BEVERLY HILLS, Calif. — Like most movie stars, Sandra Bullock has been endlessly sliced into snackable bites by the celebrity media. In Vanity Fair’s estimation, this Oscar-winning actress is “friendly and direct and so unpretentious.” (True.) Ms. Bullock is “America’s sweetheart,” according to dozens of color-by-number profiles, a gifted physical comedian who has suffered the occasional flop. (Fair enough.)
After her 2010 divorce, she briefly got the tabloid treatment, with one overseas outlet publishing an article accompanied by this headline: “Sandra Bullock Finally Leaves the House — Looking Like the Witch from She-Ra.” (Extremely doubtful.)
But one of her most noteworthy attributes is almost never mentioned, perhaps because it’s not always easy to notice on camera. You have to peer behind her performances to see that Ms. Bullock, who returns to cinemas on Oct. 4 in the space thriller “Gravity,” is arguably Hollywood’s gutsiest A-list actress.
Sure, “Two Weeks Notice” does not exactly scream fearless. But consider what came shortly after that 2002 romantic comedy. Ms. Bullock abruptly steered away from what was working, instead fighting for smaller dramatic roles that weren’t always flattering. (Her racist rich woman in “Crash” comes to mind.) That perilous professional shift led her to “The Blind Side” (2009), a difficult film that could have easily turned into a Lifetime melodrama. Instead, it won her an Academy Award.
Last year, Ms. Bullock, 49, appeared naked in a long, raunchy skit on “Chelsea Lately.” You don’t see Julia Roberts doing that. Speaking of daring leaps, Ms. Bullock almost drowned by taking one into the North Atlantic in 2009 to film a scene for “The Proposal.” After bobbing in the water for take after take, she went into hypothermia and couldn’t breathe. “I’d put her toughness against any tough-guy actor out there,” said Todd Lieberman, a “Proposal” producer.
Still not convinced? You will be after “Gravity.”
Directed and co-written by Alfonso Cuarón, the meticulous filmmaker behind “Children of Men” and “Y Tu Mamá También,” both critical darlings, “Gravity” stars Ms. Bullock and George Clooney as astronauts adrift in space after surviving a shuttle mishap. But it’s largely a solo performance by Ms. Bullock in the way that “Cast Away”rested squarely on Tom Hanks, securing him an Oscar nomination in the process. (Hint, hint.) Mr. Clooney only appears in about a third of the film.
“I actually never thought about being alone on screen for such a long time until I started doing press, and everyone asked me if that made me nervous, and then I started panicking,” Ms. Bullock said over lunch last month at the Polo Lounge. “I was mostly concerned about the Vomit Comet.”
Ms. Bullock has been “deathly afraid of flying,” she said, since surviving a Wyoming plane crash in 2000. Her jet missed the runway, shearing off its landing gear and sustaining severe wing and nose damage. But she nonetheless agreed to make “Gravity,” knowing that Mr. Cuarón planned to spend day after day filming inside a jetliner that simulates weightlessness by climbing sharply and then plunging downward. NASA astronauts gave the plane its nickname, for the obvious reason.
“I convinced myself it was the universe telling me I needed to get over my fear,” she said. “I said I would do it. I wasn’t happy about it. But I said I would do it.”
Mr. Cuarón ultimately abandoned that cinematic torture device in favor of another one — a 10-foot- by- 14-foot box equipped with special lights and placed on a darkened soundstage. Ms. Bullock was “clamped” inside a “gruesome” harness, he said, and placed inside, where she remained isolated for hours at a stretch. A camera mounted on a robotic arm pivoted and circled around her. This newly developed technology made it look as if Ms. Bullock were floating through the darkness of space.
“I was literally acting off of nothing for up to 10 hours a day, with headphones my only connection to Alfonso,” she said. “We made a catalog of music clips — whale sounds, Radiohead, weird screeching of metal — and I memorized them. I would say, ‘O.K., give me No. 4. That’s not working. Try No. 2. That’s better, that’s getting me to the emotion I need.’”
