In 0 BBY, the Rebel Alliance launched an attack to preemptively destroy or significantly damage the first Death Star while it was nearing completion in orbit above the planet Despayre.
It was an unconditional disaster for the Rebels. The group lost at least 500 of their premier starfighter assets as well as a large carrier capital starship. For the Imperials, it represented the first operational testing of the Death Star's superlaser and gave the crew confidence in the capability of the battlestation.
The battle was preceded by a series of acts of sabotage during the construction of the Death Star that culminated in the destruction of the Imperial-class Star Destroyer Undauntable. This caused Grand Moff Tarkin to suspect the presence of a cell of Rebel agents or sympathizers working within the project, and privately he had anticipated some form of military incursion.
The modified Rebel Lucrehulk-class starfighter carrier Fortressa unexpectedly slipped out of hyperspace within close proximity to the Death Star in a surprise attack. Reverting to realspace 2,200 kilometers out from the battle station in Sector Seven of its defense grid, the Rebel ship managed to bypass the Sector Fleet, commanded by Admiral Motti, stationed in-system and charged with the Death Star's protection.
The Fortressa immediately commenced the launch of two waves of T-65 X-wings of 250 starfighters each. On training maneuvers close to the surface of the Death Star, 1,120 TIE fighters from several squadrons, including Alpha Squadron, moved quickly to respond. They were led by Flight Commander Drolan and included notable pilots such as Lieutenant Commander Villian Dance.
The Imperial fighters held to a perimeter 1,000 km from the station while the Rebel fighters closed to range. From within the command center, Moff Tarkin ordered the Death Star's superlaser station to target the Fortressa. From within 28 seconds of receiving the warning to confirmatory order, the Rebel starship was completely atomized at a range of 2,209 km using only four percent of the station's destructive power.
The Imperial starfighters then engaged the first wave of disoriented Rebel fighters, who were continuing on mission towards the Death Star. The Rebel fighters were flying non-evasively towards the main objective and were largely annihilated with relativity minor losses incurred by Imperial forces. The second wave of 250 Rebel fighters were destroyed by TIE squadrons launched from the Star Destroyers, with none making it to the Death Star's fighter screen.
During the course of the engagement, Admiral Daala, who had been inbound to the Death Star when the Fortressa arrived, was critically injured when her ship was attacked by a squadron of X-wings causing damage to the bridge.
- The Essential Guide to Warfare