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Mach 6 Test Aircraft Set For Trials

Posted by Soulskill on from the fly-her-apart-then dept.

coondoggie writes "The aspiration that jets may someday fly at over six times the speed of sound took a very real step toward reality recently, as the US Air Force said it successfully married the test aircraft, known as the X-51A WaveRider, to a B-52 in preparation for a Dec. 2 flight test. The X-51A flight tests are intended to demonstrate that the engines can achieve their desired speed without disintegrating. While the X-51 looks like a large rocket now, its applications could change the way aircraft or spaceships are designed, fly into space, support reconnaissance missions and handle long-distance flight operations. At the heart of the test is the aircraft's air-breathing hypersonic scramjet system."

29 of 131 comments (clear)

  1. Hmmm... by voss · · Score: 4, Insightful

    Engines reaching desired speed without disintegrating....thats a GOOD feature to have.

    1. Re:Hmmm... by KangKong · · Score: 3, Funny

      Nice to be the test pilot. "Increase the speed to mach 6, we're just gonna check that the engines don't disintegrate."

    2. Re:Hmmm... by Z00L00K · · Score: 2, Interesting

      The biggest problem for general use is to achieve speeds above about Mach 3.5.

      This was roughly the maximum speed for the SR-71 and the problem was the friction heat from the air. And the SR-71 had a hull of Titanium. The Concorde did achieve about Mach 2 and had a hull from Aluminum. So for commercial use it's probably not practical to exceed the speed of the Concorde. What has to be done for commercial use is to get a more economic version and a version that has a less annoying sound bang.

      But there is a use for faster vessels and that is to decrease the amount of fuel needed for putting a vessel into orbit by using the air in the atmosphere. And other uses are of course military use allowing for rapid strikes from long distance.

      --
      If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
  2. With lube strip by imashination · · Score: 5, Funny

    Mach 6, how blades is that?

    1. Re:With lube strip by Shadow+of+Eternity · · Score: 3, Funny

      Fuck everything, we're doing 10 blades.

      --
      A bullet may have your name on it but splash damage is addressed "To whom it may concern."
  3. "the aircraft's air-breathing hypersonic scramjet" by MRe_nl · · Score: 4, Funny

    WHOOOSH!

    (ducks)

    --
    "Kill 'em all and let Root sort 'em out"
  4. Rockets vs Scramjets by sanman2 · · Score: 4, Interesting
    Rocket supporters say that it's better to clear the atmosphere asap, and accelerate cleanly in a frictionless environment. Scramjet supporters say it's better to accelerate inside the atmosphere as much as possible to exploit its available oxygen, rather than carrying it as extra weight.

    Which costs more energy - carrying the extra O2, or overcoming the friction from having to accelerate in an atmosphere? Which imposes more design compromises?

    Which would be more economical in the long run? Bear in mind that there are 2 kinds of people that need to achieve very high velocities -- astronauts trying to make orbit and intercontinental travelers trying to get to the other side of the world.

    1. Re:Rockets vs Scramjets by CrimsonAvenger · · Score: 2, Insightful

      Which would be more economical in the long run?

      Depends almost entirely on how fast you can get on scramjets. I don't think Mach six is enough to make it worth the bother. But I'm pretty sure Mach twelve would be enough to make it worthwhile.

      --

      "I do not agree with what you say, but I will defend to the death your right to say it"
    2. Re:Rockets vs Scramjets by HiThere · · Score: 2, Interesting

      It's worth remembering that Mach numbers are dependent on the current speed of sound.

      If a scramjet can reach over 7 miles/second in the very upper stratosphere, then the scramjet would clearly win....at least if it didn't need the same G forces as the rocket. And particularly if it could carry a sizable cargo. (I.e., anything better than an Apollo capsule, but the larger the better.)

      A scramjet might make an admirable second stage for a rocket, but then you need a first stage to get it up to speed. Note that these first two stages are airplanes, and are expected to be built to be re-useable.

      There's a bit of a question as to how feasible this is, however, given that this little test plane requires a B-52 to launch it.

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    3. Re:Rockets vs Scramjets by cheesybagel · · Score: 2, Insightful
      The problem with using scramjets is that you need another engine for liftoff, and yet another engine for space travel (scramjets are made for travelling inside the atmosphere at only startup at a certain Mach number). With a rocket engine you only need *one* engine to go for zero velocity to space. In other summary, scramjets make no sense for space travel.

      Scramjets would be nice for a high speed reconaissance platform or bomber though.

  5. Not for aircraft. by Stan+Vassilev · · Score: 2, Funny

    While the X-51 looks like a large rocket now, its applications could change the way aircraft or spaceships are designed, fly into space, support reconnaissance missions and handle long-distance flight operations.

