The Mk I Superlaser was the first model of kyber crystal-powered superlaser developed by the Galactic Empire. It was the primary weapon of the first Death Star battle station. Components for the superlaser dish were constructed at the Narkina 5 Imperial Prison Complex.
The Mk I Superlaser was a superlaser array consisting of a focusing lens that housed eight tributary lasers. Inside each of the lasers was a giant kyber crystal, assembled by the conglomeration of myriad crystal shards into a compound crystal mimicking the physical properties of a natural normal-sized kyber. The lasers were arranged in a circular shape around the dish and magnetically shielded to prevent influence from . A series of spherical targeting field generators were arranged around the center of the dish, while a circular focusing magnet was placed immediately behind it.
To fire the weapon, the Death Star's hypermatter annihilation reactor would power up to a single or a full reactor ignition, and hypermatter channels would be forced into the crystalline array by means of deflector shields placed along the power amplifier leading to the weapon. The hypermatter energy powered four induction hyperphase generators which kickstarted the firing process, and was then focused through the compound kyber crystals in the tributary lasers to create eight massively powerful green-colored beams. Focused containment channels worked in tandem with the targeting field generated from the lens dish to force the beams to converge into a singular point, accumulating the full power of the reaction, before being released in the form of a single beam towards the target. Fully powered, the superlaser had the capability of reducing any planet to an asteroid field. Recharging the weapon after a full-power shot took 24 hours.
The Mk I Superlaser was the most important component of the DS-1 Death Star Mobile Battle Station, the Galactic Empire's single most powerful superweapon. Without it, Grand Vizier Mas Amedda considered the Death Star to be merely a very expensive artificial planetoid. It was key to Grand Moff Wilhuff Tarkin's Doctrine of rule through fear, as he believed that the fear of ultimate destruction would alone serve to keep star systems under the Empire's rule in line.
Development of the weapon started as early as in 19 BBY, almost simultaneously to the establishment of the Galactic Empire. Working under Project Celestial Power, scientist Galen Erso, who was misled by project leader Orson Krennic into believing that he researched a means to solve the galactic energy crisis began to investigate kyber crystals. By 17 BBY, the project had managed to create a prototype kyber-powered weapon which was test-fired in the Hero Twins system, unleashing unprecedented amounts of power. At that time, however, Erso figured out that his work was intended to be weaponized and escaped Coruscant with his wife Lyra and daughter Jyn during the All-Species Week. In truth, the platform that was to carry the weapon he unwittingly designed, the Death Star, was already assembled over Geonosis. Afraid of retaliation, Erso left his notes untouched, providing Celestial Power engineers with enough material to continue the work. Indeed, fellow Project scientists Vlex Onopin and Rasett Milio managed to develop computer models for the targeting and firing of the still-theoretical superlaser.
By 13 BBY the project had been transferred to the Tarkin Initiative, a think tank of Imperial scientists, in the hopes that the absence of Erso's genius could be covered. However, the scientists proved inadequate, and Krennic personally tracked the Ersos down to their farm in Lah'mu and recovered Gailen after having his death trooper escort kill his wife. Erso, devastated but pragmatic was forcefully recruited to the Initiative, where he realized that the project could in fact very easily be completed without him. To have his revenge, he pretended to cooperate with Krennic and Tarkin's ambitions to gain their favor, and soon he was given access to the entire battle station's assembly project which he codenamed Project Stardust after his lost daughter and placed a small thermal exhaust port which would destroy the entire station when fired upon.
Thanks to Erso's expertise in crystallography, the secrets of kyber were finally cracked and fellow scientist Ames Uravan was finally able to synthesize a compound crystal large enough to be used for a fully functional superlaser. Assembly of the weapon started soon after, and by 5 BBY inmates of the the Narkina 5 Imperial Prison Complex were tasked with constructing parts for its dish which were delivered to the assembly zone over Scarif on board Zeta-class heavy cargo shuttles. The last parts to be completed were the compound crystals in 1 BBY. To ensure their protection, these were carried on board heavily guarded civilian freighters such as the Orca-class Freighter 2716, and dropped off in empty regions of space to be picked up by Imperial-class Star Destroyers and finally carried to the weapon itself.
The weapon was fully assembled and joined with the Death Star station during the same year, in an empty region of space and witnessed by both Krennic and Tarkin. By that time, Erso's betrayal was already suspected, as the defector he had tasked with revealing his secret weakness into the station to his daughter, a cargo pilot named Bodhi Rook, was discovered by Imperial Intelligence. Although he managed to reach the Partisans in Jedha, the Empire was actively pursing him. At the same time, Tarkin was doubting the functionality of the superlaser, and had already began to limit his support of the project over Grand Admiral Thrawn's TIE/D Defender Elite starfighter project. As such, Krennic decided to solve both his problems at once, and invited Tarkin, the Galactic Emperor and Darth Vader to a test-firing of the weapon against the planet of Jedha. Tarkin considered the Emperor and Vader's presence unnecessary -supposedly to "protect" Krennic in case the test failed-, and instructed the test to be limited in scope, prompting Krennic to target Jedha City with a single reactor ignition. The test was a complete success, and the city was instantly vaporized. Tarkin apologized to Krennic, and promptly took control of the station as both the highest-ranking officer and the original inventor of the idea, enraging Krennic.
Soon later, following the Battle of Scarif, the Rebel Alliance managed to steal the Death Star plans from the Imperial Center of Military Research and carried them away on board Princess Leia Organa's CR90 corvette. Despite Vader capturing her and her ship, the Princess managed to send the plans away with astromech droid R2-D2. Now a prisoner, she refused to reveal the location of the rebel Alliance's base and was carried to the Death Star for interrogation. When all else failed, Tarkin invited her to the Overbridge, where she asked her to make a choice: reveal the location of the base and have it destroyed with the superlaser, or Tarkin would order her home planet of Alderaan to be destroyed instead. Terrified, Leia revealed the location of a past base, Dantooine, but Tarkin proceeded to nevertheless order the destruction of Alderaan. The superlaser fired at full power, reducing the once mighty planet to dust.
The weapon was destroyed along with the rest of the station during the Battle of Yavin, right before firing at the true Rebel base in Yavin 4.
- Dawn of Rebellion