Scramjet Success in Australia

glengyron writes "Australia's ABC reports today that a University of Queensland team have successfully tested a supersonic scramjet (air-breathing supersonic combustion ramjet engine). Read more here or here. Great to see after previous problems. Does the future of air travel still include those breakfast egg-roll things?"

Comments

Southern California sure has strange earthquakes.

[Daxbert]

"Until this morning no organisation, including NASA in the United States, has been able to successfully test fly a scramjet - an air-breathing supersonic engine. "

I'm not too sure about this... donuts on a rope anybody?

Rome Invented Scramjets

[AndyChrist]

Rome invented scramjets.

Re:Rome Invented Scramjets

[susano_otter]

You're probably thinking of the time machine, not the scramjet. Don't worry, though. I get the two confused all the time.

A little more info

[Bastian]

A diagram of the difference in design between a ramjet and a scramjet engine can be found here.

For more information, check out the HyShot homepage.

Re:A little more info

[ender81b]

A little more info from Encylopedia Astronautica. A scramjet is vastly more efficent than standard chemical rockets because only half the fuel has to be carried (hydrogen). Also scramjets have a greater ISP than most regular chemical engines and have no moving parts, unlike the hundreds of parts on moden rocket engines.

Taken from here

air/LH2 (scramjet) ISP=1,550

Space Shuttle Main Engines

ISP = 453

Obviously scramjets are vastly more efficent. Of course ION engines have ISP values of roughly 5,000-6,000 and fusion another magnitude greater, etc. Still lots of room for improvement.

Re:A little more info

[tony_gardner]

Unfortunately, the diagram is not totally correct. It's possible to have scramjets with duct convergences, and ramjets without duct convergences. The difference lies in the fact that in a ramjet the air becomes subsonic, and in a scramjet the air does not become subsonic.
Making the air subsonic provides a great deal of control over the combustion process, thus the problem with scramjets.

Re:A little more info

[JimPooley]

Obviously scramjets are vastly more efficent.
In an atmosphere, yes. Once you get outside the atmosphere, they're useless.

Re:A little more info

[Rubyflame]

Of course ION engines have ISP values of roughly 5,000-6,000 and fusion another magnitude greater, etc. Still lots of room for improvement.

Yeah, except ion engines don't work at all in an atmosphere, and scramjets only work in an atmosphere; they're two totally different systems for totally different purposes. Also, ion engines need an external power source, which increases vehicle mass, while scramjets are self-powered.

Fusion engines could potentially replace all propulsion we use now, sure, but we don't have fusion engines, and it's uncertain whether we'll ever be able to build a small enough fusion engine to fit on any spaceship smaller than a few thousand kilograms. And even then, you still need some reaction mass, just like in a nuclear thermal rocket. What should you use as reaction mass? Well, if you're in the atmosphere, you could use air. Kind of like a scramjet.

Of course, we could build a fusion pulse rocket right now. Just get a huge bowl, with shock absorbers and a spaceship above it, and explode a few hydrogen bombs underneath.

Re:A little more info

[hplasm]

Interesting points. Tho' scramjets aren't totally self powered; they do need fuel ;)

Re:A little more info

[Yazeran]

Of course, we could build a fusion pulse rocket right now. Just get a huge bowl, with shock absorbers and a spaceship above it, and explode a few hydrogen bombs underneath.

Actually, this is an old concept known as Daedalus and was invented by the British Interplanetary Society.

Yours Yazeran

Plan: To go to mars one day with a hammer.

Re:A little more info

[phayes]

Obviously scramjets are vastly more efficent.

Not neccesarily. Not having to bring any oxidiser gains you nothing if scramjet engines mass magnitudes more than rocket engines (as they do at present). Scramjets need something else to get to >mach 1, then peter out at less than Mach 10 when orbit needs >Mach25. By using scramjets you're replacing one system (rockets) with 3 (???+scramjet+rockets).

As an analogy imagine this: Currently your car uses one engine to do 0-60mph. Use of scramjets is like somebody offering to add a 700lb, $3000 solar powered motor to your car so that from 10-30mph you can use solar power instead of gasoline.

Rockets are working technology & the most efficient power source known to man. Scramjets are in their infancy and development costs are unknown.

Re:A little more info

[WolfWithoutAClause]

Also scramjets have a greater ISP than most regular chemical engines and have no moving parts, unlike the hundreds of parts on moden rocket engines.

In its simplest form rocket engine has no moving parts either (ok, there's usually a few valves, but scramjet would need them also.)

The Space Shuttle Main Engines have complicated turbopumps, but I wouldn't exactly hold that up as a shining example of rocket engineering; but the SRBs don't have any moving parts.

ISP is not everything- it's recently been realised that fuels that have lower ISP can give more payload to orbit than hydrogen/LOX. Reaching orbit is much more subtle than you would expect. Scramjets actually look like a bad idea for reaching orbit; they're too heavy- but may be good for a first stage, where the weight doesn't matter nearly so much.

Re:A little more info

[Dyolf Knip]

As an analogy imagine this: Currently your car uses one engine to do 0-60mph. Use of scramjets is like somebody offering to add a 700lb, $3000 solar powered motor to your car so that from 10-30mph you can use solar power instead of gasoline.

What you neglect to mention is that your existing engine (i.e., the rocket) is 2000 lbs, costs $10000 to buy, must be taken into the shop every week for another $5000 worth of repairs, and is so fuel inefficient that 99% of your car is gas tank.

Rockets are working technology & the most efficient power source known to man

Rockets are barely working technology. I find it ironic that the failure of both NASA's and Australia's previous scramjet tests were due to the rocket booster screwing up. They are insanely complicated and expensive beyond all reason. And they do not even come close to being the most efficient. As was pointed out, in the atmosphere Scramjets are 3 times more efficient. Outside the atmosphere, ion drives and even a simple pulsedrive are orders of magnitude more efficient. Rockets' only saving grace is that they can be used in both.

And where'd you get the idea that scramjets peter out at mach 10? There's nothing in the theory that keeps them from going as fast as you want. Your biggest problem is that heat from air friction melts your plane at these speeds.

Re:A little more info

[kzinti]

Of course, we could build a fusion pulse rocket right now. Just get a huge bowl, with shock absorbers and a spaceship above it, and explode a few hydrogen bombs underneath.

Actually, this is an old concept known as Daedalus and was invented by the British Interplanetary Society...

Readers of Niven/Pournelle's Footfall will recognize this as Orion, which was used as part (first stage?) of the Daedalus project's craft.

--Jim

Re:A little more info

[some guy I know]

the hard-sf novel "Footfall" by Niven + Pournelle

Wasn't that "King David's Spaceship"?

Re:A little more info

[phayes]

Sorry, you're mistaken all counts.
- Good rocket engines weigh about 1/15 as much as jet engines with similar sea-level thrust & scramjets weigh even more than jets.
- Terrier-Orion sounding rockets (from surplus military stocks) can be obtained on a university budget. The dev costs on scramjets are easily in the billions.
- RL-10's as used on the DC-X were reusable immediately after refueling -- no repairs needed.
- Finally, who cares how much is tanking. Fuel costs are negligable compared to the rest.

Hmph, barely working says a proponent of scramjets. Ha, pull the other one... Please tell me how the rocket engines were responsible for the failure of the previous scramjet tests? (hint: they weren't. Scramjets will be subject to the same guidance problems).

As was pointed out != as has been proven. Please point me to your real-world proofs or stop presenting "I hope" as "It has been proven".

Henry Spencer convinced me : I think a rocket would be simpler and cheaper, and would need only a fraction of the development work. Note that nobody has ever demonstrated actual thrust (exceeding drag) from a scramjet in flight.

