The United States successfully tested a scramjet-powered hypersonic missile in secret last month, according to new Lockheed Martin and DARPA press releases. Hypersonic missiles are advanced new weapons capable of exceeding Mach 5, or about 3,838 miles per hour, in flight. The combination of speed and maneuverability provided by these weapons makes them practically indefensible. Russia and China have hypersonic boost-glide vehicles in service, but no nation on earth has managed to put a scramjet-powered missile into operational service in history.With Russia’s Zircon not confirmed to even have a scramjet and Chinese scramjet testing efforts lagging behind, the US now appears to have two functional scramjet designs for weapon applications… and it may have just taken the lead in scramjet-powered hypersonic cruise missiles.