The Lockheed SR-71 “Blackbird” is a retired long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft developed and manufactured by the American aerospace company Lockheed Corporation.^{[N 1]} The SR-71 has several nicknames, including “Blackbird” and “Habu“.

The SR-71 was developed as a black project from the Lockheed A-12reconnaissance 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 Lockheed A-12, which was one of the first aircraft to be designed with a reduced radar cross-section in mind. Initially, a bomber variant of the A-12 was requested by Curtis LeMay, before the program was focused solely on reconnaissance. The SR-71 was 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 in July 1964; it entered service in the United States Air Force (USAF) in January 1966. 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, using it as a research platform; it was retired again in 1999.