The director, along with stars Matthew McConaughey, Anne Hathaway and Jessica Chastain, open up about the leaking space suit that almost led to hypothermia ("At some point, I wasn't sure if I could feel my toes," says Hathaway), their thoughts on space travel (McConaughey: "I'm up for the risk") and their doomsday prophecies

Two years ago, Christopher Nolan sat down with an unlikely collaborator on a new project. The collaborator was Kip Thorne, one of the most renowned theoretical physicists of the modern era — and also, improbably, the executive producer of the film Nolan badly wanted to direct.

The script, initially written by Nolan's younger brother Jonathan (known as Jonah), was Interstellar. And over the following months and years, the two men — one, a daring director whose last seven movies, including Inception and The Dark Knight trilogy, grossed a collective $3.55 billion worldwide; the other, a pioneering scientist who specialized in such arcana as black holes, singularities and event horizons — would embark on an intellectual exploration as Nolan, 44, repeatedly met with Thorne, 74, to kick around ideas about time, space and the time-space continuum. In the process, they explored everything from questions about wormholes to whether it might be possible to go faster than the speed of light.

The result of all this work is an audacious, two-hour-and-47-minute drama that cost $165 million to make (Paramount, Warner Bros. and Legendary Pictures split the budget; Paramount will release the film in the U.S., Warners will handle international) and is expected to contend in the best picture Oscar race. Interstellar opens Nov. 5 and follows more in the vein of mind-bending science fiction classics such as 1968's 2001: A Space Odyssey than 1977's Star Wars — both Nolan favorites.

Reworking Jonah's script (originally written for Steven Spielberg to direct), Nolan refined the story of four astronauts who embark on a mission that takes them through a wormhole and into another galaxy, where they must search for a habitable planet before ecological problems doom Earth. For much of the shoot, which was shrouded in secrecy, the story was referred to by the code name "Flora's Letter" (a reference to one of Nolan and producer Emma Thomas' four children), perhaps indicative of the shift in emotional temperature that this sometimes-cool filmmaker wished to take here.

The film stars Matthew McConaughey and Anne Hathaway as two of the astronauts and also features Jessica Chastain, Casey Affleck and Michael Caine in supporting roles (Caine in what appears to be a bearded incarnation of Thorne). Putting all this on film took the cast and crew from cornfields in Calgary, Alberta, to a glacier that had been strafed by a volcano in Iceland for a four-month shoot that largely used physical sets rather than CGI — including a spaceship manned by a monolith-like robot named TARS, played by comic Bill Irwin, who also served as an effective puppeteer, using a specially constructed rig to move the robot.

Among the practical challenges were transporting the 10,000-pound spaceships to Iceland; planting acres of corn through which the actors would drive at dizzying speeds; figuring out how to make them weightless in space (Nolan used a rig named "the parallelogram"); and deploying a biodegradable product known as C90 to create a huge dust field, much to the chagrin of the cast that constantly struggled to escape its particles. For inspiration, Nolan drew on everything from a Ken Burns documentary, The Dust Bowl; to the architecture of Ludwig Mies van der Rohe; to astronaut Marsha Ivins, who visited the set; to the 1983 film The Right Stuff; to the music of his regular composer Hans Zimmer, whom he asked to draft part of the score before a single frame was shot — and before Zimmer even knew the title of the movie in question.

Chris, Interstellar began with your brother and Spielberg. What happened?

Christopher Nolan: Well, pretty much everything my brother and I do, we tend to bounce off each other. So I'd been hearing about Interstellar for years while he was working with Kip Thorne. I always thought it sounded like a very exciting project — certainly it's a good sign if your brother's working on something [with Spielberg]. When I saw the opportunity to get involved, I didn't hesitate. I always loved science fiction. One of my earliest movie memories is my dad taking me to see 2001 in [London's] Leicester Square on the big screen. It was such an extraordinary feeling: to be taken off this planet and to the furthest reaches of the universe. It has really been an ambition of mine: If I ever had the opportunity to get involved in a large-scale science fiction project, something about exploring our universe, I would try to seize the opportunity.

Do you feel intimidated when you think of films like 2001?

Nolan: Massively.

How do you get over that?

Nolan: You don't. You just do your best. You're intimidated, but you're also inspired. Kubrick's film made such an impression on me as a kid; it was rereleased in the wake of the success of Star Wars, so I was probably 8 years old or something like that. I certainly couldn't have understood it, but I'm not sure I understand it now.

Does a film need to be understood?

Nolan: I don't think it does. And I think that 2001 is one of those rare instances where it's a purely cinematic narrative and it really tells you that it doesn't need to be understood — it needs to be felt. But it also becomes one of the great inspirations and one of the great touchstones that you can talk to anyone about.

Did Chris bring those films to you as actors before you began shooting?

