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Scramjet Test Flight Less Than Successful

Sunthorn writes: "After much hype NASA was forced to destroy the X-43 prototype seconds into the flight after the launch rocket went out of control." The BBC has another story with some pre-flight pictures. Anybody have actual flight photos? Update: 06/02 8:28 PM by michael : Emperor writes "The official NASA take on the X-43 destruction." Update: 06/03 10:18 AM by michael : And someone else sent in this photo gallery, with some really nice close-ups.

12 of 139 comments (clear)

  1. Re:ramjets vs. scramjets by The+Mayor · · Score: 4

    Hmm. The SR-71 uses ramjets. The SR-71 was delivered (i.e. operational) in 1966. So, in fact, we've had operational ramjet engines for about 35 years now. Actually, it's a turbojet/ramjet--it operates as a turbojet at subsonic speeds, and as a ramjet at supersonic speeds.

    Scramjets are another issue altogether. They are closely related to ramjets, but the only alleged operational scramjet is on the Aurora, the successor to the SR-71. Of course, that is *pure* speculation, as the Aurora has not been officially confirmed.

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    --Be human.
  2. some misconceptions about scramjets by The+Mayor · · Score: 5

    From everyone's posts so far, it seems like there are some misconceptions about scramjets.

    People keep asking why they didn't separate the booster from the scramjet so they can gather as much information from the scramjet as possible. Others are asking why they didn't separate, then let the scramjet operate to gather information.

    Well, folks, a scramjet has to get to sufficient speed before it will even work. I am no supersonic aeronautical engineer, but my failing memory (too much LDS in college ;-) tells me it's something in excess of Mach 3.

    Well, in that case, if there's a failure with the booster rocket, there's absolutely nothing you can gather from the experiment. You can't fire the bloody scramjet engine. Separating the booster from the scramjet wouldn't do any good.

    Furthermore, we've all seen the damage caused when a 747 hits the water at ~250mph. It breaks apart in a spectacular fashion. It takes years for experts to piece together the reckage to determine what happens. Now, imagine what happens when an object hits the water at 700+mph. It would be pretty damn difficult to get any valuable information from it. Furthermore, the risks to public safety would be incredibly high if NASA let this thing go.

    In the end, that's the reason they blew it up. No information can be gathered about the scramjet, and it poses a risk to public safety.

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    1. Re:some misconceptions about scramjets by eallison · · Score: 4
      Ok, first of all, I am an aerospace engineer.

      The basic premise of a jet engine is that it essentially burns air! In a typical fuel/air ratio, the air far out-weighs the fuel, so a lot of air is needed. In a turbojet or a turbofan, there is something called a compressor stage that compresses the air coming in (and in the process slowing it down) which also increases the temperature of the air (remember chem 101?).

      As the free stream velocity (how fast the plane is going, becomes supersonic, this becomes more difficult, because the blades of the compressor aren't able to handle the flow. So, the solution is, get rid of the compressor - and use the shape of the nozzle to do the job for you. A normal shock wave is formed, which compresses the flow and reduces the air velocity to the subsonic range. In the process, the temperature in the flow goes way up, again. A normal shock wave always reduces the velocity of the flow to the subsonic range, so as the plane goes faster and faster, the temperature of the flow after the shock gets higher and higher (the energy in the velocity has to go somewhere). For example, if the free stream is at Mach 10, and the flow velocity at the combustor is Mach .2, the temperature increase in the flow is well over 4000 K. The pressure increase is 32 atm, which is not trivial. This is a big problem.

      The only way to solve this, if you still want to burn air at hypersonic (>Mach 5) speeds, is to inject the fuel in the combustor into a supersonic stream, and burn it in flight. This is not simple. In fact, it's never been done in an actual airplane (It's what was supposed to have happened today). That's also where the name SCRAMjet comes from. Supersonic Combustion RAM jet.

      The design of one of these things is so complex, that basically the whole vehicle becomes part of the engine - the exact shaping of the bottom of th plane is essential, and very difficult. That's why this has taken so long. Remeber, the X-15, and every other hypersonic vehicle to date has been rocket-powered, which does away with air all together.

  3. Re:How often do YOUR major progs work right 1st ti by devphil · · Score: 5

    my bugs don't explode in a giant supersonic fireball and rain shrapnel on the test site.

    Clearly you're using the wrong programming language. I understand that this is perfectly normal in, say, Perl. :-)

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    You cannot apply a technological solution to a sociological problem. (Edwards' Law)
  4. Re:Space research should be privatized by be-fan · · Score: 4

    I'd be cautious of having an opinion about something like that without hedging a bit. While I can see the point that private industry would be more efficient in implementing space programs, but I'd argue that it would lead to short-sightedness in research. Corporations are notoriously short-sighted (ex. AT&T not recognizing until 1998 that the internet would put long-distance carriers out of business) and space research could go from focusing on projects that have little immediate returns (but long term potential gains) to focusing on projects that can make a quick buck. I'd argue that a blend of both public and private research would be ideal, with a public agency like NASA focusing on long-term research (like studying comets, deep space, etc), and private companies focusing on short-term projects (like a moon base).

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    A deep unwavering belief is a sure sign you're missing something...
  5. Re: above post is uninformed by deglr6328 · · Score: 4

    there are images of this flight somewhere. you don't spend tens of millions on an X project without doing something as basic as taking video of it's launch. whether or not you will ever get to see them is another story, of course. here is an example of still images and an mpeg video from another pegasus launch.