    The Concorde flew at 2.2 Mach and in order to achieve this, it ended up too expensive to create, manufacture and maintain. It would be awkward to see airlines adopt airplanes which are more expensive to fly than current models. The trend is towards less fuel usage, and cheaper flight, in fact, at the expense of speed at times. On the other hand I'm happy to see that US is working heavily on creating a replacement for F-22, an insanely expensive jet with a nearly 30 year history that was barely ever used for something at all, before being discontinued :P...

    1. Re:Not for aircraft. by maeka · · Score: 3, Interesting

      When calling the Concorde (or any other aircraft) "too expensive to create, manufacture, and maintain." on needs to take into account the ticket price the market will bear.
      Since the Concorde was not designed with a range suitable for flying the Pacific routes, it was forced to try to make up it's high costs on the much tighter margins of the Atlantic routes. Had it been able to fly the higher margin Pacific routes it is quite possible it would not have been too expensive to be sustainable - even at the same (or slightly higher) cost basis.

    2. Re:Not for aircraft. by moosesocks · · Score: 4, Interesting

      The concorde was profitable in its last years (not extremely profitable, but it made money, which is more than most airlines can currently say).

      In the end, its operators decided it wasn't worth maintaining/refurbishing the planes, scrapped the program, and wouldn't let competitors purchase the unused aircraft. Richard Branson allegedly made several serious offers for the planes, all of which were rejected. Numerous allegations have been made that the grounding of the Concorde fleet was a result of a conspiracy between Airbus and the airlines (unsubstantiated, but certainly plausible, especially in light of their refusal to sell the craft to other carriers at a time when the company was losing money)

      In short, we got lazy and stupid.

      --
      -- If you try to fail and succeed, which have you done? - Uli's moose
    3. Re:Not for aircraft. by DerekLyons · · Score: 2, Insightful

      When calling the Concorde (or any other aircraft) "too expensive to create, manufacture, and maintain." on needs to take into account the ticket price the market will bear.

      And on that issue - the market has spoken loudly and clearly. "It ain't worth it".
       
      Yeah, I know the Concorde made a paper 'profit' towards the end - but the proof is in the amount of money the airlines were willing to spend to keep this 'profitable' airliner in operation, which coincidentally is equal to the number of Concorde's still in service...
       
      Zero.
       
      I you can't make enough money to pay your own maintenance bills, then making a 'profit' is pretty much meaningless.

    4. Re:Not for aircraft. by Myrcutio · · Score: 3, Funny

      The F-22 wasn't created for our time, it's intended use is to aid our future brethren in overthrowing their tyrannical alien overlords. See the documentary here.

    5. Re:Not for aircraft. by smoker2 · · Score: 2, Informative

      Utter shite. No amount of money would have kept the manufacturers in the business of maintaining the airframes. They have too much else to do. The airlines didn't shut it down, the manufacturers did. Without a place to go for regular maintenance, you don't keep your airworthiness certificate. This means you don't fly. And the airlines did indeed spend a lot of money to try and mitigate the mechanical circumstances of the Paris crash, which wasn't even their fault. Crap on the runway is crap on the runway, no matter who or what runs over it. If that incident had not happened, I'm willing to bet Concorde would still be flying, even in the current climate.
      But Airbus is the new darling, so they've distanced themselves from Concorde and concentrated on their own designs. With recent advances in engine design and composite technology, a new supersonic plane would not consume so much fuel and would doubtless get longer range, given it's only a matter of initial design choice.

      It fucking annoys me - one accident (not even self inflicted) in 30 years and people turn round saying "I told you so".

    6. Re:Not for aircraft. by wagnerrp · · Score: 2, Informative

      This need not be the case (well, the noise issue likely does) with a future supersonic passenger aircraft.

      There is no regulation against flying supersonic over the continent. The regulations are for maximum decibel levels generated over populated areas. You can fly high enough that the pressure waves have dissipated by the time they hit the ground, although this has been found to have limited effect. You can design your fuselage and wing such that the pressure wave is spread out over a longer area, and directed laterally, so it never spikes above the limits. There is been a lot of work in that area over the past few years with the intent of bringing back SSTs.

  6. Titanium may well get cheaper by PeterM+from+Berkeley · · Score: 5, Interesting

    Recent advances in the production of titanium may bring this metal into wide use in airframes. And everything else.

    1. Re:Titanium may well get cheaper by greyhueofdoubt · · Score: 2, Informative

      Ti is the 9th most abundant element in the crust (7th most abundant metal).

