Mission to recover Imperial codes In the year 2 BBY , Phoenix Cell dispatched Phoenix Leader Hera Syndulla and her Spectres crew on a mission to recover Imperial codes from the Imperial Security Bureau station on Killun 71 for the Alliance to Restore the Republic ' s attack on Lothal . Wedge Antilles , disguised as an Imperial pilot , flew a stolen " Sentinel " - class landing craft to Killun Station carrying the droid s AP - 5 and Chopper , who entered the base to steal the codes . AP - 5 , as a former Imperial droid , passed through the security and successfully acquired the codes without any problems . Chopper , however , was unlicensed , and had come to Grand Admiral Thrawn ' s attention as a rebel infiltrator after several of his past missions . Due to this , LT - 319 , a controller for the Imperial Information Office , detected the astromech droid from his listener ship and took Chopper over when he tried to steal the clearance codes from a port in the base . LT - 319 decided not to alert Killun Station ' s personnel , as he wished to use Chopper to discover the location of Phoenix Squadron ' s base . AP - 5 quickly noticed that something was wrong with Chopper , and attempted to inform Wedge on route to their rendezvous with the " Ghost " . However , the inventory droid ' s excessive pushiness , including following Wedge into the refresher , coupled with the controlled Chopper acting nice to Wedge , led the Lieutenant to assume that the droids were " playing some kind of spy game " . Upon their return to the " Ghost " , however , Hera quickly realized that something was wrong with her droid . LT - 319 swiftly used Chopper to lure the Rebels into the freighter ' s cargo hold and trap them there , before installing a data spike to try and steal the base ' s coordinates from the ship ' s navicomputer . An attempt to blow the Spectres , AP - 5 and Wedge into the vacuum of space was thwarted , and Hera sent AP - 5 onto the " Ghost " hull to access some controls that would open the hatch to the cockpit . He accomplished this , but was witnessed by the controlled Chopper , who was sent outside to finish the protocol droid off , and knocked him off the " Ghost " hull , setting him adrift in space . Upon returning , Chopper was ambushed by the Spectres , and Hera used the spike to reverse the control feed , remotely blowing up LT - 319 ' s surveillance ship . Afterwards , they went back to retrieve AP - 5 . As the controller had not informed any other Imperial authorities of the theft , the Rebels ' mission was successful . Prelude . The C1 - series astromech droid known as Chopper was a member of the rebel cell known as the Spectres , which was part of the Alliance to Restore the Republic . . He was a friend of the former Imperial RA - 7 inventory droid AP - 5 , who had joined the rebellion after helping the rebels to locate a safe base on the planet Atollon . Together , the two droid s undertook several missions on behalf of the rebellion , and even helped foil an Imperial operation to locate Chopper Base . As part of the rebellion , Chopper undertook numerous undercover missions into Imperial installations and starship s . On these occasions , he was painted in black and red colors to mimic Imperial astromech droid s . During a mission to infiltrate the Imperial Armory Complex on Lothal , Chopper was detected by the Imperial tactician Grand Admiral Thrawn , who identified him as an unregistered C1 astromech droid . Thrawn kept a catalogue of the rebel droid ' s sightings for Imperial forces . The mission . Killun Station . While preparing for Phoenix Cell ' s attack on Lothal , Phoenix Leader Hera Syndulla dispatched AP - 5 , Chopper and Lieutenant Wedge Antilles on a mission to steal a set of clearance codes from the Imperial Security Bureau ' s base on Killun 71 . Hera placed AP - 5 in charge , and he and Chopper were tasked with downloading the codes from the station ' s central computer . The Rebels managed to obtain permission to land at the base under the pretext of delivering two service droids . AP - 5 managed to pass through the base ' s sensors without any problems . However , Chopper caused an alert when he passed through the scanner , which went unnoticed by the stormtrooper s on guard but was detected by the crew of an Imperial Information Office IGV - 55 surveillance vessel in deep space . The ship ' s controller , LT - 319 , recognized Chopper as the unregistered rebel droid that Thrawn had referenced in his manual on Phoenix Squadron . While one of his subordinates , 3 - 9 , wanted to inform the ISB station , the Imperial controller