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USAF Hypersonic Scramjet Successfully Scrams
cold fjord writes "It looks like another milestone for hypersonic flight has been reached. From the story: 'The final flight of the X-51A Waverider test program has accomplished a breakthrough in the development of flight reaching Mach 5.1 over the Pacific Ocean . . ."It was a full mission success," said Charlie Brink, X-51A program manager for the Air Force Research Laboratory Aerospace Systems Directorate. The cruiser traveled over 230 nautical miles in just over six minutes over the Point Mugu Naval Air Warfare Center Sea Range. It was the longest of the four X-51A test flights and the longest air-breathing hypersonic flight ever. . . This was the last of four test vehicles originally conceived when the $300 million technology demonstration program began in 2004. The program objective was to prove the viability of air-breathing, high-speed scramjet propulsion. The X-51A is unique primarily due to its use of a hydrocarbon fuel in its supersonic combustion ramjet, or Scramjet, engine. ... The use of logistically supportable hydrocarbon fuel is widely considered vital for the practical application of hypersonic flight.'"
Mach 5.1...
Was that a Whooosh as it went over my head or just a bang as the compressed sound finally caught up?
Moved to http://soylentnews.org/. You are invited to join us too!
That's the last of 4 test units built and there's no immediate successor to the program (TFA). Thank god it worked.
Probably liquid methane, but why didn't they just say it?
Set your phasers on "funky"!
Ludicrous speed!
A short definition for all those non-native speakers who wonder - like me - how 6 minutes of flight are more than hours of flight by a Concorde:
Supersonic: Above speed of sound but only up to Mach 5
Hypersonic: Above Mach 5
The fact that both the latin Super and the greek Hyper translate into the same word does not really help the distinction.
Ethylene to get it started.
The way you're framing it, you consider the Chinese your opponents (the more "sports-like" view, hopefully) or your enemies (the more military view, less hopefully).
In any way...
I suppose they'll steal the plans for making one once the US perfects it.
you are underestimating your opponents. Mistake number one. Way to go!
What is the circumference of the Earth? How far around is the Earth?
The average radius of the Earth is 3,959 miles (6,374 kilometers).
The equitorial diameter of the Earth (distance from one side of the Earth to the other at the equator) is about 7,926 miles.
The ratio of the circumference to the diameter of a circle (circumference/diameter)
is written as the symbol pi.
Pi is approximately 3.141592.
3.14159265
3.1415926535
Therefore, to determine the circumference from the diameter given above:
equitorial diameter x 3.141592 = equitorial circumference
| |
7,926 x 3.141592 = 24,900
| |
The earth has a circumference of approximately 24,900 miles.
More precisely the circumference of the earth
at the equator is 24,902 mi / 40,076 km.
Source:http://lyberty.com/encyc/articles/earth.html
5.1Mach = 1.7355km/s
Source: http://www.metric-conversions.org/speed/mach-to-kilometers-per-second.htm
It depends on what type of plane you are flying in and what air routes you plan to take. The typical duration is usually 2 days to 4 days.
For instance, an F-16 could theoretically circumspect the world in slightly less than 78 hours. But that's only possible if all the refuellings are conducted as in-flight refuellings, via airborne tankers. With luck and some good currents around, it might shave 2 hrs or so off the total time needed. But then again, unless you can stay awake for 3 days without sleep, its damn near impossible to do that.
For a civilian airliner like a Boeing 747 or an Airbus, it would take around the same amount of time, largely due to the need to bring it down to an airstrip for refuelling. But because of its huge internal fuel capacity, it could remain airborne far longer than an F-16.
To help you with your essay, I'm going to list the conditions required to accomplish this in a realistic manner:
1) Type of aircraft and its configuration
A civilian airliner jet (like those 2 mention earlier) typically have intercontinental ranges in excess of 3,000km. Also, they are capable of carrying huge quantities of internal fuel. Assuming you take a Boeing 747, removed all the seats in the passenger compartment and turn them, along with the cargo area into fuel storage, that range will be increased dramatically, from 3,000km to 7,000km.
Taking it further, by adding a refuelling receptor to the jet itself, similar to those used by the Air Force for its planes like the C-17 Globemaster III, the maximum range effectively becomes unlimited.
