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X-43 Scramjet Rollout
PenguinRadio writes: "The Washington Post is reporting that NASA is readying the X-43 space plane for a 10 second test flight, after which is will plunge into the ocean and not be recovered. The X-43 is an unmanned aircraft (there are three of them) that is used as a testing bed for hypersonic aircraft and may lead to a commercial version in about 20 years or so. Anybody got an extra wet suit?" See also the Reuters article on the same subject, and our previous story about an Australian version.
This is important aerospace research, and if you read the article, it's pretty easy to see why. The ability to fly at such speeds for intercontinental, oceanic flights is of great societal benefit. Speed of transport will make this work commercially.
The military aspects are a bit more challenging, though. If you're going to build a bomber so fast it can't be shot down, fine--but then you have to either slow down the craft so that the munitions can exit the slipstream, or you have to come up with some design that will allow you to drop iron at high speeds--such as the Valkyrie, which dropped munitions out the tail.
Either is a huge design problem. If you slow the craft down, you have to design a craft that performs at all speed ranges with in-theater fidelity. If you kick the munitions out of the back, you have to compensate for the mass changes with aerodynamics, because you change the center of gravity all the way through the release profile, and you better hold the craft steady during release, lest you hit the bomb on the way out. "Somebody set us up the bomb," indeed!
But this won't replace STS. Yes, a scramjet is nice. Yes, this is similar to rocket-based combined cycle. But we could more cheaply build a reliable, two-stage system to get into orbit. Mass fractions are all you have to look at to wonder why Single Stage To Orbit [SSTO] is some perverted NASA priority. As a NASA sub, I know they don't live in reality, but damn...
But this is, for once, a positive example of your tax dollars at work.
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Geof F. Morris TOTK.com Sports--Sports for Geeks, Commentary that Matters
...in this Wired article.
The VCs will only go for it if $Commercial_Scramjet_Entity sets up a website named eScramjet.com, and sells tickets and Snap-Tite models at a loss, but intends to make up the profit in volume.
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
Probably, but it won't work as shown on TV. It'll only sit dead on your lawn.
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
My favorite parts of the article:
"Two other X-43As will fly after the initial test at six-month intervals. If successful, the 12-foot-long, surfboard-shaped planes will smash the speed record of Mach 6.7, set by an X-15 in October 1967."
followed shortly by:
"The X-43A, or Hyper-X, will probably never carry commercial passengers because of the high acceleration, heat generated by friction with the atmosphere and the difficulty of turning a plane at such high speeds."
Something tells me that a 12 foot long commercial aircraft is going to have other problems besides heat/acceleration with enticing passengers onboard.
Well, that is unless they use footage from Dr. Strangelove as an advertisement. (Cue Slim Pickens' product endorsement - "YEEEEHAAAA!!!")
Sheesh. Do these writers ever run a brain-check on their articles?
zeke
Good thing it's stuffed to the gills with telemetry. It's a one-shot drone...that's one reason they didn't put people in it. Or landing gear.
Not needing to figure out how to land an aircraft dramatically simplifies your design.
Why yes, I AM a rocket scientist!
NASA project managers are just as prone to say hilarious things as anyone else. They are managers, after all.
A hypersonic cruise missile, however, actually would be pretty darn hard to intercept. With ballistic missiles you can usually detect them about 10 minutes or so before they reach their target. A hypersonic cruise missle at only 100000 feet altitude is both harder to detect and harder to intercept.
So then we'd be the "National Space Administration". Cool! I always wanted a super-l33t firstname.lastname@nsa.gov email address ;-)
Unfortunately, everyone also knows that in order to get any kind of accuracy with a railgun, you need a really high framerate and fast reflexes.
And if you look at the whole flight, with the lift from the B-52 and then a booster rocket, I'll bet that mileage goes way down.
Also parts from all three will appear on Ebay within days.
Bob.
Moderators!!! up! Up! UP!
:-)
Those are cool photos. Better than the few on CNN and other news sites. These photos show the scale of this model, which is really tiny.
