They say we don’t go to outer space anymore. But Christopher Nolan is doing a pretty good job of faking it.

It’s October 2013, and we are on the set of code name Flora’s Letter, a.k.a. Interstellar, an epic sci-fi adventure that represents the beginning of the director’s post-Batman life. Working on the same soundstage where he once built a dank batty cave for Christian Bale to skulk in, the British-American helmer has constructed a starship to take Matthew McConaughey and Anne Hathaway across the universe to find salvation for the human race. On screen that ship, the Endurance, will be composed of 12 interlocking pods. Right now it’s only three pods resting at a slant on a mammoth steel gimbal tilted at a 30-degree angle. It resembles a seesaw for giants.

The Endurance Double Negative/Paramount

Walking up into the narrow interior—designed from galleys, jump seats, and control panels salvaged from junked airplanes—is like trying to keep your balance inside a mystery-shack tilt-house. Look through the small double-paned windows, and what you see, projected on a large black floor-to-ceiling curtain, is a vertiginous swirl of stars, which is exactly what you would see if you were inside an actual spacecraft swiftly spinning to generate 1g of gravity. Another director would have hung bluescreens and then animated space in postproduction. Nolan, zealous about verisimilitude, loathes bluescreen the way the Amish loathe zippers. (There’s a robot aboard the ship, too. But nobody talks about TARS.)

At the heart of this sophisticated filmmaking machine, Nolan stands with a portable video monitor hanging from his neck, chasing authenticity of a deeper kind. He radiates strong, quiet authority and wears his signature business-casual outfit: dress shirt sans tie, khakis, and a sports jacket with deep pockets. Inside, you’ll find pens, notebooks, and a flask of Earl Grey, no milk. (“My assistant director once referred to it as a magician’s coat,” Nolan says.) He’s shooting a close-up of Hathaway, who plays a scientist named Brand, confessing a secret that will change the course of the story.

Interstellar (rated PG-13, out wide Nov. 7) tracks a group of spacefarers tasked with finding a new home for humankind before an ecoapocalypse wipes us out. Led by McConaughey’s Cooper, a widower who has left behind two children to pilot the mission, the four-person crew (which also includes Hathaway, Wes Bentley, and David Gyasi) traverse a mysterious wormhole near Saturn and reach a set of planets, but they can’t visit them all. Which way to go? Brand’s revelation will help decide the matter, and it takes the form of a soliloquy about—of all things—the nature of love as an unquantifiable, higher dimensional force.

It’s a risky move for Brand and a risky beat for the movie; the speech could easily veer sentimental or incredible. But after a few takes and a few gentle words from Nolan, Hathaway satisfies her director and the production moves on. “I was a little lost in that scene,” she admits later. “I started playing the scene like she had been bottling it up for a long time, and Chris said there is more power in underplaying. And of course he was absolutely right.”

Hathaway and McConaugheyMelinda Sue Gordon

For Nolan, Brand’s speech expresses much of his vision for Interstellar. “What happens when scientists bump up against these things that defy easy characterization and analysis—things like love?” Nolan says. “We are at an interesting moment where science realizes it has to begin addressing abstractions and human elements, and I wanted to get that in the film. It also speaks to the heart of the movie and the dilemma facing our characters. You have an intellectual commitment to duty, you know you are doing the right thing, but you have your emotional response to these things, too. How do you weigh them? These felt like interesting questions, and I wanted the audience to ask them consciously. You have a choice: You leave these things as subtext, or you try to bring them to the foreground, so the audience can be plugged into the themes that interest you, be part of that ride.”

“The heart of the movie.” Nolan uses this phrase often when discussing Interstellar, partly because grounding a heady sci-fi film with real feeling is no-duh smart, and partly because finding new ways to emotionally engage an audience has become increasingly important to him. Since his indie breakout with the Möbius-strip pulp of Memento in 2001, Nolan has evolved into Hollywood’s premier maker of big-studio spectacle in the gone-geek era, gifted with a knack for producing prestigious blockbusters such as The Dark Knight that transcend genre, dazzle critics, and sell tickets. Interstellar is proof of his power: It’s a two-hour, 47-minute saga that is not based on a comic book, doesn’t launch a franchise, and has more in common with the serious-minded 2001: A Space Odyssey than the escapist Star Wars. That doesn’t happen every day in Hollywood.

