Death Star

The Death Star is a fictional moon-sized space station and superweapon. It was invented for the Star Wars movies. It was a huge spherical space station which fired a ray of energy which could destroy a planet.
Origin and design
The details of the Death Star changed between different models during production of Star Wars Episode IV: A New Hope. These changes include the position of the superlaser. The idea of the Death Star as a large, spherical space station was the same in all the models. The sound of the Death Star counting down until it fires comes from the Flash Gordon movies. Making a Death Star that was only partly built (but was still powerful) was a problem for Industrial Light & Magic's modelmakers for Star Wars Episode VI: Return of the Jedi. Only the front side of the 137-centimeter model was finished. The image was flipped horizontally for the final movie. Both Death Stars were created in the movies by using a full models, models of sections of the space station and matte paintings.
Depiction
Movies
The first Death Star was shown in its finished form in Star Wars Episode IV: A New Hope. It was commanded by Grand Moff Tarkin (Peter Cushing). The Death Star was the Galactic Empire's "ultimate weapon". The movie begins with Leia Organa (Carrie Fisher) attempting to take the station's plans to the Rebel Alliance, wanting to help them destroy the Death Star. Onboard her vessel, she was captured by an imperial ship and taken captive to the Death Star. There, Tarkin tries to make Leia reveal the location of the rebel base by threatening the use of the Death Star to destroy Leia's home world, Alderaan. She tells them a location but not the real one, but Tarkin has her planet destroyed anyway. Later, Luke Skywalker (Mark Hamill) and his small crew are also captured and taken to the station, escaping with Leia shortly after. In the movie's main battle scene, the force ghost of Obi-wan Kenobi tells Luke to use the Force to help him direct proton torpedoes from his x-wing into the Death Star' reactor core and not with his ship's targeting system. Luke obeys and successfully launches the torpedoes into the core. This ultimately resulted in the destruction of the battle station.
Return of the Jedi takes place four years later. At this time, the Empire is building a new Death Star. It is half-finished in the movie. Darth Sidious (Ian McDiarmid) and Darth Vader (David Prowse/James Earl Jones) send the Rebels false information with the intention of trapping the Rebels, saying that the station's weapons systems are not fully functional. They also want to get Skywalker on board so they can turn him to the dark side of the Force. In the movie's climax, Vader throws Sidious down one of the station's reactor core, apparently killing him. However, Sidious fires a large amount of sith lightning during this process and critically damages the electronics on Vader's suit that keeps him alive. Luke tries to get his father out of the battle station but he dies shortly after. Luke then takes Vader's body and leaves the Death Star just before it is destroyed by Lando Calrissian on board the Millennium Falcon.
The first Death Star is also dealt with in the Star Wars prequel trilogy. Its schematics are shown in Star Wars Episode II: Attack of the Clones. At the end of Star Wars Episode III: Revenge of the Sith, the Death Star is shown starting to be built.