Science Fiction & Fantasy




Interview: Mary Roach

Mary RoachMary Roach is the author of the nonfiction bestsellers Stiff: The Curious Lives of Human Cadavers, Spook: Science Tackles the Afterlife, and Bonk: The Curious Coupling of Science and Sex. Her latest book is Packing for Mars: The Curious Science of Life in the Void. She has also written articles for, Outside, National Geographic, New Scientist, Wired, and The New York Times Magazine, and she reviews books for The New York Times. Her 1995 article called “How to Win at Germ Warfare” was a National Magazine Award finalist. You can learn more about her at and follow her on Twitter @mary_roach.

This interview first appeared in io9’s The Geek’s Guide to the Galaxy podcast. Visit to listen to the entire interview and the rest of the show, in which the hosts discuss various geeky topics.


Your new book is called Packing for Mars. Why don’t you start us off by telling us a little bit about that.

Packing for Mars is about all the surreal physical and physiological challenges of trying to live in space as a human being, and human beings are just not in the slightest bit equipped to do that, so it’s kind of an entertaining challenge. And it’s also about all these bizarre simulations that happen on Earth—weird behind-the-scenes NASA shenanigans, and I took part in some of those. You can almost go to space without leaving Earth, in a way. So that’s what the book is about.

All your previous books have one word titles: Stiff, Spook, and Bonk. Why’d you decide to break that trend?

Well, we didn’t decide to break the trend, we just failed to follow the trend. We couldn’t come up with anything! Because I wanted something that suggested the human side of space. I didn’t want something rockety, you know, I didn’t want Orbit, Zoom, or Space. We really spent an embarrassing amount of time trying to come up with something.

Did you ever consider the title Pooping in Space? Because listening to interviews with you, the subject of pooping in space seems to come up an awful lot.

And that is not my fault! I do not bring it up.

Speaking of which, I think most people think of spaceships as being really clean and sterile, but you make them sound pretty filthy.

I spent a fair amount of time reading the Gemini 7 transcript. This was the very first time anybody had been in space for two weeks, and we were leading up to the moon mission—back in the sixties—and this was a mission where one of the things they were looking at is: Just how revolting and gross and unhygienic does it get to be in this little capsule and sleeping in your spacesuit without a shower, crapping in a bag—is it beyond the tolerance of a human being? And so I interviewed Jim Lovell, the Apollo 13 guy. But I wasn’t interested in Apollo 13. I was interested in Gemini 7. And I asked him about some of the yuck stuff, like dandruff. When you don’t shower, all the cells that you exfoliate don’t get washed down the drain. In zero gravity, the dandruff doesn’t fall to the floor or to your shoulder, it just sort of floats, so I asked him if it was sort of like a snow globe in there. I saw someone interview him and he said it was like living in a latrine. He said they had some problems with the urine containment—they had a comment in the mission transcript somewhere that they were doing a urine dump and he said, “Not very much though, most of it ended up in my underwear.”

Actually, speaking of urine, there’s a part in the book where you’re talking about a comment one of the astronauts makes about how amazing the view is, and it’s unclear whether or not he’s talking about the Earth or the crystallized urine.

Yeah, I read that description in at least two memoirs. When they eject the liquid urine it sublimates, and if the sun is hitting it it’s this beautiful—I mean, I haven’t seen it myself, but it sounded almost like fireworks or this sparkly beautiful thing, and they would remark on how beautiful this was.

What sort of physical attributes do space agencies look for when selecting astronauts?

Some of the physical attributes are kind of entertaining. In Japan I was talking to the flight surgeon about things that would disqualify you, and he said if you snore a lot that would disqualify you, because it’ll wake everybody up. I also remember reading that the Chinese space agency would disqualify someone with very bad breath. Not because it suggests that you have some problem with tooth decay or gum disease, but because it would be unpleasant for the other astronauts.

And there’s this whole thing where they looked at digestion, right?

There was, yeah. I found this study from the 1964 Conference on Nutrition in Space and Related Waste Problems, and one of these guys suggested that one of the things NASA should consider is what type of intestinal bacteria the person had. Not because of the smell, mind you, but because if you produce methane … well, methane is explosive, and hydrogen is as well. I mean, most everybody produces some hydrogen. But one of the things they should look at is how much of your flatus is explosive, since some people have more explosive flatus than others.

