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Technology

Australian Scramjet Launched 196

Posted by michael from the lawn-dart dept.
CaptainAlbert writes: "The University of Queensland, Australia is reporting the (possible) success of their "HyShot" scramjet test. The BBC have got this covered too. Apparently, they're now poring over the data loggers, trying to figure out if it actually flew under its own power." We had a story about these guys a while back.
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Australian Scramjet Launched More

Australian Scramjet Launched

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  • Maybe if NASA has spent it's budget more wisely, on perhaps investing more money into these kind of developments and research rather than wasting it on kamikazee projects and shuttle launchings, we'd probably be on Mars by now...

  • "The scramjet needs to reach Mach-5 to start working"...

    This isn't too practile... need to be moving very fast to start working
    • Yeah, cos it would provide no efficiency savings at all to have to accelerate using an inefficient method to mach 5, then travel via a more efficient method for a potentially infinite distance.
    • "The turbo needs to reach 10,000 rps to start working"

      This isn't too practicle ... needs to be moving very fast to start working.

      Adding a scramjet to an existing setup (or something like that) allows you to cut back on traditional thrust, which in turn means you can cut back substatially on liftoff weight, which means it becomes less expensive to send up stuff.

      You're right - it's not "practile" [sic].
    • Seriously.
      The point of the scramjet is that you don't need to carry a supply of oxygen onboard once you reach those speeds, which are NOT that fast if you consider orbital velocities. That's a HUGE weight difference.
      The idea is that you get enough compression at those speeds that you can force enough oxygen into the chamber to burn fuel without the need for a supply of liquid-oxygen. Of course, you may still need that liquid oxygen in space, when you have no atmosphere.. but still.
      The whole point is to save fuel on the way up.

      A working scramjet is MUCH more efficient than a non-scramjet.. why else do you think they are doing this?
    • Maglev Launch helps too

      Sure it wont get you to Mach-5, but its fuel you dont have to carry

  • They answered their own question...... (Score:4, Funny)

    by Nick's Name ( 531306 ) on Tuesday October 30, 2001 @08:49AM (#2496730)
    Scientists are not quite sure what happened after launch

    We've bought a lot of bits and pieces off the shelf from automotive shops

    I think they answered their own question.

    • We've bought a lot of bits and pieces off the shelf from automotive shops


      So did it go something like this:

      Scramjet eh ?

      Well, I can do it, but it'll cost ya...tell you what, I'll give you the parts for $2,500 but the labour'll cost you $1,000,000...


    • Lots of top developments have been made by these sorts of projects while large funded defence projects fail miserably.

      Look at how long the Russian's could keep people in space. And of course the ultimate

      US: We spent millions of dollars developing this pen which will work in Space or underwater, what did you do

      USSR: We used pencils and crayons.

      Millions of dollars on one side, 5 cents on the other.

      Defence is stupidity with a budget.
      • The interesting thing is that the "we're going to build a space pen that works, no matter what it takes" attitude is what results in long-term and sustainable success, since it allows you to build on your achievements and make progress, rather than constantly battling the limitations of your tools.

        This reminds me a little of what happens in third-world countries (I've spent many years in a couple of them). You don't need a drain system if your town is on a hillside leading down to the ocean. But every time it rains hard, the streets flood and you can't get around. No town in most developed nations would be built without a drain system, no matter how convenient the local geography. And the result, in the end, is that more gets done, in a more sustainable way.

        Extrapolate that attitude, and you've got the space pen. The people using the pencils and crayons are no longer able to mount space missions without outside help.

        • It all depends on the Requirements:

          If what was needed was a tool to allow an astronaut to take notes while in Space, then the end result in both cases was that the problem was solved, altough the pen approach was clearly the LEAST efficient use of the available resources (time and money).

          On the other hand, if what was needed was a system to deposite a fine layer of an ARBITRARY liquid or soluble substance (for example special inks), then the pen approach was the only one to solve that problem.
          • The point is that requirements are not some fixed and absolute thing - they have to be chosen subjectively. My argument is that having high standards for requirements can have benefits that aren't always obvious from a superficial examination of the situation.

            In this particular example, I don't have enough facts to compare the two cases: for example, did the Russians experience any direct problems from using pencils and crayons, such as written material becoming smudged? If not, then it might be argued that developing a space pen was overkill, in that limited scenario. But I'm arguing that the ramifications of such decisions can go far beyond the context in which they're made. That's why architects and designers with vision can often make a big difference - because they look at the "requirements" in a much broader context, and end up creating something that provides far greater benefits in the long run.

            Kennedy did this when he started the moon program - the spinoffs from space research have always been a major benefit. I often do design work on a pad while lying down, for example, where the pen ends up upside down - and guess which pen works best in this situation? The Fisher Space Pen [spacepen.com]. According to the Fisher site, these pens are now used on Russian space missions, too. So the space pen seems to have been a good investment - after all, if the pencils and crayons were good enough, why would the Russians have switched? Besides, the Fisher company creates economic value, providing jobs and a useful product.

            So it isn't really about whether a device to deposit arbitrarily liquids was needed. It's about the benefits that fully addressing a problem can bring, and thinking of wider applications and benefits, as opposed to coming up with something that's simply minimally acceptable. If you always only produce what's minimally acceptable, your progress will ultimately be self-limiting.

            In hindsight, there was a requirement to create a space pen. The smart people are the ones who could tell that ahead of time, instead of simply saying "we'll use pencils".

        • Oh, come on. Look at California, where people build their houses where they can't exist for more than ten years, because they'll either go downhill with a mud-slide or burn to a crisp in a wildfire. You'll also find people abusing the drains somehow, often resulting in drownings.

          Sure, if the russians had developed the Space Pen, they wouldn't need "outside help" (in the fom of money, not technology), but could have made the money by selling it on Sharper Image instead.

          • Sure, if the russians had developed the Space Pen, they wouldn't need "outside help" (in the fom of money, not technology), but could have made the money by selling it on Sharper Image instead.

