Russia and China are ahead of US in hypersonic missile technology. Here's why

Interview by CNN of Christopher S. Combs, Ph.D. is the Dee Howard Endowed Assistant Professor in Aerodynamics at the University of Texas at San Antonio (UTSA) Department of Mechanical Engineering

Russia and China are ahead of US in hypersonic missile technology. Here's why
https://www.youtube.com/watch?v=sHa6acUdHLg