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A Million Bucks, Mach 7.6, Straight Down 186

Dspiral writes "At the Canadian publication, The Globe and Mail, they write about the scramjet. A jet engine, with theoretical speeds over 8000 Kph, and pollution free!" Zero pollution because its fuel is hydrogen (a scramjet takes its oxygen from the air). The HyShot homepage is amazing; the beast has been built on a shoestring, barely over a million dollars Australian, and my favorite part is their planned test: "...shooting an engine into the atmosphere on a rocket, and hoping it will ignite as it plunges back down to Earth. Mr. Paull's speed objective is Mach 7.6, and the engine should ignite 23-35 kilometres off the ground."
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A Million Bucks, Mach 7.6, Straight Down

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  • by Anonymous Coward
    From the HyShot home page: "Developing an engine with net positive thrust is the subject of future flight trials. " Now I see why it only cost a million bucks.
  • by Anonymous Coward
    Woomera is right in the middle of nowhere so it's a bit hard to hit anything.

    It was the major British missile-testing range in the 1950's and '60's, so it's no stranger to high-Mach crashes (especially the disastrous ELDO European launcher program; oh well, at least the Ariane project found out from it what *not* to do!!!). Similar flights to this experiment were done during the Black Knight project, where a rocket was fired out of the atmosphere, then back down, with the added twist that a second stage rocket was fired on the way *down* to accelerate it! The purpose was to test ICBM/IRBM re-entry cones, so I imagine they came down a *lot* faster than Mach 7.6.

    I believe it was some of the most important work done at Woomera, and assisted the development of ablative coatings in the US Mercury manned capsules as well as re-entry cones on the first generation of US ICBMs.

    My great dream as a kid was to work there, but its glory days were over by 1980. Now it's used as holding area for illegal immigrants... Ironic, innit; when I was a kid Woomera was a symbol of how far Australia had come since being founded as a prison. Now it's a prison itself :-(

  • The NASA project I think will be being launched from a B52 aboard a Pegasus rocket, so it still needs a boost.

    Of course, there's also the question of whether a scramjet is a good idea at all. It needs hydrogen, which is one of the least dense rocket fuels out there, which makes the structure larger for a given payload (which is bad); also, since a scramjet needs to hang around lower in the atmosphere than a rocket, it's subject to much higher aerodynamic forces and heat loads. Finally, the engines thus far designed have weighed more than the oxygen they're replacing. When you consider how cheap liquid oxygen is, a lot of people wonder, why bother?

  • What I like about that is uses a reusable and enviromentaly friendly fuel. Also it has no need for an extra oxygen tank so it is lighter. This is really cool.
  • This is kind of cool, but I really wonder if anyone is really interested in making hypersonic passenger vehicles. Wasn't the X-30 (or something) cancelled?

    Of course I bet if it costs $1M Aus to make, it will cost the US Military about $50M US to make. :)

  • oooo free cheers for Mr. No it All and my ass is so tight I cant' see I joke if it got up and bit me

  • yea I really like my brains in the back of my head. reminds me of the Ren and Stimpy episode " must saaaaavve braain"

  • didn't they used to attatch these things to helicopter rotors. The Rotors were powered by a minimalist engine then as they began to turn the air forced through the system would be mixed with some fuel and come shooting out the other side. very simple design my question is it only works most efficiently at lower altitudes as opposed to space since they require O2 from the atmosphere. Not only that they require an initial velocity to get them going. I can see it now tomohawk missles being launched off the USS Nimitz with large elastic bands.
  • Yes, it's much better to fly in a jet filled with highly-flammable kerosene....

    Two thirds of the Hindenburg passengers lived, which is a better record than a lot of airliner crashes.
  • The concept has been around for a long time. Paper designs aren't new. But real, flying scramjets are another matter.

    Ramjets that slow the air to subsonic speeds before combustion are old hat, of course.
  • err I meant 80's obviously ;)
  • or a darwin award ;)

    "Man and car missing in Illinois"
    "Illinois license plate found in Australia"
    (20 years later)
    "1990 Volvo Stationwagon found in the Mariana Trench"

  • Maybe not, but they belive in image tags
    The page actually reads under lynx

    (and any pointers to getting X 6.4.1 to run on a
    Toshiba Satellite Pro 420CDT?)

