Interviews
10:17 am
Thu December 26, 2013

Astronaut Chris Hadfield Brings Lessons From Space Down To Earth

Originally published on Thu December 26, 2013 11:36 am

This interview was originally broadcast on Oct. 30, 2013.

While floating weightless in the International Space Station last spring, Commander Chris Hadfield recorded his own version of David Bowie's "Space Oddity" — a video that's now been viewed more than 18 million times on YouTube. But when he wasn't busy being an Internet phenomenon, the Canadian astronaut was witnessing awe-inspiring beauty, facing life-threatening dangers and, at times, holding onto a spaceship orbiting Earth at 17,500 miles an hour.

Hadfield has flown three space missions, conducted two space walks and spent a total of six months in space. On Earth, he's been the chief of international space station operations in Houston and chief CAPCOM commander — the person at mission control who communicates directly with astronauts in orbit. In his book, An Astronaut's Guide to Life on Earth, he shares some of the lessons he learned in space.

"There are no wishy-washy astronauts," Hadfield tells Fresh Air's Terry Gross. "You don't get up there by being uncaring and blase. And whatever gave you the sense of tenacity and purpose to get that far in life is absolutely reaffirmed and deepened by the experience itself."


Interview Highlights

On what it's like to do a spacewalk

I've been so lucky to have done two spacewalks. If you looked at your wristwatch I was outside for about 15 hours, which is about 10 times around the world. ...

The contrast of your body and your mind inside ... essentially a one-person spaceship, which is your spacesuit, where you're holding on for dear life to the shuttle or the station with one hand, and you are inexplicably in between what is just a pouring glory of the world roaring by, silently next to you — just the kaleidoscope of it, it takes up your whole mind. It's like the most beautiful thing you've ever seen just screaming at you on the right side, and when you look left, it's the whole bottomless black of the universe and it goes in all directions. It's like a huge yawning endlessness on your left side and you're in between those two things and trying to rationalize it to yourself and trying to get some work done.

On doing a spacewalk amid Southern Lights

I was coming across the Indian Ocean in the dark. I was riding on the end of the robot arm ... [and] I thought, "I want to look at Australia in the dark," because everyone lives along the coast, starting with Perth and across and it's like a necklace of cities. So I shut off my lights, and I let my eyes completely adjust to the darkness, but as we came south under Australia instead of seeing just the lights of the cities of Australia we flew into the Southern Lights. Just like the Northern Lights they erupt out of the world and it's almost as if someone has put on this huge fantastic laser light show for thousands of miles. The colors, of course, with your naked eye are so much more vivid than just a camera. There are greens and reds and yellows and oranges and they poured up under my feet, just the ribbons and curtains of it — it was surreal to look at, driving through the Southern Lights. ...

To me it was taking time to notice something that is almost always there but that if you didn't purposefully seek it out you would miss — and that is our planet and how it reacts with the energy from the sun and how our magnetic field works and how the upper atmosphere works — what it really is, is just beauty.

On claustrophobia

They don't want claustrophobic astronauts, so NASA is careful through selection to try to see if you have a natural tendency to be afraid of small spaces or not. Really, it's good if you've managed to find a way to deal with all of your fears, especially the irrational ones. So during selection in fact, they zip you inside a ball, and they don't tell you how long they're going to leave you in there. I think if you had tendencies toward claustrophobia then that would probably panic you and they would use that as a discriminator to decide whether they were going to hire you or not. For me, being zipped inside a small, dark place for an indeterminate amount of time was just a great opportunity and nice time to think and maybe have a little nap and relax, so it doesn't bother me. But you can get claustrophobia and agoraphobia — a fear of wide open spaces — simultaneously on a spacewalk.

