A space battle was fought over the planet Kessel between the Rebel Alliance and the Galactic Empire during the Galactic Civil War. Around 0.5 ABY, shortly after the Battle of Yavin, Alliance Admiral Gial Ackbar, along with a number of other Rebels, was captured by the bounty hunter Boba Fett during a mission to the Saleucami system. Ackbar was sold to the Empire and was later transported under heavy Imperial guard to the prison colony on Kessel for interrogation. When Alliance High Command discovered that the Mon Calamari Admiral had been taken captive, they dispatched a Rebel fleet and Renegade Squadron—the Alliance's new elite fighting force—to ambush the Imperial fleet holding Ackbar in space over Kessel.
Under the command of former smugglers–turned–Rebel Commanders Han Solo and Col Serra, Renegade Squadron destroyed the communications array on the Imperial-class Star Destroyer where Ackbar was being held and additionally incapacitated two Victory II-class frigates. After dogfighting Imperial starfighters and bombers, they boarded the Star Destroyer, broke the captive Ackbar out of prison, and transported him to safety. After the fleet jumped into hyperspace, Renegade Squadron decided to launch a mission to liberate the rest of the Rebels that had been captured in the Saleucami system.
Around 0.5 ABY, during the Galactic Civil War and shortly after the Battle of Yavin, the Rebel Alliance recovered a data holocron that contained prospective locations for a new Rebel stronghold to replace the Alliance's recently lost main base on the moon Yavin 4. Alliance High Command assigned Mon Calamari Admiral Gial Ackbar to take a small scout party to research Saleucami, one of the planets on the data list. However, when Ackbar and his small team arrived in the Saleucami system, they were ambushed by the Mandalorian bounty hunter Boba Fett and his ship, Slave I. Ackbar's transport was quickly disabled, and he and his crew were captured by Fett. The bounty hunter soon sold Ackbar to the Galactic Empire, while the rest of his crew were given over to the Hutt Cartel on the planet Tatooine as slaves.
Ackbar—considered a valuable leader and a military genius amongst the Alliance—was placed aboard an Imperial-class Star Destroyer under heavy guard and set to be transported to the Empire's prison colony on the planet Kessel for interrogation. When the Alliance learned that Ackbar had been captured, it quickly dispatched a fleet, along with its new elite fighting force, Renegade Squadron, to intercept the Imperial fleet holding Ackbar over Kessel. A group composed of former pirates and criminals under the command of smugglers–turned–Rebel Commanders Han Solo and Col Serra, Renegade Squadron was ordered to board the Star Destroyer containing Ackbar and free the Admiral. The Rebels believed that if they did not rescue Ackbar in time, he would break under Imperial torture, and all of the Alliance's secrets would be in jeopardy.
Renegade Squadron engages the Imperial fleet over Kessel.
The Alliance fleet, composed of a Mon Calamari Cruiser and a pair of Nebulon-B frigates, jumped out of hyperspace over Kessel just as the Imperial fleet entered the system. Renegade Squadron launched its starfighters from the Mon Calamari Cruiser's hangar bay, including X-wing, Y-wing, and A-wing fighters, as well as Solo's personal freighter, the Millennium Falcon. The Renegades began to attack the incoming Imperials, with Serra ordering them to destroy the communications array on the Star Destroyer holding Ackbar, thus preventing any Imperial reinforcements from being called. During the Renegades' initial sweep, they were able to wipe out the Star Destroyer's comm array, as well as incapacitate both of the Victory II-class frigates escorting the larger Star Destroyer by disabling their laser cannons. With the frigates unable to defend the fleet, the Star Destroyer proceeded to launch its complement of TIE Fighters, Bombers, and Interceptors to fight off the assaulting Rebel forces. Renegade Squadron engaged the Imperial fighters, quickly dispatching six of the TIE Fighters.
With the Imperial starfighters neutralized and the Imperial frigates no longer a threat, Solo ordered a member of Renegade Squadron to gather a Low Altitude Assault Transport/infantry gunship from their hangar and use it to send a boarding party—made up of Rebel troopers, vanguards, and Wookiee warriors—onto the Star Destroyer and free Ackbar. The Rebels were able to land the gunship inside the Star Destroyer's hangar, and the boarding team engaged the ship's stormtrooper crew, forcing its way deeper into the Imperial vessel until it found Ackbar, who was held in a small room near the hangar.
Escorting the Mon Calamari back to their gunship, the Renegades found that they were unable to leave, as the Imperials had deployed a force field around the magnetic containment field of the hangar, sealing the Rebels inside. From his command post, Serra managed to locate a shield generator at the side of the Imperial launch bay powering the shield and radioed its location to the boarding party. One of the Renegades destroyed the generator, allowing the Rebels and Ackbar to get into their transport and flee the Star Destroyer. Once Ackbar was safely aboard the Mon Calamari Cruiser, Solo ordered his forces away from Kessel and to jump into the safety of hyperspace.
When Solo and his fleet returned to Alliance High Command, Ackbar reported to those present what had led to his capture and the events surrounding his imprisonment. The Mon Calamari Admiral informed the Rebel leaders that Fett had not given the rest of the captured scouting party to the Empire, but had brought them elsewhere. Using his knowledge from his days as a smuggler, Serra concluded that the bounty hunter had sold the captured Rebels to the Hutt slave market on Tatooine. As a result, Renegade Squadron soon launched an attack on the Hutts' slave pens in the Tatooine city of Mos Eisley to free the captured soldiers.
Years later, after the formation of the New Republic, Jedi Knight Tionne Solusar tracked down Col Serra to gather information about Renegade Squadron for her Jedi Archives. Serra told the Jedi about many of the group's battles and exploits, including the rescue of Ackbar at Kessel.
The battle of Kessel has only appeared in the video game Star Wars Battlefront: Renegade Squadron, released on October 9, 2008, which tells the history and feats of Renegade Squadron during the Galactic Civil War. The battle itself makes up the fourth level in the game's campaign mode, in which the player, as a member of Renegade Squadron, must assist in rescuing Ackbar from Imperial custody. The player's main objectives in the level include taking out the Star Destroyer's communications, shooting down six TIE Fighters, disabling the Victory-class frigates' turrets, and boarding the Star Destroyer and freeing Ackbar.