    Lord Bhaal
  • Uh, Enterprise was never slated for space flight. It was retrofitted for space flight after Challenger was lost. Never for a moment did anybody think that the 747 was going to be the first stage of a launch vehicle, since the Shuttle carries about zero fuel for its main engines onboard. The Shuttle was designed from the outset to ride up on the external fuel tank and its SRBs. The 747 was used for glide testing with the Enterprise, and also to transport the operational shuttles back to Kennedy when they land at Edwards AFB.
  • Nope. Won't work. 1) To get to orbit, you have to go through a band (commonly called "space") where there's no oxygen around to combust. If you ain't got any with you, your motor turns off and you turn into a very expensive lawn dart. 2) Nobody's figured out how to get the same hunk of metal (the "engine") to operate both as a ramjet and as a rocket, so you need more hunks of metal inside your spacecraft to get through "space". 3) Scramjets have a very high cross-sectional area relative to their thrust potential compared to rockets. That is, they produce far more drag (up to an order of magnitude more) than a similarly powerful rocket.

    High speed air breathing flight is STUPENDOUSLY difficult. It's only been in the last five to eight years that the computers are fast enough to even BEGIN to model the supersonic flows through a scramjet, and the problem is very far from being solved. Rockets are ugly and pedestrian, but they do the job better than any technology on the drawing boards.
  • When on the ground the SR-71 leaks JP like a sieve, after takeoff it has to refuel within 2 minutes or it will run out of fuel.

    Didn't you ever wonder why the SR-71 has all those corrugations? That is the design, when it is hot the joints seal.

    Pretty cool if you ask me, and this from 1960 tech.

    Too bad the XB-70 never made it into production, it was cooler on all points, and a much cleaner aerodynamic design.

  • You must be fun at parties.
  • Gasoline is far more dangerous than hydrogen.
  • One of the old scifi magazines by chance?

    A Hawk Among Sparrows?

    That story has haunted me since I read it.
  • That's right. They have carefully designed it to run out of fuel just before it hits the ground.

  • "Cut to Sydney Harbor [Fireball blasts upwards behind opera house.]"

    You mean like this [venco.com.pl]? Note this comes from the album 'Red sails in the sunset' by that very fine aussie band Midnight Oil. One of their better albums by the way.
  • How fast can a plance accellerate before the average business traveller will lose conciousness from the g-force?
    ________________________________________ _____________________
  • At mach 7.6 it will reach the ground in no time! How will they slow it down? How will it, "stop".

    They're going to throw a planet at it. That'll stop it real good.

  • Hydrogen is pollution free, and will be a huge part of energy storage once we convert from fossil fuels to clean nuclear power.
  • > Haven't they heard about all the troubles NASA has had trying to develop this technology?

    Yeah, when NASA sends something straight down at Mach 7.6, it costs way more than a million bucks. And sometimes it doesn't even achieve Mach 7.6 on impact.

    Anyone want a couple of slightly-used Mars probes?

  • I left my Doctorate in Rocket Science in my other pair of pants. Any interesting/useful links on rocket fuel consumption?

    Erik Z
  • How do you bench test something that needs to be traveling at mach 1 to operate?
  • That why it's called a Supersonic Combustion Ramjet!
  • I always thought that was because the engines burnt it all up getting it off the ground; very inefficient at low speeds they were.
  • Yeah, given we're already too busy looking out for Mir if it ever comes down....
  • The "zero pollution" claim is a bit dubious. When the ydrogen fuel it uses is burnt, water vapour results. Of course, water vapour is produced naturally and falls back to the earth's surface as rain.

    Unfortunately, water has one of the highest specific heats of atmospheric gases. Some information I have seen (I forget exactly where) labels water vapour as a much worse green-house gas than carbon dioxide.

    All in all, I would rather have our atmosphere contaminated with water than with CO2. In high concentrations, we just get hotter, more humid days. With CO2, breathing becomes labourious.
  • So, cutting the mass the rocket needs to carry by a third (by having an oxygen-breathing engine), you'll need to carry significantly less hydrogen to reach the same velocity.

    True, but O2 weighs ~ 24 times that of H. I would think the weight cutting benefits would be just as enormous... someday... :-)

  • The technology to make pollution free scud missiles!



    Check out my diary [diaryland.com].

  • "Two flights are planned for the late in 2000."

    and at the bottom of the page,

    "Modified:19 June 2000"

    did they all just forget or something.

    Maybe the new Australian cencorship laws kicked in, and they werent allowed to publish anymore info.

    Rocket=Phalack symbol????
  • "Cleared for takeoff, Bumthruyourmouth Air 993...oh , and cleared to land too."

    Think, air rage would be a thing of the past if everyones lips are flapping behind their heads and they're unable to move due to the sheer force of takeoff.

  • So true, so very true...

  • I'm no fan of off-topic First Posters, but how can a first post be called Redundant?

    Nipok Nek
  • Alas, they only claim 11.5k/s for their champaigne cork - the 40k/s figure is for the wild corks presumed to exist in the jovian system.
  • To build it for $1M, you use grad students to do all the heavy lifting.

    This is a university project.

  • Ramjets and scramjets are wonderful. But they're plagued by one problem: they're only efficient at speeds over 3 or 4 hundred miles per hour (depending on the configuration, type of engine, etc).

