R3 - A3 R3 - A3 was an R3 - series astromech droid and member of a local rebel cell on Mykapo called the Iron Squadron . He was responsible for maintaining the " Sato ' s Hammer " systems and customized it to his own specifications . Following a skirmish with an Imperial patrol , R3 - A3 and his fellow rebels came into contact with the Spectres and Phoenix Cell . While initially reluctant to leave , R3 and his comrades Gooti Terez and Jonner Jin heeded the warnings of Ezra Bridger and Sabine Wren and managed to escape the system . However , their leader Mart Mattin was left behind . R3 took part in a combined rescue effort to save Mart . He joined forces with the astromech droid Chopper to remove a magno - mine attached to " Sato ' s Hammer " . Later , he accompanied Mart during the failed attack on Lothal ' s Imperial Armory Complex , in the astromech socket on his T - 65B X - wing starfighter . After Mart crash - landed in Lothal City , R3 attempted to protect him from several stormtrooper s , and was destroyed . Mart was rescued by Hera Syndulla and Chopper . She and Mart took out R3 ' s transmitter to use as a replacement for Chopper ' s , which had been damaged when Hera crashed . Biography . Background . During the Age of the Empire , R3 - A3 was part of a rebel cell based on Mykapo called the Iron Squadron . He served captain Mart Mattin , Gooti Terez , and Jonner Jin and was responsible for maintaining their starship , " Sato ' s Hammer " . Mart ' s father was the leader of the Iron Squadron and his son succeeded him after he died . The Iron Squadron had no contact with other rebel cells including Mart ' s uncle Commander Jun Sato ' s Phoenix Cell . The Iron Squadron constituted the only rebel group in the system . Joining the rebellion . In 2 BBY , the Iron Squadron clashed with an Imperial advance patrol . Despite sustaining damage to their hyperdrive , the Iron Squadron managed to destroy their Imperial opponents with the help of the Spectres and Phoenix Cell . " Sato ' s Hammer " destroyed a " Gozanti " - class cruiser by dropping several cargo containers containing explosives . Later , the Spectres docked their ship , the " Ghost " , with " Sato ' s Hammer " . Hera Syndulla , the leader of the Spectres and Phoenix Leader , attempted to recruit the Iron Squadron . The rebels chanced upon R3 - A3 repairing the hyperdrive . R3 entered into a fight with the rebels ' astromech droid Chopper , who wanted to fix the hyperdrive . Only Gooti and Ezra Bridger , one of the Spectres , managed to break up the fight . Hera ' s meeting was unproductive since Mart and his crew refused to leave Mykapo . After Ezra convinced Hera to let him have another go at reasoning with Mart , R3 accepted help from Sabine Wren and Chopper to repair the hyperdrive . Despite repairing the hyperdrive , their efforts came to naught when Mart diverted the power to the ship ' s laser cannon s and deflector shield s . After Imperial reinforcements under Admiral Kassius Konstantine entered the system , R3 - A3 along with Gooti and Jonner heeded Ezra and Sabine ' s warnings to leave and evacuated aboard the " Phantom II " , the Spectres ' shuttle . However , Mart decided to stay behind and disengaged the " Phantom II " . He attempted to attack Konstantine ' s " Arquitens " - class command cruiser but the ship ' s engines were disabled . R3 - A3 and the other rebels escaped into hyperspace aboard the " Phantom II " . R3 - A3 later participated in a joint mission by the Spectres and Iron Squadron to rescue Mart Mattin . After the rebels learnt that Konstantine had attached a magno - mine to the hull of " Sato ' s Hammer " , Hera dispatched R3 - A3 and Chopper to remove the mine . The two droids were deployed via the Spectres ' starship " Ghost " cargo bay . R3 was afraid so Chopper pushed him into space . The two droids then activated their rocket booster s and flew to " Sato ' s Hammer " . Working together , they removed the magno - mine with R3 removing the magnetic field . The two droids then reattached the mine to cargo box hanging from " Sato ' s Hammer " . Under orders from Hera , they entered the ship ' s cockpit to await pick - up by the " Ghost " . R3 - A3 reunited with his captain aboard . Shortly later , rebel forces led by Commander Sato arrived and attacked Konstantine ' s Imperial forces . After the " Ghost " picked up " Sato ' s Hammer " , they dropped the bomb - laded cargo box onto Konstantine ' s ship . The resulting explosion badly damaged the cruiser and allowed the rebels to flee just as Grand Admiral Thrawn entered the system in the " Chimaera " . Later , R3 reunited with the other rebels at Chopper Base on the planet Atollon . He witnessed Mart hugging his uncle Jun , Jonner , and Gooti . Attack on Lothal . Later , Mart became a starfighter pilot in the Rebel Alliance Starfighter Corps , flying a T - 65B X - wing starfighter , with R3 as his astromech . The two participated in the attack on Lothal , flying under General Hera Syndulla . The attack failed , and the Rebel fighters were shot down , with a few managing to crash - land in Capital City . Mart and R3 were among those who survived . When Imperial stormtrooper s approached Mart ' s crashed fighter , intending to arrest him , R3 defended the injured and disoriented pilot . The stormtroopers wanted to take the droid captive , as his memory banks would be valuable intelligence . They eventually shot and destroyed R3 , shortly before Hera and Chopper arrived and helped take out the Imperials . Hera asked Mart for permission to use R3 ' s transmitter to replace Chopper ' s , which had been damaged when her fighter crash - landed . Mart gave them permission , stating that R3 would have wanted to help the other Rebels . Personality and traits . R3 - A3 was a temperamental and territorial astromech droid who maintained the systems aboard the " Sato ' s Hammer " . While he was initially bristling at help from Chopper , the two came to form a strong bond and joined forces to repair the ship ' s hyperdrive and to remove a magno - mine . R3 had a conical head , like those of the R4 astromech line , and was equipped with a rocket booster . R3 - A3 ' s devotion to his master Mart Mattin led him to sacrifice his own life . Mart ensure that R3 ' s sacrifice was not in vain by replacing Chopper ' s damaged transmitter with the fallen droid ' s one . Behind the scenes . R3 - A3 and the rest of Iron Squadron first premiered on the eponymous Disney XD " Star Wars Rebels " episode " Iron Squadron " , which premiered on November 11 , 2016 . As with C1 - 10P ( " Chopper " ) , a fully articulated , life - size model of R3 was constructed and featured in the " Rebels Recon " web sketch series " R3 - Cam " , formerly known as " Chopper Cam " . Operating at Lucasfilm Ltd . , R3 led the series in the sketches attached to the first half of " Star Wars Rebels " Season Four until he witnessed his on - screen death in " Rebel Assault " , at which point he followed suit and Chopper took back his corner .