by Daryl Mayer
88th Air Base Wing Public Affairs
5/3/2013 - WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- The
final flight of the X-51A Waverider test program has accomplished a
breakthrough in the development of flight reaching Mach 5.1 over the
Pacific Ocean on May 1, 2103.
"It was a full mission success," said Charlie Brink, X-51A program
manager for the Air Force Research Laboratory Aerospace Systems
The cruiser traveled over 230 nautical miles in just over six minutes
over the Point Mugu Naval Air Warfare Center Sea Range. It was the
longest of the four X-51A test flights and the longest air-breathing
hypersonic flight ever.
"I believe all we have learned from the X-51A Waverider will serve as
the bedrock for future hypersonics research and ultimately the practical
application of hypersonic flight," Brink said.
The X-51A took off from the Air Force Test Center at Edwards AFB,
Calif., under the wing of a B-52H Stratofortress. It was released at
approximately 50,000 feet and accelerated to Mach 4.8 in about 26
seconds, powered by a solid rocket booster. After separating from the
booster, the cruiser's scramjet engine then lit and accelerated to Mach
5.1 at 60,000 feet.
After exhausting its 240-second fuel supply, the vehicle continued to
send back telemetry data until it splashed down into the ocean and was
destroyed as designed. All told, 370 seconds of data was collected from
"This success is the result of a lot of hard work by an incredible team.
The contributions of Boeing, Pratt and Whitney Rocketdyne, the 412th
Test Wing at Edwards AFB, NASA Dryden and DARPA were all vital,"
This was the last of four test vehicles originally conceived when the
$300 million technology demonstration program began in 2004. The program
objective was to prove the viability of air-breathing, high-speed
The X-51A is unique primarily due to its use of a hydrocarbon fuel in
its supersonic combustion ramjet, or scramjet, engine. Other vehicles
have achieved hypersonic -- generally defined as speeds above Mach 5 --
flight with the use of hydrogen fuel. Without any moving parts,
hydrocarbon fuel is injected into the scramjet's combustion chamber
where it mixes with the air rushing through the chamber and is ignited
in a process likened to lighting a match in a hurricane.
The use of logistically supportable hydrocarbon fuel is widely
considered vital for the practical application of hypersonic flight.
As a technology demonstration program, there is no immediate successor
to the X-51A program. However, the Air Force will continue hypersonic
research and the successes of the X-51A will pay dividends to the High
Speed Strike Weapon program currently in its early formation phase with