- Development of a low-cost space plane
took a step forward last month when one of three technologies essential
to its success was declared "ready for flight".
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- The rugged, metallic thermal-protection
panels designed for NASA's X-33 technology demonstrator passed an intensive
test series that included sessions in high-speed, high-temperature wind
tunnels. The panels also were strapped to the bottom of a NASA F- 15 aircraft
and flight-tested at nearly 1.5-times the speed of sound.
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- Additional laboratory tests duplicated
the environment the X- 33's outer skin will encounter while flying roughly
60 miles high at more than 13 times the speed of sound. Also, a thermal-panel
fit test successfully demonstrated the ease of panel installation and removal.
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- The thermal protection system combines
aircraft and space- plane design, using easy-to-maintain metallic panels
placed over insulating material. As the X-33 flies through the upper atmosphere,
the panels will protect the vehicle from aerodynamic stress and temperatures
comparable to those a reusable launch vehicle would encounter while re-entering
Earth's atmosphere. Tests have verified that the metallic thermal-protection
system will protect vehicles from temperatures near 1,800 degrees Fahrenheit.
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- "NASA is focusing on creating a
next generation of reusable launch vehicles that will dramatically cut
the costs associated with getting into space," said Dan Dumbacher,
NASA X-33 deputy program manager. "One way to cut costs is to design
rugged systems that require less maintenance and that are more airplane-
like in their operations.
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- "By developing and proving these
systems, we're creating the ability to build space planes that eventually
will fly to orbit, return for servicing, and launch again as often as today's
commercial airplanes make scheduled flights," he added. Dumbacher
is assigned to NASA's Marshall Space Flight Center, Huntsville, AL, the
lead center for developing future space transportation systems.
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- The remaining two technologies important
for low-cost space access are an efficient propulsion system ideally suited
to power a lifting body and, more importantly, lightweight-yet-strong composite
cryogenic fuel tanks and structures to minimize vehicle weight. Work on
those two challenging technologies continues as the X-33 program enters
a phase of intense testing and qualification of the vehicle's components.
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- NASA expects the metallic thermal-protection
panels -- developed and built by team member BFGoodrich Aerospace/Aerostructures
Group in Chula Vista, CA -- to dramatically cut maintenance time and costs
associated with more fragile thermal-tile systems. Because the metallic
panels on the lower surfaces of the X-33 make up the vehicle's windward,
aerodynamic structural shell, the system also will obtain significant weight
savings over traditional thermal systems, while being much more durable
and waterproof.
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- The X-33 is a half-scale technology demonstrator
of a full- scale, commercially developed reusable launch vehicle (RLV)
which Lockheed Martin has named "VentureStar", planned for development
after the turn of the century. Through airplane-like operations and a single-stage-to-orbit
design, a full-scale RLV could dramatically reduce the cost of putting
payloads into space from $10,000 per pound to $1,000 per pound.
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- The X-33 is scheduled to make as many
as 15 test flights from Edwards Air Force Base, CA, to Dugway Proving Ground,
UT, and Malmstrom Air Force Base, MT, beginning in 2000.
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- Although suborbital, the X-33 will fly
high enough and fast enough to encounter conditions similar to those experienced
on an orbital flight path to fully prove its systems and performance.
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