"We can shoot it in one year and we’re out,” director Alfonso Cuaron once said of his latest film, “Gravity” (our review) to his cinematographer Emmanuel Lubezki; And in Cuaron’s mind when the frequent collaborators first discussed the project in 2009, the intimate, performance-driven drama in space could theoretically fit that production window. But as filmmakers including David Fincher and James Cameron warned him of technology’s limits in bringing his vision to the screen—not to mention that Cuaron’s natural tendencies aimed as ambitious as possible—the full process from conception to Venice premiere ended up clocking in at nearly five years in total.

Luckily, the end result makes full use of that technological delay: The films harnesses a near-perfect visual approach to convey the glittering vastness of space, along with the simmering tension that any error holds for astronauts Ryan Stone (Sandra Bullock) and Matt Kowalksi (George Clooney). The worst scenario comes true—the duo sustains a horrendous debris hit and Ryan is launched away from safety without a tether—and the camera stays in tight on Bullock’s face, picking up her panic while she works to return to Kowalski and find a way home. During a recent Los Angeles press conference, Cuaron, his son and co-screenwriter Jonas Cuaron, Bullock, and producer David Heyman spoke about the film’s extremely detailed production, while NASA astronauts Catherine “Cady” Coleman and Michael Massimino touched on how close the film hews to the real deal.

Gravity, Cuaron

1. Alfonso Cuaron Recovered From Hardship Through Collaboration With His Son, Jonas
Considering its eventual size, it’s odd that “Gravity” began as a Plan B for Cuaron, forming from the ashes of another foreign-language project, “A Boy and His Shoe.” He pulled together a cast of Charlotte Gainsbourg, Guillaume Canet, and Daniel Auteuil before it fell apart due to lack of funding, but for the “Children of Men” director, it only took coverage of his son Jonas’ script “Desierto (Desert)” to envision a new collaboration and idea: a stripped-down narrative with two characters, described by Jonas as “visceral and primal.”

Alfonso said of the process, “When we were working on this screenplay I was in the midst of one of those periods where everything is in adversity. And when I started working with Jonas and we decided to do this film about space we talked about the possibility of a rebirth. In other words, maybe I was clinging to the film with a hope that it was going to bring an end to those adversities, and a rebirth meaning new knowledge.”

“You can see this film as just a big metaphor. Forget about space, this is a film about a woman that is drifting into the void.”

The plot of “Gravity” also held significance for Cuaron on a thematic level. “You can see this film as just a big metaphor. Forget about space, this is a film about a woman that is drifting into the void,” Alfonso said of Bullock’s character, “And all these other elements are voices—voices that are part of her own psyche that represent that search for life. So in many ways you could see it as an internal journey of a woman, but instead of it taking place in a city apartment, it's just in space.”

Once they nailed down a first draft, the duo approached NASA for research and input, an experience that Alfonso found “very humbling.”

“You can write a whole fiction, but you're talking with people who have done that in real life,” he said. “So in an early draft we had scenes that, after talking with one astronaut, were absolutely moronic. Definitely in the physics of space we tried to be super accurate, but all this stuff about orbits, trajectories, a lot of physics involved in traveling to space—we have to take our leaps in terms of fiction.”

When it came to the pivotal event of the film—a incoming field of debris that threatens to doom the mission—astronaut Michael Massimino, who’s twice flown on the shuttle to the Hubble space telescope, confirmed that situation’s possibility. One of the things that we looked at was getting a debris hit,” he said. “Now we see a very sensationalized version of one here, so when that happens it's kind of like, ‘Okay, God, I get the message.’ But there was a reasonable chance—not very large—but there was a chance.”

Cady Coleman, who’s flown on two Space Shuttle missions and one trip to the ISS, praised the film on its accuracy and technical aspects, but was most disturbed by a scene where Bullock enters a ravaged spacecraft filled with floating debris. “That visual is so absolutely foreign to the way that we live up there, because anything floating untethered will be gone,” she said. “You will never find it. There are ventilation shafts where you'll find this stuff. To me that was very emotional to see in the movie, because it was the epitome of devastating-- it's just not going to look that way in a space ship unless something's gone very wrong.”

Gravity, Bullock

2. Common Logistics Were Not Enough For Production on “Gravity” And Its Demands
Tasked with a shoot in which everything had to be calculated to the nth degree, Cuaron and his team crafted a comprehensive previz animation that would essentially cover the film’s duration. In this process, Cuaron caught his first glimpse of the immense difficulties awaiting a realistic film set in space, chiefly with its cinematography. “[Our] brain thinks from the standpoint of gravity -- of horizon and weight,” he said. “And it was a whole learning curve because it is completely counterintuitive when working on previz with animators. You could tell who the newest animator was in the room, because he was the guy who was completely stressed out and wanted to quit.”

Tim Webber, visual effects supervisor on “Children of Men,” returned to Cuaron and Lubezki’s side during this period, and together they devised the tools that would be used during the production. These included the use of industrial robot arms to simulate space weightlessness with precision, and also a nine-foot LED “Light Box”—allowing the actors to remain still while 1.8 million LED bulbs (replicating different light sources) revolved around them.

Acting-wise, Bullock faced an isolating reality, saying “there was just blackness, or bright white lights and metallic objects” surrounding her during scenes. She also had to reorient to an entirely new way of moving with zero gravity. “Everything that your body reacts to with a push or pull on the ground is completely different in zero-g. So to make that second nature it just took training, weeks of repetition, syncing it with the mathematics of it all, and then separating it from your head where you had to tell the emotional story.”

A major source of help came from Coleman, who connected with Bullock by pure chance—Bullock’s brother-in-law attended a wine tasting with one of Coleman’s brothers during pre-production. As part of her aid to the actress for preparation, she described the extent of how little it takes to move anywhere in space. “The example I gave Sandra was that you could take a single long hair, and if I put up against a handrail and just pushed, I could move myself across the entire module until I ran into something else.”

Besides the physical aspect, Bullock and Cuaron extensively explored the nuances of the human voice in space. “It's very specific — it's a voice in the breath… of someone that is that cut off,” Bullock said. “If I went a little higher pitched in my panic it always rang false unless it was absolutely perfect.”

The film’s overall sound design is extraordinary, using a faithful, absence-of-sound approach to the space environment, and combining with it a largely percussion-less score by Stephen Price to completely immerse the viewer. Says Alfonso of the undertaking, “Historically there's a fight between sound designers and composers; you'll see them in the mixing room and they're always fighting because the composer wants the music to be heard, and the sound designers want their effects to be heard. But here, they were working together. It was a very holistic process in many ways.”