Posted on 07/15/2004 8:13:19 PM PDT by KevinDavis
EDWARDS, CALIFORNIA -- Engineers here are on the fast-track, readying the next flight of NASAs X-43A, a super-sleek, high-speed craft powered by a scramjet engine.
(Excerpt) Read more at space.com ...
Space Ping! This is the Space Ping List! Let me know if you want on or off this list by freep mail!
Is Space.com on the excerpt list?

<|:)~
I don't know...
But this speed could never be reached
"I don't know" is good enough for me. ;-)
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X-43A: Full Speed Ahead to Mach 10
By Leonard David
Senior Space Writer
posted: 7:00 am ET
15 July 2004
EDWARDS, CALIFORNIA -- Engineers here are on the fast-track, readying the next flight of NASAs X-43A, a super-sleek, high-speed craft powered by a scramjet engine.
Earlier this year, the unpiloted 12-foot-long, 5-foot-wide surfboard-looking vehicle howled its way into the history books. The X-43A reached its test speed of Mach 7 -- seven times the speed of sound, or about 5,000 miles per hour. In doing so it set a world-record speed for air-breathing flight, the rocket technology advanced by NASAs Hyper-X program.
The X-43As air-breathing scramjet breathes in oxygen from the atmosphere rather than toting along an oxidizer, mixing it with a cache of onboard rocket fuel to produce combustion and forward thrust.
Being the hypersonic air-breather it is, the X-43A also caused some hyperventilation among project leaders when they watched the vessel tear itself apart on its inaugural flight on June 2, 2001. On that day the X-43A never reached test conditions.
But on a successful second flight, the X-43A flew freely for several minutes following scramjet engine operation. The vehicle's supersonic combustion ramjet, or scramjet, ignited as planned and operated for the duration of its hydrogen fuel supply.
Now its full speed ahead to Mach 10.
Blistering temperatures
Here at NASAs Dryden Flight Research Center, the third X-43A is undergoing short-stack integration, explained Joel Sitz, X-43A project manager at the center. The craft is being outfitted and tested for a Mach 10 mission in the September-October time frame, he told SPACE.com .
Jacking up the speed will mean the vehicle will see higher heat loads than those observed on the Mach 7 flight on March 27.
At Mach 7, the front leading edge of the vehicle would see about 2,400 degrees Fahrenheit. At Mach 10, its probably twice that
twice the heat load essentially, Sitz explained.
Those blistering temperatures will be tamed by special thermal protection applied to the Mach 10 vehicle, Sitz said. The coatings that we are using were sort of a mini-research experiment in itself.
Higher degree of confidence
Like the two previous tests, the next X-43A is mounted to the front of a modified Pegasus XL booster. The combo is hauled skyward from Edwards Air Force Base under the wing of NASAs B-52B carrier plane. Once unleashed from the carrier plane, the Pegasus will rocket to 100,000 feet above Earth where the X-43A separates and then powers itself to Mach 10.
At Mach 10 -- or 10 times the speed of sound -- the X-43A is traveling at about two miles per second. Thats in the range of 7,500 miles per hour. Speeds over Mach 5 are defined as hypersonic.
It is definitely easier to start with a successful Mach 7 [flight] and go to Mach 10. Had we not been successful at Mach 7 we would have had a big job ahead of us, Sitz said. Predicting the aerodynamic forces should be pretty straightforward. But the thermal is the challenge.
Thanks to the triumph in March, wind tunnel data, design tools and predictive skills have been validated. So we have confidence that they are telling us the right things. Designing a control system around that
youve got a higher degree of confidence, Sitz added.
The X-43A research vehicles are built for one-way, non-recovery flights. Heavily instrumented, they end their mission dropping into the Naval Air Warfare Center Weapons Division Sea Range off the southern coast of California.
Fin, fin finale
The X-43As maiden voyage into the hypersonic realm ended in failure in 2001. That attempt to reach Mach 7 was over in seconds following Pegasus ignition. Fins on the booster broke off, taking the X-43A for a ride all over the sky except in the right direction.
For one, the Pegasus/X-43A was deployed from the B-52B at 25,000 feet. The Pegasus is normally dropped at 40,000 feet. The fins ended up being more effective than we thought
and we just drove it out of control, Sitz said.
We mispredicted the aerodynamic forces on the fins. That was a huge contributor, Sitz said.
Furthermore, theres a black art to calculating forces around a craft flying transonic. While a vehicle isnt moving at supersonic speeds, air moving around an aircraft might be, producing small shocks that can influence aircraft control.
You might get one answer in the wind tunnel
and it could be something completely different in flight, Sitz said. You get vortices and shockwaves dancing around.
Trying to be a dance partner and sense what transonic moves are going to occur ahead of time is tough sledding. NASA has been trying to do it for 30 years. And I dont think weve got it down yet, Sitz explained.
End of the program?
The upcoming Mach 10 run of the X-43A appears to mark an end of the program. The seven-year, approximately $250 million Hyper-X program was created to provide unique "first time" data on hypersonic air-breathing engine technologies.
Right now the program on paper ends when were done with Mach 10, Sitz said. Shifting budget priorities at NASA have dictated closure of the program. A follow-on X-43C project has also been cancelled at this point, he said.
NASA's Dryden Flight Research Center is responsible for X-43A flight-testing. The space agencys Langley Research Center in Hampton, Virginia manages the program.
ATK-GASL (formerly MicroCraft Inc.), based in Tullahoma, Tennessee, built both the X-43A and its engine. The Boeing Company's Phantom Works in Huntington Beach, California designed the thermal protection and onboard systems. The booster is a modified Pegasus rocket built by Orbital Sciences Corporation of Chandler, Arizona.
Moving along
NASA, in my opinion, needs to continue hypersonics research. We need to stay involved in this. Scramjets look pretty promising from a technology perspective, Sitz observed. What we have to prove now
can you combine them with turbojets? Can you combine them with rockets?
Sitz admitted that some individuals argue that integration of the technology is too big a problem - a problem that cant be solved in a practical sense. And some people say you can do it, and have the designs that show it can be done. So thats where Id like to see NASA aeronautics go.
For right now, Sitz concluded: We have the worlds fastest air-breathing aircraft. Were going to fly at Mach 10
even though its only for a few seconds. Were moving along.
Thanks! Nice ping and cool project. :-)
Couldn't they call it somethibg else besides X43 ?
NO!
OMG, not even CNN can be THAT sloppy/stupid... can they?
thanks for the bedtime chuckle!
Bookmarking CLASSICS! Thanks!
Getting close to oxyacetylene.
Those are great!
Aurora.
BTW, the Blackbird was good for Mach 6 or 7.....without a crew on board. Gotta keep cool....or roast.
Right now the program on paper ends when were done with Mach 10, Sitz said. Shifting budget priorities at NASA have dictated closure of the program. A follow-on X-43C project has also been cancelled at this point, he said."
Which means it will now become an off-budget black project run by DARPA to develop hypersonic cruise missiles.
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