            Hey, you need to learn to extrapolate. The Space Pen is an example, even a metaphor. Extrapolated, your statement is absolutely correct: if the Russians had commercialized their space technology, and other technology, and sold it on an open market, they would have had a stronger economy and might have been able to fund their version of communism for longer - although with nice open markets, it soon would have turned into capitalism. So lack of a Space Pen led to unnecessary anarchy and turmoil that could have been avoided!

            As for California, everything's relative. California still manages to survive earthquakes that would kill tens of thousands of people if they occurred elsewhere in the world (Turkey comes to mind). Same principle in action.

      • Urban Legend! (Score:5, Interesting)

        by Tassach ( 137772 ) on Tuesday October 30, 2001 @11:48AM (#2497663)
        This urban legend has been debunked [snopes.com]
        many times



        The US Space program used ordinary pencils in space throughout the Mercury and Gemini programs. Paul Fisher, founder of the Fisher Pen Company, spent over one million dollars of his own money developing the Fisher Space Pen before he came up with a working prototype in 1965, which he submitted to NASA for evaluation. NASA approved it for space flight in September 1965, and purchased 400 pens at $2.95 each in December 1967. The Soviet space program adopted them in 1968.

  • They don't know...it was too fast.

  • Russians first? (Score:4, Informative)

    by 4im ( 181450 ) on Tuesday October 30, 2001 @08:56AM (#2496759)
    They say in the BBC article that the US first achieved the supersonic combustion bit a few weeks ago. But, IIRC, the russians tested a ScramJet a while back, also from a rocket - and succeeded. Of course, poor funding probably delayed/cut further research, which is a shame - they're excellent at experimental (vs. theoretical, simulated) research.
    I don't have references, unfortunately... but I'm sure google might provide some...
    And let's not forget, ramjets have been in use for quite a while - again, the russians being in advance on the west, check out their air-to-air missiles.
    Anyone reminded of those supercavitation torpedoes? Yet another area where those "technologically backward" russians are by far more advanced than the west...

    Just how much brainwashing do we get?
    • I believe the Russians mounted a scramjet model on top of a former SS-20 missile to see how it works at high speed. I'm not sure if they got decent research results, though.

      By the way, those supercavitation torpedoes you mentioned are a bit dangerous to use--I've read that one of those torpedoes exploded in the torpedo launching tube of the Kursk, which caused its unfortunate sinking.
      • One American sub lost in the 60's is believed to have tried to launch a (regular) torpedo with the outer tube door closed, so even though this has got to be one of the stupidest things you can do on a submarine, it can happen... I doubt that the supercavitation torpedos are inherently more dangerous than regular ones -- except that I think they are still experimental. One other thing may have worsened the odds for the Kursk -- when you can't pay your crew regularly, they are apt to get sloppy.
        • I had a high-school friend who went into the Navy and spent time on a sub. This was back in the 70's, so things may have changed since then, but...

          According to him, those things were *immensely* manual. He described some valve that was part of the diving process being behind/beside his bunk. When the dive alarm sounded, he (or whoever was bunking at the time) had to turn that valve. He got to where he could do it in his sleep and never know he had touched the valve.

          From my own tour of the Battleship Massachusetts, that thing was a giant machine where some of the moving parts happened to be people. It took 25 men to keep one of the 5" gun turrets firing and fed with ammo, and 125 men for a 16" gun turret. There wasn't much automation. Granted it was WWII, but it also signifies a mind-set. I've been through the Albacore and Nautilus (both 50's era, I know) and have seen nothing to refute that mindset.

          I can readily believe that opening the torpedo door was someone's personal responsibility, and perhaps he was even sleeping between torpedos at the time.
          • The Navy likes manual controls because they _work_. Sailors are more likely to survive hits and still do their job than electronic controls -- and sailors don't corrode away in salt spray and tropical heat, but electronics sure will. So you definitely should have manual controls for everything possible and drill the crew on them now and then.

            That said, electronics could be used much more than it is to bring information to the few men actually controlling the ship, and to give them more direct control. E.g., one reason that sub surfaced underneath a Japanese trawler was that the sonarman couldn't get through the crowd of civilians to mark contacts on the whiteboard. Whiteboard??? Why not a big flat-panel display so the sonar & radar operators can mark all contacts without leaving their stations?

            Finally, I was under the impression that even in WWII, subs had mechanical interlocks on the torpedo tube doors and firing mechanism. That is, you're blocked from opening the inner door if the outer door is open and vice versa, and whatever it is that switches the torpedo on shouldn't work until the inner door is closed and the outer door open. Plus the crewman should check the indicator for the outer door before firing. But obviously even mechanical interlocks break sometimes, and the crew must have ways of defeating them when needed.

            All this is second-hand at best. I was an electronics tech in the Air Force myself (relatively cushy job, right -- that's why I picked that branch to enlist ;-). My son is on the USS Ogden (LPD -- that's a troop transport with a well-deck for landing craft). It's definitely heavy on the manual control, but then it's 50 years old!

            • Its getting to be now that sailors, though most flexible and survivable, are very expensive. Consider the battleships that were mothballed, refitted for tomahawks, then mothballed again. Old boilers and teak decks are all about man power, and manpower is expensive, especially when the navy (and all other services save the marines) can't meet their recruiting goals. The navy would love! to have 16" guns again. Fire support of amphibious landings is sorely lacking with the current 5" guns mounted.

              Having said that, the current thought in naval design is a balance between low manpower automation USS Yorktown Smart Ship [navy.mil] and the arsenal ship [cdi.org] and manpower for flexibility and most importantly, damage control

          • According to him, those things were *immensely* manual.

            During that era, they certainly were. I had a look at an Australian Oberon diesel submarine from the era (it's moored at the maritime museum in Sydney), and to make it do *anything* was incredibly complex. Firing a torpedo required adjusting half a dozen different valves, manually loading the torpedo from storage, and so on.

