Rotating Detonation Engines Could Propel Hypersonic Flight

Yesterday, Vladimir Putin presented his country with a belated Christmas present: the Avangard hypersonic missile. According to Russian media, it's capable of reaching Mach 20. And if its ability to conduct evasive maneuvers at high velocity is as good as the Russian president boasted back in March, it would render missile defense systems effectively useless. Cold War recidivists aren't the only ones hoping hypersonic technology will deliver a futuristic throwback.