    So you need to speed up the damn thing for it to work properly. Booster rockets work well for this, so they'd have to use those.

    Btw, the V2 rockets used by Germany in WWIV used ramjets, if I'm not mistaken. I guess they just made them a bit faster now.

  • Ramjets are basically a pipe which is closed on one end during combustion to produce thrust.

    This happens at a pretty high frequency, depending on the how efficient the combustion is.

    So you need air to make this thing work. You need fuel, which you carry already. If you wanted to travel in space, you'd need to carry oxygen, too, and keep one end permanently closed. So you end up with a rocket.

    Oh well. No space travel with these babies.
  • That reminds me of the Hindenburg [nlhs.com]. It also used hydrogen to fly. Unfortunately, it was not that pollution-free...

  • That's not true. If we use solar or wind power to generate the hydrogen, then it IS pollution free.
  • I'd imagine that a couple miles of magnetic linear accelerator might do the trick to get them up to >= mach 2. Wouldn't be practical unless you planned on launching a lot of them though.

  • There's no reason why a (sc)ram jet has to be powered by hydrogen, you could probably power one with kerosene if you wanted. As a matter of fact there was a USAF project a few decades ago to develop a fission powered scram jet ( Project Pluto [voughtaircraft.com]) for deliverng nuclear warheads. Needless to say it wasn't nearly as environmentally friendly as hydrogen power.

    Also, I've seen ram jets built by hobbyists that about the size of a soda can - scram jets don't neccesarily have to be any bigger.

    I think scram jets can be developed into a very viable means of providing very fast, cheap, sub-orbital propulsion.

  • by Anonymous Coward
    Glad to help debunk that lose use of terminology. The SR-71 propulsion system really contains two Pratt and Whitney J-58 turbojet engines. Now, keep in mind several things: first of all, the flow at the jet engine face must be subsonic. To date, no operational gas turbine engine has supersonic axial flow through it. So all of today's gas-turbine engine'd supersonic planes have an intake system that sets up a shock system to make the flow following the last shock (a "normal" shock) subsonic. This is the flow the engine face sees.

    The SR-71 incorporates what's called a mixed-compression inlet, that is the _external_ big (movable) cones do some of the compression, setting up a conical shock wave, and then an _internal_ "shock train" (several small "linked" shock waves) inside the inlet lip do the rest of the slowing down and inlet flow compression to subsonic. Now at full speed, the SR-71 is operating with the J-58s in full afterburner. The "ramjet" designation comes from two details.

    One is that at full speed, a good portion of the air that passes through the inlet then gets ducted directly to the exhaust nozzle -- but this air has already contributed to the thrust because it is part of the high-pressure stream pushing on the back of the inlet cone (higher-pressure against aft-facing area is thrust, boys and girls).

    The other detail is that the J-58 engines have big tubes that at high Mach, bypass a lot of flow past the high-pressure compressor stages and directly to the afterburner. This bypassed air doesn't see a turbine, so it's "like" a ramjet in that sense. But because the majority of the flow at least passes through the gas turbine engine's compressor and afterburner, it's not a "true" ramjet.
  • by Anonymous Coward
    You are correct regarding subsonic operation of ramjets. What differentiates the two is that scramjets have supersonic flow all the way through the engine flowpath, whereas scramjets turn their flow subsonic before combusting it. Both engines use the exact same principle for air compression -- setting up a shockwave system that the air passes through. As the air passes through the shock wave, it slows down and its static pressure goes up. The ramjet must have the flow following the last shock be subsonic, whereas in the scram it is supersonic. However, the air gets slowed down in both cases (if it didn't, there would be no compression).

    While an engine that could do ram/scram certainly would have a larger operational flight Mach number range, it wouldn't be able to get off the ground on its own (i.e. no static or subsonic thrust). Research has indeed been done on combined gas-turbine ("conventional jet")/(sc)ramjets (known as "combined-cycle" engines), and that kind of beast could potentially have the the full envelope capability. Also, don't confuse the SR-71's so-called "turboramjet" as being a combined-cycle engine. It doesn't have a true ramjet-type flowpath, and the compressor would start to melt if the flight speed reached "true" high-speed ram/scram speeds.

    All this kind of talk, though, is sort of pie-in-the-sky and ignores the fact we've still not yet demonstrated a free-flight scramjet-powered vehicle. That's what NASA's Hyper-X project is supposed to address. You can get more info on Hyper-X via http://www.dfrc.nasa.gov/ [nasa.gov]

    BTW, as you might have guessed, IAAE (I am an Aerospace Engineer)... :)
  • Isn't that what Michael Knight turned KITT's engine into in that episode of Knight Rider when they got stuck in the dessert?
  • IANAAE (I Am Not An Aerospace Engineer) but IIRC (If I Recall Correctly), a huge proportion of the fuel used to put a shuttle into orbit is used in the first mile or so, getting up to the speed of sound.