To film one sequence, Ms. Bullock had to stay perfectly still and in character while a camera rushed toward her at 25 miles per hour, stopping only about an inch from her face. Other scenes required her to be strung up horizontally by 12 wires while puppeteers, including some who worked on “War Horse” on Broadway, maneuvered her through choreographed movements.
“I got into it and didn’t last 20 seconds,” Mr. Cuarón said.
“Gravity” knocked out critics on the opening night of the Venice Film Festival late last month with its edge-of-your-seat intensity and simultaneous sense of both claustrophobia and expansiveness. “Bullock is aces in by far the best film she’s ever been in,” Todd McCarthy wrote in The Hollywood Reporter. The 3-D film is also notable for its originality and short running time of 90 minutes. It opens with a 12-minute continuous shot and has deep-running emotional currents, although it’s hard to explain why without spoiling the plot.
“It’s about rebirth,” Ms. Bullock said. “How do you let go in the worst possible situation so you can have some kind of release and peace?” She added, “Life is not going to stop coming at you. In the end, you just have to say, ‘I have no control.’ Your time is precious. Are you really going to waste it worrying about this stuff?”
She was confronting those same questions in her personal life in 2010, when Mr. Cuarón flew to her Texas home and tried to talk her into “Gravity.” She had retreated there following the public revelation — one week after winning her Oscar — that her husband of five years, Jesse James, a motorcycle customizer and reality TV star, had been serially unfaithful.
She divorced him, went forward with the adoption of a baby and made it clear to her agents that she had no interest in acting anytime soon. But Mr. Cuarón wanted her badly for “Gravity” and, after considering several other actresses, including Angelina Jolie, he decided to try and coax Ms. Bullock back to Hollywood. (“The Heat,” which came out in June and co-starred Ms. Bullock and Melissa McCarthy, was actually filmed after “Gravity.”)
“All I had the energy for was being little bun-bun’s mom,” Ms. Bullock said, referring to her now 3-year-old son, Louis. “I didn’t want to work. But it’s hard to say no to Alfonso Cuarón. And ‘Gravity’ truly felt like a once-in-a-lifetime experience.”
When you sit before her, Ms. Bullock is everything you expect: friendly, witty, pretty, steady, normal. At one point, a waiter broke out in a cold sweat after noticing the table was wobbling on uneven legs. “That’s what sugar packets are for,” she said brightly. She was more concerned about a reporter’s pen. “I’m worried about that touching your shirt,” she said, moving an uncapped black Flair to a safer spot.
Does she see herself as daring?
“No,” she answered quickly.
She took a bite of her salad (no beets or avocado, please) and thought about it for a few seconds. “I appreciate people saying ‘gutsy’ and not, ‘Ooh, well, she’s just a little ignorant,’ ” she said, putting on a twangy Texas accent for the last bit. “ ‘She goes in with blinders on, poor thing.’ ”
You get the sense that Ms. Bullock feels as if she has something to prove with “Gravity.” The moviegoing masses still seem to have a flicker of doubt that she earned that Oscar, perhaps because her first big movie after winning it was “The Heat.” (Yes, she played a Sept. 11 widow in “Extremely Loud & Incredibly Close,” which she filmed after Mr. Cuarón’s visit to Texas. But that 2011 drama was not widely seen, at least not by studio standards, and her role, with 24 minutes of screen time, was a supporting one.)
“It’s hard not to feel that this brand of deeply forgettable fare is beneath Bullock,” Texas Monthly wrote of “The Heat,” which has taken in more than $200 million at the global box office.
Translation: Please don’t become another Julia Roberts, the Oscar-winner who has lately been slumming it in movies like “Eat Pray Love” and “Mirror, Mirror”; or Halle Berry, who won an Academy Award only to churn out “X-Men” sequels, or Reese Witherspoon, who.... You get the idea.
“What roles that are available will always be a factor,” said Octavia Spencer, an Oscar winner for “The Help” and a friend of Ms. Bullock’s since 1996, when they met on the set of “A Time to Kill.” “But Sandy has been very successful at not letting anyone put her in a box, and that will continue.
“She has done it by continually taking risks — showing us these other colors, hello ‘Gravity’ — and working her guts out, and not fixating on how she looks in every scene. Those are things that not a lot of other actresses of her echelon do.”