In late 1950, construction began on
Charleston Air Force Station. Known as Bull Hill for its location in the town, the station was one of twenty-eight stations built as part of the second segment of the permanent
Air Defense Command national radar network. Prompted by the start of the
Korean War, on 11 July 1950, the Secretary of the Air Force asked the Secretary of Defense for approval to expedite construction of the second segment of the permanent network. Receiving the Defense Secretary's approval on 21 July, the Air Force directed the Corps of Engineers to proceed with construction. Completed in early 1951, and fully manned and operational when the 765th Aircraft Control and Warning Squadron brought Charleston AFS to life in April 1952 and assumed coverage that had been provided by a temporary
Lashup Radar Network site at
Dow AFB (L-l). The site initially had
AN/FPS-3 and
AN/FPS-5 radars, and initially the station functioned as an aircraft control and warning station. In 1957 an
AN/FPS-6 replaced the AN/FPS-5 height-finder radar. Another height-finder radar came in 1958 along with an
AN/FPS-20 search radar that replaced the AN/FPS-3. During 1959 Charleston AFS joined the
Semi Automatic Ground Environment (SAGE) system, feeding data to DC-05 at
Topsham AFS, Maine. After joining, the
squadron was redesignated as the 765th Radar Squadron (SAGE) on 1 October 1959.' In 1963 the site became the first in the nation to receive an
AN/FPS-27 radar and on 31 July 1963, the site was redesignated as NORAD ID
Z-65. This radar subsequently was upgraded to become an AN/FPS-27A. The AN/FPS-26A was then converted into an
AN/FSS-7 submarine-launched ballistic missile radar in 1966 for Detachment 6,
14th Missile Warning Squadron (MWS) to monitor for Ballistic Missile launches by submarines. In addition to the main facility, Charleston operated two unmanned Gap Filler sites: • Topsfield, Maine (P-65A/Z-65A) • Sedgwick, Maine (Z-6BB) Topsfield was equipped with an
AN/FPS-18; Control of Sedgwick was transferred to Charleston AFS after
Brunswick AFS (Z-13) closed in 1965 and was equipped with the
AN/FPS-14. Over the years, the equipment at the station was upgraded or modified to improve the efficiency and accuracy of the information gathered by the radars. The 765th Radar Sq was inactivated and replaced by the 765th Air Defense Group in March 1970. The upgrade to group status was done as Charleston AFS' was designated as a [Backup Interceptor Control] (BUIC) site. BUIC sites were alternate control sites in case SAGE Direction Centers became disabled and unable to control interceptor aircraft. The group was inactivated and replaced by the 765th Radar Squadron. The 765th Radar Squadron was inactivated on 29 June 1979 as part of a general draw down of air defense forces by
Aerospace Defense Command and the transfer of the mission to
Tactical Air Command. The 14th MWS detachment was inactivated a year later. After the base closed, the radar site was abandoned, with several radar towers still standing. The station area was transformed into the
Charleston Correctional Facility, which opened in 1980. The family-housing area has been entirely demolished. ==Air Force units and assignments==