world, if you were to land on Mars, what would you want that to look like? I’m guessing, I mean, can it be as simple as they land on Mars and they’re good? They get out of the capsule. Or is there, you know, is there other things that we are going to have to sacrifice based on the knowledge we have now to make that as easy as possible?

John Charles:I think the answer is going to be yes and yes.

Host: Awesome.

John Charles:I think astronauts come in varieties just like other people do, and some people will have problems accommodating, adjusting, adapting, and others will not. Some folks are going to be able to land on Mars, and bounce right up, and feel like they want to go to work. We’re probably going to insist that the landing vehicle be able to accommodate them for a couple of days.

Host: I see.

John Charles:Because we don’t want to bet that they’re all going to be perfect, they’re all going to be bulletproof. And by perfect, I mean in this particular regard. Because they’re all going to have, they’re all going to be perfect in some way. It’s not just, you know, the, not just the ’70’s kids. [laughs] We’re all perfect in some way, but they’re all not going to be perfect at adjusting to Mars. There’s going to be some that are slower, and some that are faster, and some that are sort of run of the mill. We have to accommodate all of them because you can’t leave the guy behind that’s not feeling the best, then go and start exploring Mars.

Host: Right.

John Charles:So the goal is to make the landing vehicle as lightweight as possible. Previous discussion about mass, and power, and volume.

Host: Right.

John Charles:Which means minimize the amount of mass that you dedicate to life support systems. You don’t want to build a two-week life support system into the lander if you’re only going to use it for a couple of days, then you’re going to feel good enough to go out and then traipse across the desert to the habitat that’s waiting for you with all the life support you can use inside of it.

Host: Right.

John Charles:But you don’t want to carry excess life support, but you don’t want to carry too little life support in case it turns out to be, just by the luck of the draw, you’ve got four people that are going to have a tough time readjusting, and–

Host: Yeah.

John Charles:They don’t want to get, put their space suits on and stumble across Mars face down into the dust, you know. Things like that.

Host: Yeah [inaudible].

John Charles:So what I would like to see the landing on Mars look like is that the entire crew feels good, and it was the luck of the draw that we got four people that just turned out to feel good this time. They’re, they understand the importance of the design of the habitat, of the lander, so they take their time getting suited up and making the excursion out. Maybe they, maybe we’re clever on the first landing and we don’t make them actually walk very much at all. We make them have a radio-controlled rover that deploys from the habitat, and comes over, and is waiting out their front door on the lander. And they get into that, and they drive off to the habitat, and they get in, and set up housekeeping instead of actually having to stress themselves for the first time in a six- or eight-month period of time after they transited to Mars.

Host: That’s a cool concept. Nice.

John Charles:So, you know–

Host: Valet service.

John Charles:Yeah, valet service. [laughs] And it might be even, may be even a self-driving car, so maybe Uber or–

Host: Yeah. [laughs]

John Charles:Google’s going to have something to say about it.

Host: That’s right.

John Charles:And then, they gradually become accustomed to their environment on Mars so they can go to work on Mars. The habitat will have the gym, whatever it looks like, as well as the food, and the fresh water, and the fresh air. But the point of all this is not to cater to the astronauts. The goal is to make sure that the astronauts are, as I like to say, in the best condition of their lives when they land so they minimize the time they spend readapting–

Host: Right.

John Charles:Because the Mars missions will be the most expensive undertakings humanity’s ever embarked upon.

Host: Sure.

John Charles:And if we want to have a second, and a third, and a fourth, and a fifth one, the first one had better be productive. And the way to be productive is to be in good condition so you can get to work as quickly as possible, allowing for the accommodation time of a few days, or a week, or so, and then get to work, and show us why we sent you to Mars, and make those Nobel Prize winning discoveries on Mars so that Congress, and the parliaments of all the partner agencies, and everybody, all the taxpayers, think, yeah, that was a good thing. We want to do that some more. [laughs] We’ll have more Mars missions and build up the flow to Mars and the infrastructure for Mars. So it’s, it sounds like I’m altruistic, but Gary, you know me well enough to know that [laughs] I’m not altruistic. I want the astronauts to be in great condition when they land on Mars not just for themselves but for us too because if we have hopes of becoming a multi-planet society, our first emissaries to other planets will have to be, will have to demonstrate how productive we can be in other planets, and that’s really the goal here.

Host: John, I want you to lead the charge and lead us [laughs] all the way to Mars.

John Charles:I’m not going to Mars, then.

Host: You’ll be the guy landing. [laughs]

John Charles:I want to stay at home and cheer them on.

Host: [laughs] Well, this was awesome. Thanks for coming on the show and talking about, you know, really analyzing what Shane was feeling and what, why we are doing what we’re doing, you know, obviously for later missions and landing on Mars. So obviously, you know, there’s something that, there’s some stuff that Dr. Charles was not able to address today, so for those listening, if you want to know more or you have a suggestion on what we need to talk about, stay tuned until after the music to learn on where and how you can submit some ideas. So John, thank you so much for coming on the podcast.

John Charles:Delighted. Thank you [inaudible].

Host: Glad to have you, and we’ll probably have to have you again.

John Charles:Okay.

[ Laughs ]

[ Music ]

Host: Hey, thanks for sticking around. So I hope you enjoyed our talk with Dr. John Charles and Astronaut Shane Kimbrough. If you want to learn more about kind of all the things that specifically Dr. Charles talked about, there’s, we actually have a website for that, per usual — This is the website for the Human Research Program, and you can learn about everything that they’re studying there. All of these things that Dr. Charles was talking about — the human body, bone density, even we have some stuff about the twin study that happened just actually a couple years ago now when Scott Kelly launched in 2015. So you can find all that information there. A lot of the research that’s done and especially with Shane Kimbrough on the International Space Station was done up there on that orbiting complex. You can go to to learn about the latest updates on the International Space Station — all the latest blogs and scientific findings. We also have a lot of cool pictures that we like to put up on that website. On social media, we’re very active. Facebook is the International Space Station. That’s their Facebook page. On Twitter, we’re @space, underscore, station. And on Instagram, it’s @iss. If you want to submit an idea or you have a question about something that we talked about on the podcast, just use that hashtag #asknasa on your favorite platform. Doesn’t matter. We’ll check them all. And we’ll make sure that we address it on one of the next podcasts that we do. And maybe we even will make a whole podcast out of, episode out of it. So this podcast was recorded on April 19th thanks to John Stoll and Eric Sparamin [phonetic] for helping to produce the show. Thanks again to Dr. John Charles and Shane Kimbrough for coming on the show. See you in 6.79 sols. Get it because the Mars? Okay. See you next time.