Matthew McConaughey: He didn't say, "Here's some homework." But one of the things I noticed very early on was that he's always on to something original. I remember the dust storm. What dust storm do you have that's actually in a downpour? We were shooting the dust storm and saying it was raining! I was like, "[That's hardly] ideal for a dust storm." He goes, "No, but I don't think it's been done before. It's original."

The other intimidating thing about this is the science. Humans can travel through a wormhole to another galaxy. True or false?

Nolan: If a wormhole could be brought into existence, it would be possible. It's really one of the only ways it would be possible because the distances involved are so vast. It's one of the tremendous, limiting factors about whether we could ever find other inhabitable planets; the nearest star within our galaxy [involves] thousands of years of travel. And so there are different ways of looking at how you address that. And the film explores various different ways. But Kip's research into the mathematical possibility of wormholes, the fact they can exist, gives you a way that this could happen and was essential to the jumping-off point in the story. When I came to the project, [Kip] and Jonah had worked on a vast array of ideas involving a lot of the different things you're talking about. And one of the most important parts of my job was to say: "OK, we can't use all of this. I'm going to have to choose."

They loved you, of course.

Nolan: Exactly. It was, choose a couple of things that I think as a director I can get across to the audience and hopefully not lose them. And one of the things that I found really inspiring about working with [Kip] is that, when I would ask him a question, he would never answer in the moment. He might give me his initial thought of, "OK, I don't think that's possible, but let me go away." He would always go away and spend a couple of days doing his own calculations and talking to other scientists and researching all the different papers that had been published on the subject, and then he would come back with an answer. He would never get frustrated [with] my endless questions.

What did you ask him?

Nolan: Well, we would get into long debates about, [can] you go faster than the speed of light, and those kind of questions are a little frustrating to a physicist. We'd meet pretty regularly while I was writing. [But] certainly when Matthew came on board, the more focus it seemed to give on who these people are as human beings.

Did you all get involved with the science? Did you all meet Thorne? What did you ask him?

Anne Hathaway: I tried to understand the science in the movie, but I don't remember anything about what I talked to Kip about except at the end, when we talked about playing the trumpet. Because he played the trumpet and I used to play the trumpet.

Jessica Chastain: I remember on set I was writing this very complex equation, and of course I needed to know, I needed it to look like I knew what I was talking about. I was trying to memorize this "XYZ3" insane [equation] — and he said, "In actuality, this could be three blackboards long." (Laughs.)

McConaughey: Any conversation with Kip, you don't come away with any more acute of a finite answer. You come away with more questions. Every answer opens up another question. So it sort of exponentially gets longer and longer. We talked about the bending of timelines — theoretically, how you would go faster than the speed of light.

Did this change your feelings about anything, philosophically or religiously?

McConaughey: It opened my view a little bit. My views of what's out there expanded for me after doing this film called Contact [1997]. Carl Sagan: to hear him speak for four hours. I've always been someone who didn't go to see sci-fi films; I didn't read sci-fi books as a child. And my thoughts were always [about] what's tangible, what we have right here, maybe what's beneath the sea, but I was never looking out there. That always was sort of an unknown. "Oh, don't worry about that; it's not attainable."

Hathaway: I think [this] affirmed certain things about the interconnectivity of things. About trusting others and the meaning behind things, even if it doesn't make sense, even if it hurts. Over the long, infinite arc of time, things tend to happen as they should and they usually find their place, their slot.

Chastain: It also coincided with this idea that I believe that we're all connected. Not just in this moment but in every moment. So as I was wrapping my head around the science of the film, I was incredibly moved by the human component of the film, and definitely it coincided with my spiritual beliefs.

I'm fascinated by some of the other research you did, Chris. You went to NASA, and it had a database of 2.5 million stars. You also went to Elon Musk's space base. What surprised you in that research?

Nolan: You hear about these things as abstractions, and then you go to SpaceX, and they're building rockets. They're getting out there. [Our] generation has grown up with far too little interaction with the idea of leaving this planet, with the idea of getting out and exploring our place in the solar system and then the galaxy and then the universe. In making it seem attainable, you think about it very differently. Your perspective immediately starts to change. You have to start wrestling with the idea of scale, with the idea of these vast distances, these enormous planets, what a wormhole would look like, what a black hole would be like. You have to start examining these things as practical possibilities. It all becomes much more tactile. Which is incredibly exciting.

What did you discover in those places that you hadn't expected?

Nolan: Learning about the Apollo missions, they tended to use not the cutting-edge technology but step back a little bit, use basics that were a bit more tried and tested. Look at the design of space suits: They found these women who knew how to make incredibly tight stitching that no one else could do, and that's what went into the suits. It's that kind of tactile sense [that makes you deal] with reality. For the last 35 years, that really hasn't been a massive part of our culture. And I think now we're ready to get back to the bigger question of getting out there.

