Mary Roach is such a good interviewer that interviewing Mary Roach feels like an impossible task—like out-complaining Andy Rooney or trying to match Shane MacGowan in a drinking contest. In her newest book, Packing for Mars, you can see almost all of that interviewing skill on the page: She convinces the most straight-faced NASA engineers to loosen up and joke around about space toilets. Turns out, Roach is just as charming an interviewee as she is an interviewer: She's funny and relaxed and forthcoming about her process. Two minutes in, she had already relaxed her questioner into forgetting that he's taking on Muhammad Ali with a feather duster.

Were you into space travel as a child?

You know, I was born in 1959, so I was 10 for the moon landing. So you would think I would remember that. I was probably watching Gilligan's Island or something. [Laughs] I can't remember! Isn't that weird? I was 10 years old, it was a huge thing, and yet, I have no memory. I mean, I remember when John Lennon was shot. I'm at the age where I should remember and yet I don't. I do remember stumbling around the Smithsonian Air and Space Museum and seeing the lunar [landing] module and going, "Whoa." I mean obviously it was a mock-up, but still, I kind of got choked up. I was probably a little stressed out and tired that day or something, but I remember really getting choked up. I am a bit of a space geek, but I don't watch Star Trek. I didn't grow up as a space buff.

You make a couple of references to fears about President Obama cutting NASA's budget in this book. Now that we know a little more about his plans for NASA, what do you think?

I share—well, I don't really share—the frustration, but NASA is in this limbo period that is first of all a tremendous waste of money. People are just in sort of a holding pattern, not knowing where we're going next and when. Let's figure it out. You know, to me, the decision to scrap the moon base—I mean the amount of time and money that went into it so far—it kills me, because I'm a cheap person. [Laughs] I do understand that among the population there's a sense of "Hey, the moon. Been there, done that." Though if you understand what they're doing up there, you know that there's a lot more to be done. I think if you want to get people behind the space program, you know, aim for Mars, or even the nearest asteroid—something new and different and exciting. It's important that the public be behind the space program, because it's their tax dollars.

Do you think you'll see a human land on Mars in your lifetime?

They're talking like 2040 now? So 30 to 40 years? Yeah, sadly, probably not. But I can't abandon the hope that they might rally onto the idea of getting people behind it. I think it should be an international, global effort, not like Apollo, which is very much like, "We want to get there first." If it really were a global effort, I think it could be really inspirational. This is sounding like that whole "We Are the World" crap, but...

No, I think that's a really good idea, actually.

I mean, the Apollo landing—other than me, everybody was watching. It really was a global event. How often do you get people together on the same page? Not that everyone supported the moon landing, but it could be a pretty cool thing. That I will miss.

Did you do any looking into private efforts? For instance, Google was talking about a trip to Mars the other day.

Private efforts, yeah, that's a possibility, but right now where we're at with private space travel... I mean they've gotten up to speed really fast, but we're still talking about suborbital and the first orbital flights, which takes us back to 1961. There's a long way to go. They're obviously more streamlined and less bloated, and there are a lot of reasons to be optimistic about private space travel, but there are a lot of kinks to work out.

You made a reference to how difficult it was to deal with NASA. But it seems like you had some pretty great access, in your research. How much effort went into that?

You have no idea! Persistence is nine-tenths of this game. It's just making an endless pest of yourself. When someone says no, it's saying to them: "Well, why? What's your concern? Let's see if we can address your concerns. I'll let you check your quotes, I'll let you read that passage, we can talk about making things anonymous." It's just figuring out why they're saying no. With NASA, it's tough, because it's almost like: "We're saying no just because we're NASA. You make us uncomfortable." Which was frustrating. Because normally I can work around that. Usually when people say no, it's a fear of the unknown, like, "What are you going to do? I don't want to be taken by surprise." So if you can remove the elements of surprise, usually people relax. But dealing with a large government agency was a novel experience for me.

You've got a nice rhythm of books coming out; it seems like almost one a year.

No, no, more like one every three years! It takes a year from the time you turn it in to when it comes out, and two years to research and write them. My books are 2003, 2005, 2008, 2010. It seems like a long time to me, but people often get the sense they're coming out every few months. Believe me, they're not!

Well, still, it seems like you have a rhythm going, anyway. Do you just do one book at a time?

Oh, yeah. And when I'm working on a book, I'm not doing much else. I'll do some book reviews and some short pieces, but I'm not really doing a lot of magazine feature work. So, you know, when you have full time to devote to a book, you can really do them fairly quickly. I feel that I'm very slow, actually, as there are people who actually do put out a book a year or every other year, I don't have any idea how they do that. I guess sometimes they're not reported books, which makes a difference.

Was it your plan to do something about human space travel or were you thinking about doing a broader story about the space race?