Oh, here’s another great one from that same conference. I think people must have been high at this conference. But there was this one guy who said that rather than launching all this food you could launch obese astronauts—that for fifty pounds of weight, that would be one hundred and eighty-four thousand calories you wouldn’t need to carry the food for. So you could just launch them and give them vitamins and let them live off their fat.

Speaking of odd characteristics that you might want for a spaceship crew, what do you think would be some of the advantages of sending a crew of aging, deaf-mute eunuchs into space?

Aging, yes, certainly for a trip to Mars, because you’re going to get a heavy dose of dangerous cosmic radiation, and by the time you get the cancer—if you’re sixty when you left, maybe get the cancer when you’re seventy-five or eighty, and you’re heading toward the end of your life anyway, so that would be a good choice. And eunuchs absolutely. Eunuchs are the way to go—avoid all the soap opera, all the falling in love and the anger and the possible murder and jealousy, definitely. Self-castration is a good position for a Mars mission. And deaf-mute—you mean just so you don’t have to listen to the tedious babblings of your other crew members?

Didn’t you say that would make you immune from space sickness?

Oh yeah, that’s right. The inner ear is what determines whether or not you’re going to get motion sickness. Yeah, deaf-mutes frequently don’t get motion sick. I don’t know exactly what the mechanism is, but they’re frequently immune.

What sort of effects does weightlessness have on the human body, and how long can people last under those conditions?

Weightlessness does a number on the human body. You name an organ, something happens. If you’re just floating instead of walking as a way to get around, your body starts to dismantle your skeleton and your muscles, figuring, “Well, I guess we don’t need these anymore. Let’s streamline things and use this material and our energy more efficiently.” So you lose bone—you become like an old woman. On a Mars mission, you’re looking at a one-third to one-half drop in bone density, which is pretty scary. When you come back down to Earth gravity, you’d start to regain that, but not necessarily in quite the same way. Some places would remain compromised. In zero gravity, you have less blood, because all the blood floats to the upper half of your body. Not all of it, but you have a lot less in the legs. The sensors in your body that figure out how much blood you have think you have too much because it’s all migrating up. You lose weight, you’re immuno-compromised a bit because you’ve got less blood. Your bladder doesn’t work the way it’s supposed to or the way it’s designed to in Earth gravity, because it’s an organ that works via stretch receptors. When the urine starts to accumulate on the floor of the bladder, when you’re standing up, eventually that pushes the sides out—your stretch receptors are activated, telling your brain it’s time to go pee. Well, that doesn’t happen in zero gravity, because now the urine is floating all around the organ, sort of clinging by surface tension to the whole thing, so by the time the stretch receptors are activated you might have so much urine in the organ that the urethra’s pressed shut. So then you could have a minor medical emergency involving an embarrassing call to the flight surgeon and getting out the catheter kit.

But there’s also the space beauty phenomenon, right?

The space beauty treatment, yes. That has to do with having more fluid in the upper half of the body, so your wrinkles are plumped out. Also, your organs migrate up under your rib cage, so your waist is smaller, your boobs are more pert, and your hair is fuller. But the other thing to bear in mind is that the alternate name for all of this is the “puffy-face chicken-leg syndrome,” so it’s debatable as to how attractive it actually makes you look.

How long could you last in zero gravity?

Well, that depends on if you were ever planning to come back to Earth gravity. If you were going to continue on in zero gravity—if you weren’t going to need your muscles or your bones ever again—you’d be fine. You’re adapting to that situation. The danger comes when you return to Earth. Say you were in a situation where the capsule’s splash down didn’t go right, and you needed to get out quickly because something was on fire, and you’re trying to jump down out of the capsule and run away, and you’ve lost a third of your bone mass—that could be dangerous. And if you’ve been up there for six months or more, then you have to completely readjust your vestibular system. So you’re dizzy, and it seems like everything’s spinning around because the little bones in your inner ear have adapted to weightlessness. So now you come back down and you’re sick and disoriented all over again. It’s called Earth-sickness. And your legs and arms haven’t weighed anything for so long that you literally forget how to use them. That’s what I was told by one of the ISS space station astronauts.