On coping with moments of fear and panic in space

Half of the risk of a six-month flight is in the first nine minutes, so as a crew, how do you stay focused? How do you not get paralyzed by the fear of it? The way we do it is to break down: What are the risks? And a nice way to keep reminding yourself is: What's the next thing that's going to kill me? And it might be five seconds away, it might be an inadvertent engine shutdown, or it might be staging of the solid rockets coming off. ... We don't just live with that, though. The thing that is really useful, I think out of all of this, is we dig into it so deeply and we look at, "OK, so this might kill us, this is something that would normally panic us, let's get ready, let's think about it." And we go into every excruciating detail of why that might affect what we're doing and what we can do to resolve it and have a plan, and be comfortable with it. ...

It's not like astronauts are braver than other people; we're just meticulously prepared. We dissect what it is that's going to scare us, and what it is that is a threat to us and then we practice over and over again so that the natural irrational fear is neutralized.

On losing orientation in space with no sense of "up"

What does it feel like when you close your eyes when you're weightless? Normally on Earth when you close your eyes you can feel your feet on the floor or your rear end on your chair or something and that gives you a sense of up. You can balance with your eyes closed, you can walk with your eyes closed because of all of the external references. When you're weightless and you close your eyes it's as if you just stepped off a cliff into complete blackness and you're falling forever, so the perception of that is really odd. You can do it as like a thought experiment and instead of closing your eyes and thinking that you're just floating, close your eyes and picture that you've just stepped off the Half Dome in Yosemite and are now falling into the blackness, and it's interesting to see how your body reacts to it.

On losing friends and colleagues in the 2003 Space Shuttle Columbia disaster

I'd already been an astronaut for a decade when the crew of Columbia was killed. ... Rick Husband and I were out at Edwards at test pilot school together. He was the commander of Columbia ... I knew everybody onboard and I was very close with Rick. So it was an awful thing to go through ... they die so publicly.

... It's redoubled my efforts to try and do this job right in the future and to try and convince everybody that we can solve problems like this and we can be smart and brave enough to take those risks again. And to our credit, it took years, but we made significant changes in a lot of the way we did business.

We flew out the rest of the entire space shuttle program without hurting anybody else. We finished building the space station and we've learned so much about how to safely fly in space as a result of those guys losing their lives. So yeah, it's not a risk-free business when you want to try something hard and new, when you want to explore someplace you haven't been before.

On space travel and faith

The big pervasive feeling onboard looking at the Earth [from space] is one of tremendous exquisite privilege that it exists. ... But I think what everyone would find if they could be in that position — if they could see the whole world every 90 minutes and look down on the places where we do things right, and look down where we're doing stupid, brutal things to each other and the inevitable patience of the world that houses us — I think everybody would be reinforced in their faith, and maybe readdress the real true tenets of what's good and what gives them strength.

Copyright 2013 NPR. To see more, visit http://www.npr.org/.

Transcript

TERRY GROSS, HOST:

This is FRESH AIR. I'm Terry Gross continuing our holiday week series of some of our more popular interviews from 2013.

(SOUNDBITE OF "SPACE ODDITY")

CHRIS HADFIELD: Ten, nine, eight, (Singing) Ground control to Major Tom. Seven, six (Singing) Commencing counting engines on.

GROSS: While floating weightless in outer space at the International Space Station last spring, my guest Commander Chris Hadfield recorded his version of David Bowie's "Space Oddity." It was turned into a video that has gotten over 18 million hits on YouTube. Hadfield has flown three space missions, conducted two spacewalks and spent a total of six months in space. He's witnessed awe-inspiring beauty, faced life-threatening dangers and held onto a spaceship orbiting Earth at 17,500 miles an hour.

This year, Hadfield published his memoir, "An Astronaut's Guide to Life on Earth." A former Royal Canadian Air Force fighter and test pilot, he's been the director of operations of NASA in Star City, Russia, and the chief of International Space Station operations in Houston. In space, he served as the commander of the International Space Station. We spoke in October after the publication of his book.

Commander Hadfield, welcome to FRESH AIR. I just want to start with your "Major Tom" video, since that's gotten over 18 million views. Talk about going viral.

(LAUGHTER)

HADFIELD: That's crazy.

GROSS: So, is it hard to sing and play guitar in space?