Before stating that scramjets can accelerate to mach25 in the atmosphere you are going to have to solve the materiels problem. Rockets generally need to throttle back shortly after takeoff until after leaving the atmosphere to avoid the problem, scramjets by definition cannot. Using unobtanium is against the rules & will be grounds for disqualification. Until then, kindly refrain from proposing theoretical yet unachievable limits.

Re:A little more info

[Dyolf Knip]

Good rocket engines weigh about 1/15 as much as jet engines with similar sea-level thrust & scramjets weigh even more than jets.

Regarding jet engines: got a link? Regarding scramjets: so you mean this technology they've spent billions of dollars on is further along than the one that got virtually no funding at all? What a surprise.

Terrier-Orion sounding rockets (from surplus military stocks) can be obtained on a university budget

Can you get to orbit in them?

The dev costs on scramjets are easily in the billions

And, what, orbital rockets were developed in someone's backyard on a shoestring budget? They spent billions on them, too.

Finally, who cares how much is tanking. Fuel costs are negligable compared to the rest.

What we're interested in here is mass. To get to orbit, a rocket has to take thousands of tons of oxidizer along with it. A scramjet could leave most of it behind.

(hint: they weren't. Scramjets will be subject to the same guidance problems).

What, you mean the guidance problem of having all your thrust at the very bottom of the vehicle, which is basically a requirement for rockets?

As was pointed out != as has been proven. Please point me to your real-world proofs or stop presenting "I hope" as "It has been proven".

Oh, I do apologize. Shuttle engines specific impulse in a vacuum of 452. And let's see, here's an experimental air-breathing jet engine with a specific impulse in the atmosphere of around 2000. Or this one, from NASA themselves. In particular note the specific impulse of ion engines at 20000 which, if I'm not mistaken is higher than 400. Also it specifically states, "The chemical rocket engine is a fairly lightweight device. However, the specific impulse is not high. Solid and liquid propellants in present use deliver an impulse of around 250 seconds. The best liquid propellants so far conceived and evaluated yield an impulse of about 350 seconds." And of, course, there's this one, also at NASA, stating that Scramjets' specific impulse varies over the Mach range from 1000 to 1500. Want more?

Before stating that scramjets can accelerate to mach25 in the atmosphere you are going to have to solve the materiels problem

Gee, I seem to recall saying that very same thing. How kind of you to tell me what I already knew and act like you are all-knowing in the process.

scramjets by definition cannot [throttle back]

Eh? They have to accelerate constantly the whole time? Can't slow down, can't cruise, can't do anything except go faster? Do explain to me where you learned this.

Until then, kindly refrain from proposing theoretical yet unachievable limits.

You're the one proposing limits pal, not me.

Re:A little more info

[phayes]

The 15/1 weight difference between rockets & jets is a direct cite from a post by henry spencer in sci.space.tech. You want a specific cite, ask henry.

Can you get to orbit in them?

Can you get to orbit in a scramjet? No. that wasn't the point. The development costs for rockets have already been spent. Billions are needed before we see the first operational scramjet (with a paying customer). Scramjets cannot replace rockets as I said initially (you never answered that btw). If we can find the ressources to spend billions on improving our acces to space we need to spend it responsably & not piss it away on dreams.

What, you mean the guidance problem of having all your thrust at the very bottom of the vehicle, which is basically a requirement for rockets?

No, I meant the guidance & other reliability problems will not go away through use of scramjets. Do you contend that systems failures will dissapear because scramjets are used? If not then stop using systems failures to try & prove that rocket engines are the root cause.

Nice links. None of them give proof of a real-world scramjet showing positive thrust, though. You tried to point out that scramjets are 3X more efficient than rockets. I point out that these are not proofs until achieved outside a lab. Funny, it's been days since the test, no news on results... Wanna bet that once again, no net positive thrust?

Eh? They have to accelerate constantly the whole time? Can't slow down, can't cruise, can't do anything except go faster? Do explain to me where you learned this.

Simple enough: Using rockets 90% of orbital velocity is acquired outside the atmosphere. Orbital rockets throttle back while still in the atmosphere in order to avoid melting. Orbital scramjets cannot cannot accelerate in space. Orbital scramjets must therefore accelerate to >mach25 in the atmosphere. Orbital Scramjets must be made of unobtanuim.

Whether or not scramjets can throttle is not the point. Its that rockets can accelerate where scramjets cannot & that scramjets have materiel limits imposed on them that rockets do not.

I prefer exchanging tons of oxidiser for unobtainium. It has been proven to work.

You're the one proposing limits pal, not me.

Exactly my point. You propose spending billions to "solve" reliability problems in rockets by using scramjets made out of unobtainium. I'd prefer spending the money on something with a reasonable chance of being useful and feasible. DC-X before Nasa sandbagged it or Rotary, (RIP).

Re:A little more info

[Dyolf Knip]

The 15/1 weight difference between rockets & jets is a direct cite from a post by henry spencer in sci.space.tech. You want a specific cite, ask henry

Excuse me? You ask me for proof and I cite four references. I ask you for proof and you tell me, "Go see Bob. Bob knows all."?

Scramjets cannot replace rockets

And you know this how? Oh, right, Henry told you.

Nice links. None of them give proof of a real-world scramjet showing positive thrust, though. You tried to point out that scramjets are 3X more efficient than rockets.

You are unbelievable. So because the second working prototype doesn't outperform the technology that has had billions dumped into it already, you say, "Throw it away"?

Furthermore, there has been a scramjet test that produced net acceleration. Exhibit A. Not much, but it worked.

[Scramjets can't not accelerate]

Drag does decrease the higher you go. I realize that with anything air-breathing, that also limits your thrust, but it does allow for higher speeds. And I'm not suggesting they try to reach orbital velocity in the atmosphere. I'm well aware that it's stupid to try with air around anyway. Rocket assists can be used for the last bit.

scramjets have materiel limits imposed on them that rockets do not

I think fuel qualifies as a material. Rockets have fuel efficiency limits imposed on them that scramjets do not, at least not to the low level of rockets.

Do you contend that systems failures will dissapear because scramjets are used?

Rockets just don't scale well. Sure, for fireworks (or adding the last 1 or 2 kps to a launch vehicle) they're fine. But if you want to rocket any significant payload, especially to orbit, the mass of the fuel has to exceed the mass of the payload by orders of magnitude. You're right, cost of fuel isn't a problem, but mass and space is. To make a rocket vehicle capable carrying enough fuel to get to orbit and the fuel needed to get this huge mass of fuel up(true for even scramjets, but less fuel and oxidizer), it's gotta be absolutely huge. And insanely complex. And expensive. Chemical rockets are about as fuel efficient as they will ever get. Find the cheapest per-kilo rocket-based booster we've ever built and that's about it. A scramjet, needing less fuel, doesn't have to be built to even close to the same scale and can end up being simpler. Simpler systems usually mean less systems failures. Also, rockets are fairly unique regarding guidance in that your thrust is taking place entirely at the bottom of the vehicle. This is not just a 'systems failure'. This is a fundamental, inescapable problem of rockets that makes guidance very difficult, and therefore more failure-prone than something that is air-breathing and thrusts from closer to the center of mass.

Scramjets can be better than rockets. That we don't have a working orbit-capable one yet is irrelevant. We know this because aerospace engineers are bright guys and have done the math.

You propose spending billions to "solve" reliability problems in rockets by using scramjets made out of unobtainium.

Never said anything of the sort. I said that rockets were nowhere near as efficient as scramjets and that rockets suck for getting to orbit. I've provided links for the former and today's $10k/kilo pricetag on launches demonstrates the latter. Will scramjets be cheaper? If we can get them to work, the theory says they will be. No way to know for sure without trying.

