The new speed record for a jet-powered aircraft, set by the US space agency (Nasa) in November, has been recognised by the Guinness World Records.
The X-43A was carried to speeds of Mach 9 by a booster rocket
The X-43A "air breathing" scramjet plane reached speeds of almost Mach 10 (7,000 mph or 11,000km/h), which is nearly 10 times the speed of sound.
The flight was the culmination of Nasa's Hyper-X programme, a project to explore alternatives to rocket power.
This is the second world speed record achieved by the Hyper-X project.
The first came when the unmanned aircraft reached Mach 6.8 (nearly 5,000 mph) during a flight over California in March 2004.
Both records will be featured in the 2006 edition of the Guinness World Records book, which will be published in September of this year.
Scramjet engines get their oxygen from the atmosphere, allowing more flexibility, affordability and safety in ultra-high-speed flights and for the first stage to Earth orbit.
"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," said Paul Reukauf, who served as deputy project manager for the X-43A flight research and testing.