The Lockheed SR-71 "Blackbird" is a retired long-range, high-altitude, Mach 3+ strategic reconnaissance aircraft that was developed and manufactured by the American aerospace company Lockheed Corporation. Its nicknames include "Blackbird" and „Habu". The SR-71 was developed in the 1960s as a black project by Lockheed's Skunk Works division. American aerospace engineer Clarence "Kelly" Johnson was responsible for many of the SR-71's innovative concepts. Its shape was based on the Lockheed A-12, a pioneer in stealth technology with its reduced radar cross section, but the SR-71 was longer and heavier to carry more fuel and a crew of two in tandem cockpits. The SR-71 was revealed to the public in July 1964 and entered service in the United States Air Force (USAF) in January 1966. During missions, the SR-71 operated at high speeds and altitudes (Mach 3.2 at 85,000 ft or 26,000 m), allowing it to evade or outrace threats. If a surface-to-air missile launch was detected, the standard evasive action was to accelerate and outpace the missile. Equipment for the plane's aerial reconnaissance missions included signals-intelligence sensors, side-looking airborne radar, and a camera. In 1974 the SR-71 Blackbird sets (and holds) the record for flying from New York to London in the time of one hour, 54 minutes and 56.4 seconds at a speed of 1,435.587 miles per hour (2,310.353 km/h). On average, an SR-71 could fly just once per week because of the lengthy preparations needed. A total of 32 aircraft were built; 12 were lost in accidents, none to enemy action. We celebrate this remarkable feat of aeronautic engineering with a stamp honouring the SR-71 Blackbird…