Since you wrote Packing for Mars and you also wrote a book called Bonk, which is about sex, I feel like I should ask you about sex in space. What was it like doing research for that aspect of the book?

Oh, it was very, very entertaining. I spent time in Moscow, in Star City, where the cosmonauts train, and cosmonauts tend to be pretty straightforward. They’re funny, you can ask them anything. So I asked this one guy, Alexander Laveykin, I said, “So, you guys were up on Mir, two guys, for six months. You were a healthy young man then, what do you do about libido? What do you do about sexual urges? Was that a problem?” And he said, “Mary, people ask me this all the time. They say ‘How are you making sex in space?’ And I say, ‘Of course, by hand.’” You know, he’s just very—of course, we jerk off. He also said that the Institute of Biomedical Problems, which is the physiological research institute for the space agency in Russia, thought about sending up inflatable sex toys, and the reason they didn’t is because mission control said, “No, we’re not going to work that into your schedule. We’re just not going to do that.”

In the book you talk about how astronauts might want to eat their clothes and then fly home in a ship covered in feces. That sounds like quite a party.

I don’t think “want” would be the right term there. But yeah, someone proposed that you could make clothing out of edible fibers, and that when the astronauts were done wearing the clothes—presumably when they were dirty enough—that then they could actually eat them, which just sounded ghastly. Someone else suggested that components of the spacecraft that you don’t need on the return could be made of some kind of edible, I don’t know, hydrolyzed protein, that you would then just sort of dig into on the way home.

The business with feces—this was a radiation protection idea, because hydrocarbons are apparently very good at absorbing radiation. You can’t line the thing with lead, it would make it too heavy, so you’d use water, food, and feces. That would add a protective layer. So presumably you’d have some sort of device that would plastinate it, so you wouldn’t be smearing shit all over the interior of the spacecraft. At NASA Ames there’s a machine that makes these tiles, and you would just tile the capsule.

Let’s say you’re a science fiction writer and you wanted to write a scene in which an astronaut aboard a space station goes berserk and whips out a knife and tries to murder his fellow astronauts. What sort of facts about zero gravity should you keep in mind when writing that scene?

If you stab somebody in zero gravity, you’re going to kill them pretty much the way you’re going to kill them on Earth. If you cut an artery, you cut an artery—the heart’s still going to be pumping. It’s going to be pumping the blood out just as it would in Earth gravity.

Would you have any trouble with, say, your body going backward as fast as your arm was going forward? Or would you have trouble penetrating because you’d have no leverage? Stuff like that?

Yeah, that’s the other thing I was thinking, because when you’re out on a spacewalk and you’re trying to tighten a bolt, if you aren’t in a foot restraint and you try to turn a nut you’ll turn instead of the nut. So you have to have something to push against. So if you stab somebody, it isn’t going to be the same sensation because you’re not anchored to the ground in the same way. So yeah, you might want to practice first on a melon or something.

And if you were to make your first cut, would the blood just start coming out and obscuring your view?

Well, if you cut an artery, the blood isn’t going to drop, it’s not going to do the same thing as on Earth. It would start forming a sphere—a blobby-looking thing. Showers don’t work in zero gravity—the water just comes out and starts making a growing blob.

How about if instead of a knife it was a machine gun?

Well, now you risk losing pressurization of your spacecraft. Hopefully it’s made of Kevlar or something quite durable, but I wouldn’t want to try using any sort of armor-penetrating bullets, because you’re going to penetrate the spacecraft and then you’ve lost pressurization and everybody dies. And the kickback. That would be quite an interesting ride for the person holding the gun, because it would fire you backward.

But that reminds me—there’s a myth that if you fart in zero gravity, it works like rocket propellant and would “propel you across the mid-deck.” That was the rumor, and one astronaut I interviewed said he didn’t buy it, because he said that human lungs hold more air than the average fart, and when you exhale it doesn’t blow you back, and so he didn’t believe it. And he—he must have eaten a bunch of beans—he said he had “a real voluminous and rapidly expelled purge”—those were his words—and he said, “I failed to move noticeably.” There’s a debate among people I’ve talked to, but he said, no, he tried it. He was wearing pants, though, because it was a mixed-gender mission …

Hopefully he would wear pants anyway.

