AFMC Command News

X-51A flight planned May 25

  • Published
  • By Derek Kaufman
WRIGHT-PATTERSON AIR FORCE BASE, Ohio --  Weather permitting, Air Force officials said the X-51A Waverider will make its first hypersonic flight test attempt May 25, after it's released by a B-52 bomber off the southern California coast.

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

The unmanned X-51A is expected to fly autonomously for five minutes, powered by a supersonic combustion ramjet (scramjet) engine, accelerating to about Mach 6 and transmitting vast amounts of data to ground stations before breaking up after splashing down into the Pacific, as planned. There are no plans to recover the flight test vehicle, one of four built.

"In those 300 seconds, we hope to learn more about hypersonic flight with a practical scramjet engine than all previous flight tests combined," said Charlie Brink, X-51A program manager with AFRL's Propulsion Directorate here.

The shark-like shape of the 14-foot-long X-51A cruiser gives a hint to the technologies it is designed to explore, Mr. Brink said. Virtually wingless, it is designed to ride its own shockwave, thus the nickname, Waverider. The heart of the system is its Pratt & Whitney Rocketdyne SJY61 scramjet engine, but other key technologies that will be demonstrated by the X-51A include thermal protection systems materials, airframe and engine integration, and high-speed stability and control.

Officials said the X-51A program will pave the way to hypersonic weapons and future access to space. Since scramjets are able to burn atmospheric oxygen, they don't need to carry large fuel tanks containing oxidizer like conventional rockets and are being explored as a way to more efficiently launch payloads into orbit.

The X-51 will depart Edwards Air Force Base, Calif. and be carried aloft under the wing of a B-52H belonging to the Air Force Flight Test Center. It will be released at approximately 50,000 feet over the Point Mugu Naval Air Warfare Center Sea Range. A solid rocket booster will accelerate the X-51A to approximately Mach 4.5, before being jettisoned.

The May 25 hypersonic test will actually be the third time the X-51 has flown, but in each previous instance it has remained attached to the B-52's wing. The first captive carry flight Dec. 9, 2009, verified the B-52's high-altitude performance and handling qualities with the X-51 attached and tested communications and telemetry systems. The other flight, intended essentially as a dress rehearsal for the hypersonic flight, took place earlier this year.