I'd prefer spending the money on something with a reasonable chance of being useful and feasible

I'm all for it. But the guys with money have spent 50 years putting everything into rockets. That they are even considering something else is an achievement. Laser boosters, beanstalks, whatever. Never said that scramjets were the best, simply that, if they can be made to get to orbit, they'll likely do so more cheaply than any straight-up rocket launcher. I have explained why rockets are so pitiful. I realize the materials problem for scramjets is really, really difficult. But hey, so were the problems with rockets.

Lastly, NASA is the one that spends billions of dollars on programs. Hyshot put this thing together for 1 million. Not exactly chump change, but NASA's test was many times more than that and they have yet to try again.

Successfully tested???

[Ratface]

How come the site says this then?
"Dr Paull said although the signs so far have been positive, it is still too early to say the scramjet experiment has succeeded. The scramjet experiment took place within only the last few seconds of the flight, lasting almost 10 minutes."

(OK - I'm hair splitting, it looks positive, but jumping the gun like this doesn't help anyone if it turns out that everything was just a fluke ;-)

Re:Successfully tested???

[af_robot]

"Successfully tested" should be read as: "At leased it has not exploded"

Re:Successfully tested???

[squaretorus]

But hey! Who wants to read THIS story?:

"Scramjet tests looked positive in Australia"

Hey! Wait a minute! That IS the story we're reading. Call a shit Lola and its still a shit!

Re:Successfully tested???

[tony_gardner]

Mainly because last time, the rocket veered off course and crashed into the ground before the test could be conducted. This time, the rocked stayed on path, they received telemetry from the package, and nothing spectacular went wrong. It is still very possible for something non-spectacular to go wrong, and clearly they're avoiding talking before thinking (an increasingly rare occurrence).

Re:Successfully tested???

[Gwaihir the Windlord]

It was a successful test, in that the engine ignited properly, and they collected bucketloads of data from it.

However, Dr Paull is being cautious (and rightly so) because the program itself is not yet a success. They have to make sure it's repeatable, and then start the task of transforming it from a nice /. article into something that can be used practically.

Good luck to them, the more space research we have in Queensland, the better.

Re:Successfully tested???

[BitHive]

They managed to conduct a 10-minute scramjet experiment within a few seconds? Damn, those things are fast!!

Re:Successfully tested???

[Ashtangi]

The testing world is a lot like politics. It is funny to watch the testers (especially in the OT world) spin every test as successful. In the THAAD program for instance, we got to watch in the news as the interceptor failed test after test. That is, the missile failed to impact with the target. However, the tests are documented so that even in this case, the test is successful. Actually, any test that you get to take, regardless of pass or fail can be considered successful -- you tested it -- wheather it worked or not is another matter entirely.

Scramjets are really a neat propulsion system . . . I hope they got it to work.

Better information at :

[EvilBastard]

Little bit less of a press release, little bit more information including a better explanation of the flight profile at

http://www.mech.uq.edu.au/hyper/hyshot/

confused as usual (big surprise)

[Em Emalb]

OK first off, the abc.au news piece was an abomination of English:
"In South Australia's outback history has been made with a team from the University of Queensland successfully flight testing their supersonic air-breathing scramjet engine atop a rocket.

How about:
A University of Queensland team made history today when they launched their super-sonic airbreathing scramjet engine atop a rocket. The test was conducted in the outback and was the first successful one of it's kind.

Yech, even that one sucks, easier to read though.

Anyhow, on to the point. Later in the article, it said data was recorded from the descent. Is that descent back to earth or what? Was it controlled or did it just crash land? The other page has almost as little information too, unfortunately.

Re:confused as usual (big surprise)

[marcsiry]

Later in the article, it said data was recorded from the descent. Is that descent back to earth or what? Was it controlled or did it just crash land?

The descending flight plan was intentional; the speed needed to ignite the motor is quite high, and a gravity assist helped to attain it. The scramjet fired during the last portion of a parabolic flight.

Plus, I bet they didn't want to risk the vehicle flying off in an unintended direction if it worked too well; with the chosen flight path it was stopped directly after the experiment concluded :-)

Re:confused as usual (big surprise)

[tony_gardner]

Yes it was controlled, and yes it did crash land (Why should the two be exclusive?) The rocket has a ballistic trajectory, and the experiment is performed on the way back into the atmosphere (between 32km and 22km altitude), for about 4 seconds, you can work out the speed yourself. It then has about 10 seconds before it hits earth. When the payload of the last attempt was found, the nosecone was buried about 1 meter below ground, and it only flew upward for about 10 seconds. The current experiment goes upward for 5 minutes.

Suffice to say, that this is an unmanned experiment.

Re:confused as usual (big surprise)

[Em Emalb]

cool. Thanks for the info. Too bad ABC didn't expound more upon this. It's pretty neat stuff.

Re:confused as usual (big surprise)

[Charm]

I just saw the new one fly on the ABC news. Cool at last they got one of these rocket[1] thingys up.

I spent some time looking for the origional crash report. Mentioned in this page
ABC News Space
At the moment I can't get the report maybe later

[1] Yes I know its not really a rocket.

Re:confused as usual (big surprise)

[Charm]

I got through the dumb industry site to get the report. hyshot accident report

Woomera is the place to be in Australia...

[v8interceptor]

Successful scramjet tests, crazy Japanese rocket flops - I don't know what the refugees are complaining about, look at all the entertainment they get!

Russians?

[4im]

Didn't the russians already test ScramJets (brought up to speed by rockets, just like this one) a couple of years back? IIRC it was even successful. Definitely not a first here in Australia, then...

Re:Russians?

[tony_gardner]

There was a joint flight experiment between NASA and CIAM (Central Institute of Aviation Motors, Moscow), in 1998. There were three tests. they were launched on modified Russian SA5 missiles. One failed outright. One tested the engine in subsonic mode, and the third did not achieve supersonic combustion in the engine.

I think that the outcome from these experiments could be summarised as that no working scramjet was flown. As a note though, the main objective was to prove the Hypersonic flying laboratory, "Kholod", which is a package with fuel and telemetry to attach to a rocket so that any experiment can be easily flown on a rocket. This package was successfully tested (ie fuel, power and telemetry were provided to the model)

Re:Russians?

[Morky]

Yes, they did. But out of fear they would upset the military balance between the superpowers, the U.S. military sent Clint Eastwood on a successfull mission to steal it. Everyone knows that.

Re:Russians?

[bbc22405]

[Three USA/Russian scramjet tests failed to "scram" but,] the main objective was to prove the Hypersonic flying laboratory, "Kholod", which is a package with fuel and telemetry to attach to a rocket so that any experiment can be easily flown on a rocket. This package was successfully tested (ie fuel, power and telemetry were provided to the model)

That sounds awfully much like they retroactively diminished their expectations to match their diminished results.

Re: Russians?

[Baldrson]

Undoubtedly what actually happened was that DoD/NASA secretly tested a scramjet already and are not releasing their success due to the need for National Security. We can be sure this happened during the "Orient Express" project announced by Reagan during his 1986 State of the Union Address after the Challenger blew up, because the Challenger 7 shall not have died in vain. The joint flight experiment with the Russians was therefore a cover for a covert op to ensure Russia did not acquire a working scramjet due to the danger of Russian technology ending up being used in the United States and its allies by terrorists.

Let's be reasonable here:

The Australian team being a small crew of academics and amateurs from a former prison colony obviously could not have developed anything so sophisticated as a scramjet and must therefore have stolen the secrets from the United States Government. This is prima facia evidence they are potential allies of Al Queda terrorists and should be monitored for any suspicious activity; after, of course, their facility has been put under 24 hour guard and surveillance by Homeland Defense.

Australia's inventing all the cool stuff.

[marcsiry]

First the Metal Storm, now this!

Soon Australians will be able to fly up to anyone, anywhere in the world, within minutes, and then cut them to ribbons.

I wish I was Australian.

Re:Australia's inventing all the cool stuff.

