After Years of Silence, We Finally Know More About the SR-71 Blackbird's Successor
Lockheed Martin
By Jay Bennett
Jun 7, 2017
Lockheed Martin's Skunk Works recently divulged some information about the SR-72 program to build a successor to the iconic SR-71 Blackbird reconnaissance aircraft. The advanced aircraft development division of Lockheed Martin told Aviation Week that hypersonic technologies, including a combined cycle propulsion system that merges a supersonic jet engine with a rocket engine, have advanced to the point that work on the planned SR-72 can begin in earnest. On paper, the SR-72 will be a strike and reconnaissance aircraft capable of topping Mach 6.
http://www.popularmechanics.com/military/aviation/a26796/hypersonic-sr-72-aircraft/