Built in the 1960s by Lockheed using designs that were kept secret in the 1950s, the SR-71 Blackbird is the fastest manned aircraft to have ever flown the skies. To get an idea of how fast, watch the below video of the plane taking off.
Capable of reaching speeds up to Mach 3 (2,200 mph) with a maximum altitude of almost 26,000 meters (85,000 feet), the two-seater SR-71 Blackbird was used as a reconnaissance plane from 1964 to 1998. Lockheed built only 32 of these super-fast planes, and now, they want to build an even faster one that will act as a strike and recon aircraft.
The SR-72, the leading project under Lockheed's Advanced Development Programs (ADP) or Skunk Works, promises to be even faster than the Blackbird. The company wants to develop a plane capable of hypersonic flight — speeds of Mach 5 (3,836 mph) and higher — and the SR-72 is expected to reach a Mach 6 (4,600 mph) top speed.
The inspiration for this hypersonic plane may come from the past, but it is poised to take military aircraft well into the future.