66th Missile Squadron The 66th Missile Squadron ( 66 MS ) is an inactive United States Air Force unit . It was last assigned to the 44th Operations Group , stationed at Ellsworth AFB , South Dakota . The 66 MS was equipped with the LGM - 30F Minuteman II Intercontinental ballistic missile ( ICBM ) , with a mission of nuclear deterrence . With the end of the Cold War , the 66th was inactivated on 1 September 1993 . History . World War II . Established in early 1941 as a B - 24 Liberator heavy bombardment squadron ; trained under Third Air Force in the southeastern United States . After the Pearl Harbor Attack , engaged in Antisubmarine patrols over the Gulf of Mexico . Deployed to the European Theater of Operations ( ETO ) , being assigned to VIII Bomber Command in England during the summer of 1942 . One of the first B - 24 Liberator units assigned to the ETO . Engaged in very long range strategic bombardment missions over Occupied Europe and Nazi Germany , attacking strategic targets in France , Belgium , the Netherlands and Germany . Among the targets attacked were submarine installations , industrial establishments , airfields , harbors , shipyards , and other objectives . Detachment deployed to Twelfth Air Force in Algeria in June 1943 to help facilitate the Allied invasion of Sicily by bombing airfields and marshalling yards in Italy . The detachment also participated in the famous low - level raid on the Ploesti oil fields in Romania on 1 August 1943 . Most of the detachment returned to England at the end of August , however some crews and aircraft remained in the Mediterranean Theater of Operations ( MTO ) and flew very long range attacks over Italy , Romania , Austria , and Sicily and supported Allied ground forces in Sicily as well as attacking Axis forces in Italy supporting the Salerno Invasion of Italy . All aircraft and personnel returned to England in October . Returned to VIII Bomber Command operations , and supported the Allied Invasion of France in June 1944 by attacking strong points in the beachhead area and transportation targets behind the front lines . The group aided the Caen offensive and the Saint - Lô breakthrough in July . Dropped food , ammunition , and other supplies to troops engaged in the airborne attack on the Netherlands in September . Attacked enemy targets during the Battle of the Bulge , December 1944 - January 1945 , by striking bridges , tunnels , choke points , rail and road junctions , and communications in the battle area . The squadron attacked airfields and transportation in support of the Western Allied Invasion of Germany , and flew a resupply mission during the airborne assault across the Rhine in March 1945 . Combat operations concluded with the German Capitulation in May 1945 . Returned to the United States in June 1945 , being reassigned to Second Air Force and redesignated as a B - 29 Superfortress Very Heavy bombardment squadron . Trained with B - 29s and planned to deploy to the Western Pacific , however the Japanese Capitulation in August canceled deployment plans . Assigned to Kansas as part of Continental Air Forces ( later Strategic Air Command ) but inactivated in July 1946 as part of the general demobilization of the AAF . Strategic Air Command . Reactivated in 1947 under SAC as a paper unit ; not manned or equipped and inactivated in 1949 due to budget constraints . Reactivated in 1950 and used as an Operational Training Unit for B - 29 aircrews and maintenance personnel being deployed to for Far East Air Forces during the Korean War . Replaced the propeller - driven B - 29s with new B - 47E Stratojet swept - wing medium bombers in 1953 , capable of flying at high subsonic speeds and primarily designed for penetrating the airspace of the Soviet Union . In the late 1950s , the B - 47 was considered to be reaching obsolescence , and was being phased out of SAC ' s strategic arsenal . Began sending aircraft to other B - 47 wings as replacements in late 1959 , being phased down for inactivation in 1960 . Intercontinental Ballistic Missile Squadron . Reactivated in 1962 as a SAC ICBM missile squadron . Trained with the 850th SMS in HGM - 25A Titan I operations in 1962 , being made operational with LGM - 30B Minuteman I missiles in 1963 . Upgraded to the LGM - 30F Minuteman II in 1972 . Remained on Cold War nuclear alert until in response to President Bush ' s directive to stand down the Minuteman II . Dissipated launch codes and pin safety control switches at 15 launch control facilities . Deactivation of the entire missile complex ended in the summer of 1993 ; squadron inactivated on 1 September . 66th Missile Squadron Launch Facilities