Lockheed SR-71 Blackbird

The Lockheed SR-71 "Blackbird" is a long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation.[N 1] It was operated by the United States Air Force (USAF) and NASA.[1]

Quick facts: SR-71 "Blackbird", Role, National origin, Man... ▼

SR-71 "Blackbird"
An SR-71B trainer over the Sierra Nevada Mountains of California in 1994. The raised second cockpit is for the instructor.
Role	Strategic reconnaissance aircraft Type of aircraft
National origin	United States
Manufacturer	Lockheed Corporation
Design group	Lockheed Skunk Works
Designer	Clarence "Kelly" Johnson
First flight	22 December 1964
Introduction	January 1966
Retired	1998 (USAF) 1999 (NASA)
Primary users	United States Air Force (historical) NASA (historical)
Number built	32
Developed from	Lockheed A-12

The SR-71 was developed as a black project from the Lockheed A-12 reconnaissance aircraft during the 1960s by Lockheed's Skunk Works division. American aerospace engineer Clarence "Kelly" Johnson was responsible for many of the aircraft's innovative concepts. The shape of the SR-71 was based on that of the A-12, which was one of the first aircraft to be designed with a reduced radar cross-section. Initially, a bomber variant of the A-12 was requested by Curtis LeMay, before the program was focused solely on reconnaissance. Mission equipment for the reconnaissance role included signals intelligence sensors, side looking airborne radar, and a camera;[2] the SR-71 was both longer and heavier than the A-12, allowing it to hold more fuel as well as a two-seat cockpit. The SR-71's existence was revealed to the public on 24 July 1964, and entered service in January 1966.[3]

During aerial reconnaissance missions, the SR-71 operated at high speeds and altitudes (Mach 3.2 and 85,000 feet, 25,900 meters), allowing it to outrace or entirely avoid threats.[2] If a surface-to-air missile launch was detected, the standard evasive action was simply to accelerate and outpace the missile.[4] On average, each SR-71 could fly once per week due to the extended turnaround required after mission recovery. A total of 32 aircraft were built; 12 were lost in accidents with none lost to enemy action.[5][6] In 1989, the USAF retired the SR-71 largely for political reasons; several were briefly reactivated during the 1990s before their second retirement in 1998. NASA was the final operator of the Blackbird, who used it as a research platform, retiring it in 1999.[7] Since its retirement, the SR-71's role has been taken up by a combination of reconnaissance satellites and unmanned aerial vehicles (UAVs); a proposed UAV successor, the SR-72, is under development by Lockheed Martin, and scheduled to fly in 2025.[8] The SR-71 has several nicknames, including "Blackbird" and "Habu".[9] As of 2023^[update] the SR-71 holds the world record it set in 1976 as the fastest air-breathing manned aircraft, previously held by the related Lockheed YF-12.[10][11][12]