      The wiki page answers all your questions.

      http://en.wikipedia.org/wiki/Titanium

      Ti is abundant enough that we use it in toothpaste and toilet cleaner; I don't think you need to worry about it going anywhere.

      -b

      --
      No offense, but I've stopped responding to AC's.
    2. Re:Titanium may well get cheaper by WindBourne · · Score: 3, Informative

      Actually, China is trying hard to lock up LOADS of resources all over the world, but the biggies are Rare Earth minerals as well as Uranium. This last week, they quit exports of a select group of REMs that they have control of, and others that they do not have total control of, they dropped the possible exports. At this very moment, Australia is deciding whether to sell them several of their mines. Hopefully they do not as they are REM mines and will be needed by the entire rest of the world. These minerals are concerned with making permanent magnet motors that are going into Electric Cars as well as are used in nearly all electronics.

      --
      I prefer the "u" in honour as it seems to be missing these days.
  7. Real step? by SlayerofGods · · Score: 3, Insightful

    The X-43 already did mach 9.68.
    This is actually a bigger step towards making a mach 6 missile rather then a mach 6 plane....

    --

    Technology, the cause of and solution to all of life's problems.
  8. Cool but... by Brad1138 · · Score: 2, Interesting

    What ever happened to the Aurora?

    --
    If you could reason with religious people, there would be no religious people
  9. That's fine for the Air Force, but ... by PPH · · Score: 2, Insightful

    ... they could save me more travel time by not making me take my shoes off and stand in endless, pointless security lines.

    --
    Have gnu, will travel.
    1. Re:That's fine for the Air Force, but ... by D+Ninja · · Score: 4, Insightful

      Hmmm...I'm reading my post, and I don't mean to say that it would be great 9/11 would still happen. Don't get me wrong - 9/11 sucked and I would never want that to happen again. But, when I say "what's great" is the fact that nobody seemed to stop and think about how pointless many/most of the security measures actually are. (AKA, I was attempting sarcasm and it definitely did not come through...my apologies.)

  10. it sorta works...we have to admit to it by speedlaw · · Score: 2, Insightful

    At some point, some of the Black projects bear fruit. We now need to admit that this can happen, now that we want to go big with it. Sorta like stealth, we had it for a while but at some point needed to go "white" with it. If it is ready for prime time, cool. You didn't think the SR 71 wasn't replaced, did you ?

  11. It's no concorde by Errol+backfiring · · Score: 3, Interesting

    It's no Concorde in any sense. The Concorde was created to make an efficient aircraft, not a fast one. This is the history I learned in college:

    Jet engines are more economical the faster you get. Too bad the air friction (drag) gets worse the faster you get. For subsonic aircraft with single flow engines, the optimum lies just a bit below the speed of sound. As there were only single-flow jet engines at that time, the Concorde was created to try to shift the optimum to above the speed of sound. They succeeded in that.

    But then, the multi-flow jet engine was invented. Instead of blowing the air out even faster, a more powerful jet engine could now mount an extra turbine that drove an extra flow of air, thereby spreading the power over more air, that was accelerated less. Bummer. Now the Concorde was just a fancy fast-flying airliner.

    --
    Nae king! Nae laird! Nae yurrupiean pressedent! We willna be fooled again!
  12. Re:Worthless by WindBourne · · Score: 2, Insightful

    Scramjet is one of the easiest engines to build. In fact, they will be a great deal less expensive for maintenance. It is just difficult to get it correct. It will also be difficult to get it up to the speed. Right now, we are using a rocket to get there. But down the road, we will likely use a ramjet which will be inefficient taking off (probably will use an electronic runway launcher to get going), all the way to the mach 5.

    --
    I prefer the "u" in honour as it seems to be missing these days.
  13. Re:Worthless by pohl · · Score: 2, Insightful

    You sound very sure. I'm curious, how would a Patriot (traveling at its top speed of Mach 5) overtake and intercept something traveling at the same (or greater) speed given that the latter has a rage of 600 nautical miles and the former has a range of 99 miles?

    Are you sure that stealth is a priority given the X-51's intended mission?

    --

    The "cue the foo posts in 3, 2, 1..." posts will commence with no subsequent foo posts in 3, 2, 1...

  14. Re:it sorta works...we have to admit to it by greyhueofdoubt · · Score: 2, Informative

    You didn't think the SR 71 wasn't replaced, did you ?

    Um... Yeah, it was replaced... With *satellites*.

    And just a word of wisdom from someone who works for 'the dark side': Supersonic aircraft are not stealthy--http://en.wikipedia.org/wiki/Sonic_boom

    http://www.pbs.org/wgbh/nova/xplanes/stea-flash.html

    -b

    --
    No offense, but I've stopped responding to AC's.