By Marina Malenic
LONDON–The engine manufacturer for the experimental Air Force X-51 Waverider hypersonic vehicle that flew for a record-setting 200 seconds in May said the system performed “flawlessly” and that no major changes are expected to the design ahead of a second flight that could come next year.
“From an engine performance perspective, it was everything we expected it to be,” said Jim Maser, president of Pratt & Whitney Rocketdyne, a division of United Technologies Corp. [UTX]. “It performed flawlessly.”
Maser was speaking at a Pratt & Whitney press conference at the Farnborough Airshow outside London.
Maser said the Air Force has thus far indicated a desire only to implement adjustments to the system that would help ensure a full 300-second flight next time so that more data can be collected.
“But relative to the propulsion system, it performed exactly as designed, so if we do any changes they won’t be major,” he said.
The Air Force, Rocketdyne and X-51 prime contractor Boeing [BA], are studying the details of the May 26 flight. Air Force Research Laboratory (AFRL) officials have called the test “95 percent successful” (Defense Daily, June 5).
The X-51A was launched over the Pacific on May 26, but the scramjet engine ran for only 200 seconds “just under” Mach 5, according to officials, instead of the planned 300 seconds beyond Mach 6. The vehicle was destroyed in flight when it began to slow down and telemetry was lost.
A development effort initiated by AFRL, the program has produced four test vehicles. However, further test flights are on hold because delays in last month’s flight have eaten away at test funds. The original plan was to fly in December 2009, then three more times in 2010.
AFRL officials have said an Air Force request for additional funding in FY ’12 is possible but that existing flight test money in next year’s budget could suffice.
The program has spent $246.3 million since its FY ’04 start, which includes about $210 million in contracts to Pratt and Boeing. Remaining funds were used to pay for Air Force and Navy test assets, NASA wind tunnels and supercomputers, as well as other government-furnished equipment.
The May test-flight was the first using a hydrocarbon-fueled scramjet in which the fuel is used to cool the engine, and the heat is used to crack the fuel so that it will burn when injected into the supersonic flow. The thermal equilibrium achieved allows the engine to operate for as long as it has fuel.
The technology is expected to revolutionize space lift systems, high-speed weapons, and intelligence, surveillance and reconnaissance in the future.
Hypersonic speed describes velocities upward of Mach 5, or five times the speed of sound.