What we know about Lockheed Martin’s mysterious SR-72

In 2013, Lockheed Martin announced development of the successor to the SR-71 Blackbird spy plane. Built by Lockheed Martin in the 1960s, the SR-71 could reach speeds exceeding Mach 3 (above 2,200 mph). Lockheed claims it will reach speeds topping Mach 6 — over 4,500 mph — and they also want the jet to do more than just recon missions, including the ability to strike targets.

Source: www.businessinsider.com