2) The human factor
Flight operations are no trivial task. While computers and automated intelligent system have made it easier for modern day pilots, the task of flying itself is still a tiring activity. Pilots need to maintain vigilance not only over the flight systems on the aircraft but also need to keep an eye out for weather conditions. Although the availability of long range radar and weather satellites have made detection of distance storms easier and earlier, its ultimately a human that takes actions to avoid it.
Maintaining wakefulness is a mentally exhausting affair, especially when is also an extremely dull affair, since an un-occupied mind is a bored mind, which translate into mental lethargy, which is also sleepiness. A human being usually loses his ability to react quickly after 12 hours of continuous flying. After 18 hours, that ability falls by 10% for every 2 hours after that.
3) Flight profile and weather conditions
The reason why airliner jets can sustain long range flights is because it cruises along at high altitudes. This is one of the aspects of aerodynamics, the higher you fly, the less fuel you burn, thus allow maximum milage per pound of fuel.
Air currents can aid and also hinders an aircraft's performance. With the proper air currents available (dependant on the time of
Memory is deceptive because it is colored by today's events. - Albert Einstein
A fascinating development, but I worry that the applications are limited to delivering bombs. Since the engine doesn't even function below hypersonic speeds, a plane and rocket are necessary to even launch them, and that naturally limits the size. As such, I don't particularly see the development as a positive thing in the near term, nor does it make me feel any better that the US military is the one doing it.
A hybrid jet/rocket engine like the SABRE is far more attractive, as it can deliver Skylon from runway to space, and is efficient throughout. The remarkable enabling technology is a precooler which cools incoming air from 1000C to -150C in milliseconds, and has already been successfully demonstrated.
Furthermore, there is a also a variant optimized for atmospheric flight called Scimitar, which uses the precooler with a high-bypass turbofan engine, giving it good efficiency and subsonic exhaust velocities at low speeds. This flexibility and broad efficiency allow the A2 to operate over land as well, overcoming the limitations of the Concorde. It has the potential to make commercial hypersonic flight ubiquitous.
For those of you who asked what fuel it uses:
Mg(OH)2
Top Secret.
Ah good old America, spend hundreds of millions, develop scram prototype, attach it to expensive plane on custom mount to get it up to speed, finally succeed.
Australia on the other hand, spend hundreds of thousands, develop scram prototype, attach it to cheap rocket and let gravity get it up to speed, succeed way earlier than America.
The whole Sabre engine is still conceptual and not one working engine has flown anywhere. Also, the SABRE relies totally on liquid helium to cool air and can't use any other gas. Since Helium supplies are very limited and the price is kept artificially low, no large commercial flight will ever be possible with this technology.
I was promised a flying car. Where is my flying car?
Ease off the hyperbole.
1991: The first recorded successful scramjet test, when a modified Russian SAM was used as a booster for an engine which achieved supersonic combustion for 5 seconds.
1992: Another similar test, with French funding, pushed that out to 15 seconds.
2002: HySHot demonstrated the first controlled flight with supersonic combustion ...
2013: A milestone! A breakthrough!
"Mistles", eh?
So now the TLAs are secretly training Mistles to home in on the hated enemy? At least they're a good choice, the poor little bird ranges "over all of Europe and much of Asia. Many northern birds move south during the winter", perhaps this new strain of Avian flu that seems to be affecting a part of Asia is the result of an ongoing proof of concept exercise?
As for conscript armies, ill-trained or otherwise, just consider the use of human wave tactics. In Korea the US and its Allies were technically more advanced, but got pushed back to the current border by the Chinese and North Koreans pouring bodies into the fight. And that war still festers today, still heaving bile some 60 years later. What about 'nam? The casualty phobia engendered by that adventure still has the ability to spook the US. Getting a bit more modern we have the Iran Iraq war in the 80s, both sides threw people into the battlefield like confetti, to little effect. Admittedly they were techinically similar so the death rate was immense without any gain. My point is, you can have the worlds greatest volunteer army and still be overwhelmed by the army of a nation that has a resident population that exceeds your own by 300% or so, controls their media and can afford to soak up the casualties. As far as the US is concerned, there could be no repatriation of the fallen of such a conflict, there would be too many for the organisation to cope with, and a sentimental stay-at-home public would be horrified by the waves of bodies and bits of bodies that would otherwise return. "Some corner of a foreign field", eh?
You say you've been a practicing grunt and know of what you speak; "war is your profession". Well, good for you but you probably don't have the same degree of empathy with your fellow civilians as with your comrades in arms. Its well known that professionals can be blinkered and if we want a military example, the conflict of 1914-18 demonstrates that in spades on both sides. Lets be a little less gung-ho,eh?