            As well as the controls on the bridge, though, they were duplicated in various other parts of the ship, so if the bridge controls were damaged you could launch a torpedo from the crew quarters, IIRC. They basically slept next to them.

            Of course, these days you could replace most of that with a controller and some relays. It'd be interesting to have a look at a Collins-class sub to see how much of the fire sequence is now automated.

        • It's more likely that the torpedo activated itself in the tube, rather than it being accidently launched. First, there are interlocks to prevent the launching hydraulic ram from operating with the door closed. Second, torpedoes even when correctly launched, don't become "hot" until they've left the tube. And Third the boat apparently maneuvered to attempt to disarm the torpedo. Torpedoes disarm themselves if they turn 180 degrees in order to prevent looping back and killing the parent sub.

          Taken altogether, it would appear that the torpedo went hot in the tube, or on the rack, and exploded before it could be disarmed.

    • Re:Russians first? (Score:2, Insightful)

      by Anonymous Coward
      Having taken Russian in college and been exposed to their culture via instruction, as well as meeting many Russian citizens, I can tell you without a doubt that their culture as a whole has a much stronger academic tradition and reverence for knowledge than here in America. Being a thinker to them is an extremely honorable thing.
      So while their funding may be screwy limiting experimental progress, their theoreticians have always been top-notch. As an example, when Eastern Europe opened up to the West, we discovered that their theoretical research into computer science topics was at about the same level as the West's in terms of sophistication, even if their hardware was somewhat primitive. Another example would be the Mig-25 which the West ridiculed as being essentially plain steel welded together unlike our sophisticated titanium et al. fighters ... the Mig-25 was in the same speed class as the SR-71.
      • However, the MiG-25 was mostly stainless steel, NOT titanium. Sure, it was very heat resistant, but it was also quite heavy on a per kilogram basis in regards to that plane. And while the Mig-25 could dash to Mach 3 it's top cruise speed was more like Mach 2.5 due to limits on the huge Tumansky-designed engines.
        • Actually, the impression that the MIG-25 was such a fantastic plane was due to poor intelligence by the CIA (or good counter-intelligence by the GRU, depending on how you look at it). It seems that the Soviets flew a MiG-25 flat-out a couple of times where it could be seen by US forces. And it was indeed insanely fast. What the US didn't know was that after flying that fast the engines would have to be completely replaced.


          The US didn't learn the truth about the MiG-25 until 1976 when Lt. Victor Belenko (a Russian pilot) defected, bringing his plane with him. CIA stripped the plane completely down and mailed it back to the USSR one little piece at a time. Between the technical analysis of the plane and the debriefing of the pilot, they learned that the MiG-25 was actually an unreliable piece of shit and that they had seriously overestimated it's capabilities.

          • Re:Russians first? (Score:2, Informative)

            by Jburkholder ( 28127 )
            This is correct. When Belenko defected by flying his Foxbat to Japan [migman.com] in 1976, the US got a chance to inspect the plane up close and all of the mis/dis-information about the platform became apparent.

            Interesting thing was that the entire F-15 program was geared towards countering the capabilities of the Foxbat.
          • I'd call it excellent intelligence-spoofing on both sides. The MIG-25 was apparently first built to intercept a rumored bomber version of SR-71. I don't think we actually flew SR-71's into Soviet airspace very often because they would have eventually managed to knock one down, but they definitely couldn't stop them the first time, and with nukes once is enough. The MIG-25 flew high and fast, but not very far -- so it could nail an SR-71 if they put the MIG-25 base in the right place... Then we didn't make an SR-71 bomber (and it probably wouldn't have worked anyhow, from what I know now. It had no payload, no maneuverability, and it leaked fuel all over the runway on takeoff, so you just hoped nothing went wrong and it outran the fire. If other reliability issues were handled like that...) Instead we tried for improved penetration at low-level (F-111, cruise missiles), and eventually for stealth technology.

            So the MIG-25 got the secondary job of making the Americans nervous, and it certainly did since it's defects were no more obvious to us than the SR-71's were to the Russians. But the steel construction isn't that unreasonable -- it made it heavier, cutting down on fuel or weapons capacity, but this didn't affect the design mission. The vacuum-tube electronics wouldn't be burned out by EMP when the first nuke dropped. The most reassuring thing we learned from Belenko may have been that this complex piece of precision equipment was serviced by drunks...

    • Re:Russians first? (Score:2, Interesting)

      by Skinny Rav ( 181822 )
      Anyone reminded of those supercavitation torpedoes? Yet another area where those "technologically backward" russians are by far more advanced than the west...
      Just how much brainwashing do we get?

      Come on, they were first on orbit, their MiG-29 used to be considered better than their western counterparts - I think these facts are well known worldwide, so what brainwashing?

      Soviet Union was technologicaly behind and as well is Russia if you don't stick to military technology. Go to an average Russian house and just look for a mobile, a PC - you probably won't find any unless you search in Moscow or Skt. Petersburg. And Russian TV sets were famous in the Eastern Block as "home explosive kits" because they tended to explode "just because". And these lovely Russian clocks famous as "the fastest in the world".

      I come from Poland and I used a lot of these "far more advanced" Russian technology and I know how everyone counted their money because it was better to buy (extremely expensive for us then) no-brand western or Asian electronic equipement than to stick to Russian stuff.

      And now even their military industry is falling behind due to fund reductions.

      Rav
    • Umm, let's put this into perspective.

      It's a well known fact that the former Soviet Union spent, and later earned, the lion's share of its hard currency on the manufacture of arms. While they were building some of the most lethal weapons systems on earth, an ordinary citizen could not buy a decent refrigerator, let alone a reliable automobile. I contend that this led to the collapse of the nation and put them where they are today, having to rely on space tourists and such to help fund their high tech programs.

