Aug. 30, 2004

Elvia Thompson
Headquarters, Washington
(Phone: 202/358-1696) 

Keith Henry 
Langley Research Center, Hampton, Va.
(Phone: 757/864-6120)

Leslie Williams
Dryden Flight Research Center, Edwards, Calif.
(Phone: 661/276-3893)

RELEASE: 04-279

GUINNESS WORLD RECORDS RECOGNIZES NASA SPEED RECORD

Guinness World Records has recognized the world speed record set by 
NASA's hypersonic X-43A aircraft earlier this year in an experimental 
flight over the Pacific Ocean. Using a scramjet engine, the 
unpiloted, 12 foot-long aircraft achieved Mach 6.83 -- almost seven 
times the speed of sound -- or nearly 5,000 mph, in a March 27 
flight. 

The accomplishment will be included in the 2006 Guinness World Records 
book, set for release this time next year, as follows: 

"On 27 March 2004, NASA's unmanned Hyper-X (X-43A) airplane reached 
Mach 6.83, almost seven times the speed of sound. The X-43A was 
boosted to an altitude of 29,000 m (95,000 ft) by a Pegasus rocket 
launched from beneath a B52-B aircraft. The revolutionary 'scramjet' 
aircraft then burned its engine for around 11 seconds during flight 
over the Pacific Ocean."

If NASA researchers have their way, the record won't stand long. The 
final flight in the Hyper-X program is scheduled to take place in 
October, when another X-43A aircraft will attempt to fly at Mach 10 
-- ten times the speed of sound -- or 7,200 mph. 

The March 27 flight was part of NASA's Hyper-X program, designed to 
demonstrate advanced high-speed propulsion system concepts to 
overcome one of the greatest aeronautical research challenges -- 
air-breathing hypersonic flight. The advantage of air-breathing 
flight is that the vehicle, whether it is aircraft or spacecraft, 
scoops the air its engines need from the atmosphere rather than 
carrying heavy, bulky tanks, as rockets do.

The challenge is to introduce fuel, ignite it and produce positive 
thrust while highly compressed air rushes through the engine in mere 
milliseconds -- roughly analogous to lighting a match and keeping it 
burning in a hurricane-force wind. 

Compared to rocket-powered vehicles like the Space Shuttle, scramjets 
promise more airplane-like operations for increased affordability, 
flexibility and safety in ultra high-speed flights within the 
atmosphere and into Earth orbit. 

The X-43A flight easily set a world speed record for an air-breathing 
engine aircraft. The previous known record was held by a 
ramjet-powered missile, which achieved slightly more than Mach 5. 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.

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. The X-43A more than 
doubled the top speed of the jet-powered SR-71. 

Guinness World Records' science editor David Hawksett has already 
expressed an interest in attending the fall flight. 

"Operating an atmospheric vehicle at almost Mach 7 is impressive 
enough, but to be able to use oxygen from the air, instead of a fuel 
tank, as it screams into the engine intakes at 5,000 mph is a 
mind-boggling technical achievement. It's wonderful to see scramjet 
technology finally begin to take off," said Hawksett.

The Hyper-X program is 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. 

Guinness World Records issued a certificate to NASA documenting the 
X-43A accomplishment, and will feature the story on its web site: 

http://www.guinnessworldrecords.com 

For more information on NASA's Aeronautics Research Mission 
Directorate programs, including Hyper-X, on the Internet, visit: 

http://www.aeronautics.nasa.gov 

	
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