Constituted 509th Bombardment Squadron (Heavy) on 25 Sep 1942. Activated on 1 Oct 1942. Inactivated on 28 Aug 1945. Redesignated 509th Bombardment Squadron (Very Heavy) on 11 Mar 1947. Activated in the reserve on 9 Apr 1947. Inactivated on 27 Jun 1949. Redesignated 509th Strategic Missile Squadron, and activated on 11 Oct 1962.

Assignments. 351st Bombardment Group, 1 Oct 1942-28 Aug 1945. 351st Bombardment Group, 9 Apr 1947; 381st Bombardment Group, 3 May 1948-27 Jun 1949. Strategic Air Command, 11 Oct 1962--.

Stations. Salt Lake City AAB, Utah, 1 Oct 1942, Gowen Field, Idaho, 1 Oct 1942; Geiger Field, Wash, Nov 1942, Biggs Field, Tex, 2 Jan 1943; Pueblo AAB, Colo, 28 Feb-13 Apr 1943; Polebook, England, 12 May 1943-9 Jun 1945; Sioux Falls AAFld, SD, Jul-28 Aug 1945. Wold-Chamberlain Field, Minn, 9 Apr 1947-27 Jun 1949.

Aircraft. B-17, 1942-1945.

Operations. Combat in ETO, 14 May 1943-20 Apr 1945.

Service Streamers. None.

Campaigns. Air Offensive, Europe; Normandy; Northern France; Rhineland; Ardennes-Alsace, Central Europe; Air Combat, EAME Theater.

Decorations. Distinguished Unit Citations: Germany, 9 Oct 1943; Germany, 11 Jan 1944.

Emblem. Over and through an ultramarine blue disc, an annulet white surmounted by a light red aerial bomb, winged gold, falling toward dexter base. (Approved 9 Dec 1943.)