Nuclear Test Ban Treaty was signed with the Soviet Union in late 1962, prohibiting testing in the atmosphere, in space and under water. In April 1961, the Air Research and Development Command was redesignated the Air Force Systems Command (AFSC). The new command was given the weapons procurement and production functions of ARDC's longtime rival Air Materiel Command, which effectively ended the ten years of contention between the ARDC and AMC. With the disestablishment of ARDC in 1961, AFSC took command of Kirtland and AFSWC. The replacement of ARDC with AFSC resulted in significant changes for AFSWC, but there were many adjustments that did not result solely from the change in command. AFSWC's primary role as "the AEC’s Air Force"—the primary USAF flight support for atmospheric testing—was no longer a military priority by the early 1960s owing to the 1958 moratorium on atmospheric testing. As the phase-down of testing activities continued during the moratorium, in August 1961 the 4950th Test Group (Nuclear) and 4925th Test Group (Atomic) were disestablished. Also during this moratorium period most of the missions of the AFSWC's 4926th Test Squadron (Sampling) consisted of U.S. Weather Bureau projects. On 16 August 1961 the 4926th Test Squadron (Sampling) was placed under HQ, 9th Weather Reconnaissance Group, Air Weather Service of the Military Air Transport Service (MATS), since MATS also used the RB-57D Canberra aircraft and could easily add the unit to their inventory (Jones et al. 1976). The new unit designation was the 1211th Test Squadron (Sampling). Although the unit was no longer under AFSC, it remained based out of Kirtland. Shortly after the testing groups were disestablished, the testing ban was lifted briefly when the Soviet Union detonated a nuclear device in the atmosphere in September 1961. A flurry of full-scale U.S. test activity resulted during 1961 and 1962. These tests were part of the National Nuclear Test Readiness Program, which had been set up as a direct response to President John F. Kennedy’s Safeguard C, which required readiness to promptly resume atmospheric testing should the need arise. Atmospheric testing of nuclear weapons finally ended with the 1963 Limited Test Ban Treaty. Atmospheric sampling On 16 June 1963, also after the Limited Test Ban Treaty, the 1211th Test Squadron was inactivated, and its assets were re-designated as the 58th Weather Reconnaissance Squadron, and the unit activated on 1 February 1964. The new designation created no change in