The Battle of Dega was a strike by the Rebel Alliance against a resupply operation of Task Force Vengeance, in which Imperial forces under Admiral Wooyou Senn were to receive cargo and conscripts from their Airam allies loyal to detained clan leader Ilay.
Both Rogue and Green Squadrons had been equipped with B-wing assault fighters fully loaded with proton torpedoes before the mission. Their task was to destroy any freighter carrying supplies to the resource-starved Imperial task force, as well as disable freighters identified as carrying Airam conscripts.
When the Rebel fighters arrived at Dega, they were presented with a full view of the Executor-class Star Dreadnought Vengeance and the Imperial-class Star Destroyer Rage—and eight Airam BFF-1 bulk freighters closer to their position. The Rogues split up to inspect the running freighters, but encountered a nasty surprise when they targeted the cargo vessels: before her capture, or at her prior instruction, Ilay had equipped one-shot warhead launchers to the freighters that would automatically lock and fire at any incoming starfighter that targeted one of the ships.
The booby-trap nearly bought the freighters enough time to run to the safety of the Star Destroyer's guns, but Rogue Squadron managed to disable the freighters transporting conscripts while Green Squadron wreaked havoc on the warhead-carrying freighters. Though the clever gimmick likely cost the lives (or at least the spacecraft) of at least a couple Rebel pilots, it ultimately failed to prevent the convoy's neutralization.
But the sheer scope of the Airam convoy taxed the Rebel starfighters, each of them tasked with inspecting, disabling, and destroying the appropriate freighters. More and more bulk freighters dropped out of hyperspace, eventually numbering around twenty ships. The ships were spread out over a distressingly wide area for the sluggish B-wings to cover.
Even a starfighter distraction force launched by the Vengeance and the Rage was not able to prevent Rogue and Green Squadrons from eventually completing the inspection and neutralization of the Airam ships. The multitasking Rebel pilots also succeeded in protecting the rescue shuttles sent by the Alliance to take aboard the conscripts from the disabled freighters. Once the last freighter was destroyed and all the conscripts possible rescued, the Alliance forces withdrew.
The dire supply situation of Task Force Vengeance became evident after the Battle of Dega. During questioning, the Airam conscripts reported that they were to undergo basic flight training aboard the Vengeance, then undertake suicide missions against the Alliance forces in the Airam sector—the large supply of warheads in the accompanying freighters would have proven lethal to the Rebels if such attacks materialized.
Senn's options were now cut down to very few possibilities: either withdraw the remainders of the task force and face the wrath of his superiors, or to continue his mission at all costs—an option he chose to pursue with his following attack on the Alliance shipyard in the Nocto system.