Initially, I remember thinking, "Is there a Mars race? That would be interesting." But there isn't a Mars race. So for two days I was like, "Whoa. A Mars race! That'd be cool, I'll go to the Chinese space agency." I thought you could just call up the Chinese space agency and say, "Hey, can I come hang around?" [Laughs] You can't even get in the front door. Well, I guess you could get in the front door and get some canned interview, but it wouldn't be very interesting. What intrigued me was just how frickin' surreal it is to live without gravity and how it affects—I mean, name a body part—it affects everything. You have to relearn, retrigger, retool—everything that you're going to do, you have to do it differently than you would on Earth. It was a fascinating, weird subculture.

I'm reading this horrible book right now that deals a lot with bodily functions, and reading it right after your book where you write about bodily functions in a way that is not... it doesn't feel like a bad...

Like a walk through the sewer? [Laughs]

Yeah, or like a bad teenage comedy or something like that.

What book?

Stretch, Neal Pollack's new book about yoga—there's a lot of gas and vomiting. The two books together are like night and day to me. You've obviously had some experience writing about sex, writing about dead bodies—does it come naturally to you to discuss these things in such a way that it's not completely off-putting?

It's an entertaining challenge, I think. I'm not interested in it just for its own sake—you know, shit and vomit—although some people would find that hard to believe. [Laughs] I'm not seeking out opportunities to write about that stuff just for the sake of it. For me, what was fascinating was that these are engineers with advanced degrees, and it is a really complicated engineering challenge to figure out how to create a zero-gravity toilet that is humane and that works. And the challenge of, what happens when you vomit in space? And just the thought and the expertise and the technology that has gone into this very sort of tee-hee grade-school issue I found fascinating. And the way that they talked about it, the euphemisms they come up with, that side of it is what really appealed to me. So I guess I'm coming at it from a different point of view than Mr. Pollack. [Laughs] I love to call him "Mr. Pollack."

Do you ever see yourself not writing a book about people and what people do? Do you think you could write about animals, or...?

You know, I gave some thought to writing about chimpanzees, because I did a National Geographic story in Senegal with a researcher who spends all her time with chimps and they're endlessly fascinating and interesting and entertaining. But the problem is that they're great as a documentary subject, they're very visual, but all you have to work with are your descriptions because they don't talk, you don't know what they're thinking, you can't interview them. So I think I didn't know how I would make that work. To just be constantly describing what the chimp was doing, and not being able to make people see how wonderfully antic and entertaining it was. Because you kinda had to be there. So animals would be a challenge. But I have given thought to that, and I wouldn't rule it out, because you are dealing, too, with the people who deal with animals. That would be fairly high on the list of things I'd consider, yeah. But a military history? Probably not. [Laughs]

Do you know what your next book is going to be about? Do you work that far ahead?

I do know what the next one's about, but I'm not comfortable to go on record with it because it's still larval.

Okay. But is that usually the case? When you're done with one, do you usually have an idea for the next one?

Ideally, yeah, because otherwise I'm very stressed out. If I don't know what I'm working on next, I have this sort of doom-and-gloom feeling that I'll never know and it's all over and I'm going to have to learn vinyl repair at home or something. [Laughs]

Obviously, you write magazine pieces and things like that, but you seem pretty comfortable with the length of a book. Have any of your smaller pieces expanded to the length of a book?

No, I've never had that experience—sometimes I think it [could go longer], like the chimp story for National Geographic. I even talked to my agent very briefly about it, I think, and that's the only time I can remember doing that. Usually, I'll get really into the magazine story and think, "Oh, this should be a book!" But by the time I finish the magazine story, I'll be like, "You know, I think I'm kind of done with this. I'm ready to move on." I have a short attention span.

You know a book-length story when you see it, then.

Well, yeah, but they tend to not be stories for me. They're sort of very broad topic areas. It's very easy for me to run a scan on a topic and go, "Oh, no, there's no science here," or it's too abstract and I won't be able to see and describe things. Because some people write me and say, "You should do a book on the Antichrist!" or "You should do a book on drugs!" And I go, "Well, what would the scenes be for that book? Drugs are an internal state. So I will take a lot of drugs and describe it? Or, that that's too purely historical, I like to do some history but I'm not a historian, so I wouldn't do that." So it's easy for me to know what's not a book, and it's more a process of elimination. I'll go, "Okay, the only two left standing are this and this, and that's what I'm going to do next." So it's more like I recognize what isn't a book.

Most agents I've talked to seem to think that one of the most important things a writer can know how to do is be able to figure out what is a book and what's not a book.

Yeah. It's true. Sometimes I think initially my editor is perplexed, but she trusts that I must know what I'm doing. "Okay, Mary wants to write something about space?" But in fact, this book, since Stiff, has been her favorite book, and I didn't really see that coming. She's a poet. I didn't expect that. So there is a certain amount of trust involved. "You're the author, I guess you know. I guess we'll take that leap with you."