[alatesystems]

If you have broadband, visit the videos page. It is awesome. The aussie voice makes it seem even cooler when rapid fire bullets rip through multi-layers of wood. This is quite a cool product. I can't wait to have one in my glovebox :)

Chris

Re:Australia's inventing all the cool stuff.

[Disevidence]

Yeah, just look at all of the neat things which Australia have are invent:

Yes you australias are very cool lol!

Looks like your country invented shitty grammar and spelling. Stupidity, too.

Australians invented kicking ass at all sports, as well.

Re:Australia's inventing all the cool stuff.

[jquirke]

I pray that you are not American...

Because if you are:

1. Shitty beer

Yeah, chances are you an ignorant type and have only sampled the exported Australian beers, not only that, but perhaps it doesn't taste close enough to water?

2. Crime

errr next one - Americans also invented the Second Amendment - what a great invention that was!

3. Stupidty

Yes you australias are very cool lol

--jquirke

Re:Australia's inventing all the cool stuff.

[simong_oz]

Yeah, just look at all of the neat things which Australia have are invent:

1. Shitty beer
4. Shitty beer

Based on what? sampling Fosters and XXXX? Hah - if you actually want to find a pub in Australia that serves that stuff, good luck to you. Know why that is? We don't drink it ourselves because it tastes like dishwater - we just export it to the rest of the world to keep up the image. If you want to try some decent aussie beer, I would recommend VB (Victoria Bitter), Crown Lager. I'm sure others will add to the list.

2. Crime

yeh, right. Forgot about the massive drug trade in eucalyptus leaves within the koala community

3. Stupidity

Very ironic considering the article you're posting under!

Re:Australia's inventing all the cool stuff.

[simong_oz]

trying .... to ....resist ....

I wish I was Australian.

That's just so you can be good at sport !

Re:Australia's inventing all the cool stuff.

[Muad'Dave]

errr next one - Americans also invented the Second Amendment - what a great invention that was!

At least it has kept our government from forcibly disarming its citizens, making them into subjects instead of members of the government "of, for, and by the people." Note that your crime rate climbed after the confiscation that was supposed to stop all that crime. Guess what? Your crooks now have free rein to rob and pillage, since they're the only ones with firearms. You've fallen for the old liberal crap that disarming everyone will prevent crime. Here in the US, when the states passed "shall issue" laws that required states to issue concealed carry permits to anyone who was eligible, the liberals predicted blood running in the streets. In fact, in every single state that enacted such laws, the crime rates dropped, while the rates in other states continued to climb. Don't give me your holier-than-thou liberal bs - look at the facts before you spout rhetoric.

Re:Australia's inventing all the cool stuff.

[tealover]

What's even more shocking is that people still read wired!

Maybe you do need to move to Australia, since you obviously don't know what's going on around you. ;)

Re:Australia's inventing all the cool stuff.

[Goonie]

I see this quoted again and again and again, but it's just horribly misleading.

Firstly, gun ownership in urban Australia has *always* been quite low, and pistols are extremely rare (except for police and security guards who carry them whilst at work). It is unheard of for women to carry guns for self-defence here, and always has been. Additionally, the definition of self-defence justifying the use of deadly force is much narrower here. So, the changing of gun laws had virtually no effect on the risk a criminal was taking when committing a crime.

Very few offences committed against "ordinary people" (muggings, burglaries, rapes etc) involved criminals with firearms. The career crooks have them, but they very rarely attack "civilians".

Violent crime rates have been largely steady over the past few years. Property crime went up over the last couple, basically because of an explosion of heroin availability which had nothing to do with guns.

And, finally, I've noticed that yanks don't like being told what to do by foriegners who don't understand their culture and the actual situation on the ground. Guess what? We feel the same. We like our current gun laws just fine, and don't appreciate the NRA funding loony friggin' shooters parties.

Re:Australia's inventing all the cool stuff.

[cranos]

Excuse me???

Okay lets take your points one by one

1 and 4: Shitty Beer

Do you actually drink the beer here or what? I would put up beers such as Tooheys Old or VB against any of the American or Asian beers any day of the week. The only ones who make better beer are the europeans.

2. Crime:

As I seem to recall crime had been invented a hell of a long time before Australia was even thought of.

3. Stupidity:

I refer you to your above remarks.

Sheesh

Re:Australia's inventing all the cool stuff.

[e40]

I wish I was Australian.

If you want to be an honorary Australian, follow these simple rules:

• Say crikey at least 5 times a day.
  Good Australians say it early and often.
• Pretend your dog is a 'roo. And for crikey's sake, man, watch out for
  those hind legs! They can gore a man!
• Refer to Americans as yanks.
• Above all, make fun of the English.

If you follow these rules, you too can attain that Australian aura.

Re:Australia's inventing all the cool stuff.

[ceejayoz]

Shitty beer

Comment of a friend who visited Oz - "WTF no one drinks Fosters! I thought Fosters was Australian for beer!" Quite amusing.

Re:Australia's inventing all the cool stuff.

[Jester99]

Hrm. Assume the average bullet weighs 10 grams. 1,000,000 bullets/minute * 10 g/bullet = 10,000,000 grams of lead per minute; that's 10,000 Kg... Given 2.2 lbs/ Kg, that's 4,500 lbs of lead, or about as much weight as a minivan.

So my question is... what good is this thing, if the battle lasts more than 10 seconds?
You'd have to have an ammo depot the size of a house sitting right next to the thing.

Re:Australia's inventing all the cool stuff.

[spress]

Just arrive by boat, tell them your a Muslim, and the government will take you straight to Woomera, free of charge! The only drawback is you can't leave.

Re:Australia's inventing all the cool stuff.

[vortexau]

Referring to your forth point, here is a Non-Politally Correct joke:

How do you tell if an aircraft that has just landed is from the UK?

- The whining continues after the engines have been shut-down!
.

Wrong URL

[Flamerule]

First link doesn't work for me... this appears to be correct.

Any more detailed images of the HyShot?

[RyanFenton]

No goatse links, thanks.

I'd be interested in seeing what this implimentation of a scramjet looks like on the actual craft.

I've done the usual google search and found this (which was very nice, but is a little video, not a good image), and this,but was wondering if anyone has found anything more detailed. :^)

Ryan Fenton

Re:Any more detailed images of the HyShot?

[nerdguy0]

A simple trip to the second link would give you the gallery page here.

Re:Any more detailed images of the HyShot?

[RyanFenton]

Of course, that's why I posted that link, as opposed to a half dozen links to all the different pages they had. All images shown on those pages either cropped off the interesting bits, or had someone's big mug in front of the schematics I'd love to see. I'm sure everyone here has had such frustrations finding images they are *interested in* before.

Again, I must reiterate: No goatse links. Thank you. ;^)

Ryan Fenton

Re:Any more detailed images of the HyShot?

[Charm]

Again, I must reiterate: No goatse links. Thank you. ;^)

As much as we all hate Goatse links there is quite a strange link between Goatse and this article.

Goatse is hosted on the cx domain. Christmas Island, which may one day be a space port It also another part of Austalia's dirty "Illegal immigrant" refugee handling system of which Woomera is another part.

Just remember you are not Australian if you can remember the words to the national anthem and know who the first prime minister was.

Broken links

[af_robot]

chrisd, do you actually READ articles before posting?! It's the second one with broken links out of two posted by you today :)
HINT: try to sleep more...

Slashdot *making* the news?

[KFury]

Let's see: First news link was DOA. Second one says "University of Queensland researchers say they are receiving data from the rocket, but it is too early to say whether the experiment has been a success." which /. interprets as "Successfully tested."

Salshdot editors must feel pretty giddy with their manifest-destiny powers, if writing a headline can make something so...

Re:Slashdot *making* the news?

[sirsnork]

I've thought about this a bit recently.

