The new spy plane will be capable of Mach 6 cruise speeds, making it the first hypersonic aircraft to enter service should it be produced. Only the rocket-powered North American X-15 was able to regularly fly those speeds, and the three examples built were used for research. The SR-71 Blackbird is legendary in aviation circles for its Mach 3 capabilities, and different iterations served as a spy plane for 35 years until its retirement in 1998. It still holds several records, including a flight from Los Angeles to Washington D.C. in 64 minutes, 20 seconds.