I can understand why they aren't salvaging these 3 craft, they are nothing more than large model airplanes. If they can get some good telemetry data from them, it will keep the scientists and aerospace engineers happy for years.
I'd like one in my bathroom =)
Which, a photo or one of these scale planes? It looks like one plane would fit in my bathroom, and would certainly make for interesting conversations
the AC
Hemos is like...sci-fi fans;he thinks technology is cool, but he hasn't bothered to understand the science it's based on
see if I got this right:
The cooling device and the fuel preheater are the same? SWEET!
Just out of curiosity: if a manned plane were to lose power while hypersonic, would it be able to passively slow down to subsonic without melting, or 1) is this effectively impossible due to scramjet design or 2) a powered slowdown is absoultely required, so don't fail.
.77 cents a gallon? I was at the airport last week and jet fuel cost 2.71 dollars per gallon.
Oddly enough, fuel for piston engines cost 2.70$
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
;)
DO NOT LEAVE IT IS NOT REAL
It really depends on the size of the airplane. A tiny (~12 ft) plane like the X-43 will have very little inertial energy compared to the size of the wave drag force that it will see, meaning that it will have a massive deceleration. A manned plane would be more like 90-250 ft long, weighing upwards of 2 million pounds fully fueled. Inertia and drag would be much less disparate in that case.
A better way to think about the fuel is as a heat sink. It takes a lot of energy to go from 70K to 2900K, especially since there is a phase change involved. A manned plane would also probably have much more complex cooling system, and would probably be made of materials that could support hypersonic cooling. The X-43 is so tiny that there is little effective internal mass to use as a heat sink, so the engineers were forced to improvise. I do think their method is ingenious, as long as it works...
... and there is no doubt, that one day he will be
where the eye of his telescope has already been
turn radius r=(v^2)/g(sqrt(n^2-1)) where g = 32.2 and n = load factor.
At mach 10, a vehicle pulling 3 g's would have a turn radius of ~260 miles. That means that a plane flying due west over Atlanta would enter a 3g turn, pass over Little Rock, AK, St Louis MO, and Cincinatti OH before it pointed east. (It would take 4 minutes and 12 seconds to perform the maneuver). At 2 g's it would overfly Topeka KS, Des Moines, and Milwuakee... and would take 7m 14s.
That's at sea level (a=1116 ft/s).
Neh
aero geek
... and there is no doubt, that one day he will be
where the eye of his telescope has already been
Well, like you said, it is useful for launching things into space. Getting into orbit currently uses much, much more fuel than moving around once you're in orbit, and is therefore much, much more expensive. If you only need hydrogen to burn in the atmosphere, you save a lot of weight (the oxygen weighs 8 times as much as the hydrogen), and therefore a whole hell of a lot of money.
Being able to move things around in space won't do us much good if we can't get them to orbit cheaply. That's what the scramjet's good for.
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At the risk of sounding ironically redundant; didn't we already read this article?
Perhaps here?
Slashdot: News for Nerds. Over and Over and Over and Over....
0 to Mach 5 in 10 seconds. Future commercial flight? At that rate of acceleration wouldn't the passengers become lethal object within the cabin? They better get a strong hull to contain all that goo that paid to climb aboard!
Cynically yours,
Trevor.
If you'd bother look at the acronym, you'd notice that it stands for National Aeronautics and Space Administration.
Yeah, NASA should stick to space and not develop aircraft systems like wind shear detectors, safer emergency fuel-cutoff systems, LIDAR, or computer-assisted flight systems.
Yeah, we should just make NASA stick to space...thereby widening the gap between aviationa and space, keeping space a horribly expensive venture.
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Yo soy El Fontosaurus Grande!
blog |
Given that its travelling at over a mile a _second_ I'll not be volunteering for being hit by the pointy end even if it doesn't have a warhead attached! Simply crashing one of these into the building of your choice is going to disperse a pretty large quantity of kinetic energy into it with no muss, fuss or radiation to worry about.