Wouldn't it be quite easy to code up something that went through all the links in the submissions bin and reject them (or at least edit the message to reflect it, so the editor can try to find the right one). That way it would be solved automatically

Re:Slashdot *making* the news?

[ceejayoz]

Wouldn't it be quite easy...

Yes. It could be done in PHP in about 30 seconds, I'm sure it's just as easy in Perl.

Re:Slashdot *making* the news?

[Rukkh]

What they mean by "Successfully tested." is that the rocket went up, turned around (harder than you think, the damn things rotating at 5hz) then recorded some data and smashed back into the earth.

(yeah it was a one way trip, someone above asked

Whether the scramjet itself worked, is the unknown bit, but they had it going in the T4 shock tubes so it should go Ok.

(I hope it does, maybe then our mechanical engg. lecturers will stop going on about it...)

They where originally going to name it...

[Tokerat]

...the Getthehellouttaherejet, but "Scram" was so much simpler and to the point...

Re:Southern California sure has strange earthquake

[Bastian]

I doubt it.

The donuts on a rope phenomenon has, to the best of my knowledge, not been fully explainet yet (i.e., nobody is fessing up as to what plane is making those contrails).

The most plausible explanations I can see for it require some sort of pulsejet engine. I'd expect scramjet engines to generate contrails similar to ramjet engines, since the shift to supersonic speeds doesn't turn any other supersonic engine's contrails into donuts on a rope.

Re:Southern California sure has strange earthquake

[HeLLaLaMe]

Ohh, of course, NASA should have really been first to pull this off, considering "U S A" is number 1 and all. Now we have this technology, you won't even see the planes coming till it's too late. Ha Ha Ha Ha Ha Ha Ha Ha.

Is it just me?

[cca93014]

I just cant stop thinking about Vermicious Knids.

This needs to be modded to "+5 What the Fuck?"

Re:Is it just me?

[Howzer]

No, not just you! Glass Elevator was my favourite of the two....

"Successfully tested"

[Hitokage_Nishino]

Well, considering the feat of testing was accomplished instead of the plane exploding and crashing on unaware kangaroos... one could say they had "successfully tested".

Re:"Successfully tested"

[tony_gardner]

Exactly, a siren was sounded so that the kangarooy were not takes unawares this time.

Re:"Successfully tested"

[leviramsey]

Yes, they only crashed on three unaware koalas, and an indeterminately large number of wombats and emus.

Re:"Successfully tested"

[Blackstealth]

Knowing the history of Kangaroos and flying objects I'd have expected them to fire a few Stinger missiles at the incoming object!

DARPA appear to have done it already

[sambo99]

Looks like will have faster bombs, way before we have faster airliners ...

http://216.239.39.100/search?q=cache:MKgyf6-JQS0 C: www.darpa.mil/body/NewsItems/pdf/hyfly.pdf+scramje t++Defense+Advanced+Research+Projects+&hl=en&ie=UT F-8

Re:DARPA appear to have done it already

[sambo99]

http://216.239.39.100/search?q=cache:MKgyf6-JQS0C: www.darpa.mil/body/NewsItems/pdf/hyfly.pdf

Re:DARPA appear to have done it already

[sambo99]

The Americans appear to have beaten the aussies in this race.

link to darpa press release

Note to slashdot:
If I type http://http://216.239.39.100/search?q=cache:MKgyf6 -JQS0C: www.darpa.mil/body/NewsItems/pdf/hyfly.pdf , I want to link to the site, at least warn me it will not be posted as a link. Is there any way I can edit posts I made???

read all about it on useit.com

* note to the 3l33t ha80r who hacked my account, I have changed my password

Re:DARPA appear to have done it already

[PhxBlue]

Hrm. For some reason, copy-paste puts a few unwanted spaces in the link. Oh, well--here's a link, maybe that'll work.

Anyway, I think 11 September really kinda blurred the line between airliners and bombs. A faster airliner is a bomb in the wrong hands.

First link broken...

[phunhippy]

The page or file you've requested, "http://www.abc.net.au/news/justin/nat/newsnat-30j ul2002-53.htm" doesn't seem to exist on this server.

hmmm you'd think after so many people on slashdot complaining to slashdot editors to check links before they post articles... they would!!... then again... these are slashdot editors...

Re:First link broken...

[LippyTheLip]

Therre is a better article anyway at the BBC

Re:First link broken...

[tconnors]

hmmm you'd think after so many people on slashdot complaining to slashdot editors to check links before they post articles... they would!!... then again... these are slashdot editors...

It was there when I read it. Of course, I read it before there were any posts on the board.

You have to remember, ABC is our government funded free to air TV and news channel. They are running on a rather tight budget....

They wouldn't be able to take much of a Slashdotting.

Successful... Maybe

[eander315]

From the University of Queensland site:

"University of Queensland researchers say they are receiving data from the rocket, but it is too early to say whether the experiment has been a success."

It seems the "Scramjet Success In Australia" title might be a little premature, as it is at least slightly misguiding.

Re:Successful... Maybe

[ceejayoz]

OMG! A misleading title on Slashdot? How will they ever live with themselves?

Stupid Error Message Tricks

[Bastian]

A bit offtopic, but I thought I'd share the error message popup Mozilla gave me when I tried to follow this link:

This page contains information of a type
(text/plain) that can only be viewed with
the appropriate Plug-in.

Of course, there is no appropriate plugin =)

At least this time...

[NewtonsLaw]

At least this time those clever scientist types remembered to bolt the test vehicle to the rocket engine.

Anyone remember the poor Japanese SSTV model a few weeks ago?

But seriously (did I just say that?), one of the problems with SCRAMJETs is their gobsmackingly high fuel consumption.

This is one of the reasons that scientists are also exploring pulse detonation engines as an alternative super/hypersonic propulsion engine.

It is rumored that the PDE-powered craft are responsible for those "donut on a rope" contrails seen by some high above the USA.

Re:At least this time...

[tony_gardner]

Depends that you mean by high fuel consumption. They go fast, and this creates drag, thus fuel must be expended. It you mean low efficiency, then you are half right: No scramjet achieves good fuel efficiency at the moment. However, since there are not really any working scramjets that should come as no particular surprise.
Generally, Scramjets should work in the range Mach 6 to 20. I've never seen an upper limit on pulse detonation engine operation, but I can't remember ever seeing one that worked over Mach 8, even in theory.

Confusion Part II

[Em Emalb]

I know less than nothing about this technology, nor what it would be used for, therefore I must post to this topic ;) Mod me -1 dumb if you must, but here are my questions:

1) What is this engine useful for?

2) What industries would this apply to?

3a) Is there video anywhere of the launch/flight?

3b) How bout the crash landing, I'm more interested in that. Any video on that?

Thanks.

another ABC url that should work

[Zazm]

Here's a URL for the ABC that should work.

http://abc.net.au/news/australia/qld/metqld-30jul2 002-15.htm

It doesn't really say much that the UQ page hasn't already but at least it confirms where those /. editors got their headline.

Corrected ABC.NET.AU link

[caveman]

Another route to what would seem to be the right page is here: http://www.abc.net.au/news/2002/07/item20020730140 728_1.htm

Uses of a scramjet

[tony_gardner]

Firstly, it is not really useful for passenger aircraft. The high G to get up to speed is not really sellable.

The main use is as a secondary engine for rocket propulsion. Since atmospheric air is used, the scramjet theoretically can lift more payload for a given engine weight, and it is hoped that this will translate into launch cost savings for light payloads (I've seen one estimate that put the saving at a factor of 10 for a 1-10 tonne payload), however nothing really beats rockets for very large payloads.

The biggest advantage, in a launch to orbit is that, since the engine will be going sideways to pick up speed, the cost difference between a polar and equatorial orbit is negligible.

here's the correct ABC link for the news story

[lnelson]

http://www.abc.net.au/news/australia/sa/metsa-30ju l2002-9.htm

Re:Scramjet!

