Like many dreams of seizing intensity, this one is both deliriously beautiful and charged with primal fear -- not just fear of falling, but of hurtling up, spinning out, breaking loose from our planet's embrace. Two astronauts, George Clooney's Matt Kowalski and Sandra Bullock's Ryan Stone, are adrift in space after disaster strikes during a shuttle mission to the Hubble Telescope. Tethered to each other at first, they tumble wildly out of control, then try to regain their equilibrium, conserve their oxygen and, in a cosmic nowhere, find the wherewithal to survive. He's a veteran pilot with a gift of cheery gab that may have helped him ward off unwanted feelings in the past. She's a novice, a medical engineer with not much astronaut training, and she feels everything, from horror through dread and grief to resolve, rebirth and elation.

We feel awe from the start. The film opens with a 12-minute sequence of seamless action in which Matt, Ryan, the giant telescope and the shuttle that brought them there float serenely above a vast, floating Earth until all hell suddenly breaks loose in the form of space debris. Newtonian laws of motion still apply in the maelstrom that ensues; the lawbreaker is the camera. It moves as no movie camera has done before -- so fluidly that its loops and glides transgress boundaries and film conventions. At one point it closes in on Ryan, then penetrates her helmet, without pausing at the visor, to study the stark terror on her face.

As befits a superb movie, Ryan is a marvelous heroine. She has suffered an anguishing personal loss that resonates powerfully in her desperate present; until this galvanizing assignment, she'd only been going through the motions of her everyday life on Earth. She must have been an overachiever to reach a position of eminence in her profession, but her undertraining as an astronaut leaves her in a state of utter panic when chaos engulfs not only her shuttle but a whole tier of orbiting space stations and communication satellites in the extraterrestrial neighborhood. ('Half of North America just lost their Facebook,' Matt says wryly when all the circuits go dead.)

If Ryan is to survive, she must augment everything she's recently learned with all the courage at her command. Before that, though, this wounded woman must replenish her will to live; that process is visualized through a silent, exquisitely grave moment in which Ryan becomes her own star child. (The filmmakers, you'll be glad to know, hold out the slim prospect of her making it back to Earth through a deliciously unlikely set of circumstances. She isn't quite doomed to exit the solar system, as Voyager 1 did last year.)

Until now, a Sandra Bullock film often turned on spunk or rue. The rue was a result of the loneliness that afflicted many of her characters, and became a vital ingredient of her hugely successful comedies. (My first column for the Journal, in 1995, reviewed her in 'While You Were Sleeping,' and noted the script's unlikely effort 'to convince us that this lovely young woman, this vivid life spirit with a lyrical smile, can't make friends, can't get a date.') The spunk found its finest expression in Jan de Bont's 'Speed,' an action classic that worked as well as it did largely because Ms. Bullock's Annie was so smart and endearing, as well as terrified at finding herself behind the wheel of a bomb-laden bus.

Two decades after 'Speed,' Ms. Bullock has found the perfect receptacle for her humor and intelligence: Ryan's courage is matched by her intellect. She still does her trademarked rue, particularly at the outset, when the novice astronaut can barely keep her lunch down during her first spacewalk. And she's still movie-star youthful, maybe more so than ever since her character's energy is so tightly tied to physical action. (One of the movie's myriad achievements is portraying Ryan's strength and athletic beauty without making her a sexual object.) Best of all, though, Ms. Bullock has replaced the spunk of her ardent youth with a complex woman's depth of spirit. It's the best performance of her career.

Mr. Clooney is movie-star charismatic, even in a subordinate role, a feat that he manages almost entirely with his voice, since he's encased in spacewalk wardrobe from start to finish. His character isn't there for complexity. Matt's wisecracks, his corny stories, his swashbuckling expertise and, ultimately, his gallantry are all canny components of the movie's broad appeal.

The script, by the director, Mr. Cuaron, and his son Jonas Cuaron, is as shrewd as it is inventive. Matt gets a few lines, and deeds, of heart-stopping grace. 'You should see the sun on the Ganges,' he tells Ryan from a receding position in the void, thereby evoking, in eight words, the wonder of life on Earth. Mainly, though, he's very funny, a carefree cowboy on the high frontier, and his humor serves as welcome relief in a tale of barely endurable suspense -- one that's told with startling compression in the course of 90 minutes. Objections have been raised in scientific quarters to the depiction of the international space station as being in proximity to the Hubble Space Telescope; they're actually in different orbits. This isn't nitpicking, since that proximity figures importantly in the plot, but it isn't a cardinal sin against science either; no one would mistake this movie for a planetarium lecture.

Watching the tale unfold, you're truly awe-struck, but you can't help wondering from time to time how they did it. (Though the movie is loud, don't bother bringing earplugs. The sound design is hypnotic, most of all when Ryan struggles in tight spaces, and essential to the experience.) 'Gravity' is the culmination of a yearslong collaboration between a visionary filmmaker and a team of artists and technicians who had to invent elaborate new tools in the service of that vision. Chief among them are the cinematographer, Emmanuel Lubezki (he devised a radically new LED lighting system that came to be called The Sarcophagus); the production designer, Andy Nicholson; the visual effects supervisor, Tim Webber, and the editor, in conjunction with Mr. Cuaron, Mark Sanger. The 3-D photography is effective, sometimes stunningly so, but never calls undue attention to itself.

What you're watching at any given moment is likely to be partly or wholly animated. Long may flesh-and-blood actors thrive, but in the new world of tech-heavy productions they're only one of many elements in the FX mix. 'Gravity' floats on the shoulders of the Pixar giants -- especially 'The Incredibles,' which showed that computer animation could do almost anything live action can do, and 'WALL-E,' with its mysteriously somber opening sequence (and with its comic use of a fire extinguisher, which is put to very different use in 'Gravity'). The greatest artistic debt, of course, is owed to Stanley Kubrick's '2001: A Space Odyssey,' which dared to use silence, serenity and space -- screen space as well as space space -- as never before.

Long before 'Gravity' went into production, it was choreographed to the nth degree. Yet there's a sense of everything happening spontaneously, of surreal freedom plus a fearful randomness that unleashes those debris storms. The newness is more than a function of the motion. We've never seen such striking images of the structures our species has built in space. When we're inside them, objects float, willy-nilly, with tiny lives of their own. (How odd that one of Sandra Bullock's films was called 'Hope Floats.') A movie has never brought us this close to tasting oxygen. (Or feeling mud.) And the randomness can be poetic. In the midst of that long and frightening radio silence, Ryan hears a staticky voice in an Earth language not her own, accompanied by laughter and a baby's cries. Hope floats indeed.

In the immediate future, 'Gravity' is certain to find appreciative audiences all over the world; it speaks the language of big-screen action with surpassing eloquence, and comes to a climax as thrilling as any movie lover could wish for. No one can predict what impact it will have on the movies' future, but consider what the film already represents -- the conjunction, within the studio system, of a singular cinema artist and a full array of Hollywood's most advanced filmmaking tools.

It's remarkable, when you stop to think about it, that Mr. Cuaron ever got the gig. He's no stranger to technology, having directed 'Harry Potter and the Prisoner of Azkaban' and 'Children of Men,' but he's not James Cameron, with a long history of technical virtuosity and hugely profitable action adventures. More remarkable still, he has been able to translate his vision into a film that shows the world, and the filmmaking world, what wondrous new things big studio films can do. All too often in the recent past, Hollywood's most magical tools have fallen into the hands of sorcerers' apprentices who perpetrate the same old succession of explosions, car crashes and fireballs. 'Gravity' was made by a sorcerer.