Nolan and MatthewMelinda Sue Gordon

Along the way, though, Nolan has been tagged as one of those brilliant-but-chilly auteurs, much like his oft-cited director heroes, Stanley Kubrick and Ridley Scott. Those who know and work with Nolan bristle at the perception, but they do believe Interstellar represents a leap forward. “He has never left his humanity by the wayside in his pursuit of exploring the next film horizon,” says Hathaway. “But in this film, I feel his technical prowess and his humanity are presented in the most balanced way.” Adds McConaughey: “Nobody is able to put more scope, scale, awe on screen than Chris. But I think he was wanting to take the next step, toward something more intimate.”

Jessica Chastain—who, thanks to the theory of relativity, plays McConaughey’s earthbound adult daughter—realized just how personal Interstellar was to Nolan the day she finally cracked the mystery of “Flora’s Letter.” “One day, I noticed this girl. She was really shy and sweet. I went up to her, and she told me her name. And she was Chris’ daughter,” says Chastain. “All of the clues fell into place. You had to be a little bit of a detective, and when I figured it out, I was incredibly moved: Interstellar is a letter to his daughter.”

Nine months later, on the Warner Bros. lot in Burbank, Christopher Nolan is sitting on a sound-mixing stage sipping Earl Grey and watching Matthew McConaughey cry and then fly. The sequence under review this July afternoon begins with a charged moment between Cooper and his daughter. It ends with McConaughey in space, pushing buttons and bantering with his fellow astronauts and TARS about just how much sharing and joking around should be allowed on the trip. It’s the buttons that command Nolan’s attention. He’s looking for the correct sound that might be made if a man wearing thick astronaut-suit gloves were pushing buttons. “The sound mix is my favorite part of the process,” says Nolan. “Your biggest creative decisions have been made—the shoot, the cut of the film—and you’re really in there putting the finishing touches on things or exploring different possibilities. It’s a time of pure imagination, where you can just play.”

Nolan has been playing this way all his life. In fact, Interstellar brings him full circle: As a space-crazy kid under the influence of Star Wars, Nolan cut his teeth shooting Super-8 movies with titles like “Space Wars,” making Hoth-ish ice planets on tabletops out of flour and clay and incorporating footage of NASA rocket launches. “I showed my kids one of my crude early films a while back,” says the father of four. “I had remembered them the way I wanted them to be, not the way they are.” He laughs a sheepish laugh. “They’re actually really disappointing!”

Foy and McConaugheyMelinda Sue Gordon

Interstellar may have been the movie Nolan was born to make, but it began life as a Steven Spielberg project, produced by Lynda Obst (Contact) and executive-produced by an unlikely Hollywood player, renowned astrophysicist Kip Thorne. The trio aspired to mount a realistic space-exploration film for Paramount that was grounded in solid science but also explored theoretical possibilities. Black holes. Wormholes. Quantum physics. Extra-dimensional space. The stuff you look up on Wikipedia to understand. To help turn these ideas into story, Spielberg sought out another Nolan: Christopher’s younger brother and frequent collaborator, Jonah (typically credited as “Jonathan”), the screenwriter who helped pen The Dark Knight. “My take on a realistic space-exploration film was simple: It’s not going to happen,” says Jonah, whose perspective at the time was colored by the recent shuttering of the space-shuttle program and the debate over financing a NASA mission to Mars. It bummed him out, to say the least. “We’ve peaked as a species,” he thought. “It’s all downhill from here.”

But Jonah found inspiration in his pessimism, as well as in Hollywood’s fixation on apocalyptic sci-fi like Avatar and WALL-E. He set the story in a dystopian future ravaged by blight but populated with hardy folk who refuse to bow to despair. His optimistic, Right Stuff-ish heroes would seek salvation in the stars while grappling with the remote likelihood of finding another Earth. “I wanted to confront all the things that are wrong with us and threatening us, but to focus more on hope,” Jonah says. “After all the research, all the conversations with Kip and Lynda, the thing that jumped out was how precious life is in the first place.”

