Gravity

Dr Ryan Stone, a medical engineer, is on her first shuttle mission, floating outside the craft to repair equipment she designed for the Hubble Space Telescope. Beside her works Matt Kowalski, a veteran astronaut on his last flight before retirement, drifting easily around the shuttle on a jet-powered backpack, trading calm jokes with Houston as if this were any other day at the office.

Then Houston's voice turns urgent: a Russian missile has just destroyed one of their own defunct satellites, and the wreckage has set off something far worse than anyone anticipated. Within minutes, a storm of debris travelling many times faster than a bullet tears through the shuttle. The rest of the crew are killed instantly. Stone, thrown loose from her safety line, tumbles away from the wreck in silence, spinning end over end into the emptiness, her oxygen supply already ticking down.

Kowalski finds her by following her panicked, half-coherent radio calls, matches her spin, and clips her to his own line. They are now alone, hundreds of kilometres above the Earth, with no shuttle, a dead crew, and a debris cloud that Kowalski calculates will circle back and hit them again in ninety minutes.

Kowalski and Stone's only hope is the International Space Station, and they use his remaining thruster fuel to drift towards it as the clock runs down. As they travel, Kowalski keeps Stone talking — about her young daughter, who died years earlier in a freak accident, and about how Stone has since buried herself in work rather than face the grief. It is the first time in the film she says the girl's name.

They reach the station just as the debris field returns, but it has already torn through the ISS: the crew has evacuated, one escape capsule's parachute has been triggered by accident and is useless, and the station itself is venting air and slowly beginning to spin. As Stone finally reaches the airlock, her tether catches on the station's structure and will not free itself in time.

With seconds left before the debris arrives again, Kowalski unclips his own line from Stone's, choosing to drift away rather than risk pulling her free of the airlock with him. He tells her, calmly, to let him go. She does. He disappears into the dark, and for the first time, Stone is entirely alone.

Alone on the crippled ISS, Stone puts out a fire, finds a working Soyuz capsule, and discovers — too late — that its parachute has already deployed and tangled around the outside, making it useless for landing. Exhausted and out of options, she briefly gives up, lowering the oxygen and preparing to let herself drift into sleep, until a hallucinated visit from Kowalski reminds her that Soyuz capsules use the same docking system as the nearby Chinese station, Tiangong — and that its escape capsule could still get her home.

She fires the Soyuz towards Tiangong, but runs out of fuel just short of it, as the debris field tears past yet again and damages the station further. With nothing left to propel her, she improvises: bracing a fire extinguisher and firing it like a makeshift thruster, using the force of the escaping gas to push herself, hand over hand, across the last stretch of empty space.

She reaches Tiangong, forces her way into its Shenzhou escape capsule, and undocks just as the station itself begins to break apart around her. The capsule falls, burns, and finally splashes down in a lake. Water floods in as it sinks; Stone forces the hatch open, swims up through the wreckage, and drags herself onto the shore — standing, for the first time in the film, on solid ground.

According to the European Space Agency, roughly 40,000 objects large enough to be individually tracked are currently in orbit, alongside an estimated 1.2 million fragments between 1 and 10 centimetres, and around 130 million smaller fragments still large enough to disable a satellite or pierce a spacesuit on impact. None of these numbers are shrinking.

The film's inciting event — a satellite deliberately destroyed, instantly seeding a dangerous debris cloud — has already happened for real. In 2007, a Chinese anti-satellite missile test destroyed the defunct weather satellite Fengyun-1C, creating over 3,000 trackable fragments in a single strike, still the worst debris-generating event on record. In 2021, a Russian anti-satellite test destroyed the satellite Kosmos 1408; the resulting debris cloud forced the seven astronauts then aboard the International Space Station to shelter inside their docked capsules for two hours, and threatened to pass near the station roughly every ninety minutes — the very rhythm the film invents for its own debris cloud.

Here's the honest part: the geography of Gravity is fiction. The Hubble Space Telescope, the ISS and the Chinese station Tiangong orbit at very different altitudes and angles — roughly 555 km, 420 km and 350–400 km respectively, on orbital paths tilted at different angles to the equator. In reality none of them is ever visible to, let alone reachable from, either of the others; Cuarón compressed three unrelated locations into one journey purely for the story. He never claimed otherwise — it's a deliberate artistic liberty, not an error he missed.

What the film gets right is the physics of moving your own body in zero gravity: Newton's third law, played out when Stone propels herself with a fire extinguisher — the escaping gas pushes her one way exactly as hard as it pushes the gas the other. The astrophysicist Neil deGrasse Tyson publicly listed a long string of the film's small errors (debris orbiting the wrong direction, Sandra Bullock's hair not floating with the rest of her) — and then, just as publicly, said he loved the film and praised its accurate depiction of floating water, the correct positions of the stars, and exactly that fire-extinguisher scene.