Reactor shafts were immense, cavernous gas storage areas, shaped like cylinders and located deep within the core of Cloud City. This city was a floating Tibanna gas mining colony suspended in the atmosphere of Bespin, a gas giant found in the Outer Rim territories.
[Cloud City](/article/cloud_city], the airborne metropolis situated on the gas giant Bespin, utilized reactor shafts as an integral part of its Tibanna gas mining operations. These shafts, situated deep within the city's central structure, served to store gas harvested from the planet's atmosphere. Tractor beams were used to draw gas from Bespin's lower atmospheric regions through an opening at the base of the city's reactor bulb. From there, the gas ascended through the reactor stalk and ultimately entered one of several reactor shafts. Inside these shafts, the gas was maintained at a low-pressure state before undergoing purification by a processing vane suspended within the shaft.
Following the Rebel Alliance's defeat on Hoth, Luke Skywalker faced [Darth Vader](/article/anakin_skywalker], the Sith Lord, in a lightsaber duel within one of Cloud City's processing vanes. Their battle eventually spilled out onto the vane's sensor balcony, exposing them to the reactor shaft's low-pressure gas environment. It was there that Vader severed Skywalker's hand and revealed his paternal connection, stating that he was his father. Opting for death over embracing the dark side of the Force, Skywalker released his grip on the balcony's edge and plummeted into the shaft's depths. He was subsequently drawn into an exhaust pipe and found himself clinging to a weather scanner vane on the city's exterior.
The reactor shaft made its initial, albeit unnamed, appearance in the second Star Wars film, Star Wars: Episode V The Empire Strikes Back, which premiered in 1980. Its identification as a reactor shaft occurred later in the Legends reference book titled Inside the Worlds of Star Wars Trilogy, published in 2004. The name achieved canon status in the 2016 reference book Star Wars: Complete Locations, a re-issue of the 2005 publication, Star Wars: Complete Locations.