The U.S. military has completed successful test flights of a reusable hypersonic rocket-powered aircraft, its first such accomplishment in more than a half century. The win is a sign of the Pentagon’s progress in a wartime technology race in which China has a sizable lead. Two startups conducted the test flights of a vessel called the Talon-A: Stratolaunch, the company making the hypersonic test aircraft and based in the Mojave Desert, and Ursa Major, a Colorado-based builder of liquid rocket engines. The fully autonomous flights occurred in December and March, the Defense Department said on Monday, and exceeded five times the speed of sound—the generally accepted designation of hypersonic speed. The test flights provide one of the starkest examples yet of how venture- and private-equity-backed tech firms are providing the Defense Department with a long overdue boost. The U.S. has invested billions of dollars to develop hypersonic capabilities for several decades, but has made progress in fits and starts. Hypersonic weapons reach at least 3,800 mph. The components on board must be able to withstand not only the speed, but also temperatures of many thousands of degrees, and lots of maneuvering designed to trick the enemy and evade air-defense systems. Frequent, cost-effective testing is crucial for the U.S. military, and a reusable vehicle makes that possible.

Full report : With a lift from startups, the Pentagon completed test flights of an unmanned aircraft traveling at more than five times the speed of sound.