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USAF Launch Supersonic Bomb Firing Technology

Posted by samzenpus on Wed Nov 28, 2007 08:40 PM
from the drop-it-like-it's-hot dept.
The Military Science
coondoggie writes "Boeing and the US Air Force today said they have tested new technology that for the first time will let military aircraft launch bombs from aircraft moving at supersonic speeds. Researchers from Boeing Phantom Works and the Air Force Research Laboratory used a rocket sled in combination with what researchers called "active flow control" to successfully release a smart bomb known as MK-82 Joint Direct Attack Munition Standard Test Vehicle (JDAM) at a speed of about Mach 2 from a weapons bay with a size approximating that of the U.S. Air Force B-1 bomber, Boeing said. Active flow control is a tandem array of microjets upstream of the weapons bay that, when fired reduces the unsteady pressures inside the bay and modifies the flow outside to ensure the JDAM munition travels out of the bay correctly."
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Submission: Boeing, USAF launch supersonic bomb firing tech. by coondoggie (973519)
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  • We miss often enough at sub-sonic speeds. Great.
    • We miss often enough at sub-sonic speeds

      ...and with this exact same test weapon. For a few dollars more, they'll develop an even better JDAM!

    • Re:Release bombs at supersonic speeds? (Score:5, Insightful)

      by Anonymous Coward on Wednesday November 28 2007, @11:14PM (#21514051)
      > We miss often enough at sub-sonic speeds. Great.

      Dude, check your history. In WW2, we used to send hundreds of bombers (sometimes over a thousand), each of which dropped dozens of dumb bombs, all just to hit one ball-bearing factory or bridge. We'd lose 10-20% of the attacking aircraft, and we'd send the survivors (and their replacements) out again later that week because we still didn't hit the target.

      Towards the end of WW2, we realized that the most efficient way of destroying target X was to drop enough incendiaries around target X that the resulting firestorm would sweep over target X, destroying it in the process. We killed as many people in the firebombing of Tokyo as we did a few months later using goddamn nukes.

      I'm not saying we're perfect. I'm just saying we're a hell of a lot closer to perfection than WW2-era pilots (or even Vietnam-era pilots) could have dreamed of. We spend a hell of a lot of money every year making sure we miss as infrequently as possible. If we were willing to accept the levels of collateral damage our parents were, never mind our grandparents, this war would have been over in a week, and there would have been tens of millions of civilians incinerated.

      Be angry that we miss as often as we do -- it not only keeps weapons designers employed, sometimes it's their motivation for their career choice. But be damn grateful that we don't miss anywhere near as often as we used to.

      • Not 100% true in terms of WWII history, at least in some places. High altitude bombing was never very effective, but the naval bombers in the Pacific theater got very very good at hitting their targets with less civilian casualties. How do I know? Because I lived in Japan for two years about thirty years ago, and once had friends nearby who took me to the site of an old, bombed out munitions factory that was completely surrounded by really really old Japanese houses and a nearby religious temple. I was t

          • Re: (Score:3, Informative)

            by jmv (93421)
            Actually, no. That's not at all what I was referring to. I'm referring to fact that the Air Force likes to drop 500lb bombs where they think the top ranking baddies are, and yet with all of the sophisticated air borne weapons, they've managed to get pretty much nobody of any importance with an air strike--ever.

            Sorry about the confusion. I definitely agree here.

            In other words, it doesn't matter if you can fly a 2000lb laser guided bomb into a window, if the people you really want to get are a mile away.

            Then
  • Huh? The USAF was launching bombs (and missles) out of bomb bays (and off of pylons) at supersonic speeds back in the 1950's.
     
    This new system is probably needed because the rotary launcher used by the B-1 doesn't allow enough clearance for, or won't take the stresses associated with, the kicker systems used back then.
    • I can't figure out the article: they're talking about "launching" bombs. I normally take it that 'bombs' are dropped and 'missles' are launched; bombs use gravity and missles are powered.

      Are they trying to say that they're firing the bombs backward to the direction of flight so that they end up with significantly lower forward-velocity and, thus, fall with a shorter ground track?