      Comparing a Mig-25 to a SR-71 is ludicrous. The Foxbat could sprint at high speed for a short distance while the Blackbird cruised above Mach 3 at around 90,000 feet. They are not in the same class at all. Anyone remember the Mig-25 pilot that defected by landing his plane on Hokkaido in the mid '70s? All the radios used vacuum tubes. Hardly what you could call sophisticated.

      BTW. Way back in my USAF days, stationed here [bellsouth.net] and here [tripod.com] from '78 through '81 this was the sort of thing that we kept track of 24/7. There were very few areas where their tecnology was on a par with the west.
      • >Comparing a Mig-25 to a SR-71 is ludicrous

        Mig-25 "FoxBat Vs The SR-71 "Blackbird" [wvi.com]

        Ability to intercept an SR-71: Belenko states the Mig-25 cannot intercept the SR-71 for several reasons: The SR-71 fly too high and too fast; the Mig cannot reach it or catch it. The missiles lack the velocity to overtake the SR-71 and in the event of a head on missile fire (The Golden BB), the Guidance system cannot adjust to the high closure rate of the SR-71.

  • Scramjets are the way forward. (Score:4, Insightful)

    by Anton Anatopopov ( 529711 ) on Tuesday October 30, 2001 @08:59AM (#2496768)
    Since they are cheaper than their competition, and more environmentally friendly.

    My concern is whether there is actually a demand for supersonic flight, or whether the current conventional airliners represent the 'good enough' level of technology which means there is no incentive to replace them. The current state of the travel industry makes me think it will be a long time before we see a scramjet based airliner at JFK.

    In the meantime, the Europeans seem to be about to revive the Concorde. Its a bit annoying that we don't have anything to beat that. Maybe these superjumbos will be as impressive, but they won't be supersonic

    • As a person terrified of flying, I getting somewhere faster means less time I have to spend moments away from pissing my pants over turbulance.
    • My concern is whether there is actually a demand for supersonic flight, or whether the current conventional airliners represent the 'good enough' level of technology which means there is no incentive to replace them.

      In the olden days, you could still duck for cover under your desk when you heard a jet approaching. With those newfangled scramjets, they'll be in your office before you hear them...

    • This story [bcentral.com] implies that America doens't even have the superjumbo bit sewed up. Yes it is an old story, but basically, air bus made the superjumbo, while Boeing concentrated on longer range versions of their current fleets. Do the old google search on superjumbo and boeing....

      As to supersonic, the concorde suffers greatly from being supersonic. Sure, it is wicked fast, but since it is so small (aerodynamics at those high speeds just suck) you don't really get that much room to yourself...but you do get very personalised service. Kindof ultra first class :-)

      As to whether supersonic flight is worth it. For me? Hell yes! To get back home (Australia) I have to fly for about 20 hours, I would love to cut that in half at an affordable price... Plus, think of all the smokers that would pay extra for shorter flights.... :-)

    • That new Boeing proposed jetliner is an answer to the Airbus A3XX superjumbo: same number of people as a modern-day airliner, but flying lower and faster with 'new' engine technologies at around Mach 0.92-0.95.

      Which is, admittedly, a step forward-- I don't want a flying cruise ship unless it's a lighter-than-air and I have real room-- but who doesn't want to travel above the Mach?

      The airlines don't work on the assumptions of technology; they work entirely on the principles of economics: 'good enough' is how much money we can make on the amount of discomfort the passengers will endure (also factoring in fuel costs, labor costs, and the occasional plane crash).
    • Because of the sonic boom, jets are restricted to subsonic flight over populated areas. So for planes whose primary purpose is to move passengers within the U.S. and/or Canada, the capacity for supersonic flight is a worthless, yet expensive, feature.

      • Re:Supersonic isn't much good over land. (Score:4, Interesting)

        by Nater ( 15229 ) on Tuesday October 30, 2001 @11:18AM (#2497474) Homepage
        I bet it wouldn't be too hard to get that limit relaxed to something like no sonic booms below 15,000 feet (~4500m). A military plane once passed Mach 1 less than 2,000 feet (~600m) above the house of a friend of mine (at the time, he was living about forty miles west of Detroit in a rural area). He said it was really loud and shook the Earth, therein lies the problem. Moving it higher off the ground, is IMHO, a much better solution than an outright ban. In that regulatory environment, I can imagine the major hubs having regular supersonic connecting flights to each other, with conventional flights to all other airports. Think of it as a 'backbone network' for 'people packets'.
    • The current state of the travel industry makes me think it will be a long time before we see a scramjet based airliner at JFK.

      There are a whole host of engineering problems before you can build an airliner with these engines.
      One very basic one is that any such aircraft must be able to use existing runways for takeoff and landing, also be capable of taxing.
    • Since they are cheaper than their competition, and more environmentally friendly.

      Because of their design, you still need some sort of conventional engine to power the plane up to the speed where the scramjet can even begin to operate. Which, at least for the forseeable future, means two propulsion systems per plane. Definitely not cheaper than their competition.


      In the meantime, the Europeans seem to be about to revive the Concorde. Its a bit annoying that we don't have anything to beat that.


      Concorde is impressive as hell, but even at exorbitant ticket prices, it still needs a government subsidy to operate.

      • it still needs a government subsidy to operate.

        So does the mighty USA Army, but we don't complain about that!

        IMO, Concorde demonstrates the superiority of the European and Japanese practices of 'corporate welfare'. We need to get more of this in the USA, or else these more socialist countries will run rings around us technology-wise.

        When the profit motive is the only force in the market, the inevitable result is stagnation and monopoly [microsoft.com]. The Socialist governments of France and the United Kingdom showed that two Socialist countries could achieve what even the greatest nation on earth could not: Supersonic passenger aircraft.

        It is interesting to note that the only other supersonic airliner was the Tupolev TU-144 [www.bird.ch] which came from that other Socialist utopia the USSR.

        I am not saying the USA should become socialist, but it should recognize that to achive true greatness and kick-ass status, it needs to develop a supersonic airliner of its own, otherwise people will still look to Britain and France as the most advanced nations.