HADFIELD: It is, actually. It was subtly hard. Singing, it's weird because your sinuses never drain without gravity. It's sort of like standing on your head forever, and no professional singer stands on their head forever before a performance, because it kind of fills up your tongue and your sinuses, and you sound a little bit congested. So it changed the timbre of my voice, for sure.

GROSS: It may have actually made it easier to hit the high notes. I'm not sure. And then guitar, it's just an acoustic guitar up there, but when you move your left hand up and down the fret board, because the guitar is floating weightless, it kind of flies along with your hand. So you constantly miss with you left hand.

(LAUGHTER)

HADFIELD: Clumsy, popping recordings. So it's a little bit new to both sing and play up there, but with enough takes, eventually, you can get something that's worth listening to.

GROSS: I just want to say thank you. I love that you've done that.

(LAUGHTER)

HADFIELD: You're welcome.

GROSS: That's great. So how many times were you actually out in space, out of the capsule, or out of the space station?

HADFIELD: Well, I've been so lucky to have done two spacewalks. If you looked at your wristwatch, I was outside about 15 hours, which is about 10 times around the world. And, you know, there's a whole time dilation, distortion thing.

GROSS: Excuse me, I just have to interrupt. I just have to interrupt and say that's just mindboggling.

HADFIELD: Oh, it's even more mindboggling if you're the human being out there doing it, Terry. It's - the contrast of your body and your mind inside a little one-person - essentially, a one-person spaceship, which is your little spacesuit, where you're holding on for dear life to the shuttle or the station with one hand, and you are inexplicably in between what is just a poring glory of the world roaring by silently next to you, just a kaleidoscope of it. It's just - you - it takes up your whole mind.

It's like the most beautiful thing you've ever seen just screaming at you on the right side. And when you look left, it's the whole bottomless black of the universe. And it goes in all directions. It's like a huge, yawning endlessness just on your left side. And you're in between those two things and trying to rationalize it to yourself and trying to get some work done.

GROSS: Now, during those 15 hours, when you were doing spacewalks, was there always a technical reason to be out there? Was it always part of the mission, or was it ever just...

HADFIELD: Oh yeah, we don't out recreationally.

(LAUGHTER)

GROSS: You don't go out just to, like, you know, like, this is so cool, I'm just going to go outside and enjoy it?

HADFIELD: It's a really big deal to do a spacewalk. It's much riskier than staying indoors. It's complex. It uses up a lot of the precious resources onboard. It uses up oxygen. It uses up carbon dioxide scrubbers. You know, we only go out when we absolutely have to, whether it's to build something that takes the ingenuity and dexterity of a person, or if it's to fix something, if you had an emergency and you need to fix something that broke. And those are the only reasons we go outside. And we train for it in a detail you just wouldn't believe to make it go right.

GROSS: Now, you write in your book that, when you did a spacewalk, my number one concern was to avoid floating off into space, which is a pretty major concern.

HADFIELD: It seems like a good idea. Yeah.

GROSS: Yeah. So how are you tethered to - what was it, the space station that you were tethered to?

HADFIELD: When I did my spacewalks, it was during space station construction. So the shuttle was docked to the fledgling ISS at the time. So we would always stay tethered.

GROSS: The ISS is the International Space Station.

HADFIELD: Yeah, that's right, International Space Station. Sorry for the acronym. Tethered means basically like a clothesline that you have clipped somewhere on structure. So you're either clipped to the shuttle or to the space station somewhere. There's little handrails and loops and things you can attach to.

And you go from one to the other, like a high building construction worker or something. So you're always tied off, so that if your hand did slip and you started drifting off into space, I mean, there's nobody who could come rescue you. So, you have a tether. And it reels out to about 50 or 60 feet long, if it had to. But you also wear a jetpack, just in case that tether were to fail. You could pull down a handle on your right side. A little joystick pops out in front of you. You grab it, you turn it on, and then you can fly yourself with just a simple system of a nitrogen tank and little thrusters. But you could fly yourself over and grab back onto the mothership.

