Flown by 393d commander, Major Charles W. Sweeney, it was assigned to the Hiroshima mission on 6 August 1945, as the blast measurement instrumentation aircraft. On the mission to bomb Nagasaki on 9 August 1945, it was to have been the aircraft carrying the bomb, but the mission schedule had been moved forward two days because of weather considerations, and the instrumentation had not yet been removed from the aircraft. To avoid delaying the mission, Sweeney traded airplanes with the crew of "Bockscar" to carry the Fat Man atomic bomb to Nagasaki. Captain Frederick C. Bock and his C-13 crew flew "The Great Artiste" to Nagasaki on its instrument support mission, and landed with it on Okinawa at the conclusion of the mission. It was the only aircraft to directly participate in both missions. "Enola Gay", flown by Captain George Marquardt's Crew B-10, was the weather reconnaissance aircraft for Kokura, the primary target on the Nagasaki flight. "Enola Gay" reported clear skies over Kokura.