"We are proud of the first flight results and at the same time we understand the inherent risk in a high-technology demonstrator like the X-51A," said Curtis Berger, the director of the hypersonics programs at Pratt and Whitney Rocketdyne, the company that built the X-51A's fuel-cooled supersonic combustion ramjet, or scramjet engine.
"We can't wait to get this second vehicle in the air and show what we can do."
Four X-51As were built for the Air Force by teams at Boeing and Pratt and Whitney Rocketdyne.
The X-51A made history on its inaugural hypersonic flight test on May 26, 2010, when it was launched from Edwards Air Force Base, Calif., under the wing of a B-52 Stratofortress. After release, the X-51A accelerated to Mach 5 under scramjet power.
The flight was about 10 times longer than any previous hypersonic scramjet flight and "80 to 90 percent" of flight test objectives were achieved, program officials said.
The vehicle, however, failed to accelerate as quickly as anticipated and the flight test had to be terminated after 143 seconds under scramjet power.
A perfect flight would have lasted another 100 seconds and accelerated the X-51A cruiser to Mach 6.
Boeing Phantom Works and Pratt and Whitney Rocketdyne teams said they have corrected the problems.
The next X-51 flight is scheduled for March 22 over the Navy's Point Mugu Sea Range but a number of factors with the flight-test vehicle -- weather, range availability and supporting test assets -- could push the schedule back.