In 2009 Spielberg moved his company DreamWorks from Paramount to Disney. The project needed a new director. Jonah had a recommendation. “My brother and I have this kind of symbiotic relationship,” he says. “I always talk to him, so I had been trying out material with him from the beginning. When you’re a writer, you’re always looking to see if [your scripts] pass the jealousy test. Like, ‘Damn, I wish I was doing that project.’ I could tell Chris was interested.”

NolanMelinda Sue Gordon

Chris Nolan officially boarded Interstellar in 2012. He wasn’t jealous of everything in his brother’s screenplay. “I think the first thing I told him was: ‘You realize I’m going to rewrite this, right?’” says Nolan. He wanted to reshape the middle section, the exploration of planets. He wanted to play with scale and pit man against monolithic nature. Dust storms. Tidal waves. The spoiler in the last act. He wanted to round out the story’s view of moral character with scenarios that depict humankind at its selfless best, selfish worst, and nuanced points in between. “When you take an audience as far away from human experience as possible, you wind up focusing tightly on human nature and how we are connected to each other,” Nolan says. “The film tries to be very honest in that appraisal.”

And he wanted to change Cooper’s child, Murph, from a boy to a girl. “For me, the whole movie is about what it means to be a dad,” Nolan says.

Before (re)writing a word of Interstellar, Nolan did something he had never done before, something that speaks to his desire for more emotionally potent work. He asked composer Hans Zimmer to write some music for the film, but without telling him about the genre, title, characters, or plot: “I said, ‘I am going to give you an envelope with a letter in it. One page. It’s going to tell you the fable at the center of the story. You work for one day, then play me what you have written.’ He was up for it. And it was perfect. He gave me the heart of the movie.” Zimmer says he remembers this idea from Nolan’s letter: “Once we become parents, we can’t help but look at ourselves through the eyes of our children.”

Nolan and ChastainMelinda Sue Gordon

“I do not think Chris could have or would have made this film 12 years ago when we didn’t have kids,” says Emma Thomas, Nolan’s wife of 17 years and producing partner. “Whenever I read that Chris’ films are ‘unemotional,’ I don’t agree, but I do find this one to be more emotional. And a lot of it has to do with Matthew’s performance.”

And his character. Cooper represents a spiritual departure from the protagonists of Inception and the Batman films, exemplars of our new-century romance with antiheroes. Cooper is an about-face from that archetype, a self-sacrificing neo-Chuck Yeager. Going into space scratches Cooper’s adventure itch, and his kids suffer for it, yet his motivations for leaving them are morally sound. He’s Richard Dreyfuss in Close Encounters of the Third Kind, ditching family to trip the light fantastic—except Cooper is doing it to save the world.

None of this was easy for McConaughey to play. He had just come off a celebrated streak of antiheroes himself, Ron Woodroof in Dallas Buyers Club and True Detective’s Rust Cohle. Getting inside a more classic protagonist challenged him. ‘I remember Chris saying, ‘He’s the Everyman,’’ says McConaughey. ‘I remember walking away going, ‘Who is the Everyman?!’ It’s harder to define today than at any time. I basically decided to trust in what I personally feel about it, trust in how I feel about family, trust in how I feel about adventure. I had to make it personal. I had to say, ‘Guess who the Everyman is in this movie, McConaughey? You.’”

Contrary to what you may have read or how he might sound, Nolan is neither pretentious nor aloof. He’s all British reserve and American ambition, for sure. But he’s a collaborative artist with zero tolerance for arrogance or agenda, as well as a private, grounded family man with high-low tastes. When I asked him a couple of weeks ago what was in his pockets, he pulled out six ticket stubs to Godzilla. He’s as passionate about Terrence Malick as he is about Eastbound & Down. “Chris is a lot of things we’ve been taught contradict each other,” says Hathaway. “He’s a workaholic, but he’s a present, loving father. He’s a serious filmmaker, but he loves stupid -comedy. He’s an exemplary human being, but he is a human being.”