    This is why NASA is working on a launch system that runs on an inclined rail using electromagnets. (from a past /. article).
  • Ramjets and Scramjets were used chiefly in surface to air interceptor missiles of the 1960's and 1970's. For taking out high-altitude bombers and supersonic attack planes.
  • They're more than acronyms now, they're web cliches. Had to use em. But didn't want to risk the inevitable 30 or so postings afterwards asking "what does IANACN stand for?"
    I Am Not A Clueless Newbie.
  • First, one of the heaviest components of a rocket is fuel. So, cutting the mass the rocket needs to carry by a third (by having an oxygen-breathing engine), you'll need to carry significantly less hydrogen to reach the same velocity.

    It follows that ultra-light rockets that can achieve orbit would be practical, using this kind of technology.

    Second, it -ALSO- follows that giant rockets, capable of putting entire large-scale constructions into orbit, would be practical, as it would be within the sorts of costs you expect for modern rockets.

    By implication, if the Oz engine works, you could start seeing groups of High Schools (with a bit of sponsorship) lobbing entire space-stations into orbit, rendering the ISS completely worthless.

    (Which, to be honest, is an accurate assessment anyway.)

  • What about solar panels? You can run a current through water, from solar panels, and get H and 0. This is a pollution free, allbeit ineffecient, method of getting hydrogen.

    Unfortunately, this method produces gas-state hydrogen. The liquifying process requires energy also. I know a slick way to do this with water power, but it's not very efficient...

  • I haven't tried this myself, but here goes. It should work for liquid air (mostly nitrogen), but the principle should hold for hydrogen as well. Take a pressure-safe vessel and put it in the creek. Take a paddle wheel and put it in the creek. Use the wheel to compress your gas-state hydrogen into the pressure vessel. This heats the hydrogen, but the heat is lost into the running water. When the vessel is full of high-pressure room temperature hydrogen, bleed the hydrogen out through a small valve. Hydrogen expands, cooling as it does. Liquid hydrogen then drips from your valve, with extensive loss to the air.

    Pretty crappy, eh? But for liquid air, the loss doesn't matter much, and all you had to do was go down to the creek.

    Feel free to tell me why this won't work, if anybody knows a reason.

  • Ok, is it me or does this planned test sound like an Urban Legend in the making.

    -The JungleBoy
    "You never know when some crazed rodent with cold feet
    might be running loose in your pants."
  • Hydrogen can be obtained from non-polluting sources of power such as solar. But it would seem that a hydrogen-burning engine is going to produce some oxides of nitrogen, as long as you suck an oxygen-nitrogen mixture (air, of course) into the engine.

  • There was a Canadian comedian (I forget who) I heard on the "This American Life" radio program saying that Canadians cannot let a comment about space flight pass by without saying "Canadian-made robotic arm! Canadian-made robotic arm! We made that arm!"

  • And what do you think happens to that oxygen it takes out of the air?

    Answer: it combines with the hydrogen to become water vapor, which then falls on the ground as rain, where it sustains plants, which are busily converting carbon dioxide into oxygen.

    As for "hundreds of rockets smashing through the stratosphere a day", compare the cross-sectional area of a rocket with the "surface area" of the stratosphere, say "gosh, that's a tiny ratio" and then stop to think how much worse all the petroleum fuels burned by airplanes are for the atmosphere.

    Hell, next you'll be worrying about the fact that every launch slows the rotation of the Earth.

  • This is somewhat old news. Now call me a conspiracy theorist, but I honestly believe the US govt has had atleast one of these types of aircraft for quite some time now.

    In the 90's, Reagan started the Aurora Project which was to create a hyper-sonic plane that could go from NYC to Tokyo in under 2 hours. The engines were scram jets.

    The project was never really heard of since then, but oodles of initial money was dumped into it. Also, the US' fastest airplane, the SR-71 has since been retired with no replacement (some say that satelites make high/fast flying planes obsolete). IMHO I think we have a couple of these jets being used in our military.

    I'm pretty sure I've got my facts straight on this. Anyone else heard of this?
  • "Woomera is right in the middle of nowhere so it's a bit hard to hit anything."
    "Now it's used as holding area for illegal immigrants..."

    Sooo... it's a bit hard to hit anything but illegal immigrants? Check.

    Kevin Fox
  • Laiks was the first cosmonaut. :-)
  • Ramjets may be; scramjets I doubt, as there is no self-sustaining, thrust-producing scramjet in operations, AFAIK. Little problem with trying to combust air while it's travelling higher than the speed of sound (and thus pressure waves, and thus flames) of the medium combusting.
  • Solar cells are a type of semiconductor. And we all know how clean and pollution free the semiconductor manufacturing industry is. Pollution free, hah!

