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Jan.
15, 2009: How can a rocket engine that generates
scalding 5,000 degree steam and a whopping 13,000 lbs of thrust
form delicate icicles at the rim of its nozzle?
It's
cryogenic. NASA
is using the Common Extensible Cryogenic Engine ("CECE"
for short) to develop technologies for a next-generation lunar
lander. CECE is fueled by a mixture of -297 F liquid oxygen
and -423 F liquid hydrogen. The engine components are super-cooled
to similar low temperatures--and that's where the icicles
come from. As CECE burns its frigid fuels, hot steam and other
gases are propelled out the nozzle. The steam is cooled by
the cold nozzle, condensing and eventually freezing to form
icicles around the rim.
Click
on the image to launch a movie of CECE's surprising fire and
ice:
Launch
the movie!
Above:
The Common Extensible Cryogenic Engine in action during a
recent test. Image credit: Pratt & Whitney Rocketdyne.
[Larger
image] [movie]
Using
liquid hydrogen and oxygen in rockets will provide major advantages
for landing astronauts on the moon. Hydrogen is very light
but enables about 40 percent greater performance (force on
the rocket per pound of propellant) than other rocket fuels.
Therefore, NASA can use this weight savings to bring a bigger
spacecraft with a greater payload to the moon than with the
same amount of conventional propellants. CECE is a step forward
in NASA's efforts to develop reliable, robust technologies
to return to the moon – and a winter wonder.
CECE
has just completed a third round of intensive testing by Pratt
& Whitney Rocketdyne in West Palm Beach, Florida. Get
the full story from nasa.gov.
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Editor: Dr. Tony
Phillips | Credit: Science@NASA
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