I'm no aerospace engineer, but I imagine the temperature of the aircraft skin would get hot pretty quick at such speeds. What materials is this craft made of, and how do they combat the problems of heat caused by air rushing so quickly over the aircraft ? Making an engine work in short bursts is one thing, making an aircraft capable if withstanding that velocity through atmosphere is another.
SABRE is a sound concept which combines proven technologies in a new way, enabled by the novel heat exchanger. Not only has the heat exchanger has been demonstrated, the ESA has thoroughly examined the concept and finds no fault with the engine. The helium (which is not liquid by the way) is not consumed, nor are prohibitively large quantities required.
By your reasoning, there would never be any innovation at all, and we would live in a technologically static world. I do not understand the compulsion of people to endlessly and vehemently complain about the impossibility of perfectly sound concepts. Progress still happens, though probably at a considerably reduced rate thanks to this prevailing mindset.
Seriously, what is with the total lack of vision these days? Why is it that everything that can't already be purchased, is considered to be impossible? If not a sound concept with demonstrated components, what, if anything, will convince people to support innovation? I'm genuinely curious, as this seems to be holding up other critically important innovations such as molten salt reactors.
I'm pretty sure Ray Stalker saw it as a second stage to orbit when he came up with the idea. Having to carry less fuel is a very major consideration in such a situation.
I would like to point out however that you are writing about those theoretical designs as if a test model exists but it is not the case, while scramjet models have been performing in tests since the 1980s. It's a bit misleading to write as if the engine exists when only the precooler has been tested. They may be the way of the future but if they progress at the same speed as the scramjet they are thirty years behind - let's hope they get more attention and develop faster if they do show promise.
I hope it crashes. The US can keep their warfare inside their own country.
Now we have another, faster way to deliver death to people we don't like.
Funny thing is this technology is never going to deliver anything (not even bombs) that a 20 year old ICBM wouldn't do faster, cheaper and easier. The only reason the USAF wants it is because firing ICBMs tends to get the Russians (and Chinese) a little jumpy. What everybody very hard does his best to ignore, is that the scramjet obviously also could deliver nuclear warheads, which means the foreign siblings of NORAD should be hard at work learning to detect these things. By the time this technology is operational, firing up a scramjet is going to make everybody else just as jumpy as firing an ICBM.
10 ?"Hello World" life was simple then
3 replies. 3 complaints about the spelling of a single word. Without bothering to read the initial point, or any of the 3 replies, further, I award the point to the parent post.
I come here for the love
He's just pointing out that "lees ethical" is a comparison.
So, less ethical than who or what?
You seem to acknowledge that it's not the USA, with it's faults and all.
Such an acknowledgment would actually recognize the original poster's ethics comment as a strawman.
Cause... If it's not USA and China ethics we're comparing, tossing in ethics is a meaningless digression in a form of a generalization that borders on chauvinist propaganda on one side and racism on the other.
"Chinese have fewer ethics! BAM! We've beaten them on the moral battlefield already!"
A strawman if I ever saw one.
Though, in OP's defense, probably an unconscious one.
Heck, his post is actually praising Chinese an prophesying them as winners or at least on the same level as the USA, in some imaginary battle.
It's just that Chinese have been memed into that position of inherently lower morality through centuries of sinophobic propaganda.
They've been yellow peril and godless commies for generations (and if that doesn't mean they have no morals...).
It's perfectly understandable that they are also nothing but thieves and copiers of other people's tech and makers of cheap junk practically incapable of creativity.
And that they would fight harder and with fewer ethics - i.e. fight dirty.
Mit der Dummheit kämpfen Götter selbst vergebens
mach 8 is great. but if i have to wait 2 hours in line id still rather take a train.
Well... that's several things, but mostly observer bias and rosy retrospection
In the days of old I came to Slashdot and I made my argument and, sometimes, I got my ass handed to me as people piled on with the various logical arguments that they had. They'd debate with well-reasoned and well articulated responses quite frequently.
What about those that didn't "pile on with the various logical arguments"? Or did you not make any logical arguments of your own, refuting others' illogical points?
These days it seems those debates and learning experiences are rare. Seldom do experts opine from behind their obscure education. It seems that there are fewer posting who have a profession in academia while more people are posting with little thought to accuracy, honesty, and logic. The signal to noise ratio has increased and reasoned debate is rarer. Fewer people are willing to change their views even when shown the faulty logic and the accurate conclusions.
