Guinness Recognizes NASA X-43A Speed Record
It's official. 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 flight on March 27th.
The accomplishment will be included in the 2006 Guinness World
Records book, set for release this time next year. The citation
reads:
"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.