Do you think space travel is a worthwhile investment?

Nolan: My experience of working with this film leaves me at the end thinking that it's not a question of whether we should — I mean, we will. It's part of being human and what we're eventually going to do. I would just like for it to happen sooner rather than later so that I could witness …

So, here we are: I've invented a spaceship …

Chastain: I'm not going! I'm staying here, eating corn.

McConaughey: You're eating corn. Would I take it today? Tonight? Without a return ticket? I have a few goodbyes I need to [say]. I'd rather not be the guinea pig. But I'm up for the risk. But you know, the question at the heart of this film [is this:] I've got a lot of inventory. I've got some measurements to do. If you tell me I've got to leave by noon tomorrow, I don't know.

Hathaway: Who built the ship? Who says it's good?

McConaughey: The great seamstresses who did the suits. (Laughs.)

Hathaway: Can I bring my husband? Then we're both — yeah!

What would you miss the most?

Nolan: I would miss the wind. I would miss air.

Hathaway: A breeze.

McConaughey: What would I miss? I like the obstacles here on the ground. They're tangible. I have a conception of them. I have a sense of the mortality here. I don't know where that period or that comma is down the line, but I have a sense [of] the way to navigate this place. And it still gives me great wonder. It's still an incredible mystery, and the path gives me a different buzz each time. I'm still very turned on daily about what happens here.

Matthew, you had to deal with certain obstacles to land this part. Tell us about meeting Chris.

McConaughey: I was in New Orleans working at the time. [I heard] they'd like to meet me. I don't know the title, I don't know what it's about or anything. I fly in. (To Nolan) You and I meet on a Saturday morning. We go in his office and we talk for three hours. Not one word about the film, not what it was about. I came away knowing nothing else about the film. We talked about who we are as 43-year-old men, talked about who we are as [fathers], talked about our kids. We talked about some other films and work and just got really a sense of each other. And so when I walked out, I had a little bit of, "OK, what was that?" I think he wanted to see who I was.

Nolan: The only reason I didn't talk about the project specifically is, it's important to just get a sense of how you're going to get along as people before you worry about specifics. I was interested in figuring out how we would get along. I mean, these are people at the top of their game. So really it's about trying to put together an ensemble.

At some point, he sent you the script?

McConaughey: Comes delivered to my house when I was in New Orleans. Handed through the gate [by a] Mr. Jordan. And he said, "I'm not leaving." And I [said], "I'm going to take my time reading this, and I'm also a slow reader." I stuck with it for five and a half hours, wrote a bunch of things down and had a whole lot of questions. I could not have had a perception of what it was beforehand. And what it was on the page took me a while to digest, and I had a lot of questions, but they were sort of all inspiring questions. At the heart of it, I saw this character, a father who had children, who had a choice, the most extreme circumstances: to go off, live a dream — not only a personal dream but also something that could also salvage humanity. But that would mean it's a one-way ticket without a return flight, necessarily. I saw all this part being this bloodline of the man that he was coming to me for.

There are some scenes with very big emotions. Did that scare you?

McConaughey: No, I was scared 'cause I knew I had work to do and I didn't know where I was going to come out of that. But I'll put a proverbial little tack in [a particular page] and go, "This thing's got to work." You can throw a few others, but these had to work. I just connect the dots, and this really has to work or …

Chastain: Completely. When I'm looking at a script, to me it's like an outline. Every scene leads to the next emotional journey of the character, and if the character doesn't evolve at some point in that scene as it's supposed to, that scene won't really make sense.

McConaughey: There are certain scenes that are hinge points: They switch the trajectory for the audience. And if they don't really work, the whole story can suffer. [I] was the everyman, and I was like, "Who is that? That's kind of no man. Find his problems, where he's selfish."

What's the hardest part of the filmmaking process for you?

Nolan: This! Unquestionably, this! I'm not being glib. I actually find the process of bringing the film out to the audience the most difficult, definitely. All of the other challenges — you have time, you have various resources. You have things you can throw yourself into. As you come to the end of the project, you run out of things you can tweak and change.

What was the most challenging aspect of making this film?

Nolan: I'm always very uncomfortable portraying anything in a film that we can't achieve practically to some degree. I don't fully use CG [except] for what it's most useful for, which is enhancing things that you've been able to shoot in camera. And so I've found taking on a subject matter that inevitably involves fully CG shots is a huge challenge. One of the things we did was, we screened a print of The Right Stuff, an amazing film. And we looked at what they had done technically in 1983 with reflections of visors and things like that. And we said, "Let's try to fully realize the interiors of the spaceship, so that Matthew and Anne, when they're sitting in the ship, they can look out the window and see what's actually out there, so it's not just a set, it's more of a simulator." And these guys really rose to it.

Anne, I heard you were shooting a tough scene in Iceland, substituting for a foreign planet, where you were in freezing water and there was a leak in your space suit.

