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Second Test of X-43A Scramjet Tomorrow
pinkUZI writes "NASA says its new Hyper-X, a jet capable of flying some 5,000mph - seven times the speed of sound - will be ready to take a test cruise across the Pacific this Saturday. This is actually NASA's second attempt; the first, in 2001, failed when stabilizing fins flew off the plane's booster rocket and controllers ordered the craft destroyed. CNN has the story." NASA's mission web page has more information, photos, etc.
http://science.slashdot.org/article.pl?sid=04/03/2 5/141238&mode=nested&tid=134&tid=160
the b-52 to launch the plane. Will they be able to develop on of there that can take off on its own? or will we always be launching them from the underbellies of a big plane.
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Da-dum-ching!
Gordon D. Pusch wrote in sci.space.tech: "Hypersonic travel combines all the disadvantages of airplanes with all the disadvantages of rocket flight and all the disadvantages of re-entry --- continuously."
The article starts off with this:
The space agency's dogged pursuit of extreme speed, officials hope, will ultimately make space flight easier to accomplish.
OK, so exactly how is this supposed to aid space flight efforts? There is no mention made of that in the article at all.
I would have thought that the ability to reach incredible speeds in horizontal flight inside the atmosphere is unrelated to both:
1) Entering orbit (horizontal flight).
2) Flying in vaccum (different conditions than in atmosphere).
I'm confused ... any thoughts?
I hear there's rumors on the Slashdots
They're not (directly) working on cruise missiles, although the tech could be used for that. They're trying to invent a cheaper way to get to orbit. This is just a test bed to figure out the scram jet. The plan is for a standard jet engine to get you to supersonic speeds, the scram jet to get you to hypersonic speeds and the edge of the atmosphere. Once you're going, say, Mach 7 and most of the atmosphere is below you, you fire the rocket engine to get you the rest of the way to orbit. This approach wouldn't require the rocket to carry as much oxydizer, thus less weight, less cost.
Aren't there laws governing mach speeds over populated areas?
Happened in Arizona, reputedly. I quick google yields: http://www.snopes.com/autos/dream/jato.asp
-- SKYKING, SKYKING, DO NOT ANSWER.
They're testing it over the pacific ocean.
Yes, you would hear the sonic boom of the test flight. (If you are close enough to hear it at all, of course).
At supersonic speeds, the edge of the soundwaves that are produced by an object is a cone in the object's inertial frame. Regardless of the speed. The speed only changes the angle of this cone..
Let us strap a human to it and sing "The Rocket Man"!
Depends what you're reentering I suppose...
The only possible use I can think of is hyper-range weapons. Ground-controlled planes armed with lethal cargo (nuclear or not) could be flown around the globe faster than any ICBM, and guided with better accuracy.
I'm all for "Science for Science's sake" but I think this is worthless for any practical purposes.
from the dupes-of-dupes dept.
Things are more like they are now than they ever were before.
Slight off-topic, but why do I have to go to Jet Propulsion Laboratory to find out about the Mars rovers, and then I have to go to National Aeronautics and Space Administration to find out about fancy new jet engines?!
Is it a cunning plan to out-fox those secret stealing ruskies?
You don't have to bring your own heater?
Jeroen
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The danger here is that the darn thing will carry all of these systems and have no capacity left over for payload. I recall the Boeing SST back in the late 60's early 70's was based on a swing wing concept. The scale of the mechanical systems to swing the large wing faced them with a difficult choice of a swing wing or passengers...but not both.
In the physics world one has a sense that they are on to something when the math becomes elegant and simple...I think in the "no moving parts" nature of the scram jet are appealing...a turbofan/scram/rocket combination is not
When the people fear their government, there is tyranny; when the government fears the people, there is liberty.
I've mostly forgotten almost all my physics, so could someone please answer a question for me?
Why do you need to be going 25,000 mph to get away from the Earth?
I can jump into the air and get away from the Earth, for a couple seconds anyway, and I'm not going nearly that fast.
I thought as you got farther away from a body, the gravitational pull decreases using some inverse-square rule.
