Boeing's X-51A WaveRider entered the history books in May 2013 when it carried out the longest ever sustained hypersonic flight using scramjet power, hitting Mach 5.1 in the process.
It was launched from a USAF B-52H Stratofortress strategic heavy bomber, which had earlier taken off from Edwards Air Force Base. Positioned over Point Mugu Naval Air Warfare Center Sea Range, the USAF B-52H let the X-51A WaveRider go at an altitude of 50,000 feet, at 1055hrs on 1 May 2013.
Following the X-51A WaveRider's release, the unmanned hypersonic test platform quickly reached Mach 4.8 thanks to its solid rocket booster. It then disposed of this booster and, drawing on its scramjet engine, powered on to Mach 5.1. Once all its fuel had been burnt away, the X-51A dived into the Pacific Ocean in a pre-planned manoeuvre.
Hypersonic X-51A Flight
According to Boeing officials, the hypersonic X-51A test flight saw all the development team's mission objectives accomplished.
This was the fourth such WaveRider trial sortie carried out for the USAF's Research Laboratory and one that surpassed the flight envelope created back in 2010. A previous August 2012 WaveRider test flight came to a very sudden end when the aircraft broke up mid-air, prior to falling into the Pacific Ocean.
The X-51A WaveRider programme is a joint venture between the USAF's Research Laboratory, DARPA (the Defense Advanced Research Projects Agency), Boeing and Pratt & Whitney Rocketdyne.
Hypersonic WaveRider Test
"This demonstration of a practical hypersonic scramjet engine is a historic achievement that has been years in the making", Boeing Phantom Works' President Darryl Davis explained in a statement on the hypersonic WaveRider test. He added: "This test proves the technology has matured to the point that it opens the door to practical applications, such as advanced defence systems and more cost-effective access to space."
Such applications could see the WaveRider's technology adopted in future missile designs but, equally, it's been suggested that a similar creation could revolutionise commercial air travel, bringing London-New York flight times to below 60 minutes.