Battle of Mustafar ( Imperial Period ) The Battle of Mustafar was an isolated battle on Mustafar that took place between the Galactic Empire and Separatist holdouts in the early years of Imperial rule . The engagement was fought by the Imperial 501st Legion under the command of Darth Vader , against a secret droid army controlled by Gizor Dellso . The battle resulted in the death of Dellso and the destruction of both his ground and space forces . Prelude . A Geonosian engineer , Gizor Dellso was a committed and loyal member of the CIS during the Clone Wars . After the assassination of the Separatist Council at the end of the war by Darth Vader , Dellso , in the possession of stolen Imperial starfighter plans , fled to Mustafar where he discovered the remains of his former master , Poggle the Lesser , and the other Separatist Leaders in the control room of the Klegger Corp Mining Facility . Dellso took refuge in a nearby secret bunker where he discovered an entire droid factory sitting dormant . He instantly fired up the factory , and in the short time it took the Empire to find him he had built his own droid army and fleet , which did not respond to Darth Vader ' s deactivation of the droids . Dellso also planned to use the hidden facility on the planet to create a new type of superior battle droid . The battle . Space battle . The members of the 501st Legion , under command of Vader , were transported to Mustafar by an " Imperial I " - class Star Destroyer to crush Gizor Dellso ' s uprising . However , the ship ' s hangar was immediately invaded by one of the HMPs from Gizor Dellso ' s navy , which dispatched OOM pilot battle droids and Droid marine s onto the ship . Although one of the pilots panicked when the Empire failed to launch starfighters , the Imperial Officer sent troops out , which held the droids back . To destroy the gunship , Imperial Marine s used their rocket launchers and thermal detonators , while the TIE pilot s deployed time bombs . After the gunship was destroyed , the marines and pilots then used their blasters to eliminate the remaining invaders . 501st pilots manned their starfighters , and after destroying a small number of Dellso ' s fighters , successfully knocked out the shields on the " Providence " - class destroyer . The vulnerable vessel was then pounded by turbolaser blasts from the nearby Star Destroyer , inflicting massive damage to all critical systems . Dellso ' s space blockade had been demolished . However , his ground forces , waiting on the planet , were ready for attack . At Darth Vader ' s unusual request , a pilot flew into the enemy hangar and stole one Belbullab - 24 strike bomber . The fighter was then brought to the Imperial hangar for closer study . Siege of the mining facility . 501st troopers were deployed on a landing platform outside the droid facility on Mustafar . Many had just stepped foot on the platform when droids shot them dead from the open windows of the entrance corridor . As B2 super battle droids scurried out onto the landing platform , the 501st was able to repel them . They managed to secure their landing zone , then taking losses flooded the corridors and stormed the lava observatory room , which gave them access to an outside walkway . Despite battle droid snipers firing at them , the stormtroopers were able to capture the walkway . Even with remnants of the feared IG - 100 MagnaGuards striking at their ranks , the 501st Legion managed to take command over an overlook station from the droid forces . Then , the regrouped stormtroopers rushed into the factory control center , where they were able to destroy both of the droid prototype schematics of a new , unfinished battle droid prototype , ruining Dellso ' s plans of gaining the upper hand in possible future battles . Ending the battle . A stormtrooper carrying an orbital strike beacon had been shot , and once retrieved , the beacon was set on the overlook to signal for the orbiting Star Destroyer to bombard the base . However , Gizor Dellso and his Geonosian bodyguards arrived to destroy the remaining stormtroopers , a wild firefight began . Though many stormtroopers were slain , Gizor Dellso was killed along with his remaining droids . The troopers had just enough time to depart when their overhead forces executed an orbital bombardment command on the Mustafar complex , completely demolishing the droid factory . Aftermath . Following the battle , the 501st Legion shifted its focus to overseeing the Empire , not constructing one . In the years following the battle and the destruction of the Droid foundry , the Mensix Mining Facility was built close to the Klegger Corp Mining Facility and was in operation during the Galactic Civil War . This new facility would be the site of a battle between the Imperial Remnant and New Republic forces . Behind the scenes . The space battle and the surface battle are two campaign missions in " " . The first mission , the space battle , is optional , like the other space levels in the game ' s campaign , whereas the battle on the planet ' s surface is required to advance to the next level . An exact date for the battle has not been given ; however , it is known to have occurred in the early days of the Imperial era , shortly after the Battle of Naboo ( Imperial Period ) , as the events in the game " " take place in that order .