The Blackbird (Lockheed Martin SR-71) flew in 1976 and took the distance between New York and London for 2 hours, which means that the aircraft developed top speed above Mach 3 (above 1000 m/s or 3600 km/h).
Now Lockheed Martin develops a successor of the Blackbird indexed SR-72 at the Skunk Works facility. Skunk Works is a nickname for the Advanced Development Program (ADP) of Lockheed Martin. ADP stands behind the SR-71 and other significant projects such as F-117 Nighthawk, F-22 Raptor, U-2 and F-35 Lightning II.
It is expected that SR-72 will reach top speed of Mach 6, or 6 times faster than the sound, and it will be unmanned. If everything goes smooth along the development process, demonstrator vehicle will be ready in 2018 and fully operational in 2030.
Brad Leland is a program manager at Lockheed Martin, he said: “Hypersonic aircraft, coupled with hypersonic missiles, could penetrate denied airspace and strike at nearly any location across a continent in less than an hour. Speed is the next aviation advancement to counter emerging threats in the next several decades. The technology would be a game-changer in theater, similar to how stealth is changing the battlespace today.”