        Come on, you can't tell me you don't feel a tinge of national humiliation every time you see the sleek sexy lines of the Concorde [concordesst.com] parked at JFK airport ?

        • You can't compare the US Army and the business of operating the Concorde. They are two totally different entities with very different purposes and economic realities. Besides, people do complain about the budget of the military (not subsidy - subsidies are applied to businesses - not to militaries), but people understand that the military is purely a cost - not a profit generating entity. A business is supposed to be self sufficient and create wealth.

          Naming Britain and France the most advanced nations in the world because of *one* data point - supersonic airliners - is very silly.

          You say that the US could not achieve a supersonic passenger aircraft, but I disagree. It is not an issue of can/cannot (meaning we don't have the ability technically) it is an issue of choice based on economics.

          I think the greatness of a nation should be determined on the basis of many other things besides supersonic airliners, and even other things (such as systems of government, law, justice, morality, etc) than the technology it creates.

          I feel no humiliation when seeing the Concorde.

          I think the reason these aircraft came from Socialist countries is because they were not fundamentally concerned with how much they cost - it was merely a status symbol. If you never care how much something costs then you will quickly become bankrupt and unable to keep or operate your expensive toys.

          I don't think that building these supersonic airliners was an example of "corporate welfare"; instead, they were tools of "national pride".

          I also don't believe that these other countries will run rings around us technologically because they are socialist. Look at the advances in spacecraft, electronics, and medicine in this country and I don't see anybody "running rings" around us.

        • So does the mighty USA Army, but we don't complain about that!

          I'm sorry, that's such a poor analogy I don't know where to begin. The US Army, or any army, is not expected to be economical or profitable. To compare it with United or Delta Airlines is so silly that... ah, words fail me.


        • Come on, you can't tell me you don't feel a tinge of national humiliation every time you see the sleek sexy lines of the Concorde parked at JFK airport

          Nope. I feel a rush of pride and lust every time I see a SR-71. Why? Because spy planes are cooler than jetliners.

  • Look at the shape of the vapour trail [bbc.co.uk]. Considering how crazily it wobbled, does it look like a successful rocket launch? Can you even imagine it doing that at Mach 5?

  • destructive testing (Score:3, Insightful)

    by Alien54 ( 180860 ) on Tuesday October 30, 2001 @09:13AM (#2496822) Journal
    I was at first suprised that the actual experiment took place just a few seconds before impact

    But it makes sense since it was the point in the flight where there is the highest speed and best chance of engine ignition

    but this also means the test engine is usually destroyed instead of being saved for the next test run

  • Mach 5 Planes??? (Score:2, Informative)

    by Root Down ( 208740 )
    Experts say scramjet technology has the potential to reduce the flying time from London to Sydney to two hours, and substantially cut the cost of space launches.
    ...
    But the big problem is that scramjets only start to work at speeds greater than five times the speed of sound, or Mach-5.

    Parte the firste: The idea is put forth in the BBC article that a scramjet could cut down flight times from London to Australia - great when you've got the hankering for an oil can of Foster's.

    Patre the seconde: It is stated that scramjets only work at speeds in excess of Mach 5.

    ... I'm pretty sure that most people would pass out long before the scramjet would even take off - and without the aid of the beverage cart. I can see the use in space launches, but for commercial apps it is likely quite limited for the above reason.

    An aside: If you're into rocket history, there is a recent biography of John Parsons called 'Sex and Rockets'. Parsons was one of the earliest innovators of rockets and solid fuel technologies associated therewith. He was among the handful of people at CalTech who helped take rockets out of science fiction and into reality. Worth the read.
    • ... I'm pretty sure that most people would pass out long before the scramjet would even take off - and without the aid of the beverage cart.

      And why would they pass out? I assume you're referring to GLOC (Gravity Induced Loss of Consciousness). GLOC occurs when acceleration pushes blood away from the brain. If the acceleration of an aircraft is kept small then GLOC does not occur.

      I'm not even going to bother to explain why acceleration does not have to be high to reach Mach 5. Work it out for yourself... and that goes doubly for whoever marked the parent up.
      • And why would they pass out? I assume you're referring to GLOC (Gravity Induced Loss of Consciousness). GLOC occurs when acceleration pushes blood away from the brain. If the acceleration of an aircraft is kept small then GLOC does not occur.

        You also need a relativly low acceleration to avoid damage to the aircraft's structure, cargo holds, even passenger seats
        But then the high cruising speed only makes sense for very long distances, otherwise the aircraft might never even reach it's top speed (and altitude, since you don't want to waste power friction heating or have to use the kind of expensive materials the space shuttle uses.)
    • It used to be believed that people wouldn't be able to survive travel faster than 30 mph.

      It's acceleration that makes people pass out not speed. Otherwise the rotation of the earth would keep us all out for good.
  • I forsee some problems... I mean, forget peanuts. Heres a single M&M. Chew fast. Seats wont recline anymore because of G-force issues. Tray tables will need magnetic underliners or lots of velcro. Not to mention other weightlessness issues...

    Sir, could you please float back to your seat? We'll be reentering the atmosphere soon.

    No, I think the Concorde is safe, for now.

    • Who would pay to cut a 30 hour flight to 1 hour.. hmmm...

      Scramjets are great for going from one side of the planet to the other. The actual time out of the atmosphere would be pretty short.. most of the time will be spent getting out of the atmosphere and then landing.

      The Concorde can't flight over land because of its shock wave. A scramjet would be out of the atmosphere so the shock wave would only be a problem during landing. I've heard the shuttle's sonic boom when landing at Edwards a couple of times when it flew over LA, and it's not very loud - most people don't even notice it.

  • Hey, Rocket Scientists... (Score:2, Insightful)

    by Anonymous Coward
    ... I've always wondered &ltHmmmmmm, rubing chin&gt

    - If the initial stage consumes so much fuel and the fuel to weight ratio is such a big deal in rocket science.

