mounted from Thule, Greenland, and probed deep into the heart of the Soviet Union, taking a photographic and radar recording of the route attacking SAC bombers would follow to reach their targets. The risks involved in mounting these dangerous sorties speaks volumes for the courage and skill of the crews involved. Flights that involved penetrating mainland Russia were termed SENSINT (Sensitive Intelligence) missions. One RB-47 even managed to fly 450 miles inland and photograph the city of Igarka in Siberia. The 70th SRW also assumed an air refueling mission in 1955 and was deployed at Sidi Slimane Air Base, Morocco, from 26 October to 17 December 1956. Beginning in February 1958, operations with the RB-47 were reduced, primarily as the aircraft was determined to be vulnerable to Soviet air defenses, but also its mission was being taken over by the Lockheed U-2. From June 1958 to September 1961, the wing became a B-47 bombardment and reconnaissance organization, providing B/RB-47 combat crew training for other SAC units, while undertaking RB-47 and Boeing KC-97 Stratofreighter operations. The refueling squadron transferred in August 1961, and the final RB-47 class graduated in October 1961. It converted to B-47s in late 1961 but inactivated prior to becoming combat ready. Strategic bombardment 4123d Strategic Wing On 10 December 1957, SAC established the 4123d Strategic Wing (SW) at Carswell Air Force BaseTexas and assigned it to the 19th Air Division. The wing was assigned the 4123d Air Base Squadron, which had been the host unit at Clinton-Sherman Air Force Base, Oklahoma since July 1955, preparing Clinton-Sherman, a former World War II Naval Air Station, to receive operational SAC aircraft plus the 98th Bombardment Squadron (BS), consisting of 15 Boeing B-52 Stratofortresses, which had been one of the three squadrons of the 7th Bombardment Wing and a maintenance squadron at Carswell. The air base squadron was expanded into the 4123d Air Base Group and assigned component squadrons on 1 July 1958. At the end of 1958, the wing's first operational squadron, the 902d Air Refueling Squadron, flying Boeing KC-135 Stratotankers, was activated at Clinton-Sherman and the wing moved its headquarters to the base on 25 February 1959 and was reassigned to the 816th Air Division at the beginning of March. Within a week the 98th Bombardment Squadron joined the wing at Clinton-Sherman as part of SAC's plan to disperse its Boeing B-52 Stratofortress heavy bombers over a larger