The Air Force’s unmanned X-51 WaveRider “scramjet” covered 264 miles in just over six minutes on Monday, reaching Mach 5.1 (more than 3,000 mph) on its final test flight. The experimental test aircraft was launched from a B-52 bomber out of Edwards Air Force Base in California, and the test flights took place over the Pacific near Point Mugu.
The X-51 is now retired, but its test flight program, which started in 2010 and has had noteworthy failures along with its successes, will form the basis for more research into hypersonic flight. Pentagon spending on scramjet research totals an estimated $2 billion over the past 10 years.
The B-52 released the WaveRider, so named because it rides its own shockwave, at approximately 50,000 feet, where it lit off a solid rocket booster, reaching Mach 4.8 in 26 seconds. It then fired up its air-breathing scramjet engine, and accelerated to Mach 5.1, collecting more than six minutes of data. Another X-51 WaveRider flight in August 2012 ended when control was lost and the aircraft broke up over the Pacific.
