The Norad II ambushed the Hyperion from warp space, preventing it from attempting to escape. He ordered a squad of soldiers to board the Hyperion, along with a secret agent. The plan went awry when Mengsk's forces killed his troops and the Hyperion outmaneuvered and heavily damaged the Norad II using a startling tactic. Duke believed it would take months to fix the hole in his ship.
If the unit name is changed in StarEdit, the rank changes from "Edmund Duke" to "Admiral". For example, in To Chain the Beast, one can see Gerard DuGalle, even though it is just another battlecruiser using the portrait of Duke.
The fate of the Norad II is unclear, as various sources conflict on this point. According to Liberty's Crusade, the Norad II self-destructed on Antiga Prime. According to the game itself, however, the Norad II survived its crash and participated in a battle over Tarsonis. According to Shadow of the Xel'Naga, the Norad II was refitted and renamed as Norad III, apparently retconning its destruction in Liberty's Crusade.