The Imperial kyber refinery was a secluded Imperial research and development facility located on the planet Eadu. Guarded by the Eadu Deployment, the installation was where the development research was done for the Death Star's superlaser under the direction of Galen Erso as part of the Tarkin Initiative. A team of scientists at the complex undertook two interconnected projects: the fusing of kyber crystal shards into larger forms and the creation and redirection of a controlled chain reaction.
During Operation Fracture in 0 BBY, the Rebel squad "Rogue One" travelled to the facility in a UT-60D U-wing starfighter/support craft to find Galen Erso. Director Orson Krennic arrived shortly after the Rebels in his Imperial shuttle to investigate suspicions of a Rebel sympathizer within the scientific ranks. After Erso revealed himself as the traitor, Krennic had his team executed by death troopers. The complex was then attacked by Rebel T-65B X-wing starfighters and BTL-A4 Y-wing assault starfighter/bombers, with the base's TIE/ln space superiority starfighters being dispatched to deal with the threat. During the battle, Erso was mortally wounded and died in his daughter's arms.