It's official. The new world speed record for a jet-powered aircraft, set by NASA in November, has been officially recognized by Guinness World Records.

The accomplishment, the third and final flight in the experimental X-43A project, demonstrated that an advanced form of air-breathing (jet) engine could power an aircraft at nearly 10 times the speed of sound. Data from the unpiloted, 12-foot-long research vehicle show that its revolutionary "scamjet" engine worked successfully at Mach 9.6 or nearly 7,000 mph, as it flew at about 109,000 feet over the Pacific Ocean west of California.

The flight was the culmination of NASA's Hyper-X Program, a seven-year, approximately $230 million ground and flight test program designed to explore an alternative to rocket power for space access vehicles.

This is the second world speed record earned by the Hyper-X Program. The first came following its Mach 6.8 (nearly 5,000 mph) flight in March of 2004, which easily shattered the previous, long-standing record. Both records will be featured in the 2006 edition of the Guinness World Records book, which will be published in September of this year.

NASA is interested in supersonic combustion ramjet (scramjet) technology because scramjet engines get their oxygen from the atmosphere allowing more airplane-like operations for increased affordability, flexibility and safety in ultra-high-speed flights and for the first stage to Earth orbit. 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, as rockets must.

A ramjet operates by subsonic combustion of fuel in a stream of air compressed by the forward speed of the aircraft itself, as opposed to a normal jet engine, in which the compressor section (the fan blades) compresses the air. A scramjet (supersonic-combustion ramjet) is a ramjet engine in which the airflow through the whole engine remains supersonic.

"These demonstrations proved the viability of scramjet engine technology in a "real-world" flight environment and were the result of over 40 years of high speed propulsion research within NASA," commented Dryden's Paul Reukauf, who served as deputy project manager for the X-43A flight research and testing.

The new Guinness World Record certificate reads:

"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."

Related flight records include:

The previous known record for an air-breathing vehicle -- but not an airplane -- was held by a ramjet-powered missile, which achieved slightly more than Mach 5. The highest speed attained by a rocket-powered airplane, NASA's X-15 aircraft, was Mach 6.7. The fastest air-breathing, manned vehicle, the SR-71, achieved slightly more than Mach 3.2. The X-43A more than doubled, then tripled, the top speed of the jet-powered SR-71.

The Hyper-X program was conducted by NASA's Aeronautics Research Mission Directorate with the NASA Langley Research Center, Hampton, Va., as lead center with responsibility for hypersonic technology development and the NASA Dryden Flight Research Center, Edwards, Calif., responsible for flight research and testing.