The initial site at Dobbins Air Force Base became operational in 1956 when the 908th Aircraft Control and Warning Squadron activated an AN/MPS-11 search radar, later an AN/FPS-8 and an AN/TPS-10. Circa 1958 an AN/FPS-6 was added, and initially the station functioned as a Ground-Control Intercept (GCI) and warning station. As a GCI station, the squadron's role was to guide interceptor aircraft toward unidentified intruders picked up on the unit's radar scopes. In addition to the main facility, Marietta operated three unmanned AN/FPS-18 Gap Filler sites: