Missile Master was a type of US Army Missile Command military installation for the Cold War Project Nike, each which were a complex of systems and facilities for surface-to-air missile command and control. Each Missile Master had a nuclear bunker (except for the initial Ft Meade site) housing the Martin AN/FSG-1 Antiaircraft Defense System, as well as additional "tactical structures" for "an AN/FPS-33 defense acquisition radar (DAR) or similar radar, two height-finder radars," and identification friend or foe secondary radar (e.g., AN/TPX-19 radar interrogator). The radars, along with Automated Data Links (ADL) from remote Nike firing units, provided data into the AN/FSG-1 tracking subsystem with the DAR providing surveillance coverage to about 200 mi (320 km).