"I Know You Are But What Am I?"
As another post has already mentioned, this thing is going up to 100 000 feet, speeding up to mach x (where x is large) and then freefalling down into the ocean. What exactly are you planning on salvaging?
"I Know You Are But What Am I?"
Let's be honest here...a plane hurtling into the ocean at Mach X is going to go straight to the bottom. Depending on where in the ocean it hits, this could be MILES deep.
Point two: a plane hurtling straight down at Mach X is going to get VERY hot...anyone who's ever put an ice cube in a glass that just came from the dishwasher knows what might happen to that plane once it hits the water. Also, if you've ever done a bellyflop into a pool, you know how hard water can be...
It would seem an absurd waste of taxpayer money to salvage the craft since 1.) it would probably break into a gazillion pieces and 2.) it would probably reside at unsalvageable depths.
"If at first you don't succeed, lower your standards."
I'm a space policy grad student, and we hear about McCurdy a lot. He might not be an engineer, but he knows the space business. I don't think there was too much dilution for him. B
"Fifty million Americans can't be wrong," said Rep. Billy Tauzin. Gore - 50,999,897 Bush - 50,456,002
Now, obviously, we can't exactly send a traditional fighter out to shoot this thing down, but would it be possible to detonate something in front of the craft, which would pepper the area with oversized buckshot, and let the craft fly through it?
I'm not well versed in the mechanics of air travel, and I know that at supersonic speeds, it becomes harder to maneuver (jumping into hyperspace ain't like dusting crops, boy!), but at the speeds this thing moves, would it be pretty much limited to a straight line, or could it "go around" the danger zone?
Also, if this can go from one end of the globe to another in 30 min, would anybody be able to detect it, track it, and send up a countermeasure in enough time?
Er, no.
Orbital altitude is determined solely by final speed.
I.e., once you shut off the thrust, you are in the highest orbit you will ever have.
If you think you will "coast" to a higher orbit after an impulse of thrust, you need to think about adding wings to your coaster, because you're gonna need them to help you miss the Earth on the way down.
To change a circular orbit, you do not push up, and you do not push down, you push with or against the direction of travel, tangential to your orbit. And you do so constantly, and constantly adjusting your attitude to keep the thrust purely tangential, because, again, once you shut off the thrust, you are in your new orbit, and if you add any radial thrust, you're in an elliptical orbit. And we're back to needing those wings.
--Blair
What do wings have to do with eliptical orbits?
If you're miscalculating your orbit as badly as implied here, they and a few seconds of panicky stickhandling when you re-enter the atmosphere are what keeps you from hitting the planet, splat, we can rebuild him, etc., etc.
Any orbit that gains significant altitude (radial distance) is elliptical, and turning elliptical orbits into circular ones takes more than just a little "maneuvering", unless they're only slightly eccentric.
You're not going to go hell-bent up to 180 miles and then just sort of float and puff-puff steer to 220 miles. Not unless you want to go back down to 140 miles a few minutes later. You need to fire main engines and reduce your radial momentum and acceleration both to zero. Maneuvering thrust is only for fifth-decimal-place stuff like attitude control and easing up to a space station for docking.
And thanks for the pointer to the Niven book. There's so much cloying fantasty and ersatz science in SF these days that I've given up everything in the written forms but collecting signed copies of books I've read.
--Blair
unmaned aircraft
I should hope the aircraft is unmaned. Putting a big mane on it would seem to serve no purpose other than decoration, and would increase drag a great deal.
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
Great, the Chinese will probally end up with this one too.
Sorry. You're very mistaken.
Air breathing engines have one killer drawback: the air intake. It needs to be very large, which drives up the cross-sectional area of the craft, which drives up the wave drag of the airframe. The air breathing engine has a very low impulse (thrust per unit drag) because its cross-sectional area is huge relative to that of a similar-thrust rocket.
