On June 2, 2001, NASA's first scramjet test was aborted after a serious failure of the rocket booster intended to bring the craft up to speed. According to NASA, the rocket went wildly off-course, forcing them to detonate on-board explosives to stop it.

The X-43A test craft was attached to the booster and lifted to a safe distance by a B-52 bomber. The booster and jet were then detached, at which time the rocket was ignited to lift the X-43A to 100,000 feet before turning the scramjet on. Had the booster not failed, the X-43A would have been active for 10 seconds, covering 17 miles at a burst of over Mach 7, or 5,000 miles per hour before being coasted to a stop on the water below.

July 30th, 2002
A team of University of Queensland researchers successfully launched a scramjet engine in the Australian desert today. It worked as intended during flight, then destroyed itself in the planned crash to the ground. It'll be a few days before they can say for sure whether or not it was fully functional.

March 27, 2004
NASA's X-43 hypersonic scramjet vehicle flew successfully today. It was raised to 95,000 feet, then released from its carrier for acceleration. The X-43 flew under its own power for 10 seconds, reaching a top speed of Mach 7. It then glided for several minutes to gather aerodynamic data.

November 16, 2004
The X-43A set a new speed record today, when it reached 7,000 miles per hour. This is Mach 9.6, or almost ten times the speed of sound. It is the fastest speed ever recorded inside the Earth's atmosphere.