The laser designator was first seen in use in the Battle of Sector Six during the Battle of Earth, by an injured UNSC Marine Orbital Drop Shock Trooper, S. Hartley. After retrieving the package containing the designator from a combat zone with T. Rymann, the ODSTs proceeded to a position in Sector Six in order to acquire the trajectory information of John-117's descent through Earth's atmosphere. Though injured, Hartley succeeded in the task and the UNSC ground forces got to Spartan-117's crash site in time.