GROSS: Your longest mission was 146 days in space. I think during that one trip, you orbited Earth 2,336 times and traveled almost 62 miles - again, mindboggling. You probably hear...

HADFIELD: Sixty-two million miles.

GROSS: I'm sorry, 62 million miles. Yes. You probably hear a lot of frequent flyer jokes. So I will not bother to make any. And you see another sunrise every 92 minutes, which must be very odd and disorienting.

HADFIELD: They happen really fast, the sunrises. Sometimes you specifically set the alarm on your watch to go watch the sunrise. And as you pull yourself down into the floor - and that's where the huge, bulging window is, that we call the cupola - and there's the world glowing dark underneath you. And you start to see a few faint tinges of a sunrise coming as it starts to light the upper atmosphere, and then bam. The sun just pops into view, roars into view, because we're coming around the world at it so fast.

And you can actually watch the sun move away from the Earth. And the light from it initially comes through the atmosphere. So the whole station glows with the light of dawn, with - all the big solar arrays glow blood red, and then orange. And then, as the sun clears the atmosphere, and it's directly on us, then they settle down to sort of an iridescent blue. And then you can see the dawn come across the world towards you.

And then you go back to work and wait another 92 minutes, and it happens again. It's not to be missed, and I tried to watch as many sunrises and sunsets as the work would allow.

GROSS: Wow.

(LAUGHTER)

GROSS: I'm thinking of the contrast between the claustrophobia you must experience when you're in the space shuttle or the space station, compared to the sense of the infinite when you're out on a spacewalk.

HADFIELD: They don't want claustrophobic astronauts.

(LAUGHTER)

HADFIELD: And so NASA is careful, through selection, to try and see if you have a natural tendency to be afraid of small spaces or not. And really, it's good if you're managed to find a way to deal with all of your fears, especially the irrational ones. So, during selection, in fact, they zip you inside a ball, and they don't tell you how long they're going to leave you in there.

So I think if you had tendencies toward claustrophobia, then that would probably panic you, and they would use it as a discriminator to decide whether they are going to hire you or not. For me, being zipped inside a small, dark place for an indeterminate amount of time was just a great opportunity, a nice time to think and maybe have a little nap and relax. And so it doesn't bother me.

But you can get claustrophobia and agoraphobia - a fear of wide, open spaces - simultaneously on a spacewalk. You are enclosed inside your little spacesuit with a helmet and a, like, a cap on, a Snoopy cap, and some microphones right down touching your mouth, and stuff in front of your face and your whole body enclosed. If you are susceptible to claustrophobia, that might be a trigger.

But when you look outside, when you look through your visor, you are standing on nothing, with 250 miles of emptiness between you and the world.

GROSS: If you're just joining us, my guest is Commander Chris Hadfield, who's flown several space missions, did two spacewalks. He has a new book called "An Astronaut's Guide to Life on Earth." Let's take a short break here, and then we'll talk some more. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: If you're just joining us, my guest is Commander Chris Hadfield, who's flown into space three times, and now he's written a new memoir called "An Astronaut's Guide to Life on Earth." And you may know him from his incredible space videos that have gone viral, including the one he shot in space, where he is singing David Bowie's "Space Oddity."

One of the exercises that you basically put yourself through in preparing - or that NASA puts you through in preparing to be an astronaut is what you describe as what's the next thing that will kill me because there are so many things that can go wrong and be life-threatening in space. Give us a sense of what that what's the next thing that will kill me training process is like.

HADFIELD: Terry, I found it to be so helpful in my regular life, and I didn't mean it to be that way. But of course as an astronaut, especially during launch, half of the risk of a six-month flight is in the first nine minutes. So as a crew, how do you stay focused, and how do you not get paralyzed by the fear of it?