Hathaway: We had tested the suit a few months prior; it was not successfully waterproofed the first time. And when I went under and submerged, the outer suit filled up, and then I was wearing a suit that kayakers wear, called a dry suit. And human error, we didn't close it all the way. And you're in the suit for hours and hours and hours, so there was about an inch opening in it, and I'm sitting in the water, which is not very warm. It filled up to here (points to shoulder level).

At what point did you say, "You know, I'm getting a little cold here"?

Hathaway: Everybody was cold at that point. We'd been shooting in the elements, and it's not like I was the only one in pain. I was just the only one in specific pain, and I didn't want to hold up shooting. But at some point, I wasn't sure if I could feel my toes, or they started to tingle, and then I was feeling all sorts of weird flashes and things were getting a little hazy around the edges, and that's when I turned to our first [assistant director], and I said, "Hey, I don't know that much about hypothermia, but what are the symptoms?" And I explained what was going on, and he said, "Oh! Like, right now?" And I'm like, "Yeah!" And so then he went over to Chris, and Chris was like, "OK — let's roll, let's roll, let's roll right now!" And we were done shortly thereafter.

Nolan: There wasn't anywhere to go in the vast expanse of water — vehicles adrift and stuff — so there wasn't any quick solution.

You had another difficult scene shot in a cornfield, right?

Nolan: Yeah, I spent a lot of time with my designer in the early days talking about the corn and how it's going to look. Luckily, [director] Zack [Snyder] had grown a bunch of corn, so I said, "How much can you really grow practically?" And they had done a couple hundred acres [for Man of Steel], so we looked into it; we found that where we wanted to build our farmhouse really close to the mountains [outside] Calgary. In the end, we got a pretty good crop, and we actually made money on this.

You made money on the corn?

Nolan: We made money on it because we didn't destroy enough.

There's a scene with the car hurtling through the corn …

Nolan: The stunt guys would just drive straight into it. Which I don't advise 'cause you really can't see anything. It's scary. But we had all sorts of rigs. We had one stunt guy who would drive on top of the vehicle, and then Matthew's in there pretending to drive, and you can't see him.

McConaughey: I don't know if I told you this, but I was living on the property. Not in the house [where his character lives] but in the trailer near the house. I went out when I knew we closed off that production and had a great day! Just not to be able to see, [as] you're doing 85 [mph] through that.

Chastain: I got to drive a little bit in the film. That was so fun for me, that day.

There was also this dust that was created. I think you used something called C90.

Nolan: There is some CG involved as well, but I wanted the shot to be real. Because that's where you most sense the artifice, if you're not getting the proper interaction, if the actor's not able to be in it. So we spent days and days in this dust cloud. It looked like the Ken Burns film about the Dust Bowl that he did for PBS, which was really a remarkable piece of work. We really had to scale back from the reality of what those things were actually like in the Dust Bowl because you look at the photographs, and it actually seems too crazy. I was always fascinated with the idea of presenting what seems like a science fiction doomsday scenario on this sort of big scale that's actually less than [what] really happened in America.

Do you imagine there is going to be another doomsday of sorts?

Nolan: I don't know. I hope not. I think I'm an optimist when it comes to people. I think we're all good at recognizing the things we're doing wrong. Not necessarily fixing it right away, but aiming and striving to fix it.

McConaughey: I would agree. We recognize there's many problems. Now I do think that we wait till the eleventh hour to actually do something. But I'm an optimist. A friend of mine said it best: "Look, the planet is going to be fine. It's us that we think could …"

Hathaway: I am an optimist. [But I] see a disturbing trend of cynicism right now. And that scares me because I think that doesn't serve anybody. Doesn't make you smarter, doesn't make you more prepared, it doesn't make you enjoy your life more. And I love being alive, and I love people.

Chastain: I'm definitely an optimist — [the] reason why I wouldn't want to get in the spaceship! It seems like I've definitely noticed that the public is starting to grow wise. We are damaging the environment, and the Earth, and it's definitely changed a lot in the last 10 years. I'm hoping we continue on that course [of recognition].

Chris, you've stuck to shooting on film, not digital. Will you change at some point?

Nolan: I hope not to. I don't know. I love film and will continue to use it. What it has is a particular and unique quality. It's the thing that got me doing this in the first place. And makes me keep wanting to do it.

You're on the cutting edge of film, and yet in many ways, you're very attached to the past. Which appeals to you more, the future or the past?

Nolan: Well, I think you always have to choose the future. That's just practical, frankly. But it's also emotional. You always want to be reaching for the future, reaching forward. But I've always valued experience. And so I like to try and move forward but continue to use those things that work best. Progress for progress' sake is never a good thing.

This story first appeared in the Oct. 31 issue of The Hollywood Reporter magazine.

through the characters, you are lost in it""]