Not to be confused with Islecatraz
Astratraz is a prison-ship located in deep space. The prison, piloted by "little green men" and guarded by large robots, was being used to imprison "guggets" fitted with intelligence units. Astratraz was just being used a transport until the guggets could be taken to a prison planet. Unfortunately, they escaped from their cell (a particularly flimsy one padded with mesh) and commandeered the ship.
Amy Rose and Tekno the Canary teleported here during the Eternity Ring story arc. The heroes were quickly captured but Tekno appeared to defect, taking the guggets to a planet they could invade. Upon landing, the guggets left Astratraz but were eaten by the inhabitants of Planet Terminus. With no criminal puppets left, the aliens went on to radio base to get a tow home.