Yeah, but he thought that wearing the pants might have interfered with the cleanness of the expulsion and compromised his thrust. So …

Not a valid experiment.

Yeah. He promised he’d ask other people, but I never heard back.

Do you know of any fistfights breaking out on space missions?

What I was told when I was in Star City is that fistfights—they have this term, a “friendly fistfight.” Fistfights are kind of how you settle things, and it isn’t a huge deal the way it would be here in the United States. And so I’ve heard that there have been fistfights on Mir, but I don’t have the details. Somebody at NASA Ames told me that that’s sometimes how they’ve solved disputes.

What would they do on the International Space Station if one person died, and the rest of the crew was still there?

If they were in orbit they could send up an orbiter like the shuttle and they could remove the body and bring it down, and the family could do whatever they’re going to do in terms of a memorial service. It becomes a little trickier if, say, you’re on a Mars mission. It’s an eight month trip, what are you going to do? I did a guest post on Boing Boing about this. There’s a device, and it’s just—there hasn’t been a prototype built, but there was a paper that was done jointly with NASA and these folks I met when I was doing Stiff, who do the freeze-drying and composting method in Sweden. And they came up with something where basically you’d put the body in the airlock and freeze it solid, and then it would vibrate it into small pieces, and you’d put the powder in this little pod and basically pull it behind the spacecraft until you’re reentering Earth’s atmosphere. And then to keep it from cremating you’d bring it back on board, and then when you land you’d present it to the family. It would be small, something that could be carried by two people. It was called Body Back, that’s the name of the system.

What are some of your favorite science fiction books and movies?

Oh, I loved THX 1138. I want to see that again. I just recently saw Moon with Sam Rockwell, which I liked a lot. I’m a fan of Ray Bradbury, although not so much the space stuff. I like some of his stories, like that weird one where the guy gets his skeleton pulled out through his mouth by this woman who has—you know, her hair falling over her face in this sort of sexy way for the whole story, and then it turns out it’s hiding this hideous mouthpiece that comes out. And “The Veldt,” I love that story. Red Mars, by Kim Stanley Robinson. That was pretty impressive in terms of its accuracy. It seemed like a really accurate scenario for the psychological as well as the technological stuff. And 2001 obviously I love.

When you’re talking to NASA employees and astronauts, did any of them ever talk about science fiction?

I do remember seeing a list of all the books that are on the International Space Station, and there’s a ton of science fiction. There were a lot of science fiction books up there that people read, so clearly it’s popular stuff for astronauts.

Were there any big misconceptions you had from watching movies about astronauts, so that when you were doing research for this book anything came as a big surprise to you?

I had no idea until I started this book that when you’re heading to the moon or to Mars, you’re essentially coasting. I thought it was like a car where you’d have your foot on the gas the entire time, and I used to think, “Jesus, that’s a lot of gas. How do they do that?” I didn’t realize that the initial blast propels you, and you get escape velocity, and then you’re just coasting because there’s no air resistance, nothing to slow you down, so you just keep on coasting all the way. That was just amazing to me, and for some reason—maybe cartoons that show exhaust coming out of rockets—I had this misconception about how rockets worked.

I mean, that’s really basic stuff. Just shows you how completely ignorant I am at the start of every book.

So are there any other recent or upcoming projects you’re working on that you’d like to mention?

Oh, I am working on a new book, but I’m keeping it under my hat for now.

Enjoyed this article? Consider supporting us via one of the following methods:

The Geek’s Guide to the Galaxy

The Geek's Guide to the Galaxy

The Geek’s Guide to the Galaxy is a science fiction/fantasy talk show podcast. It is produced by John Joseph Adams and hosted by: David Barr Kirtley, who is the author of thirty short stories, which have appeared in magazines such as Realms of Fantasy, Weird Tales, and Lightspeed, in books such as Armored, The Living Dead, Other Worlds Than These, and Fantasy: The Best of the Year, and on podcasts such as Escape Pod and Pseudopod. He lives in New York.