And the way we do it is to break down what are the risks. And a nice way to keep reminding yourself is what's the next thing that's going to kill me. And it might be five seconds away, it might be an inadvertent engine shutdown, or it might be staging of the solid rockets coming off, or it might be, you know, some transition or some key next thing. We've already, say, had one computer fail, and we've had one hydraulic system fail, so if these three things fail, now we're, you know, we need to react right away, or we're done.

So we don't just live with that, though. And the thing that is really useful, I think, out of all this is we dig into it so deeply, and we look at OK, so this might kill us. This is something that would normally panic us. Let's get ready. Let's think about it. And we go into every excruciating detail of why that might affect what we're doing and what we can do to resolve it and have a plan and be comfortable with it and practice is.

GROSS: And you say in order to make this work, you have to neutralize fear.

HADFIELD: Yeah, but, I mean, it's not like astronauts are braver than other people. We're just, you know, meticulously prepared. We dissect what it is that is going to scare us and what it is that is a threat to us, and then we practice over and over again so that the natural, irrational fear is neutralized.

And your first reaction is not just to scream and flee with your hands waving over your head, but in fact, to go hey, we thought about this, and I know that this is dangerous, but there are six things that I could do right now, all of which will help make things better.

And it's worth remembering, too, there's no problem so bad that you can't make it worse also.

(LAUGHTER)

GROSS: Thank you.

HADFIELD: So you have to practice and learn what's the right thing to do. But given that, it actually gives you a really great comfort. It's counterintuitive, you know, to visualize disaster, but by visualizing disaster, that's what keeps us alive.

GROSS: Tell us about one of the most dangerous things that went wrong during one of your spacewalks.

HADFIELD: Probably the most dangerous time was, I was working away, I was operating the great big pistol-grip tool, it looks like an enormous electric drill. I was tightening up some bolts, building a huge mechanical robot arm, the Cannon arm two, and suddenly my left eye stopped working.

And there had been some little balls of water floating around inside my helmet, in my water bag that we get drinking water out of, it's like a little CamelBak, it had been leaking slightly. But my eye just stung, you know, like a hornet had stung it or something. It just hurt, and it slammed itself shut, and I couldn't see through it.

I tried to open it, and, you know, when your eye has really been hurt, you just can't open it and look through it. And I couldn't rub it because it's inside my helmet. And I tried to touch something with my eye, but it's inside like a fishbowl. I couldn't do anything.

So I thought, well, I could still hear, I can still breathe, I can still see, and one of my eyes is working perfectly. So maybe it's just a transient thing; I'll keep on working. But what I hadn't really thought through was that my eye would start tearing, crying of course, just like the good flushing reaction, you know, that works on Earth, but tears in space, tears don't fall. They just build up a big ball of contaminated tear on your eye, and it doesn't drain the bad stuff away, it squirts in new tear.

So I get this bigger and bigger ball of whatever that stuff was on my left eye until, unfortunately, the ball got big enough that it went across the bridge of my nose into my right eye. And now suddenly, instantly, both my eyes are blind. And try as I might, I couldn't get them open. All I could see was a complete blur.

So now it was time to fess up, and, you know, Houston I have a problem. And I could just - I used to work in Mission Control. I was the chief cap-com for NASA for about 25 shuttle flights. So I worked as a cap-com in Mission Control, cap-com being the astronaut that talks to the crews in orbit. So I really understand how that room works and how the flight director or the doctors and everybody would react when I told them that I was blind on a spacewalk.

And they went into hyper-mode, and, you know, good calming voices, but coming up with lots of, you know, reactions that would try and fix my eyes or diagnose the problem. They thought maybe I had a problem where the chemical that purifies our air was maybe leaking into the suit, and some of the early symptoms are eye irritation. And - but it also really hurts your lungs.

So they said, strangely enough, their first big recommendation was we'd like you to open the purge valve on the side of your helmet and start dumping your oxygen out to space. So I'm just kind of smiling to myself, thinking this is not how I thought my first spacewalk was going to go, where I'm blinded, and now I open a hole, and I'm listening to a very limited supply of oxygen hiss out into the universe.

