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Topic: X-43A Aircraft Sets Speed Record at 6,500 MPH |
chas smith R.I.P.
From:
Encino, CA, USA
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Posted 17 Nov 2004 8:50 am |
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X-43A Aircraft Sets Speed Record at 6,500 MPH
Using a scramjet engine, the unmanned plane hit Mach 9.6, opening the door to passengers flying across the nation in about 20 minutes.
By John Johnson, Times Staff Writer
EDWARDS AIR FORCE BASE — NASA's supersonic surfboard, the unmanned X-43A aircraft, streaked into history Tuesday, setting an unofficial world speed record for jet aircraft of Mach 9.6, or about 6,500 mph.
The aircraft — powered by an experimental engine known as a scramjet — was carried to an altitude of 40,000 feet under the wing of a B-52 bomber and released at about 2:30 p.m.
A Pegasus rocket booster accelerated the X-43A — a rectangular disc of metal with fins at the back — before the scramjet on the underside of the aircraft took over, shooting the craft to its record-breaking run at 111,000 feet.
The scramjet burned for about 10 seconds, before flaming out and plunging into the Pacific Ocean about 800 miles off the California coast, officially ending the X-43A program after three flights.
"We had a phenomenal flight today. Everything went really well," said Laurie Marshall, the chief engineer for the flight, speaking at a news conference that turned into a celebration of the program's achievements.
The flight was part of a $230-million project aimed at showing the capabilities of a new breed of jet aircraft that could conceivably speed passengers across country in minutes and send passengers into space far more cheaply than today.
"What NASA does is open doors," said Griff Corpening, the senior advisor to the X-43A program at the Dryden Flight Research Center. "We've just opened the door to Mach 10 flight for jet aircraft."
The heart of the X-43A is its revolutionary scramjet — a contraction of Supersonic Combustion Ramjet. The engine compresses air at hypersonic velocities and ignites it in a hydrogen mixture.
Most commercial aircraft today use turbines to compress air, which ignites with kerosene to create combustion and thrust. Air flows are too low to produce high speeds with those engines.
Engineers developed the ramjet decades ago to solve those problems. A ramjet is basically a hollow tube with no moving parts; air flows into the front of the ramjet, is compressed and mixed with fuel. But the ramjet cannot go faster than Mach 5, or five times the speed of sound. Mach 1 is about 680 mph, depending on atmospheric conditions.
The ramjet's limitations led to development of the scramjet, in which gases flow into the ignition chamber at supersonic speeds. The igniting substance is called Silane, which explodes in the presence of oxygen.
Compared with rocket-powered vehicles such as the Space Shuttle, scramjet vehicles promise more airplane-like operations to improve safety and keep costs down on future hypersonic flights either in or below orbit.
To cope with the extreme heat at hypersonic velocities, the X-43A has a tungsten nose with carbon-carbon leading edges. At Mach 10, temperatures reach 3,700 degrees Fahrenheit.
The top of the vehicle is as flat as a bowling alley. The scramjet engine, essentially a copper box, is suspended from the underside of the plane.
During its 10-second engine burn Tuesday, the X-43A traveled nearly two miles a second. At that speed, a trip to New York from Los Angeles would take about 20 minutes.
There remain a number of hurdles, however, before scramjets could be introduced to commercial flight. The primary one is that the engine won't work at speeds less than Mach 4.
One answer might be to include more conventional engines on board to lift the plane off the ground.
Another solution would be to attach it to a rocket, though that would require future passengers to become comfortable with the chin-stretching forces of rocket takeoffs.
In the near term, scramjets are more likely to be used on bunker-busting missiles.
Asked if scramjets could be used for commercial transportation, X-43A project manager Joel Sitz, said: "Absolutely." But he added, "Who knows when it will be."
Until this year, the speed record for a jet aircraft was 2,100 mph, about Mach 3, established by the SR-71 spy plane.
The first X-43A test in 2001 was a failure. The craft went out of control during the booster phase. The first successful test of a scramjet engine was March 27, when the X-43A hit a top speed of 5,000 mph, or Mach 7, before being ditched into the ocean.
