Home to a secret AT-AT factory and testing range known as the Trasse Proving Grounds, Trasse was covered with laser turrets and protected by powerful sensors. It was also a home to several prisoners of the Galactic Empire who were used as targets for live-fire exercises on the Proving Grounds.
Rebel general Brenn Tantor visited the system in the months between the Battle of Hoth and Battle of Endor. He was able to sneak into the system using codes stolen from the Sounder Flats computer complex on Ruul and captured an AT-AT with the help of Beri Tulon, a defector who had been stationed at the facility as an Imperial. When their escape was threatened by the appearance of Grand General Malcor Brashin's Star Destroyer Inquisitor, Tantor and Tulon smashed much of the Imperial presence in a mad dash to the asteroid's planetary ion cannon, which was used to disable the Inquisitor.
- Star Wars: Force Commander (First appearance)