Nah... it's just that there is more people here, so you have a greater chance of reading something written by a troll or an extremist as they are more active.
As for willingness for change... You shouldn't even be looking for that.
On one hand admitting one's faults is not really the greatest pastime so you're probably not going to see a lot of that, and on the other, expecting it is kinda... rude.
Instead, just present facts and logical arguments.
Forget changing minds or winning arguments and simply inform, accepting that those actually accepting your arguments probably won't even comment while those too set in their beliefs will just end up being more convinced that THEY are right.
http://idle.slashdot.org/story/10/07/14/1235220/given-truth-the-misinformed-believe-lies-more
Mit der Dummheit kämpfen Götter selbst vergebens
I'm talking here about the first part of your post. The whole strawman thing.
All you're doing is going round-and-round inside a circular argument.
China's ethics is bad, cause compared to America's ethics which IS bad China's ethics is bad, disagreeing is "completely delusional or intellectually dishonest" - ergo, China is "demonstrably worse".
BTW... do you even recall what was it you called a strawman? Here, let me refresh your memory.
Yeah, this makes sense because America is the most ethical country on the planet.
And this is you, just now.
America has had some serious ethical violations recently and I believe our country is less because of them. I am ashamed and dishonored on behalf of my country. What we have done is horrific and may have consequences for years to come.
So... Questioning comparison to USA's ethics is a strawman, BUT pointing out those ethics as bankrupt and then using that position to "prove" China's ethics as worse is OK?
Sorry, but that's not even a strawman.
What it is though, is a case of confirmation bias and conditioning with stereotypes.
Same way many people in the USA equate socialism with communism, with a foregone conclusion that it's "bad" - while being fans of Star Trek and Federation which is a complete communist utopia.
Now, besides branding and comparing "ethics" of an entire country/nation/people being an utterly nonsensical generalization, actual comparison between USA and China would lead to only one result.
Namely that, should "ethics" of a country be judged by it's actions (trying to make that generalization at least SOMEWHAT based on facts) - USA has no ethical leg to stand on.
It would be a kettle calling kettle a kettle.
Mit der Dummheit kämpfen Götter selbst vergebens
I think GP is trying to say that innovation doesn't happen that easily, not that it doesn't happen. A sound idea may still require many refinements once real-world testing is done; and it might not pan out at all if the real-world testing reveals unforeseen flaws.
An analogy is integration testing in software development: in a large project, the time to write working components is usually much less than the time it takes to make them work together.
Many German technical words are made from normal German words, which helps understanding, IMO.
Only if you're used to it. Otherwise, you end up with Poul Anderson's "Uncleftish Beholding" from a 1989 issue of Analog.
Iraq's GDP today is nearly 5 times what it was in 2003
Afghanistan's GDP today is nearly 9 times what it was in 2001
Isn't that the same measure of "progress" which China likes to laud?
Whatever strife there is in Iraq or Afghanistan doens't matter, since if we can ignore the civil strife in Western China, so too can we ignore the civil strife in Eastern Afghanistan or Northern Iraq
Maybe try talking to the guy who says the following
(emphasis mine) Maybe he can explain it to you.
Maybe you'll claim that it's not a sound concept, but there are quite a few experimental reactors that exist now.
I like SABRE, I also like Tokamak. Will either one actually succeed? I don't know, but you seem to be making the same sort of complaints that you talk about.
The important point being, that innovation doesn't happen without effort, and the defeatist attitude helps no one.
I considered including an explanation to head off this inevitable response, but thought it was off topic. The reason is not a matter of technological advancement, but of the fundamental physics of the tokamak. When the physics makes something impossible, I occasionally resort to the term "never".
The tokamak has to be enormous for it to work, and that has a direct impact on the economics. Even today, for 1GW fission reactors, financing is difficult, and they are nowhere near as complex. Beyond the prohibitive economics, there are many reasons why we will not be building 10GW+ tokamaks, and yet there is no way to scale them down. We need distributed power sources, which are mass manufacturable and affordable, so that they can be deployed rapidly.
There are many promising (and far less expensive) approaches to fusion, and pouring endless billions into the tokomak is asinine. For people who are so risk averse, it really is ironic that we are willing to fund one approach to the exclusion of all others.
His was a straw man in that he misrepresented his opponents position.
The person he was responding to never made any such claim and such is indeed a straw man.