  • The X-15 wasn't a jet. It was a rocket. Air launched from a B-52. They have one at the National Air & Space Museum. Seriously cool looking.
  • First, one of the heaviest components of a rocket is fuel. So, cutting the mass the rocket needs to carry by a third (by having an oxygen-breathing engine), you'll need to carry significantly less hydrogen to reach the same velocity.
    Kinda like a jet engine, huh? I wonder why they don't just use those on the shuttle...
  • Kinda like a jet engine, huh? I wonder why they don't just use those on the shuttle...
    Actually, let me clarify my sarcasm a little bit, before people yell at me: I realize that air-breathing propulsion could be very useful as the first stage of a launch system. (e.g. Pegasus [scaled.com]) But at some point, you're still going to need rockets, so it doesn't make that much difference.
  • Yes. You can burn hydrogeon fairly easily on the ground and despite atmospheric conditions, the speed at which the aircraft is travelling actually creates enourmous pressures (and ammounts of O2). The problem with scramjets is that like their cousins ramjets, they must be taken to very high speeds before the engines can operate. Those speeds are estimated at around Mach 2 to Mach 4. This is because, the compression is achieved not with a turbine (as in a traditional jet) but with the velocity of the incoming air.
  • Wow, I'm not sure how this got pegged as a troll. It was supposed to be funny. Sorry if I contaminated the screenwaves. That goes for the other one too. That was just slashdot not reloading when I clicked the button.
  • They don't use everyday jet engines on the shuttle because jet engines are less efficient than brute-force rockets. Also jet fuel is heavy and expensive.
  • One thing you need to add: Things like Ozone and nitrogen oxydes aren't created by the fuel itself, but by the heat involved in the combustion. It's likely that a Hydrogen engine will still produce this kind of pollution.
  • They said the experiments would take place in late 2000. Did I miss something?

  • I think that the Arrow was mentioned as an example of the premise that: just because the US (even NASA) can't do something, doesn't mean that it can't be done by a group of foreigners.

    Because of the slightly different climate, Canadians have a tendancy to take the probability of environmental extremes more seriously. +40C~-40C is supposedly considered US Mil Spec (104F ~ -40F). In Canada, it's considered outdoor equipment. I can exceed those exremes in one year driving around Alberta. Most years I can get +30~-40 just planting it in my backyard in Edmonton.

    A friend ofmine has a story of some oilpatch equipment that froze up while stil inside of it's rated spec (rated to -45C; froze at -37C). He called down to the Texas company that supplied it to complain. The answer:

    You mean it actually gets that cold??!
    In any event, there isn't a whole lot of conspiracy theory around the Avrow. The generally accepted theory is that the US needed many of those hot engineers for the Apollo project. That's where many of them went when the Arrow was tanked.

    You didn't think that the States could get all the way to the moon without foreign help, did you?

    As to the Avro enginering data being destroyed, it makes complete sense to me. The system was capable of doing stuff that the US was either incapable of, or unwilling to acknowledge being capable of. With most of the engineers going over to NASA associated work, the project was going to be, at best, mothballed for a long time. The last thing that you want is to have all this engineering data stacked in a warehouse somewhere just waiting for a Soviet Spy to cart it off to the Embassy. Far better to just trash the existing data, and rebuild from scratch later when/if you decide to do it again. Besides -- by the time they'd get around to restarting the project available technology could be expected to have advanced beyond whatever miracles they'd produced back then.

    Pretty much the same thing was done with the Saturn 5 engines when NASA decided to go to the Space Shuttle. Although some people feel that it was done to prevent the ability to go back to non-reusable craft, I think that the security explanation is quite applicable here as well.

  • Another problem is the fact that they MUST use hydrogen -- as someone else pointed out in another thread, it's the only fuel that can combust and expand fast enough to do it while it's still in the engine.

    And hydrogen is a pain in the ass. It has a higher specific impulse (thrust per mass of fuel) than any other fuel. That's why NASA is addicted to it. But it's density impulse (thrust per volume) sucks. Plus it's a hard cryogen. So you have to have a BIG, well insulated tank. That translates into major weight and major drag. This is OK on the ground, but it's really not such a great aerospace fuel. NASA insists on using it, as far as I can tell, mostly for reasons having to do with internal politics and organizational culture. (The Russians use kerosene or alcohol, which don't have as good a specific impulse but have a much, much better density impulse.)

  • Depending on how high up the rocket sends it, it could easily, with an apogee of, oh, say, 1.6 million feet, attain a speed at reentry (300000 feet, or about 100 km) of 24,400 feet/second, well over mach 20-something (I just ran my code for those numbers for something completely different, how coincidental!).

