Mart Mattin lived on the planet Mykapo during the Age of the Empire. His father was the leader of a rebel cell called the Iron Squadron, which consisted of the Theelin Gooti Terez, the human Jonner Jin, and the astromech droid R3-A3. These rebels operated from a YT-2400 light freighter called Sato's Hammer. At some point, Mart's father was killed during a clash with Imperial forces. Mart took over leadership of the Iron Squadron and did not maintain contact with his uncle Jun Sato, the commander of the Phoenix rebel cell. Mart and his fellow Iron Squadron members regarded the Mykapo system as their home and harassed Imperial forces there.
Joining the rebellion
They dispatched an advance patrol, consisting of a Gozanti-class cruiser and several TIE fighters to lock down the system. Mart's Iron Squadron clashed with the Imperial patrol and sustained damaged to their ship's hyperdrive. Shortly later, Hera Syndulla and her Lothal rebels along with Phoenix Squadron arrived to evacuate rebel sympathizers on Mykapo. They came to the aid of Iron Squadron by attacking the Imperial fighters. Hera contacted the Iron Squadron and told them that they needed to evacuate the system. Mart thanked the rebels for their help but declined their offer of assistance. When Hera reiterated her warning, Mart replied that the Iron Squadron did not run. He then flew the Sato's Hammer towards the Gozanti cruiser and dropped several explosive cargo pieces which destroyed the Imperial ship.
Following the skirmish, Mart chatted with Hera via the intercom and invited her and her crew aboard the Sato's Hammer. Hera's ship Ghost docked with the Sato's Hammer and Mart's crew entertained Hera and her rebel comrades Ezra Bridger, Sabine Wren, and the astromech droid Chopper. Mart met with the Lothal rebels in his ship's cockpit and acknowledged that he was Commander Sato's nephew. When Mart asked Hera if his uncle had sent him, Hera replied that she and her fellow rebels had come to evacuate rebel dissidents from Mykapo. Mart rejected any idea of evacuating Mykapo as cowardice and remarked that he could hold off the Empire. When Hera warned them that the Empire would return, Mart responded that he and his crew had just destroyed a Star Destroyer; mistaking the Gozanti cruiser for one. In the end, Mart and his crew decline Hera's offer to leave and reiterated that they would defend Mykapo from the Empire.
Despite the unsuccessful meeting, Ezra persuaded Hera to let him, Sabine, and Chopper stay behind to repair the Iron Squadron's hyperdrive. Ezra was still determined to win over the squadron. Hera reluctantly sanctioned his mission but warned the rebels that they needed to leave at the first sign of Imperial activity. Mart and his crew allowed Sabine and Chopper to assist R3-A3 with the repairs. However, he still thought that it was a waste of time. Sabine and the droids managed to repair the hyperdrive. However, their efforts came to naught because Mart redirected the power to the armaments and deflector shields. Upon sighting Imperial reinforcements, Mart ordered his crew to their battle stations. This second Imperial force was commanded by Admiral Kassius Konstantine and consisted of an Imperial light cruiser and two more Gozanti cruisers.
Despite the odds stacked against the Iron Squadron, Mart refused to back down and flew the Sato's Hammer towards Konstantine's forces. Ezra and Sabine disagreed and managed to convince Gooti, Jonner, and R3-A3 to accompany them into their shuttle, Phantom II. When the ship's power broke down, Mart saw reason and accompanied the rebels aboard the Phantom II. Once everyone else had gone aboard, Mart stayed behind and disengaged the airlock. Changing his mind, Mart launched a frontal attack on Konstantine's light cruiser. However, the Admiral neutralized his explosives by unleashing his frontal batteries. Mart attempted to flee but the Sato's Hammer's engines were knocked out by TIE fighters. Trapped, Mart then told the Lothal rebels and his crew to flee without him.
Instead of blasting Mart and his ship, Admiral Konstantine ordered one of his TIE bombers to plant a magno-mine on his ship's hull. Panicking, Mart sent a distress signal to Hera and her crew. Konstantine allowed him to transmit the signal before shutting it off. While Mart reflected on his mistakes, Hera, her crew, and the rest of Iron Squadron decided to rescue him. Mart was relieved when Hera's ship Ghost exited hyperspace. He then informed Hera that the Imperials had attacked a magno-mine to his ship. Mart watched as Hera led Konstantine's TIE fighters on a pursuit. This distraction enable Chopper and R3-A3 to deactivate the magnonmine and its detonator. They then reattached the mine to one of Mart's cargo boxes.
Following a brief dogfight, Hera managed to attach the Ghost to the hull of Sato's Hammer. Shortly later, Mart's uncle Commander Sato arrived on a CR90 corvette and attacked Konstantine's cruiser. Sato reassured his nephew over the com that he was here to get him out. Hera then told Mart to get the bomb ready since she was making a run for Konstantine's cruiser. The rebels flew over the light cruiser and Mart dropped his explosive cargo. The magno-mine damaged the forward section of Konstantine's cruiser and set the ship ablaze. The rebels escaped the Mykapo system just as Grand Admiral Thrawn arrived on his Star Destroyer Chimaera. Upon seeing the Star Destroyer, Mart and his crew realized that it was difficult for them to take on the Empire by themselves.
Hera flew Mart and his ship to Chopper Base on the planet Atollon. There, Mart embraced his uncle Sato, who thanked Hera and her crew for saving his nephew. Mart then embraced his crew in the presence of the Lothal rebels and Commander Sato. Following the recent events, Mart and his crew decided to join the rebellion.
- "Iron Squadron" (First appearance)
- He is voiced by Zachary Gordon.
- He is named after Matt Martin, Lucasfilm's manager of digital content and community relations.
- Matt goes by his mother's maiden name rather than his father and uncle's name of Sato.