551st Strategic Missile Squadron

The 551st Strategic Missile Squadron (551 SMS) is an inactive United States Air Force unit. It was last assigned to the 98th Strategic Aerospace Wing, stationed at Lincoln AFB, Nebraska

The 551 SMS was equipped with the SM-65F Atlas Intercontinental ballistic missile (ICBM), with a mission of nuclear deterrence. The squadron was inacivated as part of the phaseout of the Atlas ICBM on 25 June 1965.

World War II
Activated in late 1942 as a B-17 Flying Fortress heavy bomb squadron, trained under Second Air Force. Deployed to England in the European Theater of Operations (ETO) during June 1943, assigned to VIII Bomber Command as a strategic bombardment squadron. Participated in the air offensive over Nazi Germany and Occupied Europe until German capitulation in May 1945. Personnel demobilized in England and returned to the United States; squadron reassigned to Second Air Force and was programmed to be re-equipped with B-29 Superfortresses for deployment to Pacific Theater. Japanese capitulation led to units inactivation in September 1945, being neither manned or equipped.

Effective 15 September 1947, the squadron was activated at Selfridge Field, Michigan. Having been allotted to the organized reserves, with assignment to Second Air Force, Air Defense Command, it was redesigned as a very heavy bombardment unit on 25 August. In August 1948, the squadron was assigned to the Tenth Air Force, which in December, became a part of the Continental Air Command. On 1 December 1948 it was again reassigned to Air Defense Command where it remained on reserve service until being inactivated on 27 June 1949 due to budget restrictions.

Intercontinental Ballistic Missile Squadron
Reactivated in 1960 as a Strategic Air Command SM-65F Atlas ICBM launch squadron, stationed at Lincoln AFB, Nebraska and assigned to the 818th Air (later Strategic Aerospace) Division on 1 April 1961. The squadron was assigned twelve missiles, based in a 1 x 12 configuration: twelve independent widely dispersed launch sites comprised the missile squadron.

The Atlas F was the final and most advanced version of the Atlas ICBM and was stored in a vertical position inside underground concrete and steel silos. When stored, the Atlas F sat atop an elevator. If a missile was placed on alert, it was fueled with RP-1 (kerosene) liquid fuel, which could be stored inside the missile for extended periods. If a decision was made to launch the missile, the missile was raised to the surface and the liquid oxygen tank was filled. The launch would occur shortly after completion of this process. (see below for site details).

The exposure on the surface that this procedure entailed was the great weakness of the Atlas F. It was exposed and vulnerable during this time. The Titan II and Minuteman missiles could be launched from within their silos, thereby eliminating this vulnerability. Also, since the Titan did not use a cryogenic fuel or oxydizer, and the Minuteman was a solid fuel rocket, they could be stored fully fueled and ready to launch within a very few minutes.

The 551st SMS operated twelve launch silos; one missile at each site. The missiles were retired and removed in early 1965 in favor of the more advanced LGM-25C Titan II; squadron was inactivated on 25 June 1965. Missile sites were later sold off to private ownership after demilitarization.

Lineage

 * Constituted as 551st Bombardment Squadron (Heavy) on 25 November 1942
 * Activated on 1 December 1942
 * Inactivated on 28 August 1945


 * Re-designated 551st Bombardment Squadron (Very Heavy) on 25 August 1947
 * Activated in the reserve on 15 September 1947
 * Inactivated on 27 June 1949


 * Re-designated 551st Strategic Missile Squadron, and activated, on 24 October 1960
 * Organized on 1 April 1961
 * Inactivated on 25 June 1965

Assignments

 * 385th Bombardment Group, 1 December 1942-28 August 1945
 * ETO Fuselage Code: HR


 * Second Air Force, 15 September 1947
 * Tenth Air Force, 1 July 1948
 * First Air Force, 15 August 1948
 * Tenth Air Force, 1 December 1948-27 June 1949
 * Strategic Air Command, 24 October 1960
 * 818th Air (later Strategic Aerospace) Division, 1 April 1961
 * 98th Strategic Aerospace Wing, 1 January 1964-25 June 1965

Stations

 * Davis-Monthan Field, Arizona, 1 December 1942
 * El Paso Army Airfield, Texas, 4 January 1943
 * Geiger Field, Washington. 1 February 1943
 * Great Falls Army Air Base, Montana, 11 March – 7 June 1943


 * RAF Great Ashfield (AAF-155), England, 29 June 1943-6 August 1945
 * Sioux Falls Army Air Field, South Dakota, 14–28 August 1945
 * Selfridge Field, Michigan, 15 September 1947-27 June 1949
 * Lincoln AFB, Nebraska, 1 April 1961-25 June 1965

Aircraft and missiles

 * B-17 Flying Fortress, 1942–1945
 * B-29 Superfortress, 1947-1949.
 * SM-65F Atlas Missile, 1961–1965
 * Operated twelve missile sites of one missile at each site (12 total):
 * 551-1 4.9 mi WNW of Avoca, NE    40.81639°N, -96.20611°W
 * 551-2 3.6 mi E of Eagle, NE    40.82222°N, -96.36167°W
 * 551-3 2.6 mi WSW of Nehawka, NE    40.80889°N, -96.03361°W
 * 551-4 4.5 mi W of Nebraska City, NE    40.67667°N, -95.94528°W
 * 551-5 0.8 mi SSE of Palmyra, NE    40.69444°N, -96.38056°W
 * 551-6 4.5 mi N of Tecumsch, NE    40.43139°N, -96.18972°W
 * 551-7 2.1 mi WNW of Firth, NE    40.51639°N, -96.64°W
 * 551-8 4.3 mi SW of Beatrice NE  40.22778°N, -96.81167°W
 * 551-9 6.7 mi W of Wilber, NE    40.48389°N, -97.08833°W
 * 551-10 3.3 mi ENE of Bradshaw, NE    40.89528°N, -97.68583°W
 * 551-11 3.0 mi NE of Tamora, NE    40.92667°N, -97.18639°W
 * 551-12 2.9 mi NE of Brainrd, NE    41.21111°N, -96.96167°W