    Then, of course, it will heat up very rapidly and ablate. The point is, speed is not a problem, but materials may be.
  • You're right. As the object falls into the atmosphere (300 kft is above the sensible atmosphere, and right on 'the edge'), the dynamic pressure increases and drag goes with it, slowing the vehicle down until it 1) reaches terminal velocity, or 2) slams into the ground. What I am flying slammed into the ground at 20000 fps. I looked at the picture of the hyshot on the webpage and it reaches apogee at just over a million feet. This means it might have a max v of about 18000 fps or so. Then it starts slowing down. When it hits the desired speed (I am sure it isn't as low-drag, or high-beta to be pedantic), it flicks on the jets and uses that to basically overcome the effects of drag.

    They are claiming a sustainable velocity of Mach 7.6 or so, so you are correct. It would be prohibitive to expect Mach 20, but the fact is, it may pass through that velocity. The higher they go, the harder they fall, and velocity in a vacuum is only a function of potential, that is v= const* sqrt(h), h being height at apogee.
  • As a canadian, that was my first thought...
  • essential a class of engines with no moving parts...

    I remember an old story illustrating the differance a 50 or 100 year gap in technology makes. It was based on the idea of someone from 1920 trying to cope with a jet engine from 1970 drone with semi conductors, etc. interesting stuff.

    just goes to show you what progress has been made

  • I realize they wouldnt be TurboProp Planes like the local Flight Club

    Dude, the first rule of Flight Club is: Never talk about Flight Club! You also forgot the second rule of Flight Club, which is: Never talk about Flight Club.

  • A couple of people have mentioned the Arrow, presumably because this article appeared in a Canadian publication. However, it should be noted that nowhere does it mention any Canadian involvement in this scramjet research.

    Also, I think comparisons with the Arrow are not very valid.

    The Arrow was not a research project on new technology, it was an engineering project to produce a working fighter incerceptor that can enter active service.

    It was a military vehicle, which meant that the market for it was relatively small. Furthermore, the Canadian requirements on the aircraft were so specialized that nobody else in the world was interested in such a beast.

    On the other hand, the market for a working scramjet vehicle would probably be huge.

    I'm not going to start speculating why the Arrow project was nixed, because that would probably ruffle a lot of Canadian feathers and start a flame war (it's probably Canada's biggest conspiracy theory).

    Personally, I don't find it fishy that they cancelled the project; I do find it fishy that everything related to the project was destroyed.


  • Would it be possible to strap a couple ScramJet engines to what is essentially a 'large-ish' and appropriately desgined 'airplane' and fire up a couple solid fuel rockets to propel the bastard into space?

    Someone tell me these engines will enable the takeoff of a 'Personal* Space Plane'?

    *I realize they wouldnt be TurboProp Planes like the local Flight Club - but I do mean a 'personal sized' Space Plane....

    How does MACH7.6 compare with the the speed necessary to escape the atmosphere and head off into space? Obviously I realize the mass of the vehicle is relevant. What Im getting at is would it be possible that this technology could lead to what Im describing?

  • A jet engine, with theoretical speeds over 8000 Kph, and pollution free!

    Pollution free? Maybe air pollution free, but I doubt that it is noise pollution free! At least it will fly so fast that you won't hear it for long, and by the time the noise hits, it will be long gone.

  • I may be wrong, but the fuel-less engine needs to already be at a high velocity to work. Won't it take a large amount of fuel/energy to get the engine to hydrogen-oxygen burning mode?

    It seems that is why they need to launch it into orbit first, then let it drop, so that it may ignite just before impact. Where is the path from this to a viable launch vehicle?

  • NASA is run by the US government. Of course they are going to have troubles

    Actually, just because one group is having problems doesn't mean that another group will not be able to approach the problems from a fresh perspective.

  • by Anonymous Coward on Thursday February 22, 2001 @02:06PM (#409768)
    favorite part is their planned test: "...shooting an engine into the atmosphere on a rocket, and hoping it will ignite as it plunges back down to Earth

    I think this is an excerpt from the Southwest Airlines business model.

  • by RobertFisher ( 21116 ) on Thursday February 22, 2001 @02:29PM (#409769) Homepage Journal
    As with many ideas in science and technology, the idea of supersonic jets flying at very high altitudes is not entirely new. During the 1950's, at the same time that NASA was pursuing the first manned spaceflights with the Mercury missions, the USAF was pursuing a completely separate X-plane program, designing and testing supersonic jets that approached high enough altitudes (~20 miles) that begun to approach the conventional notion of "space". (For comparison, Mercury MR-3, flown by Alan Shephard, went to about 120 miles.)

    The X-15 plane [fiddlersgreen.net] (scroll down the page for program history), which flew for the first time in 1959, exceeded Mach 6, and flew over 100,000 ft.