    - Why don't they launch rockets from under water using that submarine ICBM technology and leverage the floatation benefits for better performance?


    Then again maybe their is something to being a "rocket scientist" and I should stick to my knitting. I know the /. community is full of wanna-be rocket scientists like me so give me feedback.!

    • Interesting thought. Quite a few of the problems with be under water should already have been adressed. You know, going into space and all, it better be water tight.
    • Hrmm.. Water is pretty viscous compared to air, there would have a lot of extra resistance from it. The pointed, aerodynamic (hydrodynamic?) shape of a missile helps it get away with this, but a plane would undergo much resistance and therefore stress trying to launch from of the ocean. For underwater launches, they'd have to balance the design of the exterior with something that'd encounter minimal resistance from water. Their probably having enough trouble getting the shape right so the thing works well in the air.
    • What are you saying, let the missile float to the surface and then start the engine to launch?

      Or actually start engine underwater, using fuel to push through water (more viscous than air, therefore more resistance, needing more thrust) and then continuing into atmosphere (as sub-launched ICBMs do)?

      The first case has no fuel-saving advantage over a normal launch from sea-level, the second would require more propellant for the initial launch through the water to get to the surface.....

      • Or actually start engine underwater, using fuel to push through water (more viscous than air, therefore more resistance, needing more thrust) and then continuing into atmosphere (as sub-launched ICBMs do)?


        Sub-lauched missiles (ballistic and cruise) don't work that way. They are encased in a carrier package, which is shot out of their launch tube by (IIRC) highly compressed air. The carrier is shot out of the water and a few feet into the air. Then the carrier shell is blown off and the missle's motor is ignited before it falls back into the ocean.

    • - Why don't they launch rockets from under water using that submarine ICBM technology and leverage the floatation benefits for better performance?

      Actually the Russians are converting old ICBMs to launch satellites, but they are doing this mostly for cost reasons... i.e., they have old ICBMs lying around and they'd like to use them.

      The really cool use of floating rockets is in concepts like the SeaDragon where the rocket is so freakin' huge that it would melt the launch pad. So you build a rocket the size of an oil tanker and float it out to sea on its side, right it, and then light it off... This is how you get a rocket big enough to launch the space station in a single shot or to launch people to Mars.

      The sad thing is that the Apollo era Saturn V is in many ways the most advanced rocket ever built.. and we lack the technology to build it again without a lot of research (Nixon recycled the plans and the components aren't made anymore anyway and would have to be re-invented).

      Scramjets are cool and all, but I doubt if they will get us to Mars.. They WILL get us from London to Syndney damn fast. And they will be able to ferry people up to low Earth orbit where they could board another larger ship to go on to Mars.

    • i think the concept he is referring to is called hyper cavitation... i remember seeing an article where torpedoes were shot using this method and they recieved dramatic speed increases, although i do not remember the specifics i know that it did involve incasing it in a bubble of air somehow

  • Scramjet facts (Score:5, Informative)

    by alienmole ( 15522 ) on Tuesday October 30, 2001 @09:15AM (#2496834)
    These articles were light on facts, weren't they? Are they worried people are going to try repeating this at home, with parts scrounged from auto stores??

    A bit of Googling revealed the following:

    From The Ramjet/Scramjet Engine [aviation-history.com]:

    • a scramjet is a kind of ramjet
    • "A ramjet has no moving parts and achieves compression of intake air by the forward speed of the air vehicle. Air entering the intake of a supersonic aircraft is slowed by aerodynamic diffusion created by the inlet and diffuser to velocities comparable to those in a turbojet augmentor. The expansion of hot gases after fuel injection and combustion accelerates the exhaust air to a velocity higher than that at the inlet and creates positive push."
    • "Scramjet is an acronym for Supersonic Combustion Ramjet. The scramjet differs from the ramjet in that combustion takes place at supersonic air velocities through the engine. It is mechanically simple, but vastly more complex aerodynamically than a jet engine. Hydrogen is normally the fuel used."
    Scramjet research seems to be a hot topic in the aerospace world - I saw references to projects underway in the UK, in the US Defense Department, at NASA, and of course Australia, all of which have claimed some or other big advances in the past year or so.

    Finally, here's Scientific American [sciam.com] article that gives a bit more technical detail.

  • Cruise missiles that travel so fast they are extremely difficult to track and intercept.

    I'm sure the US military is paying attention to this.
    • There's a reason that stealth aircraft travel subsonic, anything going faster than Mach 1 is VERY detectable, and trackable.

      As for interception, just throw something reasonably solid in front of the missile. Don't forget, at that speed it is very difficult to detect and avoid something in enough time.

      There is one reason to go fast, so that your difficult to stop. Cruise missiles have to go too far to be practical users of this in anything but the final stages (for which you use a conventional ramjet).

  • So they've gotta get up to Mach 5 before they work? So assuming that they make a working passenger jet based upon this principle, what sort of distance do you have to travel to make this a feasible option?

    I assume that it'll take a while to get up to full speed (not least because I don't think passengers would like being squished by a big acceleration). So if you were going, say, London to Paris you're not really going to have much time to get up to speed. What sort of distances do you need to cover before this option becomes worthwhile (i.e. more economical)? Would London to NYC be far enough? How about LA to Tokyo?

    • Only the air moving through must be at Mach 5.
      So it would be possible to have some kind of air booster to start the process. Then as the craft approaches Mach 5 the booster wouldn't be needed.
      I'm not saying that boosting the air flow to Mach 5 is easy. Just a thought.

    • Re:How far must you travel to make this worthwhile (Score:4, Interesting)

      by markmoss ( 301064 ) on Tuesday October 30, 2001 @02:21PM (#2498689)
      Accelerating at 1/10g (3.2 ft/sec/sec) to keep the passengers comfortable:

      Mach 5 = 3000mph at high altitude = 4400 ft/sec
      Time to reach this speed: 4400/3.2 = 1375 sec = 23 minutes
      Distance covered while accelerating: 1/2(4400)(1375) = 3,025,000 feet = 573 miles

      And your deceleration is going to be at least as long, so it's not worthwhile on trips much shorter than LA-NYC.

