DS-1 Orbital Battle Station

The DS-1 Orbital Battle Station, also designated as the DS-1 Death Star Mobile Battle Station, referred to as the Ultimate Weapon in early development stages, later known as the Death Star I or the First Death Star, often simply referred to as the Death Star, and codenamed Stardust, was a moon-sized, deep-space mobile battle station constructed by the Galactic Empire. It had been designed to fire a single planet-destroying superlaser focused by massive kyber crystals which would destroy any planet targeted. It was the pet project of Emperor Palpatine, Director Orson Callan Krennic, and its eventual commander Grand Moff Wilhuff Tarkin to expound the military philosophy of the aptly named Tarkin Doctrine.

Some of the earliest plans for a mobile, planet-destroying superweapon dated back millennia to the ancient Sith. Thousands of years later, shortly before the outbreak of the Clone Wars, the Geonosians, aligned with Count Dooku and the Confederacy of Independent Systems, designed the Ultimate Weapon in secret. After the fall of the Confederacy, construction of the Death Star was appropriated by the nascent Empire. It was built in orbit of Geonosis and supported by a complex logistical network of bases. The station, which took many years longer to complete than expected, was eventually moved from Geonosis to Scarif in its final stages of construction.

The Axis network learned of the battle station's existence in a breach of Imperial Security Bureau files, and passed the knowledge through several operatives until it reached the Alliance to Restore the Republic at their secret base on Yavin 4. Though the Alliance was initially skeptical of the intel and its source, an unrelated Rebel spy soon corroborated enough of the information for the Rebels to begin an investigation. Division emerged within Alliance leadership; some believed such a weapon too great a threat to justify continued insurrection and resistance, while others believed the Death Star was too great a threat to ignore, and must be destroyed. Ultimately, rogue operatives Jyn Erso and Cassian Andor led a mission, which the Rebel Alliance soon joined, to steal the battle station's design plans, as Erso had discovered that her father, who had been the primary engineer behind the station’s superweapon, had left a fatal flaw in the design, which could enable the Death Star to be destroyed with relative ease.

Having retrieved the Death Star plans from the Imperial Center of Military Research on Scarif, Erso was able to transmit them to the Rebel fleet above the planet, and they were received by Princess Leia Organa of Alderaan aboard the Tantive IV. Leia then fled through hyperspace toward Tatooine, where she was apprehended by Darth Vader, but not before having hidden the plans in her astromech R2-D2. While the Princess was taken prisoner, her droid was able to escape and bring the plans to Obi-Wan Kenobi, a former Jedi Knight living in hiding on Tatooine.

In an attempt to coerce Leia, now held captive on the battle station itself, into revealing the location of the Rebel Alliance's secret base, Governor Tarkin ordered the first full test of the Death Star, destroying the Princess' home planet of Alderaan. Shortly thereafter Leia managed to escape captivity on the Death Star with the help of Obi-Wan Kenobi and Luke Skywalker, who had been brought to Alderaan by pilots Han Solo and Chewbacca in an effort to reunite the recovered Death Star plans to Leia's father and Rebel Alliance leader, Bail Organa.

Leia brought the plans to the Alliance leadership on Yavin 4, who quickly analyzed the data and discovered the design flaw deliberately left in the battle station by Imperial engineer Galen Erso, which would allow a single proton torpedo, fired into the thermal exhaust port, to destroy the entire station. The Alliance launched a small assault against the Death Star, which had followed the escaping rebels to the Yavin system. The original Death Star was destroyed moments before opening fire on the moon by a shot fired by Rebel pilot Luke Skywalker with the aid of the Force. While Darth Vader escaped, due to having joined the dogfight above the station in his TIE fighter, many high-ranking Imperial officers perished aboard the space station, including Wilhuff Tarkin, Wullf Yularen, and Conan Motti.

The destruction of the Death Star weakened the Imperial Military, and Rebel assaults on Imperial installations prompted the construction of a second Death Star, both as a sign of defiance and technological terror. Despite this, it, like its predecessor, was destroyed with all hands lost. Decades later, the Empire's successor state, the First Order, constructed Starkiller Base, a much larger planet-destroying superweapon considered to be an evolution of the Death Star project of the Old Empire.

Text and facts from the “DS-1 Orbital Battle Station” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.