[IXI]

There's something in that word that reminds me of last September.

Where they really the first?

[h4mmer5tein]

Not according to this press release from the Arnold Engineering Development Center at Arnolds Air Force Base, Tennasee.
They claim to have flown, albeit briefly, a scramjet vehicle in August of 2001. Acceleration to operating speeds was achieved using a very big gun!

Next week on TV

[__aahlyu4518]

A brand new series of Roger Scramjet !

*THUD*

[TheSHAD0W]

Until this morning no organisation, including NASA in the United States, has been able to successfully test fly a scramjet - an air-breathing supersonic engine.

Umm, I'm sorry, but in my humble opinion, heading straight down and digging a crater in the ground does not constitute "flying". Please be more accurate in your description.

Re:*THUD*

[h4mmer5tein]

It does if the vehicle maintains velocity under its own power.
At Mach 6.7 if there is no active thrust to maintain that velocity then deceleration will happen pretty quickly. What the flight team are looking for is data to show that the vehicle did indeed maintain velocity, indicating that thrust had been generated by the engine.

Re:*THUD*

[TheSHAD0W]

I was basically kidding. But I'd still balk at using the term "flight", whether the jet was generating thrust or not. Technically any travel through a medium is considered flight. There's still typically some horizontal movement involved, though, and I still think that using it to describe acceleration straight down into the turf isn't appropriate.

Roger Ramjet Retires....rumour Ramjet redundant

[graystar]

So does that mean we can all look forward to
Scott Scramjet and his Australian Eagles!

Re:Southern California sure has strange earthquake

[TheSHAD0W]

"Donuts on a rope" are caused by shock waves in the stream of a jet engine; they'll show up in nearly any high-output jet engine, much less one meant for supersonic travel.

If you're thinking of the neat light display behind the engines of a SR-71 Blackhawk, those engines are indeed for supersonic flight -- but they aren't ramjets. They're turbofans. They are configurable, though; the cone on front adjusts the position of a shockwave that slows the air down to the point where it will work in that type of engine.

The difference is that a scramjet, having no turbine and only basic moving parts, can operate at a much higher velocity than a turbojet. The SR-71 was limited to the supersonic realm, while a scramjet-powered vehicle can reach hypersonic speeds, above Mach 10.

Video Footage

[graystar]

If you go here to see video...really cool footage.


http://www.abc.net.au/news/2002/07/30/video/2002 07 30pm_rocket.ram

Re:Video Footage

[AGMW]

I think you will find that the thing that scramjets do is Scram!

That's one large, deep hole

[inputsprocket]

What is left of the hypersonic engine crashed into the desert 400 km (250 miles) west of Woomera and will now be recovered.

OK, so on its decent, it should have reached mach 7.6 before hitting the ground. Ehm, travelling at 133km/second and more streamlined that bullet, isn't it going to be rather difficult to recover that thing?

In fact, they should be able to be the first to collect some accurate readings from the earth's core, seeing as that is where it will likely end up.

Re:That's one large, deep hole

[WolfWithoutAClause]

133km/s would be mighty impressive!

Hint: 11.2 km/s is escape velocity (mach 25 or so).

So 133km/s would be more than mach 250 ;-)

Re:That's one large, deep hole

[inputsprocket]

tits! make that 133km/min still, the point still stands for 2.2 km/sec (133km/min, 8000km/hour) ;)

Link into Mama (ABC) seems to be broken, so...

[leonbrooks]

The hyperlink into Mama appears to be broken, try this one instead.

Re:Link into Mama (ABC) seems to be broken, so...

[vortexau]

Alternately, try ABC Aust news story here.
.

Re:Southern California sure has strange earthquake

[phayes]

"Donuts on a rope" is the characterisation given to the contrail of a secret US program thought to use pulsed detonation to achieve high mach.

"shock waves in the stream of a jet engine" are better known as shock diamonds and are the results of shock waves producing visible artifacts in the flaming exhaust of aircraft using afterburners.

Finally, as has already been stated in another post, the SR-71's engines fonction in both ramjet & turbojet modes. The inlet cone slows the air down to subsonic speeds so that it can be used in the ramjet part of the engine profile -- using hypersonic air is the definition of scramjet.

HoveRoc destroyer decoy, Jindalee OTH Radar, ...

[leonbrooks]

...LCA2003, and now working scramjet engines! Australia seems to invent the best of everything. (-:

Re:Fixing the Flight Time

[AGMW]

Well - Maybe they've fixed that...

Hmmm. Now there'll not be a pub/bar job safe anywhere in the world! They'll be able to bottle up and get home for tea!

SR71 engines

[turgid]

Do they really contain ramjets as well as turbojets? I always thought they were just plain turbojets with afterburners, and that the cones on the front were adjustable to slow down the air to subsonic speeds for the turbojet. Do you have any links explaining how the engines work> All of the stuff I've read so far says that they're just turbojets, no ramjet stage.

Re:SR71 engines

[smagoun]

Do they really contain ramjets as well as turbojets?

Yup - sort of.Studies have shown that less than 20 percent of the total thrust used to fly at Mach 3 is produced by the basic engine itself. The balance of the total thrust is produced by the unique design of the engine inlet and "moveable spike" system at the front of the engine nacelles and by the ejector nozzles at the exhaust which burn air compressed in the engine bypass system.

That link is a quick overview of the Blackbird, including a bit of info about the engines. Ram air definitely plays a big part. Anyone know if those "ejector nozzles" are what I'd call an afterburner, or is the afterburner included in the "basic engine itself?" It sounds like they're the ramjet portion, but...

Re:SR71 engines

[jafac]

Pretty much any supersonic plane uses a technique of shock-wave deflection. Look at the F4, where the intakes meet the fuselage. The deflectors are clearly visable.

What's the use?

[NorthDude]

I'm no rocket scientist :-)but I think it looks just like any other rocket...
Can someone explain me what could be the benefit of using this?
Could it be used to lauch satelites? I can't imagine sitting on this for transportation!
I would win the Darwin award for sure...

Re:What's the use?

[David Off]

I would win the Darwin award for sure...

You would only win the Darwin award if you strapped a Scramjet to the back of your Chevy Impala and took the car out to the desert for a test drive I think.

David

Re:What's the use?

[Gantoris]

From the site:

"The aim of the experiment is to achieve the world`s first flight test of air-breathing supersonic ramjet engines, also known as scramjets. These engines could revolutionise the launch of small space payloads, such as communications satellites, by substantially lowering costs."

Its also thought that it could be used as pasenger transport, once the technology has been tested and improved substancially from what it is now.

Yes, and we know exactly where to cut, too (-:

[leonbrooks]

This could do air traffic control in the USA if we wanted it to. (-:

This can't see quite as far, but does pick out nearby* stealth aircraft in stark relief without any apparent effort (`bombers flying at low altitude' includes B1s and B2s). And there are about 70 Chinese in China for every Australian in Australia...

* on the first bounce, ie, out to just shy of 1000km away.

Yes, there is!

[leonbrooks]

EMACS will display text/plain just dandy.

Re:Yes, there is!

[Pig Hogger]

EMACS will display text/plain just dandy.

EMACS? What a dog! Nothing's better than a cat!!!

Re:Southern California sure has strange earthquake

[drwho]

"Donuts on a rope" HAS been explained. It is produced by PDW (Pulse Detonation Wave) engines. What hasn't been explained is what is making them, as there are no PDW engines officially in use yet. Much speculation is that the ultra-secret US spy plane Aurora is what's creating these. Some spy plane, if it leaves such a distinctive signature!

So... the engine worked, then? (-:

[leonbrooks]

...and now they're scanning the desert looking for pieces of Woomera...?

Market Share

[David Off]

The main use is as a secondary engine for rocket propulsion.