As long as you can get airborne and are able to keep moving upwards, why doesn't it become easier to keep going the higher your altitude?
Happiness is like peeing yourself. Everybody can see it but only you can feel its warmth.
But if the earth's circumference is around 25,000 miles, and this jet can go 5,000 miles an hour, that would mean it would take only 2.5 hours to get from any location to any other.
Okay, if it only takes 2.5 hours at top speed to go anywhere on the planet, how much time is spent accelerating and decelerating versus actually flying at Mach 10? And how much fuel are you burning in the process? I remember working at LaRC when they were just starting to test scramjets and I still think the science is good for orbit, but bad for commercial applications.
Almost as interesting as the X programs is the B-52 mothership that launches them. There was an Air & Space article years ago (no online version at airspacemag.com) about it.
It's an aging early-model B-52B, evidenced by the non-pointy nose and is 49 years old. There are virtually no spare parts remaining for it, and most of the current inventory (Gs, Hs) don't have any parts commonality.
Plus, we never sold any of them to other countries, so it's not like there's a stockpile somplace else on the globe. The cost to replace it is prohibitive, given the structural reinforcements needed to carry the craft aloft. Also, the airframe is very young from an hours perspective. In fact, it's the lowest hour B-52 in the inventory.
The USAF has loaned an H-model to NASA to become the next generation launch platform, but I haven't heard much about it since the 2001 announcement.
It's a supremely important beast in the research arsenal. And, given our penchant for resurrecting C-64s as web servers and using mame to emulate decades-old cabinet games, it seems like the sort of thing that would interest the average computer geek.
Like so many things, it's the logistical details of maintaining an archaic aircraft against all odds (and lack of funding) that really become the story rather than the whizz-bang doodad that always gets the front page pictures.
Amateurs discuss tactics. Professionals discuss logistics.
For those who want to know what a scramjet is, and how it works, check this page.
A ramjet has no moving parts and achieves compression of intake air by the forward speed of the air vehicle. Air entering the intake of a supersonic aircraft is slowed by aerodynamic diffusion created by the inlet and diffuser to velocities comparable to those in a turbojet augmentor. The expansion of hot gases after fuel injection and combustion accelerates the exhaust air to a velocity higher than that at the inlet and creates positive push.
Scramjet is an acronym for Supersonic Combustion Ramjet. The scramjet differs from the ramjet in that combustion takes place at supersonic air velocities through the engine. It is mechanically simple, but vastly more complex aerodynamically than a jet engine. Hydrogen is normally the fuel used.
This is all very different from conventional airliner engines, which are a gas turbine/fan nacelle called a "turbofan". (A "turboprop" is a gas turbine driving a propeller instead of a fan, BTW.)
Let's assume for a moment here that I'm not Buckaroo Banzai and I'm a little bit vague on what the upper limit has been for manned flight (or travel in any medium, salt-plain automobiles or whatever). "Mach seven" really doesn't sound all that impressive. THIS IS 2004! We should be on mach ten-hundred by now.
For Christ's-sake, in that episode of ST:TNG where Riker had salt-and-peper hair and he didn't play trombone, I clearly heard him say: "WARP THIRTEEN! ENGAGE!" What the hell mach was Tom Cruise going before he entered into coitus with that blonde? What is the top theoretical speed of the current US fighter/and or/stealth aircraft?
What are the records here, that my tax-dollars are allegedly breaking?
Don't mod this retarded shit up, this is the uninformed wanting to become informed.
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Mach 7 is velocity. The only thing you could feel is the acceleration. But flying at mach 7 would feel the same as flying at mach 0. (Excluding external influences). You would only need inertial dampeners when the acceleration would be high.
Inertial damperners aren't exactly that hard to build. Consider that the inertial force is proportional to both mass and acceleration, the only thing you would need to acomplish is reducing mass to near zero. I'll leave that as an exercice for the reader.
Mostly I agree, but your first question starts with an incorrect assumption: a 600mph vertical dive. Pilots are trained at ditching an airplane at sea, and planes do float for a short time after this happens. In fact (though I don't know of any specific cases off hand) it has happened before, and many passangers have survived ditching at sea. Vertical dives do not happen in a significant amount of emergency situations, wings are simple devices and don't break all that often, and a wing is all you need to prevent a vertical dive.