So you've worked with the same editor for all your books?

Yeah.

That's rare. Is that in your contract? Is that something you're always going to do?

No, it's not in the contract. [Roach's publisher] W.W. Norton is independent and they tend to have a lower turnover. The employees become vested, they have shares in the company, there are reasons for them to stick around more than at some other publishing houses. But we enjoy working together, and she's good for me. She'll go through and cross out things that don't work. And initially I'll go, "Hey! That's my favorite line!" And the next day I'll be like, "Oh. Yeah, that was kind of dumb." We work well together. I feel like she is the perfect balance—she's not too heavy-handed, and yet she's definitely going to come in and say, "Don't lead with this chapter. Lead with another one. This chapter's too long, we need to cut it in half. We need to put breaks here." She's just got a really good sense of what the reader would be experiencing when they read it.

That sounds like the description of a good editor. So do you do a lot of drafts? Do you do one big one, or...?

With computers, you're kind of doing ten thousand micro-drafts. I'm changing stuff constantly as I go along, so I don't really go through and have a first draft that I then show to my editor. I show it to her when I'm done. When I think I'm done. I know there will be changes she'll want. So there is a first draft, and that's the one I give to her. I don't actually print it out until—well, this time I didn't print it out until I was going to fact-check it. But, you know, I don't hand out drafts. It feels like it's such a mess, and only I have the power to make it not a mess, because I've got all this stuff in my head. So the answer is no, I never do a first draft other than the one that goes to my editor. But I'm going through every day I work on a chapter, rearranging things, changing sentences here and there, until it goes to my editor. At a certain point, I think it develops this Teflon layer where you've looked at it so much, you just gloss over it, you can't dive back into that paragraph, it's done. You just slip off it. It's like, "Eh, I'm done with that paragraph, I'm never going to read it again."

Until you do the book tour.

Yeah. [Laughs]

You have a very conversational style that I think helps with explaining complex scientific ideas. Do you read your work aloud? Because it seems with a lot of authors, I get the sense that they talk it out. And with others, I get the sense that they don't or that it's impossible for them to.

I think it's a really good idea to read your work aloud, and I wish that I did. [Laughs] But you know what? I get to the book tour, and I start reading aloud, and I think, "Oh! This should've been taken out." I think with my books, if I did what I should do, and I did read them aloud, they'd probably be 50 pages shorter. I don't know why I don't do that; it's just another step I don't get around to. But it's really smart to do that, and I should. But I don't. It seems like too much at a certain point.

Do you think your conversational style comes from the interviews, then?

No, I think it comes from me—first of all, not having a science background and having to talk conversationally because I don't know how to talk like a PhD. I have to talk like I'm talking to someone at a cocktail party, because I don't have any other way of expressing complicated things. It doesn't make sense to me in any other way. Also, because I didn't ever really see myself as a writer, I think of writing as just talking on paper, really. And I think a lot of people don't see it that way, they think writing is some difficult thing. They get all tangled up. But I think if they just realized that good writing is like talking, it'd be easier.

Do you have any idea how many hours of interviews you did for this book?

Oh, a lot! I transcribed most of the interviews, and there are a LOT of pages. Fifty hours of interviews? It could've been a lot more. Space books tend to be memoirs or depictions of a certain mission, so they're going through hour-by-hour and talking to all the parties involved. So I think as space books go, not that much. But for every chapter, I had to get up to speed on some piece of science that I didn't know anything about, so I tended to do fairly long interviews and make people explain things to me.

Do you try to do the reading as you go in the interviews? I really liked one of the footnotes you did about the astronaut space memoir—about how it's the one you should read if you only read one astronaut space memoir.

Mike Mullane's book? That one?

Yeah. Do you start out with the books or do you supplement the interviews with books?

In the beginning, I'm doing a ton of reading. There's always a pile of books by my bedside that I'm going through—not necessarily reading cover-to-cover. But when I'm in the getting-up-to-speed phase, I do a lot more reading. That's when I read Mike's book, which really is a wonderful read. And then the reading tapers off and there's more writing. So it's really reading-heavy at the beginning and writing-heavy at the end. Although there are some phases where I'm doing both, of course. Because I come to these topics like a total idiot—I really don't know anything. For [Mars], I had to get up to speed with space history, with biomedical stuff, not just the U.S. space program but also the Russian space program. Not that I had to become an expert, but I was trying to not sound like an idiot. You don't want to sound like an idiot, especially with space history, because there are a lot of people, historians, who will really call you to task on errors. The corrections always hurt a little bit. There's always going to be something you got wrong. So I have my work cut out for me in the beginning.