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 unit mission, although the squadron then emerged into the "Age of the F Troop" . The "F" was from the assignment of the RB-57F Canberra to the squadron. According to the official history of the "F Troop 58th Weather Squadron," the RB-57F proved itself to be an aircraft gifted with the capabilities of exceptional payload, high altitude, long-range performance, and extended loiter time, all of which were useful for taking air samples.