decided to use Chopper to find Phoenix Squadron ' s hidden base . Chopper attempted to acquire the codes by plugging a network terminal , despite AP - 5 informing him that the most current codes would not be accessible there . The protocol droid , exasperated , headed for the main control room to get the codes by himself , leaving Chopper at the terminal . LT - 319 and his crew took the opportunity to hijack the rebel astromech droid , searching for the base coordinates . After discovering that they were not in Chopper ' s memory , the controller had Chopper taken over so he could lead them to the rebel base . Outside the control room , AP - 5 encountered an ISB droid , PZ - 7 , but was able to get rid of her by claiming that he was her replacement and she had been reassigned to the cargo platform . After AP - 5 stole the clearance codes , he found the Imperial - controlled Chopper still at the terminal , and taunted him about how much more effective he was before departing for the shuttle . Boarding the shuttle , AP - 5 told Wedge they had to leave at once . When Wedge asked where Chopper was , the hijacked droid boarded their stolen " Sentinel " - class landing craft . While AP - 5 was suspicious about Chopper ' s change in behavior , Wedge did not notice anything untoward , and even welcomed Chopper ' s more respectful attitude . AP - 5 attempted to warn Wedge , and even followed him into the shuttle ' s refresher so they could talk without Chopper overhearing . The controller watched through Chopper as Wedge kicked AP - 5 out of the refresher , and believed that the inventory droid had undermined his own credibility . Spy games . The shuttle docked with the " Ghost " , and AP - 5 gave Hera the disc with the clearance codes . Wedge told her about the droids ' behavior on the flight , which amused Ezra Bridger and Garazeb Orrelios . The Imperial - hijacked Chopper then made his way to the " Ghost " cockpit and proceeded to download the ship ' s hyperspace logs . By that time , AP - 5 had managed to warn Hera about Chopper ' s suspicious behavior . Hera managed to stop Chopper , who claimed that he had had files wiped on Killun , and reminded the droid that she cleared his data after every hyperspace jump for security reasons . After she went to speak with the rest of the crew , Chopper dropped the ship out of hyperspace and hid away . When Hera contacted him , demanding to know what happened , Chopper claimed that he was in the engine room and that there was something wrong with the hyperdrive . Hera roused the other crew , all of whom were now certain that there was something wrong with Chopper , in order to find him . The hijacked droid then locked the rebels in the " Ghost " cargo hold and jettisoned the stolen Imperial shuttle , flying away . After recovering the stolen Imperial clearance codes , Chopper began to install a data spike into the " Ghost " navigation computer . This enabled the Imperials to begin remotely downloading the ship ' s travel logs . In an attempt to kill the rebels , the controller ordered Chopper to open the cargo hold to space . However , Hera managed to manually shut the door . Unable to open the cockpit hatch from the inside , she sent AP - 5 to open it from the outside . While walking on the ship ' s hull , AP - 5 was seen by Chopper and the controller through the cockpit window . Determined to eliminate the rogue RA - 7 droid , the Imperial controller sent Chopper to fight off AP - 5 . Chopper managed to push AP - 5 into space , just after the inventory droid had unlocked the hatch . After Chopper returned , Zeb stunned him with his bo - rifle . Hera then linked Chopper to the " Ghost " systems and decided to send a strong message to the Imperial slicer s . Using Chopper ' s visual processor , Hera issued a threat to LT - 319 and transmitted a data overload that disabled the " Gozanti " cruiser ' s systems , causing it to explode and killing all of the Imperial crew . Aftermath . After eliminating the Imperial threat , Hera reprogrammed Chopper . After the Spectres reconciled with Chopper , they rescued AP - 5 from space . Despite the hijacking and reprogramming of Chopper , the Spectres managed to keep the clearance codes they had stolen from Killun 71 . The destruction of the Imperial communications cruiser also concealed word of the rebel theft and allowed Phoenix Squadron to continue making preparations for their strike on Lothal . Behind the scenes . The mission to Killun Station first appeared in the " Star Wars Rebels " season three episode " Double Agent Droid " , which premiered on Disney XD on March 11 , 2017 .