The payload was developed under a partnership between the AFRL and NASA, with contributions from the Navy's detachment at White Sands Missile Range, N. "At Mach 6 the inlet compression and combustion process was designed to reduce the flow to below Mach 1 -- subsonic combustion. and ATK GASL located in Ronkonkoma, N. It was the fourth of a planned series of up to 10 flights under HIFiRE and the second focused on scramjet engine research. M. "This is the first time we have flight tested a hydrocarbon-fueled scramjet accelerating from Mach 6 to Mach 8," said NASA Hypersonics Project Scientist Ken Rock, based at NASA'S Langley Research Center in Hampton, Va. " So this test will give us unique scientific data about scramjets transitioning from subsonic to supersonic combustion -- something we can't simulate in wind tunnels. The HIFiRE 2 scramjet research payload included a hypersonic inward turning inlet, followed by a scramjet combustor and dual-exhaust nozzle. During the experiment the scramjet -- aboard its sounding rocket -- climbed to about 100,000 feet (30,480 meters) in altitude, accelerated from Mach 6 to Mach 8 (4,567 to 6,090 miles per hour; 7,350 to 9,800 kilometers per hour) and operated about 12 seconds -- a big accomplishment for flight at hypersonic speeds. Y. But at Mach 8 flight the flow remained greater than Mach 1 or supersonic throughout the engine. More than 700 instruments on board recorded and transmitted data to researchers on the ground.
The HIFiRE 2 mission, the first flight of this sounding rocket configuration, opens the door for a new high--performance flight configuration to support future Air Force, Navy, and NASA flight research The success of the three-stage launch system, consisting of two Terrier boost motors and an Oriole sustainer motor, is another important achievement of the HIFiRE 2 mission. The data collected during the execution of the HIFiRE experiments is expected to make a significant contribution to the development of future high-speed air-breathing engine concepts and help improve design, modeling, and simulation tools.
The HIFiRE team has already achieved other milestones such as the design, assembly and extensive pre-flight testing of the hypersonic vehicles and the design of complex avionics and flight systems. Demonstrating supersonic combustion in flight with a hydrocarbon fueled scramjet, compared to a hydrogen-fueled scramjet, is significant, according to researchers. While hydrogen fuel is more reactive, hydrocarbon fuel offers many benefits, including operational simplicity and higher fuel density so a hypersonic vehicle can carry more fuel. This represents yet another noteworthy achievement for the HIFiRE program, with additional test flights scheduled in the coming months and years.