Maybe, at the same time, they should hook it up to that Boeing anti-gravity thingy they are working on out at area 52?

Piss poor pedant

[A nonymous Coward]

of it's kind

Apostrophe not needed for this possesive....

As for Is that descent back to earth, where else if not descent to the earth? You think this was done on Mars or somewhere?

Re:Southern California sure has strange earthquake

[smagoun]

There's speculation that the donuts-on-a-rope photos that were in Aviation Leak a few years back were created by a Pulse Detonation Wave engine. The donuts imply distinct combustion pulses (like in an internal combustion engine, only much slower), as opposed to continuous combustion (turbine).

Another theory is that the donuts are some sort of weapon; the "rope" is the contrail left by the aircraft's engines, and the donuts are exhaust pulses from a gun or something.

What it comes down to is that like you said, nobody knows what created the phenomenon.

So long....

[Linuxthess]

And thanks for all the kangaroos!

--------

Re:Southern California sure has strange earthquake

[ceejayoz]

Spy planes don't necessarily have to be stealthy - the SR-71 and U2 survived not by stealth (the Russians could easily detect them on radar) but by flying too high for Soviet interceptor aircraft and SAMs to reach them (and in the case of the SR-71, it also flew faster than anything they could throw at it).

Gun Strangeness + Woomera = spear thrower

[Mandelbrute]

At least it has kept our government from forcibly disarming

I don't recall there being any force involved - lots of grumbling but no force.

Note that your crime rate climbed after the confiscation that was supposed to stop all that crime

Yes, I saw "Mad Max/road Warrior" too - but it is just a movie. Sadly for the US gun lobby the crime rate hasn't done anything noticable.

Your crooks now have free rein to rob and pillage, since they're the only ones with firearms.

Hasn't happened, and the robbery weapon of choice has been sawn off shotguns for years (illegal for decades), instead of semi-automatics which are now restricted to the military after the changes in the laws. Fully automatic weapons have always been military weapons here. Handguns have been restricted for at least fifty years and are fairly rare in this country. Rifles and shotguns can be easily obtained, just not semi or fully automatic versions. The well armed militia is the army reserve, which I suspect is what the US constitution was talking about instead of masses of gun clubs calling themselves citizens militias.

Back on topic - Woomera is named after a koori spear throwing device, the rocket range and town were built in the late 1940s to test rockets in the middle of the desert. The scramjet project has been going for a while - I saw a model which closely resembles the current version in December 1989. It's just now that they are finally getting to put the things on rockets instead of helium filled testing tunnels (simulating mach 8 and thereabouts).

Re:Gun Strangeness + Woomera = spear thrower

[Muad'Dave]

I don't recall there being any force involved - lots of grumbling but no force.

Had anyone refused, do you doubt there would have been force? I don't.

Yes, I saw "Mad Max/road Warrior" too - but it is just a movie.

I wasn't referring to any movie. Did you read the 100's of articles I referenced?

and the robbery weapon of choice has been sawn off shotguns for years (illegal for decades),

So gun control hasn't worked "for decades", but you let your gov't pass more worthless laws? What made you think anything would be different this time around? It didn't work then, it won't work now or ever.

Re:Southern California sure has strange earthquake

[Pig Hogger]

"Donuts on a rope" HAS been explained. It is produced by PDW (Pulse Detonation Wave) engines. What hasn't been explained is what is making them, as there are no PDW engines officially in use yet. Much speculation is that the ultra- secret US spy plane Aurora is what's creating these. Some spy plane, if it leaves such a distinctive signature!

Makes sense. An explosion (a high-pressure squirt of gas) funnelled through a narrow exhaust pipe will most likely produce a torus, like a smoker blowing rings of smoke, or a diver making ring-bubbles at his decompression stop...

Hardly.

[Zone5]

Australia invents the best of everything? I have one word for you: Vegemite.

Re:What is this good for?

[Creepy]

I'm not an Aussie, or an expert, but I recall from old Popular Science's (Space Planes issue) that Scramjet engines use much less fuel because they don't go straight up (ascend more like a plane) and use the atmosphere as part of their combustion, unlike rockets, which use liquified propellents. The major problem with scramjets was accelerating to a speed where they become efficient. The airline industry abandoned the idea because they couldn't carry enough passengers to make a profit (one of the Concorde's problems, as well) and the US military abandoned it because they didn't have an immediate need and it was an easy way to save money. Since I haven't heard much about them for a number of years, I'd guess that other militaries abandoned them, as well (at least for combat uses).

There probably won't be much of a market for passengers in the near future, unless someone builds a space casino, mainly because the cost is too high, at least compared to conventional aircraft. There is a market for cheap satellite delivery, though, which conventional aircraft can't do (the plane or the satellite would need to be rocket assisted to get into the proper orbit, and orbit velocity, I'd think).

Re:What is this good for?

[Frodo2002]

Yes, but you did not answer my questions. How do you practically apply it to getting into space? People abandoned scramjets because they could not make them practical. Scramjets breathe air therefore requiring less fuel and the craft can get some lift from the atmosphere as opposed to using a rocket to go straight up. BUT here is the price you pay:

• Huge amts of dead weight from other engines needed to get up to scramjet operating speeds
• Tiny operation window: mach 6 to mach 12 maybe... (Someone who knows more can correct me here.) Bear in mind that you need to get to mach 25 to get into orbit.
• Flying "horizontally" through the atmosphere at hypersonic speeds means large amounts of energy lost to friction. Vertical launch means you do not have to deal with these problems to such an extent.

Considering all the points I have made above, I fail to see how a scramjet can be practically implemented to get into orbit. What has changed technologically which would make a scramjet practical now as opposed to 30+ years ago when people abandoned the idea?

warning if it will not be posted as a link

[mr_zorg]

Hey, there's this little button called Preview right next to the Submit button. Try it out sometime! And don't forget to set the select box to "HTML Formatted" and use an anchor tag... Sheesh, you want slashdot should write your posts for you?

Re:Southern California sure has strange earthquake

[AB3A]

Uhh, no.

The SR-71 engines are turbojets with an afterburner and a ramjet bypass which opens up as speeds build. At full cruise speed the turbojet continues to run, but it only provides about 40% of the thrust. The other 60% comes from the ramjet/afterburner structure.

The engine inlet design is a big deal for supersonic and hypersonic aircraft. However the real limitations for hypersonic flight are actually material science issues. Somewhere between the brute force approach taken by the space shuttle design and the ingenious "leave cracks in the airframe so it'll handle the expansion from the heat" approach of the SR-71 is a more economical solution.

It's nice to see the Australians build a prototype that appears to work. I'll be more impressed, however, when I hear of it surviving to fly above Mach 3 for an extended time.

Re:Southern California sure has strange earthquake

[Fluid Truth]

I'm not that familiar with the workings, but I'm pretty sure that the SR-71 is the Blackbird not the Blackhawk.

Re:RAMJET?

[THX1138]

A piece of advice from one who discovered the hard way. When ramming a female gymnast DO NOT UNDER CIRCUMSTANCES allow her to wrap her legs around your back unless you have chiropractic problems or are into pain. OUCHIES!!!!!!

Re:Southern California sure has strange earthquake

[Blackstealth]

True, the Lockheed SR-71 is the Blackbird. It's the Sikorsky H-60 helicopter that carries the Black Hawk moniker, and at 296km/h it's one hell of a lot slower than a Blackbird too :-p

ABC Changed the link.

[U2BG]

Looks like it has changed to http://www.abc.net.au/news/2002/07/item20020731071 211_1.htm

Enjoy.

Re:Southern California sure has strange earthquake

[susano_otter]

Wow. The thought of Australia being a credible threat due to superior aerospace technology is so... not at all frightening. Perhaps if they weren't convinced that Cindi Lauper was the acme of fashion, they would frighten me both more and less at the same time.

