US Air Force preps WaveRider for hypersonic flight

The US Air Force is preparing the unmanned X-51A WaveRider for its first hypersonic flight on Tuesday, May 25.

According to USAF spokesperson Charlie Brink, the unmanned aerial vehicle (UAV) will be detached from a B-52 bomber somewhere off the southern California coast.

“The X-51A is expected to fly autonomously for five minutes – powered by a supersonic combustion ramjet (scramjet) motor – accelerate to about Mach 6 and transmit large amounts of data to ground stations before it splashes down into the Pacific and breaks up, as planned,” explained Brink.

“[However], there are no plans to recover the flight test vehicle, one of four built. [Because] in those 300 seconds, we hope to learn more about hypersonic flight with a practical scramjet engine than all previous flight tests combined.”

Brink also noted that the longest previous hypersonic scramjet flight test – performed by a NASA X-43 in 2004 – was faster, but lasted only about 10 seconds and used less (logistically supportable) hydrogen fuel.

“This is an experimental X-plane and it’s a complicated test. We knew the original schedule was aggressive and we would need to be flexible. It’s also expensive to keep a staff of engineers and support staff at the ready and then not be able to fly when supporting assets aren’t available. So we elected to make only one hypersonic try this spring and then pause for a few months to conserve funding,” he added.

The X-51A program is a collaborative effort of the Air Force Research Laboratory and the Defense Advanced Research Projects Agency (DARPA), with industry partners The Boeing Company and Pratt & Whitney Rocketdyne.