And I just kept blinking and crying and blinking and crying, and after a while, I thought maybe I could start to see just a little bit. It took about - I don't know, about a half-hour, I think, and then I finished the spacewalk.

And it turned out to just be the stuff we put on the visor to make it not fog up. It was sort of like a soapy, oily kind of chemical, that no-fog stuff. But a floating ball of water had picked up the no-fog stuff, and it's just as if I'd taken the no-fog and squirted it into my eyeball.

GROSS: You had to do technical work in space. What are some of the problems of working in a weightless, gravity-less atmosphere?

HADFIELD: It's really non-intuitive, having grown up and adapted and expected everything to behave like it is on Earth. You know, if you drop your hammer, it falls to the floor. If you could let go of a little tiny washer, it doesn't float up and back behind your ear. Something like a fuse, you know, just in a fuse box. You know how it works on Earth; there's a little too much electricity, we don't want to burn up the house.

So this little tiny fuse, there's a little skinny bit of metal in the middle and it gets hot and melts and then it falls away and it breaks the electrical circuit - right? Nice, simple earthbound design. Well, if you have a fuse like that in space, of course, the little fuse will get hot and melt, but it won't drop away because there's no gravity, so the current will continue to flow through the fuse until something else gets hot.

So something as simple as a fuse or a fan on a projector or all kinds of stuff where you're counting on convection and gravity, they all have to be rethought. And it catches you unawares, all the time. Trying to do up my shoe to go running on the treadmill, you know, it's so easy on Earth, you bend over, do up your shoe. But if you think about it, when you're doing up your running shoe, you are using both hands and one foot.

And so there's nothing to hold you in place anymore. You always sit down or lean on something on Earth but in space, suddenly you're this uncontrolled 180 pound mass bouncing off everything else because you're just, you got no free hands anymore and you're just trying to do up your shoes.

So something as esoteric as designing cooling systems for standard equipment or something as prosaic as just doing up your shoes, you have to rethink it all in order to not be clumsy but also to be successful when you go to a new environment like that.

GROSS: If you're just joining us, my guest is Commander Chris Hadfield. His new book is called "An Astronaut's Guide to Life on Earth." Let's take a short break, then we'll talk some more. This is FRESH AIR.

(SOUNDBITE OF MUSIC)

GROSS: If you're just joining us, my guest is Commander Chris Hadfield who is an astronaut who's flown three space missions. He was the commander of the International Space Station for a while and he's done two space walks. His new book is called "An Astronaut's Guide to Life on Earth."

Would you describe what it's like to reenter the Earth's atmosphere?

HADFIELD: It's like riding inside a blast furnace. You come into the upper atmosphere and it gets to 3,000 degrees on the outside of the ship. You can see the orange and yellow flames licking around your vehicle. You can hear the metal responding to the heat.

In the Soyuz, the little Russian capsule, you can actually hear the banging of the big shield, the big heat shield on the bottom as it slowly erodes away from the heat and pieces of it fly off like sparks across your window and it's an interesting thing to ride through, you know.

(LAUGHTER)

HADFIELD: It makes you think, riding as this little bubble inside a blast furnace. And there's nowhere to put your heat, you know, you can't get colder while you're inside that. There is no - the ship gets warmer and warmer. The shuttle came back because its purpose was to carry big cargo home. And we could put a huge telescope or payload in the back like a great big dump truck.

It had wings and it could come back so gently and be not much different - once you've made it through the hot part - not much different than an airliner, maybe slightly more force but then circle around, just a glider, didn't have engines, but come down and land either in California at Edwards, where I used to be a test pilot, or on a runway at the Kennedy Space Center in Florida right where we launched from. So that was relatively comfortable.

The Soyuz though, it's a very simple, rugged, tough little design and it's more like riding a meteorite. And if you do everything perfectly you come in with a lot of vibration and about four times your weight with 4G. So after being weightless for half a year, it's really unfair to have to get squished like that. And if it goes a little bit wrong, it reverts to a mode where you don't fly it at all, it's just ballistic.

