The X-51A Waverider blasted itself into the longest hypersonic flight in history yesterday, streaking across the sky at Mach 5 for just over 200 seconds. That's 10 times longer than the previous record, set in 2004 by NASA's X-43. While the X-51A has already flown a couple of times while remaining attached to its mother ship, this was the first time the unmanned plane flew independently.
Hypersonic flight, defined as faster than Mach 5 (around 3,800 mph), is not easy. Conventional turbine jet engines can't handle such tremendous speeds. To complete its hypersonic flight, the 14-foot-long Waverider launched from the wing of a B-52 over the Pacific Ocean, and with the help of a solid rocket booster, screamed up to Mach 4.8 before that booster was jettisoned.
That's when its SJY61 scramjet engine took over, using its supersonic combustion to create a shockwave upon which the jet rides (that's why it's called the Waverider). After its record-breaking 200-second flight was complete, it splashed into the Pacific Ocean, not to be recovered. There are three more of these X-51A missiles, set to take their test flights later this year.
It was a big day for aviation technology. Says Air Force X-51A program manager Charlie Brink, "We equate this leap in engine technology as equivalent to the post-World War II jump from propeller-driven aircraft to jet engines." Could it be long before we can travel from New York to L.A. in the time it takes to deliver a pizza?
Here's a more-detailed video created before yesterday's historic test flight: