WASHINGTON — The U.S. Air Force tested Lockheed Martin’s Hypersonic Air-breathing Weapon Concept in March, but kept it secret to avoid increasing tensions with Russia. <br /> <br /> <br />A DARPA press release said the missile was initially accelerated up to high speeds by a booster stage. <br /> <br /> <br />It then engaged its air-breathing scramjet engine, which propelled it to a speed faster than Mach 5. <br /> <br /> <br />The hypersonic missile maintained that speed for an extended period of time, flying higher than 65,000 feet, and traveling more than 300 nautical miles. <br /> <br /> <br />Launched from a B-52H bomber, the missile can conduct short or no-notice strikes against time-sensitive and other critical targets. <br /> <br /> <br />As with other hypersonic missiles, it can maneuver within the atmosphere, meaning it can fly more unpredictably than ballistic missiles. <br /> <br /> <br />The initial secrecy around the launch comes in contrast to Russian claims of using hypersonic missiles against targets in Ukraine, but both gestures point toward a wider hypersonic arms race already ongoing. <br /> <br /> <br />On Tuesday, it was announced that the U.S. would work with Britain and Australia in developing nuclear-capable hypersonic weapons, according to The Guardian, and this is seen as a response to developments in the area by Russia and China. <br /> <br />