    The project was eventually cancelled, after a combination of spectacular crashes, exceedingly high costs, and the success of NASA's programs.

    It is interesting that the X-plane pilots viewed themselves as the true masters of high-altitude and space flight. In their opinion, they were in control of their missions from start to finish, unlike the Mercury astronauts, who were simply strapped down on top of an explosive bottlerocket. Indeed, the first astronaut was a chimp!


  • by GregWebb ( 26123 ) on Thursday February 22, 2001 @02:53PM (#409770)
    Thus, there has been a lot of research into engines that can work both as ramjets (subsonic combustion) and scramjets (supersonic combustion).

    Little thing, but Ramjets definitely don't produce subsonic thrust. No moving parts, so without a strong compressed air input there's not a whole lot they can do... They're restricted to Mach 2 ish and above, too.

    I was trying to find something on Google to back this up - hit Roger Ramjet instead :) Try http://www.britannica.com/bcom/eb/article/6/0,5716 ,64186+1+62599,00.html?kw=ramjet instead.

  • by TheDullBlade ( 28998 ) on Thursday February 22, 2001 @02:35PM (#409771)
    It's a good thing we're dumping all that CO2, then, so that the plants can get carbon to build roots to gather H2O which they can convert (together with the CO2) into hydrocarbons and free oxygen.

    Save the environment! Burn coal today!
  • by Polo ( 30659 ) on Thursday February 22, 2001 @06:54PM (#409772) Homepage
    Did you notice the careful wording of the SR-71 description?

    "The fastest known aircraft was the U.S. SR-71 Blackbird..."

  • by Greg@RageNet ( 39860 ) on Thursday February 22, 2001 @02:43PM (#409773) Homepage
    Liquid Hydrogen does not occur naturally here on earth. The most natural state of hydrogen is as a component of water. And when it's burned it turns back to water. Even with a 100% efficient process it takes as much or more energy to create liquid hydrogen as the liquid hydrogen itself has the potential to create. Therefore it's not polution free, the polution is simply pushed off to some other source that generates the hydrogen, such as a coal, gas, or nuclear power plant.

    So I wish I could stop hearing how burning liquid hydrogen is our savior as unlimited pollution free energy.

    -- Greg
  • by sonofepson ( 239138 ) on Thursday February 22, 2001 @03:04PM (#409774)
    Wow these guys are really looking to the future for this stuff. They are not limiting themselves to mere aircraft. They also posted this research [uq.edu.au] about future spacecraft.

    They also claim that they have set the world speed record for a chamaign cork (40 km/s) here (bottom) [uq.edu.au]

  • It will.


    There is a lot of it, surely. But when you get into the stratospheric levels there are delicate layers up there. The ozone layer is not just a simple 2 atom thick layer of ozone, there are support layers of other gases that help to keep it stable.

    I agree, this technology is vastly superior to using fossil fuels for transportation purposes.

    I simply hope that they work out the bugs and take the climactic effects into account, so the cure isn't worse than the disease.

    Yes we have rockets all the time, but this is a question of scale. We do not have hundreds of rockets smashing through the stratosphere a day.

  • by JediTrainer ( 314273 ) on Thursday February 22, 2001 @01:58PM (#409776)
    One example of Canadian engineering abilities might be found in some of the sites regarding the ill-fated Avro Arrow, like here [maverick2.com] and here [exn.ca]. Some of the things achieved with this experimental craft have never been duplicated, and unfortunately the project was only destroyed due to political reasons. It could be said that while the U.S. does have great research abilities, in some areas the U.S. can learn from their Northern neighbours. After all, even NASA is still using the Canadian-made robotic arm on the space shuttle.
  • by Tau Zero ( 75868 ) on Thursday February 22, 2001 @02:00PM (#409777) Journal
    Scramjet articles have been running around since the NASP and before. You can also tell that the author is a scientific illiterate, because he wrote the following:
    But the Australian version of the engine, which will use the rush of air at high speeds to ignite pollution-free hydrogen...
    Hydrogen is not inherently pollution-free; hydrogen combustion easily creates nitrogen oxides due to the high temperature. Nitrogen oxides are one of the catalyst chemicals which destroy ozone.

    On top of that, the article is so short on facts (not even any links to more information in the article body - don't these nitwits understand what hypertext is about?) that it's hardly worth reading. News for nerds? I think not.
    Knowledge is power
    Power corrupts
    Study hard

  • by evanbd ( 210358 ) on Thursday February 22, 2001 @02:59PM (#409778)
    Is more than "it operates above Mach 1"

    It means that the combustion occurs above mach 1. A normal ramjet is quite capable of operation above mach 1. However, the incoming air is slowed down and pressurized before combustion. In a scramjet, the air is still moving at supersonic speeds relative to the combustion chamber and fuel injectors. I've seen trying to keep a hydrogen/gasoline/whatever flame alive in those conditions (at the qantities of fuel burned by standard jet engines and more) compared to keeping a candle lit in a hurricane. It's difficult. No, REALLY. The benefit of a scramjet is that it can operate at REALLY high speeds. A ramjet loses too much energy slowing the air down to work above about mach 3-5. The concept is *similar* but fundamentally different.