And then you pull about eight or 9G, which is - that would be hard on anybody, let alone someone who has been thinking they're Superman flying around elegantly for so long. And then the parachute opens very violently, but then you're just coming down under a parachute but you're bracing yourself for that last second, which is impact with the world.

And, you know, the Soyuz craft weighs tons and you're lying on the floor of it on your back. But the Russians do tell you, remember, before you land stop talking so you don't bite your tongue off.

GROSS: Oh, god.

HADFIELD: That's how violent the branding is going to be. And it hits the ground - there's little retro rockets that fire and they cushion it but it still hits the ground like a car crash. And we land on the prairies of Kazakhstan and so it's always windy. So you don't just come straight down and go plunk, you hit the ground and then you tumble end over end in this little thing and finally it rolls to a stop. And it's...

GROSS: How come you don't break all your bones? Because you've lost bone mass in space, that's one of the physiological changes - one of the unfortunate ones that astronauts experience. So how do your bones survive a crash like that?

HADFIELD: They pour us a special crash seat, like a Formula One driver. And it's funny; they put you in this tub and they pour gypsum and around you and they make a perfect mold of your rear end to build this crash sheet from. So in the museum on the outskirts of Moscow, there's a beautiful rear end exhibit of every cosmonaut or astronaut who has ever flown to the Soyuz, how we all looked.

(LAUGHTER)

HADFIELD: But they build you a crash seat that supports your lower back and your neck and your head so that when you hit the ground, you won't break any, you know, your spine or your neck. And then you put your hands in a position so that they're not going to flail. And your legs actually have this like a brassiere cross strap that's latched your knees down so your legs don't splay out and rip up your tendons or break a bone.

And in truth, we do get osteoporosis because of the weightlessness but we're learning how to beat it. And the only part of my skeleton that got reduced density was just across my hip and my upper femur. And I did lose bone there, especially the sort of the spongy bone so now my bone is much more brutal and liable to break.

But what's interesting Terry, is it's reversing. As I'm sitting here talking to you, I am re-growing bone and my osteoporosis - it's a type of osteoporosis - is reversing. So there's something going on in the body that we would really dearly love to know how it's actually doing it that can reverse some of the effects of osteoporosis.

And after - about a year after I get back, so next spring, I should have the same skeleton that I launched with. And so I'm a big lab rat right now that there are studying to try and understand both the fragility of my hip cradle as it exists right now, and how the body is deciding to grow that spongy trabecular bone back.

GROSS: I want to thank you so much for the work that you've done in space, for the risks you've taken, and for the wonderful videos that you've sent that are so enlightening about - and fun - about what life in space is like.

You know, an interesting thing about talking to you and reading your book - it's like one of the extra qualifications that you brought to your work as an astronaut is your ability to be a reporter, to describe so well what it is that you've seen and then send us back reports.

(LAUGHTER)

GROSS: You know, for those of us who aren't experts.

HADFIELD: Space correspondent.

GROSS: Yes, exactly.

HADFIELD: Yeah.

GROSS: It's a wonderful thing. So thank you for all that. I wish you all the best and thanks for doing this interview.

HADFIELD: Thanks very much, Terry. It's been tremendous fun, the whole thing. It's a wonderful adventure and I count myself so lucky to have been a part of it.

GROSS: Commander Chris Hadfield is the author of the new book "An Astronaut's Guide to Life on Earth." We'll close with the recording he made singing David Bowie's "Space Oddity" while floating around weightless in the International Space Station. You can watch the video on our website, where you can also read an excerpt of his book. That's at freshair.npr.org.

(SOUNDBITE OF SONG, "SPACE ODDITY")

HADFIELD: (Singing) Ground control to Major Tom. Ground control to Major Tom. Lock your Soyuz hatch and put your helmet on. Ten. Ground control to Major Tom. Nine. Eight. Seven. Six. Commencing countdown, engines on. Three. Two. Detach from station and may God's love be with you... Transcript provided by NPR, Copyright NPR.