The new Guinness World Record certificate states:

"On 16 November, 2004, NASA's unmanned Hyper-X (X-43A) aircraft reached Mach 9.6. The X-43A was boosted to an altitude of 33,223 m (109,000 ft) by a Pegasus rocket launched from beneath a B52-B aircraft. The revolutionary 'scramjet' aircraft then burned its engine for around 10 seconds during its flight over the Pacific Ocean."

The November flight was the culmination of NASA’s Hyper-X Program, a ground and flight test program that was designed to explore an alternative to rocket power for space access vehicles. The Hyper-X Program lasted seven years and cost about 230 million dollars. This is the second world speed record earned by the Hyper-X program. The first record was broken in March 2004, when a speed of Mach 6.8 was reached. Both records will be featured in the 2006 edition of the Guinness Book of World Records, which will be published September 2005.

Scramjet engines get their oxygen from the atmosphere, which allows more airplane-like operations for increased affordability, flexibility and safety in ultra-high-speed flights and for the first stage to Earth orbit. A ramjet operates by a subsonic combustion of fuel in a stream of air compressed by the forward speed of the air itself. This differs from a normal jet engine, in which the compressor section compresses the air. A scramjet is a ramjet engine in which the airflow through the whole engine remains supersonic. Once a scramjet-powered vehicle is accelerated to about Mach 4 by a conventional jet engine or booster rocket, it can fly at hypersonic speeds, possibly as fast as Mach 15, without carrying heavy oxidizer, which rockets must do.