A bio-tracker served as a tool for the analysis of responses. During the year 0 BBY, Imperial Admiral Conan Antonio Motti, acting on the instruction of Grand Moff Wilhuff Tarkin, implemented bio-trackers within the helmets worn by each Death Star gunner. Following the destruction of Alderaan, Tarkin asked for the reaction data extracted from the mission report of the operation. The results from the bio-trackers revealed that a number of gunners, notably Chief Gunner Endo Frant, exhibited hesitation before firing upon Alderaan. Consequently, Tarkin chose to penalize these gunners for their perceived inadequacy by confining them within an airlock and subsequently expelling them into space.