Aerospace Rescue and Recovery Service
The Aerospace Rescue and Recovery Service (ARRS) was the most long-established and notable name for a body of the United States Army (very briefly) and then Air Force that began its existence as the Air Rescue Service (1946-1966); became the ARRS (1966-1993); and then was briefly designated the United States Air Force Combat Rescue School (1993-1995), before being inactivated. It was established in 1946 as the Air Rescue Service' under Air Transport Command, little more than a year before the United States Air Force's designation as a separate military service in September 1947.
Source: Wikipedia — Aerospace Rescue and Recovery Service (CC BY-SA 4.0)