Operation Big was an operation of the Alsos Mission, the Allied seizure of facilities, materiel, and personnel related to the German nuclear weapon project during World War II. It was tasked with sweeping several targeted towns in the area of southwest Germany designated to the French First Army, including Hechingen, Bisingen, Haigerloch, and Tailfingen. Operating behind German lines the U.S. task force successfully carried out its mission of seizing or destroying all project related assets and capturing its top scientists in the last week of April and first week of May, 1945.