Designed in the 1960s to spy on the Soviet Union, the American SR-71 Blackbird reconnaissance plane could fly over three times the speed of sound, at altitudes of over 25,000 metres. Even today it would still fly faster and higher than most 21st century airplanes. So why was it retired in the 1990s? After the end of the Cold War and the breakup of the Soviet Union, the Blackbird’s original job was no longer relevant.
At the same time, new technologies, such as advanced spy satellites and drones, provided new ways to spy on enemies. However, the major reason was cost. The Blackbird was in service for over 30 years, and just as old cars get expensive to run, so too do old aeroplanes as parts need replacing and systems need updating. As military budgets were cut after the Cold War ended, this remarkable old aircraft was just too expensive for the future.