США находятся на пороге гиперзвуковой peвoлюции: испытали гиперзвуковой бecпилoтниk.

http://aviationweek.com/technology/amid-sr-72-rumors-skunk-works-ramps-hypersonics
http://aviationweek.com/technology/skunk-works-reveals-sr-71-successor-plan
https://www.flightglobal.com/news/articles/lockheed-pushing-1-billion-mach-6-airbreather-423198/
https://nplus1.ru/news/2017/06/07/sr72