      If the customers can be less comfortable, accelerate at 1g and your acceleration covers 57 miles in 137.5 seconds. But the ticket is going to be very expensive -- the plane has to go faster than most fighter jets BEFORE it can turn on the scramjets. So it needs ungodly big conventional engines, or else rockets. And the seats have to swivel around because you really don't want to hang from your seatbelt in 1g deceleration for 2 minutes.

      Someone mentioned accelerating at 8g. This only takes 7 miles -- you could launch from an electromagnetic catapult to scramjet speed, IF the scramjets will run in thick air at low altitude. Of course, your passengers need a thorough physical, and there is still that deceleration issue.

      Scramjets are not for airliners. The military applications should be obvious -- and you can use something like the space shuttle boosters in that case. Other than that, they might be useful for space launches -- get to Mach 5 with solid-fuel rockets, then use the scramjets to get to the outer fringes of the atmosphere at Mach 15 or so before you have to switch back to rockets. (The trouble with rockets is that they carry their own oxygen, which outweighs the fuel...)
  • So, how is this supposed to work? Get in your plane, accelerate up to mach 5, wait for scramjet to kick in, cruise for a while, then land. At mach 5 it takes under an hour to fly across the Continental US. Of course, you need to accelerate up to mach 5, unless you want everyone tossing their cookies you can't do that too fast. It'll probably take 1000+ miles of the trip just to get up to speed. Another 1000+ to decelerate.

    Basically we've reduced this to those who fly half way around the world. And how many people do that often enough to make up for development costs? It aint ever going to happen. You're better off waiting for them to invent a transporter. The number of people with the desire for this kind of service is simply way too small.

    That being said, its fun technology to watch, but you'll never see it used in the commercial airlines. And no, I didn't actually read the article ;)
    • And no, I didn't actually read the article ;)

      And yes, it shows. :)

      The point about the "London in two hours" thing is that it gives you a frame of reference. This is mass media we're talking about, not The Journal of Astrophysics. An enormous point about the scramjet is that if it worked, it would allow vehicles to exit the atmosphere without the heavy multiple stage disposable rockets and large amount of fuel that is currently required. In theory, this could turn space travel into a commute.

    • Basically we've reduced this to those who fly half way around the world. And how many people do that often enough to make up for development costs? It aint ever going to happen.

      You'd have to be an American (what is it - 80% of Americans don't have a passport?) to make a dumb statement like that. The Boeing 747 is a device developed exclusively for just that purpose, and it seems to have made a reasonable amount of cash for its developers.

  • .. I remember when I studying at UQ, that they had built a hypersonic wind tunnel. The stream of gas could punch holes in sheets of steel.

    A mate of mine was researching how to make a mass spectrometer that could work inside/with the wind tunnel. To do the scramjet research, given the speed of the gasses, they needed to know if they could achieve combustion inside the engine rather than several kilometers behind it!

    Simon
  • Weren't the experimental prototypes of the F-16 fighter known as yard darts due to their propensity to end up in someone's back yard in the middle of the Colorado testing area? Looks like these scramjets are going to give them some good competition...

  • Cargo UAV (Score:1, Interesting)

    by Anonymous Coward
    Wouldn't it possible to apply this technology to UAVs (an aircraft without any crew onboard) transporting cargo only, you would cut the acceleration and decelaration problem (unless the cargo can't take the pressure, but this problem would be much easier to solve anyway)... Of course, there would probably be a need for cargo that needs to be sent somewhere REALLY fast, to pay for the development cost.
  • This was already attemped.


    The Arizona Highway Patrol were mystified when they came upon a pile of smoldering wreckage embedded in the side of a cliff rising above the road at the apex of a curve. The metal debris resembled the site of an airplane crash, but it turned out to be the vaporized remains of an automobile. The make of the vehicle was unidentifiable at the scene.

    The folks in the lab finally figured out what it was, and pieced together the events that led up to its demise.

    It seems that a former Air Force sergeant had somehow got hold of a JATO (Jet Assisted Take-Off) unit. JATO units are solid fuel rockets used to give heavy military transport airplanes an extra push for take-off from short airfields.

    Dried desert lakebeds are the location of choice for breaking the world ground vehicle speed record. The sergeant took the JATO unit into the Arizona desert and found a long, straight stretch of road. He attached the JATO unit to his car, jumped in, accelerated to a high speed, and fired off the rocket.

    The facts, as best as could be determined, are as follows:

    The operator was driving a 1967 Chevy Impala. He ignited the JATO unit approximately 3.9 miles from the crash site. This was established by the location of a prominently scorched and melted strip of asphalt. The vehicle quickly reached a speed of between 250 and 300 mph and continued at that speed, under full power, for an additional 20-25 seconds. The soon-to-be pilot experienced G-forces usually reserved for dog-fighting F-14 jocks under full afterburners.

    The Chevy remained on the straight highway for approximately 2.6 miles (15-20 seconds) before the driver applied the brakes, completely melting them, blowing the tires, and leaving thick rubber marks on the road surface. The vehicle then became airborne for an additional 1.3 miles, impacted the cliff face at a height of 125 feet, and left a blackened crater 3 feet deep in the rock.

    Most of the driver's remains were not recovered; however, small fragments of bone, teeth, and hair were extracted from the crater, and fingernail and bone shards were removed from a piece of debris believed to be a portion of the steering wheel.


    Now that's the best use of automobile parts yet.... Think he hit Mach 5?

    Linuxrunner

    • Many years ago when I was a BoyScout (many many years ago) I used to get Boy's Life magazine as did most Scouts. I suspect quite a few of you in here know what I am talking about thru personal experience.

