Beyond Supersonic

An experimental supersonic-combustion ramjet successfully accelerated to Mach 8 after launching atop a rocket from the Pacific Missile Range Facility in Hawaii, announced Air Force Research Lab officials. The Hypersonic International Flight Research Experimentation Program test shot yielded “unique scientific data about scramjets transitioning from subsonic to supersonic combustion,” said NASA project scientist Ken Rock in AFRL’s May 8 release. A three-stage sounding rocket boosted the scramjet to Mach 6.5 whereupon the scramjet accelerated to Mach 8, maintaining that speed for 12 seconds, according to AFRL. Pushing well beyond the Mach 5 threshold of hypersonic flight, the recent boost was the fourth HIFiRE vehicle tested in collaboration with NASA and Australia’s Defense Science Organization. And, it was “the first time we have flight tested a hydrocarbon-fueled scramjet accelerating . . . to Mach 8,” said Rock. The program may test as many as six more vehicles, according to AFRL. An AFRL spokeswoman told the Daily Report that she could not provide the date of the test, saying she was permitted only to say it occurred “recently.”