I've said it before, and I'll say it again: Air breathing engines are a bad way to get into orbit. Full stop. The math just doesn't work. It's a pretty idea, but it's impractical with anything like today's technology. We can make MUCH better rockets (aerospike engines have potential) but air-breathers are not the way to go.
And yes, I am a rocket scientist. Thanks for askin'. : )
Why yes, I AM a rocket scientist!
Yes, scramjets are less fuel efficient than a 747 because they accelerate faster to a higher speed.
If you want fuel efficiency, take a slow boat to China. If you want to get to Tokyo quickly or the edge of space, you'll need something that gives a kick in the pants.
Yes, the reason we don't have a real hotel in orbit in 2001 is because space development is moving at the speed of governments. If Pan Am had been flying space shuttles there would be a lot more activity above the atmosphere.
What exactly does everyone think is going to be left of this plane after it slams into the ocean at Mach X?
-- Bird in the Bush: The Renewable Energy Blog http://www.birdinthebush.org
``I wouldn't want to be on the pointy end of one of these things if its got a bomb on it,'' Sitz said. ``We could call someone up and say: 'We're gonna bomb you,' and there would be nothing they could do about it.''
Since this is basically what the US does anyway, it's good to know that we'll have some stability in our foreign policy during the coming decades!
I also find it hilarious that is a NASA project manager talking...
Karma: Bored. (Thinking about resurrecting the "Anyone else is an imposter" joke.)
Sounds like Nasa.
Seriously, the idea is based on the observation that alot of the time you spend going into orbit you are simply coasting. And you are also bringing along alot of oxygen for the fuel. So if you could get your oxygen for the ascent from the atmosphere, and then coast to orbit, you could save a lot of weight. You would still have enough on board for manuevering jets, etc. But this requires something that can operate in the middle range of speeds of Mach 2 to Mach 10 (and higher)
Check out the Vinny the Vampire comic strip
"It is a greater offense to steal men's labor, than their clothes"
I can't beleive that they're not going to recover the jet after it crashes. While I understand that this is a test of the engine only, it seems like there would be a wealth of data to be had from examining the structure of the device, even after it crashed.
While I'm no engineer, don't crash investigators for regular airplanes often look for things as minor as cracks in the substructure to indicate possible areas of improvement for future planes?
I think it's a horrible waste of information and effort to let this thing sink to the bottom of the ocean. Worse, they're putting information in the hands of the other few countries with the resources to salvage this guy, and you can sure bet that they won't share the results with us.
C'mon guys. Fish it out!
The next Slashdot story will be ready soon, but subscribers can beat the rush and slashdot the links early!
Isn't there a very limited market of people who want to plunge into the ocean at Mach 5?
Should have no problem getting venture capital, though.
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Yes, the nick is flamebait
I'll bite:
"A space plane like the space shuttle costs the same amount of money in terms of fuel as a jumbo jet from London to New York does."
How do you figure that? Mile-per-mile? Did you not notice the external fuel tank needed to get the Shuttle to orbit? Do you think LOX and LH are so much less expensive than jet fuel? The External Tank alone uses 526,000 gallons of fuel in the 8.5 minutes before it's jettisoned (That's 1031 gallons per second (g/s). A 747 on the other hand, has a maximum fuel capacity of 57,285 gallons, which it sips at 1.06 g/s.
Jet fuel currently costs about 77 cents/gallon, while LH costs about 75 cents and LOX costs about 35 cents, but that kind of logic is like saying it would be more economically efficient to walk to the moon.
"Wall Street would be the new mission control, and you can bet that the analysts of that city would make space trave as cheap as boarding a jumbo jet - there is no reason why it should not be."
I'd suggest you take a look at this economic analysis of the $/lb costs for the Space Shuttle under various scenarios, including daily launches. It'll never get beneath $640/lb, which is significantly more expensive than boarding a jumbo jet, unless you're a mouse. but then, mice fly free...
It would be more accurate to say that Wall Street would be able to raise enough money in an IPO to send the company's founders into space, but Wall Street itself doesn't have as much to do with the creation of economical solutions as they do the speculation of profitability of said systems.