The latest flight was originally scheduled for Monday, but was delayed a day after computer problems developed in the avionics of the vehicle.
The hypersonic plane was designed by Boeing Co. at its Huntington Beach facility and built by ATK-GASL in Ontario and Tullahoma, Tenn.
Several other countries, notably France, Japan and Australia, also are moving forward with scramjet projects.
Tuesday also marked the last test flight for the B-52, which has been launching test vehicles since the X-15 in the 1960s.
As it took off, it headed up at an unusual nose-up attitude that NASA officials said was intended as a final salute. |
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Mark Metdker
From:
North Central Texas, USA
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Posted 17 Nov 2004 9:37 am
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Wow...that's faster than a 'vette!
Seriously, I would have like to see that thing in action. |
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chas smith R.I.P.
From:
Encino, CA, USA
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Posted 17 Nov 2004 5:31 pm
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| Seriously, I would have like to see that thing in action. |
That would have been difficult. To put that speed in perspective, a 7.62 bullet travels around 2400'/sec, a 30-06 travels around 3000'/sec, a .223 travels around 3300'/sec. The SR-71 could do at least 3870'/sec and the X-43A just did 9533'/sec. "Faster than a speeding bullet, more powerful than a locomotive, able to leap tall buildings in a single bound..." |
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Mark Metdker
From:
North Central Texas, USA
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David Cobb
From:
Chanute, Kansas, USA
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Posted 20 Nov 2004 7:13 pm
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Video of the flight was on the tube last week and as they say, it was nothing but taillights.
The leading edges have liquid(H2O) circulating through them to prevent an inflight meltdown. en.wikipedia.org/wiki/X-43 is an excellent article on the craft.
Or you can Google the X-43a. |
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Tom Olson
From:
Spokane, WA
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Posted 20 Nov 2004 7:52 pm
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| a 30-06 travels around 3000'/sec, a .223 travels around 3300'/sec. The SR-71 could do at least 3870'/sec |
What if . . . an SR-71 had been designed with a tail gun? If so, the bullets would have actually been travelling backwards after being fired! 
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| the X-43A just did 9533'/sec |
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| Seriously, I would have like to see that thing in action |
What I would like to see is a "head-on" collision between two X-43's. The combined closing speed would be about 13,000 miles per hour! 
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Mark Metdker
From:
North Central Texas, USA
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Posted 20 Nov 2004 9:28 pm
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| ....hmmmmm....so this thing is 3 times faster than a bullet? So it cannot be shot down? |
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Les Anderson
From:
The Great White North
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Posted 20 Nov 2004 9:41 pm
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I wonder what kind of fuel milage that thing gets? Maybe a little more than my 1965, 400hp Mercury , 4D hard top?
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(I am not right all of the time but I sure like to think I am!)
[This message was edited by Les Anderson on 20 November 2004 at 09:42 PM.] |
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Tom Olson
From:
Spokane, WA
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Posted 20 Nov 2004 9:47 pm
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| So it cannot be shot down? |
Probably not. But, technically -- it depends on whether you're standing in front of it, or behind it when you shoot at it. |
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chas smith R.I.P.
From:
Encino, CA, USA
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Posted 21 Nov 2004 10:44 am
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When the SR-71 flew recon over the Soviet Union, they could see it on the radar screen and basically sit back and watch it fly over. It was higher than the effective range of SAMs. There were unsuccessful efforts made to convert the Foxbat to catch it.
I heard a story about when the scramjet engine was first being tested. They backed up a Phantom to the intake, to get the airspeed and heat up to what was needed to fire up the scramjet, and it ignited. However, it sucked the Pratt & Whitney emblem off the side of the engine and exploded. |
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Mark Metdker
From:
North Central Texas, USA
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Tom Olson
From:
Spokane, WA
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Posted 21 Nov 2004 1:46 pm
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| I think it's probably like most other technological advancements -- it takes a while before the technology is actually implemented commercially, or even militarily, or whatever. If there's a viable, practical use for it, it'll happen. |
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