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    - "Hear that?! The percolations are imminent! Cease your ingress!"
  6. Re:Space research should be privatized by Some+Dumbass... · · Score: 4

    All (or at least most) tax-payer funded space research and missions should be privatized. A company can do things better, cheaper, and faster than a government can. NASA has been proving that for years...

    NASA may seem bad, but since there has not yet been anything comparable to compare them to, your comparison doesn't hold water. Also, think about electrical suppliers in California. PG&E has been "proving" the opposite of your claim for quite a while now...

    Besides, all NASA does is contract out to those same companies. It's not like they build the rockets themselves. "Privatization" just means that Congress is paying Boeing directly (instead of funding NASA, who then pay Boeing or whoever). That won't create more accountability - it'll create less! Congress can't be bothered with all the details of every spending bill. At best, they'll make a committee or create an organization to deal with space funding - which basically means they're recreating NASA.

    Bids should be VERY open, so that there isn't any pork-belly pay-offs like are so common now, and there should be massive accountability with the funds (hey, thats MY money you just blew up...).

    Yeah, we all know how private corporations are historically good at being accoutable for their spending (Savings and Loan bailout, anyone?). Also, I'm sure they can run an honest "VERY open" auction without anyone checking up on them.

    The moon is 20 percent metal, 20 percent silicon, and 60 percent oxygen (not in an atmospere). It is the perfect place for solar harvesting. The panels could even be made in factories on the moon. It would be zero polution, as electricity is free on the moon, all you can eat.

    And we will be eating electricity, because there's no food on the moon :) Unless those panels are built by robots (powered by what?) we'll need a place for at least a few people. Sure, they can set up greenhouses, but they need to free that oxygen, mine that metal, set up power plants, make the actual greenhouses... don't you get the feeling that this project might take a while? I mean, it was only 32 years ago that we just barely made it to the moon, and as this article suggests, we're still at the "our equipment goes out of control sometimes" stage. And it's just a little harder to get oxygen from rocks than from water. Speaking of which, you'll need water too.

    It should be done, and it should be done immediately. Such an effort on the moon would change life as we know it here on earth, and could eliminate fossil fuel needs by 2010...

    How were we going to transmit that power back to Earth? Oh, I get it - this is the start of a new science fiction story!

    Seriously, I'm surprised that a post so full of speculation and conjecture got marked up so high. For example, replacing fossil fuels is a worthy goal, but really, why not just put more solar plants on Earth? Isn't putting them on the Moon just a bit of overkill? It's far easier to transmit power from sunny equatorial regions to the far reaches of the Earth than from the Moon to the same.

  7. People seem to not understand how this works by rebelcool · · Score: 5
    A Scramjet needs to be operating at supersonic speeds to operate. The SC in scram stands for supersonic combustion.

    scramjet's are very simple mechanically. No moving parts, just hydrogen injectors which combust supersonic oxygen to allow sustained hypersonic speeds.

    To get to supersonic speed you need to operate a scramjet, you need a booster rocket of some sort. The booster rocket is what failed in this experiment, careening the entire assembly off course. Rockets are tempermental beasts, unfortunately.

    Thankfully, this probably wouldnt set research back much. The mechanical simplicity of the test plane makes it pretty easy to build another. The 30 years of research went into the design of the airbox (and it really is just a box w/ injectors) to make it aerodynamically stable enough for use.

    What amuses me is the news stations assertions of "30 minute trip between los angeles and new york!".. well not really. You'd have to speed up to the hypersonic speed safely and then slow down safely. All in all you'd be in hypersonic mode for a couple of minutes, if that. Hardly worth it for the trip. Better for far away destinations.

    http://www.aviation-history.com/engines/ramjet.h tm has a comparison of scramjets vs. ramjets.

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  8. experiments by daniel2000 · · Score: 4

    These these are *** experiments ***
    For some reason people seem to feel that experiments MUST reach their desired outcome first go or the project is a failure.

    If we were able to do this then we wouldn't ever need to do experiments - we would go straight to production every time. (and have no more accidental discoveries either- which fairly much everything started with at some time, even electrical energy)

    At the moment I am a bit down on marketing so I blame marketing for over hyping the immediate possiblities rather than presenting a longer term view.

  9. This is not that big a set back. by CathodeJack · · Score: 5

    Sure the thing tanked before it could complete its mission and NASA didn't get nearly as much data from it as they wanted. They did get some data though. If nothing else, they learned to make damn sure their reasonably reliable Pegasus boosters are thoroughly extra checked over before ignition.

    Additionally, they intended to slam this thing into the ocean at the end of the run anyways. The test hardware that was destroyed wasn't all that expensive to begin with (compared to most other things at NASA). Most of the X-43 budget was spent on designing the space plane, not actually building the functioning single use model (not prototype; the eventual space plane is going to be MUCH bigger) that was destroyed today. Given my experience with NASA, I suspect the largest lost cost in today's failure was the Pegasus missile and all the red tape involved in scheduling the launch itself.

    NASA still has two or three more X-43's to try again with. And they will try again, and next time it will probably work. Despite what some people here might say, they're not complete fools over at NASA.

    I have to wonder just how many people out there were even aware this test was going on today before they saw this news article? How many people would have noticed or cared if it hadn't failed?

  10. In the words of Robert Goddard by sakusha · · Score: 4

    I am reminded of a report of the words of Robert Goddard when one of his early liquid fuel rockets exploded. Someone asked him how he felt about his latest failure. He said it was not a failure, "we have gathered valuable negative information!"