Those who work for Nolan will also tell you it’s exactly that: work. “You come to set, lines learned, boots polished, posture straight, ready to fight all day long on behalf of his vision,” says Hathaway. A Nolan set tends to run with clockwork efficiency and little unnecessary drama, even when you’re getting dirt blasted in your face. Nolan shot most of the film’s Earth scenes in rural Alberta, Canada, where production designer Nathan Crowley planted 500 acres of corn, just to lay waste to them with a manufactured apocalypse. “You had wind turbines chucking dust made out of cardboard, you had smoke from the fires from the burning corn; the future is not pretty,” says Chastain. “I felt a lot of pressure because I have so much respect for him. You have this feeling of ‘I don’t want to be the one who lets Christopher Nolan down.’”

Iceland doubled as a world of treacherous seas (Fun fact! Christopher Nolan has a deep fear of the sea) and a world of ice and rock (a far cry from the flour and clay of his “Space Wars” youth). While Hathaway was shooting in the frigid waters, her space suit sprung a leak. “I started to feel tingly, and things were getting wavy,” she says. “I turned to Matthew and asked, ‘I don’t know much about hypothermia. Do you know what the symptoms are?’ He went to Chris and whispered in his ear. Chris was like, ‘Let’s roll now!’ It’s not like Chris sent me off to get warmed up, but he was aware of it,” she laughs. “Wimps don’t last long on his set.”

HathawayMelinda Sue Gordon

“He is one of the greatest leaders I have ever worked for,” says McConaughey. “He wants original, yet he’s not a perfectionist. He just wants everyone to give everything they’ve got. With the actors, it’s very intimate. We were never in a rush, but it was very raw, natural, and fast. He never goes back and reshoots a scene. Never has to. He keeps the entire film feeling like you’re on a constant, bounding ascension. You never stop. You never level out. No one sobers up.”

Throughout Interstellar, Nolan put “massive pressure” on himself to raise his storytelling game. “I learned from making large films that if you have amazing things happening, the more important thing is cutting to a character going, ‘Oh, s---, that’s an amazing thing!’ The drama comes from audience identification,” he says. “That wasn’t enough here. The audience had to experience the amazing thing as an amazing thing.” In the finished version, you see that want for awe in shots like a tiny spaceship juxtaposed against Saturn, or in a fight between two characters filmed from a distance, puny figures flailing at each other on the hostile terrain of a cold planet. One thing the director admires about Kubrick is his pure-cinema pursuit of what Nolan calls “the one powerful image.” This film, he says, “was the first time where I said, ‘What is the image? What is the one shot that says everything?’” Naturally he wanted a lot of them, which helps explain the film’s bladder-busting running time. Every time Nolan tried to pare down, he says, “it subverted the tone of the movie.”

McConaugheyMelinda Sue Gordon

Nolan says he has been changed by Interstellar, but he’s still figuring out how. “The character of Cooper opened up something for me about the emotional possibilities of a protagonist,” he says, and he relates to Brand, the scientist who believes love is essential even though it defies logic. “A lot of my job is what you might call scientific,” Nolan says. “I have always tried to pour myself into the technical side of filmmaking, the things I can control. I relate to the struggle to quantify the elements that are giving you an emotional response. That always feels impossible to me. But I keep trying. A film being more than the sum of its parts is a true mystery.”

Even as the film approached its release date, Nolan strived to unlock that mystery. He and composer Zimmer conducted 45 scoring sessions for Interstellar—triple their number on Inception. Most of those were just for experimentation. Old habits were abandoned (goodbye, action-scene jungle drums), new sounds were sought. “The core of the movie is about the quest for adventure,” says Zimmer. “It seemed only right to throw everything out and make it all about invention.” When they had finished, Nolan presented Zimmer with a watch. On the back he had inscribed, “This is not the time for caution.“