Kevin Fox
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Kevin Fox
I hear they're moving the 'Taco Bell' sign
that MIR missed into the area where this
is supposed to land. If it hits it, everyone
at NASA gets a free Chalupa....
Check out these cool photos!
I'd like one in my bathroom =)
Any technology distinguishable from magic, is insufficiently advanced.
See also the Reuters article on the same subject, and our previous story about an Australian version.
Or, see the exact same previous story from the last week.
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Never underestimate the bandwidth of a 747 filled with CD-ROMs.
I hate to play devil's advocate on this, but you stated that 'Scramjets are wasteful, and in the wrong direction' then.. do not go anywhere near that topic in the body of your message. Any particular reason you made this omission?
As for the government retarding space exploration, of course they have. You see how corperations act on planet Earth, right? Imagine that up in space, where things like a misplaced bolt traveling at orbital speeds can take out satellites. NASA tends to be very exacting about how and when they do things. Corperations go for the bottom line. Does it make them profit? If so, they don't care about the little details like debris. Can you imagine the difficulty we'd face in even getting out of the atmosphere if our entire LEO sphere was a mass of garbage and debris left from satallite leavings? (well, at least til they managed to drift back to the atmosphere)
I've been following this project for years since I heard it announced. While I'm not the utmost on what they're current plans are, there are reasons for doing things this way. The more disposable pieces they take to orbit (fuel tanks on the shuttle), the more explosive bolts they fire, the more garbage there is. If they can make a SSTO craft (Single Stage to Orbit for those that need it explained), then they cut down on the ammount of crap left in space.
Problem number one is getting the speed involved to reach orbit without booster rockets. Scramjets are the answer to this. They operate at high speeds only (well into the Mach range) and are ideal for use in situations where you don't need the compression of turbo fan blades in other jet engines. Read: A Scramjet is a ramjet only for use at higher speeds.
Problem number two is that, if they really want to make a SSTO craft, they have to carry Everything they need within that craft, all fuel to break escape velocity, everything. The current shuttles carry just enough fuel for maneuvering in space, and dropping back to earth. They do not and cannot (without external fuel tanks) have the reserves within to break out of the atmosphere. The only reason why this new space plane will be able to do it is because it will carry only half it's fuel. The other half (the bulk of the oxygen needed) will be gathered from the atmosphere itself as it flies.
Now, saying this is wasteful is frankly trolling and misinformation unless you can prove that it is wasteful. This plane will be lighter than it must be if it were to burn LOX and Liquid Hydrogen, and will therefor require less power to get the speed necessary to reach orbit. How is this more wasteful than before? What other methods would you use to get to space? A space elevator? Linear accelerator based on the ground? (Check out your Sci Fi book stores for what I mean by these). These ideas are nice and far more efficient, but are a little out of our league at the moment.
Until we can manage to build some of these things and overcome the technical hurdles involved in their creation and use, we still have to use rockets and jets to reach orbit. I'm all for a SSTO craft. They are more cost effective, they are more easily maintanable (The shuttle takes months on the ground for refits of lost tiles, damage from orbital debris, and other maintenance). If they can do this right, they can make this space plane more usefull by making it able to fly more often. Get a small fleet of them, and you could have daily flights to orbit. Tourism anyone?
Oh, and as for why NASA only bought 6 shuttles, several month downtimes, and single missions to orbit. At the moment, I doubt you'll see several shuttles in orbit at the same time. With all the monitoring tools they have, I don't think Nasa has the manpower to handle 2 or 3 in orbit at once. With those factors in mind, and a price tag in the billions (IIRC), they don't need more, they can't handle more, they're certainly not going to spend that much money on something they can't utilize effectively. Would you?
My prediction: the scramjet will successfully accelerate to Mach 5, plowing into a Chinese observation plane and obliterating it. The flaming wreckage will fall from the sky and land on a Japanese pleasure cruiser, sinking it.
George Bush will blame the Russians.