Vegemite

[leonbrooks]

Vegemite has an interesting history; it was actually invented by a Seventh-day Adventist named John Harvey Kellog (Kellog company of cereal fame was started by a relative of his), Catholic-owned Kraft then stole the recipe and after manufacturing it for a while, turned around and sued JHK's company for using `their' recipe. Yes, JHK was a Yank. (-:

I actually prefer Promite, but will accept Marmite as a fallback. Then again, I'm a weird Aussie, I don't like beer or watermelon.

In answer to the tourist questions, the only kangaroos hopping down the main street are bronze, prawns on the barbie are very rare (and a bad idea) - usually it's steak and/or `snaggers' (sausages), and it takes over two days of nonstop (except for fuel) driving at the speed limit (110km/h in WA, 100km/h SA and NSW) to get to Sydney from here in a taxi (sorry about all the parentheses).

Table wines

[leonbrooks]

I prefer the juice before it goes rotten. Ambrosia!

The French or people near them actually invented most kinds of wine, but it took Australians to get the recipe right... (-:

Yep, and I wonder...

[leonbrooks]

...whether `decoding' the position of a `stealth' aircraft constitutes a DMCA violation.

The Chinese antennas look very similar for a variety of reasons. One obvious one is that there are only so many reasonable configurations that work well, another is that some of Jindalee's technology was public while the Chinese were building theirs. While I don't think conspiracy is necessary explanation, it wouldn't shock me if the Chinese picked up some other information covertly.

Their OTH performs differently to Jindalee (some things better, some worse), but never mind, either installation sees much more than countries like the USA, Russia or Germany are happy about. (-:

One thing that neither site makes clear is that multiple bounces are routine. Jindalee can actually see itself by looking around the globe, and IIRC in practice has enough range/resolution to see around 2 and a half times. When I mentioned diong ATC in the US, I wasn't kidding. The resolution is good enough to manage (for example) JFK's traffic, although I imagine many pilots would be startled by the Aussie accents.

Re:Southern California sure has strange earthquake

[Deadstick]

Varying degrees of accuracy in the replies to this...I'll try to clarify a little.

I'll agree with the comments on "donuts on a rope"; the reported phenomenon is about the appearance of certain contrails, not the pattern of shock wave intersections in the exhaust flame known as "shock diamonds".

The Blackbird engines are turbojets, not turbofans. Turbofans have a fan that extends outside the combustion gas flow and moves "bypass air" around the engine. You can see the fan on most airliners; it's right at the point where the diameter of the engine housing abruptly decreases. The Blackbird achieves a similar effect by enclosing the engine in a complex-shaped duct that moves bypass air by means of a phenomenon called "entrainment". It takes a lot of chalk-pushing and arm-waving to make the principle clear, but the effect is to generate a lot of heat energy in a relatively small airflow and then couple it into a large flow. At full speed only about 15% of the thrust appears on the engine mount; the rest is supplied by a nonuniform pressure distribution on the housing. There's nothing new about entrainment, by the way; it's also what combines the steam and the smoke on the way out the smokestack of a steam locomotive.

There are no separate ramjets, or ramjet "components", and there is no such thing as "turning on ramjet mode". A ramjet is simply a jet engine with no compressor or turbine, which has the disadvantage that it doesn't begin to work until it's going fast enough to ram a lot of air into the intake; consequently, a pure ramjet can't take off under its own power. However in a turbojet engine, the amount of compression required from the compressor decreases as speed increases. At supersonic speeds the compressor becomes totally unloaded, and basically just turns in the breeze; the engine is then functioning as a ramjet. In other words, ramjet behavior is what any jet engine does when it's really hauling ass.

In both ramjets and turbojets, the flow through the engine is always subsonic, decelerating as much as necessary in the compressor or ram section and then accelerating on the way out the tailpipe. There are all manner of aerodynamic and thermodynamic demons that set to work when you try to burn fuel supersonically, and the scramjet is an experimental approach to doing this. It's been an active development objective since the 1960s -- i.e., about a decade less than controlled fusion, and mostly with equal frustration. Maybe it will pan out this time, but don't stake too many hopes on it.

Deadstick

Re:DARPA test was a Ground Test

[aebrain]

The Americans appear to have beaten the aussies in this race.
link to darpa press release [216.239.39.100]

Not quite. That was a Ground Test. DARPA and others - like the Uni of Queensland - have had scramjets in the labs for a while. This is the first time that one has been successfully flown. It may or may not have worked - we'll see in a day or two.

Way offtopic gun strangeness

[Mandelbrute]

I wasn't referring to any movie. Did you read the 100's of articles I referenced?

No I glanced at a few and gave up - nothing appeared to have been written by anyone that has even been to Australia. I have read a magazine called "lock stock and barrel" which expounded the exact same views, written in Australia in 1994 (before the gun laws) and talked about how we needed to arm so that we could overthrow the government at will, shoot Indonesian invaders (the Javanese are happier in Java anyway instead of annexing a lot of desert) and kill members of the "Jewish Conspiricy" (there are almost no jews at all in Australia - the writer lived in his own little world). That sort of publication would appear to have been the only Australian source of material for those articles. The murder rate here was low, so three loonies with armalite semi-automatic rifles raised the murder rate considerably - hence the ban on semi-automatics.

So gun control hasn't worked "for decades", but you let your gov't pass more worthless laws?

But it has worked - violent crime here mostly involves blunt instruments, single shot rifles, syringes, or fists. The violent crime rate in large cities in Australia is very low in comparison to the middle states of the USA, and of course even Belfast (Ireland) has a much lower violent crime rate than Liousiana, Washington DC and New York.

I can own a gun if I want to (I don't have a criminal record so I can get a licence), just not an easily concealable weapon (and I'm glad that no-one is likely to ever point a pistol at my head either) or a miltary weapon (fully or semi-automatic). My granny's shotgun is legal, the .22 rifle I first fired when I seven is legal, and the one inch bore "Brown Bess" style musket that a friend made is legal. The semi-automatic that my uncle got to deal with animals that ate his fruit trees wasn't, so he had a few months to sell it back to the government. A lot of firearms on the banned list are still out there - hence the proposal to have a second gun amnesty - it looks like the "forcible disarming" has only happened in a few minds across the Pacific. The previous posters "doubts" or fluffy feelings don't really hold up against reality.

It's a difference of culture - when the USA revolted the right to bear arms was a big issue. When Australia was made independant most people in rural areas had firearms anyway, and as colonies each area had it's own volenteer army. The miliary still reserved the right to be the only ones with artillery, and now the only ones with automatic weapons. Hence the second amendment in the USA, and other countries looking on and saying "only in America" when someone uses that amendment as a flimsy excuse to own a .45 automatic or similar military sidearm. The problem, as in the national parks, is not the bears, but the huge numbers of guns carried in fear of the bears.

There are a lot of things wrong with Australia, but the gun laws have no impact on any of them. The worst thing an Austalian leader has been hit with is a cricket ball (during a game) - and we didn't even have a federal police force until someone threw an egg at a prime minister.

I want photos of the impact

[zekt]

From 'The Age' newspaper, Melbourne, Australia.

Data was fired off in a capsule after the engine ignited while the rocket was travelling about 8000 kmh. The scramjet then crashed, destroying itself and completing the test.

A rocket at 8000kph is going to make a hell of an impact, does anyone know of photos of the impact site?

Re:Southern California sure has strange earthquake

[Spacejunior]

meanwhile we starve...

Re:Southern California sure has strange earthquake

[Spacejunior]

Cindi Lauper? Should I be offended at this?

*shuddering aussie-style*

Re: What about for payloads to space?

[wessman]

I don't see viability in using ScramJet for airtravel, but what about for payloads to space or satellite insertion? You don't see a use for ScramJet there?