  • by maggard ( 5579 ) <michael@michaelmaggard.com> on Thursday February 22, 2001 @02:25PM (#409779) Homepage Journal
    There's more then the Australian project, the USA's NASA has been working on this in-house for years. Originally the National Aerospace Plane (NASP) program it was retooled into the Hyper-X program when NASP proved to be infeasible; too many blue-sky ideas in one box, all stepping on each other's toes. Here are some Hyper-X links:

    Now, before everyone goes getting all starry-eyed over this stuff there's a few caveats: There's a 20-30 year evolution period in civil aviation. This is not a plug-and-play technology. It won't bolt on to anything we've got flying now like a new turbo-prop might. It requires all new hardware from the airframe up. You'll likely to see this technology developed first for militaries then later adapted for civilian use. However it is likely that an unmanned "courier" version will be used before anything carrying folks for when it really-really "absolutely positively has to get there overnight" (or depending on locations even yesterday.) There are legitimate questions about how much material the upper atmosphere can absorb. Pumping out quantities of hot steam at high altitude may have a negative long-term impact. There's already a good deal of evidence that civil and military contrails lead to increased cloud-formation, what effects would be at even higher altitudes is not yet known. There's also the question of long-term economics: Will it really be cost-effective to build a craft with the various types of engines and structure and cooling required to get it to a height and altitude where these motors can operate to get around the planet in half to an eith the time it might take otherwise? Supersonic aircraft have yet to prove economically viable (the Concord only flies due to it's development being underwritten at great loss by the UK & France.) Next, yes these aircraft are a staple of many SF stories, we've all read them too thank you very much, no need to recite from your favorites (I hate when every freshman feels a need to relate every /. article to a Gibson et al story.) All of that aside this is really neat technology. I admit however I wonder where this material will land? Is there a nice rabbit warren the Aussies have picked out for ground-zero? Mmmm, impacted coney a la hydrogen flambé?
  • by hpa ( 7948 ) on Thursday February 22, 2001 @02:18PM (#409780) Homepage
    One problem with scramjets is that they must operate at or above some low-integer Mach number (usually 2-4). The "sc" stands for supersonic combustion. This, obviously, means that some other engine has to be used to bring it up to those speeds.

    Conventional turbine engines can of course be used, but they don't really like getting all the way up into the scramjet operating range. Thus, there has been a lot of research into engines that can work both as ramjets (subsonic combustion) and scramjets (supersonic combustion). Whereas they would still need to be moving around Mach 1 before they can start operating, it means conventional engines would be used for less of the flight, OR that the use of rocket combustion (bring your own oxygen) for the initial part of the flight without a serious weight problem. After all, the whole point with this whole thing is to avoid the rocket weight problem of having to bring your own oxidizer and just use the O2 in the air. Since for an H2-fuelled engine the oxygen is 8/9 of the weight, the advantage is obvious.

    (Did I mention that I really hate that Slashdot don't let you use <SUB> and <SUP>?!?)

  • by KFury ( 19522 ) on Thursday February 22, 2001 @02:07PM (#409781) Homepage
    Call me crazy (go ahead, do it) but I see a rocket going up really fast, turning over, coming down really fast in order to build up the speed to go down even faster (2 kilometers per second) and then it hits the ground (or whatever). Isn't anyone concerned about a system that has no uplink at all, using only internal instruments for navigation, with this kind of power? There's no way to turn it off once the launch pad umbilical is cut, and even if things go right, 2km/sec is faster than anything else I've ever seen hit the ground. Even the terminal velocity of meteors is often slower, because they aren't falling and pushing at the same time.

    I'm worried, but I wanna see...

    Kevin Fox
  • by JesseL ( 107722 ) on Thursday February 22, 2001 @01:42PM (#409782) Homepage Journal

    "Thank God it landed in that smoking crater!"

  • by Blind RMS Groupie ( 218389 ) on Thursday February 22, 2001 @01:57PM (#409783)
    When I first read the post I thought "wow, this engine is going to propel this thing to mach 7.6 as it goes down!", but according to the article this is not the case. The engine is designed to provide readings that will help to calibrate supersonic wind tunnel tests and as such its optimal configuration for this purpose is one that doesn't produce any significant net thrust. Engines that produce thrust will come later.


Houston, Tranquillity Base here. The Eagle has landed. -- Neil Armstrong