WASHINGTON — The U.S. Air Force and the Defense Advanced Research Projects Agency have wrapped up captive carry tests of two hypersonic weapon variants that will perform their first free-flight tests later this year, the organizations announced Sept. 1.

Both Lockheed Martin and Raytheon have designed scramjet-powered hypersonic missiles as part of the Hypersonic Air-breathing Weapon Concept (HAWC) program run by the Air Force and DARPA.

The companies have validated that their separate air vehicle designs can achieve and sustain flights in excess of five times the speed of sound. Upcoming flight tests will evaluate that the weapons’ propulsion and thermal management systems will be able to withstand hypersonic cruise speeds, DARPA said in a news release.

“Completing the captive carry series of tests demonstrates both HAWC designs are ready for free flight,” said Andrew Knoedler, DARPA’s HAWC program manager. “These tests provide us a large measure of confidence – already well informed by years of simulation and wind tunnel work – that gives us faith the unique design path we embarked on will provide unmatched capability to U.S. forces.”

In its release, DARPA made no mention of whether one of the missiles had been destroyed when an accident occurred during captive carry tests, as Aviation Week reported in June. At the time, DARPA declined to comment to Defense News about the report, citing the classification of the tests.

The completed captive carry tests put the Air Force one step closer to fielding a hypersonic cruise missile. In April, the service issued a request for information about technologies that would enable an air-breathing hypersonic cruise missile small enough to be launched from a fighter or bomber. HAWC is likely validating many of the technologies that would be applicable to that weapon.

Until recently, the Air Force had focused its prototype efforts on boost glide hypersonics which fly just below space. But as scramjet propulsion has matured, air-breathing hypersonic missiles — which can fly through the thick atmosphere and engage different targets than boost glide systems — have become more technologically feasible to produce.

“In the case of how fast we could go with the scramjet technology getting into cruise missile and missionizing it, I think we can go fast,” Air Force acquisition executive Will Roper told reporters April 30. “I don’t know how fast — that’s why we’re reaching out to the street. But given how far scramjet technology has matured, I’d expect that we’ll be able to go pretty quickly on this.”

On Aug. 12, the Air Force released a separate solicitation for an air-breathing hypersonic weapon it is calling Mayhem. It would be able to carry three distinct payloads of a larger combined weight over longer distances than current systems, the request for information stated.