I never stated that comparison was a straw man...
1 - It is not a strawman when you're pointing out a flaw in one's logic. OP was questioning GP's logic of comparison.
2 - GP was implying higher ethical standards for one side. OP was using sarcasm to question that implication and to point out the case of "pot meet kettle".
3 - Questioning the comparison with some imaginary notion of "USA ethics" as if it is some kind of a measurable standard IS THE POINT of OP's comment.
You are seeing a strawman in a "Yeah? Who died and made YOU a judge of ethics?" statement.
From crushing people with a road grader, propping up North Korea, sending North Korean refugees back, environmental crimes, Tibet, damming the river ruining lives and property and likely eventually resulting in the greatest disaster the world has ever seen (that's what I'm expecting anyways), to far far more I can go on listing ways. I can do the same thing for the American government as well. At the end of the tabulation I'd say that it is obvious which is less ethical.
Oh, please do. Tabulate.
Really. I'd love to see that.
Don't forget to wind it back all the way to first European colonists landing on North American soil.
Then do a tally of all genocides, wars, human rights violations internal and external and generally calculate the "historic asshole index" of China and USA.
And don't forget to mention the lynching of Negroes and whatever is the Chinese equivalent.*
Ah fuck it. Just wind it back to 1950s and count the military actions around the world.
https://en.wikipedia.org/wiki/Military_history_of_China_(1949%E2%80%93present)
https://en.wikipedia.org/wiki/Timeline_of_United_States_military_operations#1950.E2.80.931959
And you know what's the best part? IT DOESN'T... FUCKING... MATTER!
There is no way one can quantify a country's "historic asshole index" NOR would it matter if it could be done.
Should Germany be forever blamed for WWII and everything that came after that? How about Austria? Japan?
I know! Let us begin every conversation by first mentioning American slavery, racism and genocide of the native population and end every conversation with the mention that Americans nuked innocent civilians and a special mention of Vietnam and Iraq.
GP's error (and yours in supporting the idea of comparison of "ethical standards of countries" as if it is a real thing) is one of generalization and labeling.
He basically said "All Chinese are... {insert whatever here}".
INDIVIDUALS have ethical standards - NOT COUNTRIES. Not peoples or nations. Such generalization is WRONG ON MANY LEVELS.
That's what the OP was sarcastically pointing out.
*Just to be completely clear, I'm pointing out that "And you are..." and such attempts at quantification of the "historic asshole index" are a fallacy.
Mit der Dummheit kämpfen Götter selbst vergebens
Thanks for the explanation.
I agree with you about the need for distributed power sources. But maybe there would still be situations where such a large amount of power would make sense if it was feasible and economical. Aluminum smelters already have their own GW power stations.
The financing issues for fission reactors may be related to the problems of long term storage of large amounts of waste. Unfortunately too many people may simply have the idea that "nuclear" means bad.
The real irony is how much money is spent on research into better ways to kill other people, and in actually doing so.
Planes that travel this fast are not useful. You can't steer them in a small enough time for it to be practical and going this fast is very very expensive. Business executives wanting to be half way across the world in 20 minutes would be looking at a few hundred million per trip (one way). But these hypersonic vehicles aren't intended to be multi-use aircraft. For a scramjet to work, you need to be going nearly supersonic in the first place. That's either a (reasonably fast) jet, or a rocket. Why use a jet when you can use a rocket? The rocket goes very fast, but burns through fuel quickly. Unless its very large, its range is limited. A scramjet (supersonic combustion reaction motor jet) is good for going between mach 2 and mach 5 or 6. Not as fast as a rocket, much faster than a jet. Burns more fuel than a jet, less than a rocket. These are best used as a long range interceptor missile. Fuel it to run for 12 minutes of flight. The rocket gives you 3000 meters at 3000 meters per second. At that point, the scramjet kicks in. It can fly up to 60,000 feet, and hit anything you want up to 600 miles out in about 12 minutes.
Seriously, what is with the total lack of vision these days? Why is it that everything that can't already be purchased, is considered to be impossible? If not a sound concept with demonstrated components, what, if anything, will convince people to support innovation? I'm genuinely curious, as this seems to be holding up other critically important innovations such as molten salt reactors.
"What, sir, would you make a ship sail against the wind and currents by lighting a bonfire under her deck? I pray you, excuse me, I have not the time to listen to such nonsense. --Napoleon Bonaparte