Dr. Ryan Stone uses the fire extinguisher as a thruster in outer space.
The Fire Extinguisher was a key plot point in Gravity.
Gravity
After Dr. Ryan Stone enters the International Space Station and breathes for the first time in several minutes, she is able to rest and calm down. Dr. Stone follows Kowalski's directions over the radio to find the Soyuz escape pods. The remaining crew of the ISS has fled in one of the two pods, so the second capsule should be fine for re-entry, Kowalski said. Dr. Stone tells Kowalski that she will come get him after she boards the Soyuz but Kowalski insists that she not worry about him. She then realizes that the parachute on the second Soyuz capsule has been opened, presumably in a failed escape attempt, which renders it useless for a return to Earth. Nonetheless, she starts heading towards the capsule, intending to get Kowalski with it and head to the abandoned Chinese Tiangong-1 station which contains a Shenzou escape pod which could take them home. However she was too distracted by all this planning that she failed to notice tiny balls of fire floating into the station from an electrical source. Stone smells smoke and realizes that the pure oxygen environment is fueling a massive fire. She tries to put it out with a nearby fire extinguisher, but forgets that she is in zero-gravity. After she presses the handle on the fire extinguisher, she is thrown back into a wall, leaving a cut and bruise on her face. Luckily Stone is able to escape to the Soyuz capsule and escape the fire, cleverly taking the fire extinguisher with her should there be another fire. Stone winds up having to put on a Spacesuit to untangle the parachute from the station so she can go rescue Kowalski and get to the Tiangong.
Stone remembers the landing rockets on the Soyuz and uses them to navigate to the Tiangong, only to realize that she will miss it by several meters. The Tiangong, which has been damaged by the debris chain, is sinking into the atmosphere and Stone realizes that she needs to go to the station now or else it will be too late. She ejects herself via explosive decompression and uses the fire extinguisher to push herself towards the station. She has just enough chemicals in the extinguisher to push her to the Tiangong airlock, reaching the Shenzou and getting back home.
The ultimate fate of the Fire Extinguisher was left unknown. Stone threw it into space after it ran out of chemicals, presumably sending it tumbling into the void or leaving it in orbit.
Trivia
- The Fire Extinguisher's appearance in the film is a reference to WALL-E, another film about space.