      In the back of that magazine there were your typical ad's for worthless shit that nobody needs, one of which was a kit to build a small jet engine at home.

      I can't TELL you how many times I thought about ordering up a couple-three of those things to strap onto the Go-Kart I had then.

      Hindsight is always 20-20, but considering the only brakes on that beast were a pair of Nikes, I am glad I didn't.

      But, imagine the fun that would be.... ;-)
    • My favorite version of the rocket car story:

      http://www.ddave.com/rocketcar/

      Read it. Yes, it is long - but it is arguably the best story on the internet...

      So - is this the truth about the rocket car? Or is it...something else?

      I leave that for you to decide in the end...

  • Hmmm. Not so bad as you'd think. (Score:4, Informative)

    by dinotrac ( 18304 ) on Tuesday October 30, 2001 @10:33AM (#2497207) Journal
    Some posters seem to be under the impression that a SCRAMjet/RAMjet powered "plane" would need to spend an hour accelerating to speed in order to keep people from passing out or heaving guts, etc.

    It's not nearly that bad.

    People can generally withstand sustained G forces in the neighborhood of 8 Gs if properly supported. That works out to about 200 miles per hour per second. 5G to ignite the scramjet is about 3800 mph sea level, close enough to use 4000 mph back-of-the-envelope to get 20 seconds to scramjet ignition, maybe 40 seconds to Mach 10.

    A two minute climb should be very endurable.

    The limiting factor is more likely to be power-to-weight ratios than G-forces.
    • The limiting factor is more likely to be power-to-weight ratios

      Ahhhh ... but it depends on if it's an African Scramjet or a European one.

      I mean a 200-pound man cannot hang on if he feels like he's 1600 pounds.

      It doesn't matter where he grips it, even if it is under the dorsal fin.

    • It could actually be better than that. If I'm not mistaken, the Mach 5 figure is airspeed. Airspeed can be increased around the engine using an air scoop to produce a long Venturi chamber. The scoop could be made variable to get predictable performance as the vehicle speed increases.

      With this change, the vehicle could be poking along at Mach 2 or 3 and still work.

    • At multiple g accelerations, the issue isn't just people passing out or throwing up -- if you let the general public on the plane without physicals, some of them will die.

      Then, you've also got to decelerate. You can't do that at even 1g, because the passengers and crew would basically be hanging from their seatbelts. I think the maximum tolerable for the "fit" general public would be .1 to .2g. Deceleration would take 11 to 23 minutes and cover 286 to 573 miles. On a NYC to Chicago flight, most of the flight would be deceleration... NYC to LA would work, but the tickets would be extremely expensive. And that's the reason that the Concorde is not more used on trans-atlantic flights -- few people find it worthwhile to spend maybe $1,000 extra just to save four hours. The Concorde was a gov't subsidized prestige project; I don't know if they've ever made back the R&D costs.
      • Hmmm. Deceleration.

        You certainl wouldn't want them heaving at their seatbelts, would you? That would be very bad news.

        An interesting point, though. Adding to the complexity is the need to support people equally for deceleration as for acceleration.

        Otherwise decleration is just acceleration in the other direction.

        As to a fit person only tolerating .1 to .2g, many people experience more than that every day in their cars. The best modern sports cars can pull a full 1G on a curve.
        • There's a difference between a few seconds of sideways or forward force in a car and hanging from the seatbelt for several minutes while a plane decelerates. I don't have measurements, but I'd estimate the deceleration I experience in a jetliner on landing approach as .1g most of the way (with flaps and spoilers), rising to perhaps .2 to .3g when the wheels are on the ground and they use wheel brakes plus thrust reversers. It's not real uncomfortable, but the time duration is a lot shorter.

          The prop planes that serve the smaller airports descend faster and with more deceleration. This gives me an upset stomach, much more than bumpy takeoffs or level flight, but I don't think this is due to deceleration pressure against the belt buckle. Maybe it's the cabin pressure increasing? Whatever, if the same conditions were maintained for much more than 10 minutes I would be using the little bags every time...

          If you made the chairs swivel 180 degrees for descent and landing, then you could decelerate at 1 G -- only 57 miles. But the tickets would be very expensive...

          This, of course, is the real problem with supersonic airliners on medium length runs. You go to the airport 2 hours before flight, then the airplane sits on the ground an hour or so after you board, you wait around for your baggage 1/2 hour after the flight, maybe you spend hours more in customs and immigration. So why are you going to spend a whole lot more to shave an hour or two off the flight time? The Concorde costs twice as much per passenger as a 747 and cuts transatlantic flights to 4 hours from 8, but it only gets a small percentage of the passengers.

          With a scramjet airliner you'd have something even more expensive. If it can go trans-Pacific nonstop, that would be viable -- 20 hours Minneapolis to Singapore is way too long a time in an airplane... But flying NYC to Paris in under two hours is not worth that much when it takes 3 hours to get in the air, and hours more to get off the airplane and out of the airport.
  • As mentioned in the BBC article, DARPA made the first successful scramjet launch this past August. Here [af.mil] is the DARPA report on the launch. The BBC's description of the DARPA launch is a tad misleading - they say it was launched from a "gun", but really it was a 2 stage, 150 foot railgun capable of launching a 17 pound projectile at 9,200 mph. [af.mil]

  • The HyShot home page [uq.edu.au] has lots of cool stuff, such as pictures. The thing is launched on a suborbital rocket which goes to 300km altitude and Mach 7.6 (with some help from gravity on the way down). Compare with Mach 25 for orbit - many rocketplane [xcor.com] companies [tgv-rockets.com] are aiming for suborbital instead of going straight to orbit.

    Anyway, back to HyShot, the home page contains lots of details about what happens in what order and all that good stuff.

  • It didn't work (Score:2, Informative)

    by jonhirsch ( 533219 )
    Apparently it didn't do what it should have after all. http://www.uq.edu.au/news/index.phtml?article=2567

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