Death Star

"That's no moon. It's a space station."

- Obi Wan Kinobi as he and his allies approaches the Death Star.

The Death Star I, also known as the DS-1 Orbital Battle Station, the Imperial Space Station, and commonly the Death Star, is a moon-sized military space-station that is the Galactic Empire's ultimate weapon of doom, capable of destroying planets with a single shot of it's super-laser. The Death Star was to be an instrument of terror, meant to cow treasonous worlds with the threat of annihilation. It had a formidable array of turbo-lasers and tractor beam projectors, giving it the firepower of greater than half the Imperial starfleet. Within its cavernous interior were legions of Imperial troops and fightercraft, as well as all manner of detention blocks and interrogation cells.

In a brutal display of the Death Star's power, Grand Moff Tarkin, one the Empire's preeminent governors, targeted its prime weapon at the peaceful world of Alderaan. Princess Leia Organa, an Imperial captive at the time, was forced to watch as the searing laser blast split apart her beloved homeworld, turning the planet and its populace into orbital ash and debris.

Episode 2
Count Dooku and his servants developed the plans to the Death Star known as the "Ultimate Weapon". He later gave them to his master.

Episode 4
20 years later after episode 3, the Death Star (also called Death Star I) is completely built and fully operable. It is used to destroy Princess Leia's home planet of Alderaan, and later in the movie is destroyed by Luke Skywalker, who manages to fire a proton torpedo into the Death Star's exhaust port, which aused the whole thing to explode, almost as if it had a self-destruct button.

Episode 5-6
Another Death Star, the Death Star II, was under reconstruction by the Galactic Empire. It was much larger than its predecessor, measuring over 900 kilometers wide, and was built after the destruction of the first Death Star at the Battle of Yavin. Emperor Palpatine insisted on the reconstruction of the battlestation, as it was an integral part in his plan to destroy the Rebel Alliance, leaving the galaxy in the hands of the Empire.

The Death Star's superlaser was revealed to be operational before the construction of the station was completed, surprising the Alliance attackers during the Battle of Endor. This was Emperor Palpatine's plan all along, and it nearly led to the loss of the Rebels. That is until the Emperor was defeated and ultimately killed by Darth Vader after he tried to lure his son Luke Skywalker into the dark side while the Alliance ground forces on the forest moon of Endor managed to deactivate the energy shield surrounding the battlestation, and the Rebel fleet proceeded to destroy the station from within, signifying the beginning of the downfall of the Empire.

Trivia

 * According to the Star Wars: Incredible Cross-Sections fact book, the first Death Star in A New Hope was 160 kilometers in diameter. According to the Inside the Worlds of Star Wars Trilogy fact book and detailed scaling of the station in Return of the Jedi, the second Death Star was 900 kilometers in diameter. Some Expanded Universe sources state much smaller figures—120 kilometers for the first Death Star and 160 kilometers for the second—however, most of the evidence argues for the larger sizes.
 * The Dalek Crucible in Doctor Who from series 4 in 2008 is said to be inspired by the Death Star, apart from the 'wings' on the side, the Crucible is very similar, but the eye is covered by a shield were as on the death star it is not.
 * Several of the Star Wars games are concerned with the Death Star's destruction, or the theft, protection, and transmission of its plans until reaching Tantive IV. Some games also focus on the immediate aftermath, such as Rogue Squadron III: Rebel Strike.
 * In the Italian version of Star Wars, the Death Star is called "Morte Nera", which literally means "Black Death".
 * The Death Star is available as a cheat in Star Wars: Galactic Battlegrounds: Clone Campaigns. It acts like an air cruiser unit, but is much slower. It more than makes up for its speed with excessive hit points, shielding, armor, and the most powerful attack in the game—any object on the map, even trees and rocks disappear after the Death Star fires. It is virtually impossible to destroy it. There is a limit on the number of Death Stars the player can conjure up at any time.
 * A number of Death Star battle stations appear in sources of uncertain canonicity. The Star Tours theme-park ride includes another battlemoon at Endor, clearly different than the one seen in Return of the Jedi, while the French-language RPG Magazine Casus Belli 99 includes another prototype, named the "Nocturnô". The former, however, was officially entered into continuity by Leland Chee, the gatekeeper of the LucasFilm Holocron Continuity Database, with it being named the Death Star III.
 * The Death Star has also influenced popular culture; a tribute to the Death Star, the "Death Egg" made an appearance in the Sonic the Hedgehog series after its debut as the final level of the 1992 videogame Sonic the Hedgehog 2.
 * Besides its role in Star Wars: Rogue Squadron III: Rebel Strike, both in the main campaign and its appearance in the co-op mode for the game (based on Rogue Squadron II: Rogue Leader), the Death Star also had an appearance in the game's opening and arcade mode, as a disco ball.
 * The Death Star in his form as a giant disco ball made an appearance in Family Guy: It's a Trap! when Rallo Tubbs (as Nien Nunb) says it went into "Glitter Ball Mode" after it's shield is down.
 * The Death Star's other name "Ultimate Weapon" is the name of the dangerous device in the Pokémon franchise.
 * In The Force Awakens, the Death Star's arguable successor, known as the Starkiller Base, was produced by First Order, and General Hux used it to committed a greater scale of destruction even beyond Tarkin's.