So you want to be an astronaut?

Alfonso Cuarón’s gripping, often spectacular thriller Gravity sends George Clooney and Sandra Bullock flying into space, where they encounter every explorer’s worst nightmare, the deadly kind you can’t hope to control, but can only pray you can somehow survive through luck, nerve, and training.

Matt Kowalski (Clooney) is the experienced commander of an American shuttle on a mission that will be his last before retirement from space flight. Ryan Stone (Bullock) is the neophyte, a scientist conducting an experiment while floating hundreds of miles above the Earth. The story begins on the final day of the mission, with Kowalski testing out a new jet pack while Stone and another scientist / astronaut work diligently, tethered to the shuttle in their space suits.

They are in constant contact with mission control on Earth, represented by the voice of Ed Harris, when a report comes in that the Russians have accidentally struck one of their own satellites with a missile. The resultant debris quickly strikes other orbiting crafts, and the disaster reaches the unfortunate astronauts within moments, leaving them desperately struggling to stay alive.

Cuarón co-wrote the original screenplay with his son Jonás Cuarón, and the story barrels along on a direct line from the disaster through to its resolution, in something close to real time. The Cuaróns absolutely refuse the temptation of flashbacks and avoiding dipping too far into backstories, beyond what is reasonable under the circumstances. Clooney and Bullock trade on the goodwill created by their respective careers, which allows a bit of cheating to fill in the necessarily sketchy outlines of their characters.

None of that is important for the first 30-40 minutes of the movie, though, because Cuarón and his team of collaborators — notably Emmanuel Lubezki (gorgeous cinematography), Steven Price (unsettling musical score), Mark Sanger (seamless editing with Cuarón), and Andy Nicholson (meticulous production design) — have created a setting and a mood and a tempo and a feeling that sweeps from sheer beauty quickly into sheer, sustained terror.

It’s an all-enveloping, immersive experience in 3D, which is used judiciously, and IMAX. Like all large-screen experiences, however, at a certain point the wonder of the visuals becomes second-nature and the limitations of the story and characters exerts a downward tug. It’s not enough to bring the movie down to earth, but there is a sense that Cuarón is furiously trying to avoid painting himself into a corner. He is working with a canvas that is both larger than any he has attempted before, yet simultaneously smaller, more intimate, and more daring. And he is marvelously inventive in dealing with that challenge.

Gravity is well-worth watching on the biggest screen possible, with the best sound possible. It’s enough to make anyone think twice before signing up for the astronaut recruitment program — or encouraging their children to go into space.

Screening note: I attended an advance screening at the AMC NorthPark, with a smaller IMAX set-up, which was splendid, but I imagine that the Cinemark 17 IMAX will be the full-size screen to beat. If that’s not possible, spring for 3D, if you can; I’m not an advocate for 3D, but this is exquisitely handled and adds to the experience.

The film opens wide across the Metroplex on Friday, October 4.