Inside ‘Gravity’: How Sandra Bullock Went From a ‘Torture Chamber’ to an Oscar Nom

For Alfonso Cuarón and his team to pull off the series of seamless cinematic feats they did with his 10-time Oscar-nominated space drama "Gravity," it took some pretty out-of-this-world ingenuity and collaborative spirit from all involved — especially from its leading (and, for much of the film, lone) star Sandra Bullock.

"So much had never been done before," explains the Best Actress nominee in this online exclusive half-hour behind-the-scenes look at the flick called "'Gravity': The Impossible Journey," produced by Warner Bros. Pictures. Bullock said, "It was an extraordinary advancement in film."

Indeed, much would be accomplished over the years after Cuarón and his son, writer Jonás Cuarón, first conceived of the epic drama with a relatively spare set of ideological blueprints — even if at the time they had no idea of the scale they were creating.

"When we were writing it, we were not writing a special effects film," director Cuarón remembers. "I thought it was going to be much simpler."

"We started talking about this idea of making a movie that was a 90-minute ride where you would be grabbed to the edge of your seat, but at the same time it would have a lot of metaphorical connotations," Jonás Cuarón recalls in the vid. "We started trying to decide where we would set this movie, and suddenly we both came to this image of an astronaut just floating into the void."

Said image, of course, would ultimately become the haunting centerpiece of a $100 million 3-D blockbuster's terribly effective and exciting promotional campaign. Still, for Alfonso Cuarón, it is the symbol of a "character-driven piece in which that spectacle and visual effects are a byproduct of the drama."

[Related: Alfonso Cuaron on ‘Gravity’: ‘Awards Don’t Make Your Film Better or Prettier’]

That initial visual — of Bullock's Dr. Ryan Stone, a rookie astronaut, being catapulted into the helpless vastness of space — ended up as just one of many massive physical and landscape moments which made way into the movie's script. And while Cuarón, cinematographer Emmanuel Lubezki, and the special effects gurus were responsible for making each of them work on a technical level, it was up to the leading lady to pull off basically becoming a living marionette without anyone being able to tell.

Sandra Bullock, whom Alfonso Cuarón deems "the real hero" of his picture, was strung up by a 12-wire rig system for her weightless scenes, with her every movement being manipulated by an off-camera puppeteer. It was up to her to hold her body straight and to naturalize those sometimes involuntary body motions to legitimize an eerie effect of existing in zero Gs.

Per Cuarón, the major challenge in that was making those movements "seem free and spontaneous" even where she was being pulled and prodded by his contraption. But Bullock was game — even when stripped down to her underwear with a confining harness underneath.

"Months ahead of time, I saw what some of the rigs might be, and I was like, if that's just the tip of the iceberg, how? You need someone who's fit?" she remembers. She then trained for months to give Stone a dancer-style physique in order pull off those lithe mid-air motions.

"When I met with her, she said 'I want to come out of my comfort zone,'" says Cuarón. "Pretty much we put Sandra in a torture chamber for like 14 weeks."

This would prove to be quite the success, with her character swimming in and out of frames without any indication of the mechanisms which hoisted her. Yet, it wasn't the only obstacle she would have to overcome in flying so solo for the film.

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"It's very scary for an actress only realizing that she's going to be playing huge, huge chunks of the film on her own, without interacting with any other humans," Cuarón adds.

"You're acting in a box, you're strung up by wires. There's no human connections," says Bullock. "It's just incredibly isolating, which, actually in a weird way helped because it made you feel so alone." (The arrival of the jovial George Clooney on set offered a welcome change of atmosphere, so to speak, for her and everyone else, too.)

Despite being tied up and alone for so much of the process, however, Sandra Bullock has come to regard "Gravity" as "the most collaborative experience I've ever had."

"That's Alfonso," says Bullock. "He had every single person struggling so hard to give him what he wanted because they knew that this man, who'd created great films before, was creating something amazing and new."

If Yahoo's awards season pundits have predicted correctly, it will all pay off soon for Cuarón in particular — above the already sweet pay-off which came by way of a $700 million box office smacker intake, that is — as he is all but guaranteed to take home the gold trophy this year for Best Director.

[Related: 2014 Oscar Predictions: 'Gravity' Will Win the Most Oscars (But Not Best Picture)]

Will he and his team also bring home the Best Picture prize for their earth-shattering flick? Will Bullock defy the odds and earn her second statuette? That remains to be seen when the Oscars air on Sunday.

"Gravity" lands on Blu-ray and DVD on Tuesday.

Tune in to Yahoo's live Oscars pre-show this Sunday at 8 p.m. ET / 5 p.m. PT, and then watch the big show on ABC.