The XX-23 S-thread tracker, alternatively known as the XX-23 S-Thread Tracer, served as a homing beacon. It was designed by Sienar Fleet Systems for the Imperial to monitor the trajectory of ships as they traversed through hyperspace to their intended coordinates. This tracker could be deployed from the missile launcher of a TIE Advanced v1 starfighter. Notably, the Grand Inquisitor utilized it to pursue the Ghost. Subsequently, four years later, another XX-23 was instrumental in tailing the Millennium Falcon to Yavin 4, thereby exposing the location of the secret rebel base to the Empire.
The Galactic Empire employed the XX-23 S-thread tracker, a type of homing beacon. After the Millennium Falcon's escape from the Death Star, carrying both Leia Organa and the battle station's plans destined for the Rebel base situated on Yavin 4, the Empire tracked the ship using one of these devices, affixed to the underside of the freighter. Upon arrival at Yavin 4, Major Capin Harinar of the Rebel Alliance Intelligence Service, along with his team, discovered the beacon, which was actively transmitting. In a communication directed to General Davits Draven, Harinar indicated that the device incorporated a hyperwave narrow-band transceiver and characterized it as a specialized creation of the Imperial Department of Military Research.