Airplanes have backup batteries, and backup radios. You can be sure that before the plane hits the water emergency people know that it is going down, and about where. They might not be able to get to you in time to save you, but they at least know where to look just in case.
I'd prefer to float around the North Atlantic than die. Though I think it is safe to assume that if it really is several days before rescure workers find you they will find a dead body. However depending on where the crash happens, rescure workers may find you sooner.
My sister Caity died of cancer at 11 years old a couple years ago..
Caity was out in California for proton radiation treatment, Joel (uncle in law / NASA engineer) held a party for his Engineering Section at his house and Caity drew a picture of the X43 plane's logo on the sidewalk in chalk.
After Caity passed Joel took the picture of her sidewalk drawing and went to Nasa to have the plane named in Caity's honor and have her picture on the side of the plane.
I hope this one does a lot better than the last time, it has a lot of sentimental value!
Mountain Dew and doughnuts, because breakfast is the most important meal of the day!
I already posted this in another discussion here, but probably it is worth mentioning again. The bigger cousin of X-43A, X-43C, is being cancelled because it does not fit in the new space plans.
The article claims travel benefits, going from New York to London in 2 hours. But honestly, travelling that fast, if anything went wrong you're toast.
I imagine this is almost exactly what was claimed when the combustion engine was being developed..
Just think about it:
The inventors claim travel benefits, going from New York to Bostin in 3 hours. But honestly, travelling that fast, if anything went wrong you're toast.
echo '[q]sa[ln0=aln80~Psnlbx]16isb572CCB9AE9DB03273snlbxq' |dc
Maybe since Sci-fi authors started using the normal system NASA felt they needed to distence themselves from the logical way of doing things so as to gain/keep credibility?
I don't have time to comment my code, the program is late already.
No, they didn't. It was a rocket test.
and maybe I'm slightly mistaken here
Yes, you are.
but I find it almost typical of NASA to so completely ignore these other countries who in this case actually got there first and are possibly (?) more advanced than NASA in this area.
No, NASA's statement, as it was worded, was correct. It is you who are in error.
Of course if your world view is limited to America and the occassional country it chooses to bomb
Would you please fuck off and die, you ideological bigot? Can't we keep the worst of the international politics out of the sciences, or has ideology fucked over your brain that much?
Like everything else the govt pays for... its an offensive weapon. take a look at the calculations
((1 / 2) * (1 000 kg)) * ((7 000 mph)^2) = 4.89619666 x 10^09 Joules
a 20 kiloton bomb is ~10^13 joules...
What these means is... if they can put these engines on largers chunks of mass (i.e. increase the mass of the object flying at 7 times the speed of sound). They could have a bomb, with the explosive power of an atomic weapon... without using atomic methods. There is no need to strap a atomic warhead to this missle.... the missile is the warhead. And the best thing is... you would never hear it coming (radar wouldnt give you enough time to react (bleep bleep boom)).
Jon Bardin
No, they just don't like it when a project that cost a fraction (arround AU$1.5 million) of what theirs did suceeded before theirs did, by a bunch of mechanical engineers at a university that nobody knows about. More details about the project are available at the Center for Hypersonics and UQ news.
We had some lectures from the head of the engineering faculty in first year, and he went into a fair bit of detail on how the system worked. Last I heard was that the project has received further funding, but that was shortly after their mostly sucessful trial run (they couldn't find their rocket for a few weeks in the Australian desert). I've heard nothing else about it since, though. But that's probably because all anybody talks about now is mice in space.
SCRAMJETs will not use kerosene-derived propellant. They will combust hydrogen with oxygen from the atmosphere (maybe you should have done 2 seconds of research).
A flight on a Mach 5 aircraft will be shorter than the same flight on a Mach
If what you mean by "somewhat" is "not really." I can't see the 20 Concordes built adding significantly the net pollution of thousands of supersonic military aircraft in service around the world.
They don't need to.