      I can figure it must be merry hell trying to sight a target SO far ahead (at your given speed and altitude) that you have to drop
    • Maybe we were launching bombs off pylons as supersonic speeds, but probably not bomb bays. As the article indicates, supersonic airstream around the plane would have blown the bomb back into the bomb bay, with obviously disastrous results. What this technology does is use small jets to locally slow down the airstream around the bomb bay so that the bomb can fall out of the bay without getting pushed back inside.

      As another poster indicated, this technology would be useful for the F-22, which has to carry i
  • How much did we pay for this?

  • Great news everyone! (Score:5, Funny)

    by Bragador (1036480) on Wednesday November 28 2007, @08:52PM (#21513111)
    There is no such thing as investing TOO MUCH in the military. People that are saying we should focus more money on social problems and the economy don't understand that military technology can be applied to fix social problems eventually.

    Rejoice for now we can drop food and medical supplies at supersonic speed! I can't wait to see the look on those African kids!

    • Re:Great news everyone! (Score:5, Funny)

      by Cassius Corodes (1084513) on Wednesday November 28 2007, @09:00PM (#21513169)
      Why drop food, which fixes the problem for a few days at most, when dropping a bomb will permanently fix the problem.
    • Totally off-topic, but you just gave me an odd idea. I wonder if perhaps bunker-buster bombs could be fired into a patch of land at such an angle and to such a depth that the blast propelled the soil up and as low to the ground as possible (to prevent it from blowing aside and forming a hole,) essentially tilling a patch of land all at once for us! Back on topic, now what I just said done in Africa at supersonic speeds!

  • Not to be outdone... (Score:4, Funny)

    by YU5333021 (1093141) on Wednesday November 28 2007, @09:20PM (#21513311) Homepage
    ... upon hearing the news, the Russians have taken the concept to the next, logical extreme. Code named "Mamushka" the first supersonic plane will fire a smaller plane traveling twice as fast, which will fire yet another smaller plane traveling 4 times faster than the first one, and so on until the very last, smallest plane (traveling an nearly the speed of light) will fire a potato that will hit the original big plane in the back, thus demonstrating that like many other US expenditures, they are at least good for HUMOR.

    Next up, basketballs that bounce 10 times as high. Is gonna change the game!
    • They can't do that. That idea is the intelectual property of Dr. Suess.

    • Next up, basketballs that bounce 10 times as high. Is gonna change the game!

      Try this one on for size.... stack up a small playground ball on top of a medium one anmd stack those on top of a large one... drop the 3 of them from about six feet and watch the little one hit the ceiling...

  • The sled train accelerated to more than 13 g's to get to peak velocity, then decelerated at 7.5 g's for more than a mile to stop," the company said.
    I want a ride on that.

    • Re: (Score:3, Informative)

      by stox (131684)
      If I am not mistaken, at 7.5 negative G's, your eyeballs would pop out of your head. The human body can take significantly more positive G's than negative. Oh, and at 13 positive G's, sustained, you would pass out. Doesn't sound like much fun to me.
  • almost 50 years ago. The B-58C, if it had been built, would have been able to do it at Mach 3.
  • The tagging beta includes the word sopwith [die.net], a reference to "Sopwith Camel", a game I used to place on an 8086 box as a kid :). Your goal was to drop bombs on ground targets in a simplistic side-scroller sort of map. You can install a modern-day Linux version (pretty close to the original) by doing "sudo apt-get install sopwith" on Debian-based distros.

    Maybe not as much fun as dropping real bombs out of a supersonic jet, but pretty darn close :).

    • Well, perhaps this is more reliable. It doesn't sound like it, as there seem to be way too many moving parts in a chaotic environment to be 100% reliable. In this case, any misfire or malfunction, and the plane blows up, not the target, so it's imperative to be rock solid.

    • Very very incorrect. (Score:5, Informative)

      by Rank_Tyro (721935) <ranktyro11 @ g m a i l.com> on Wednesday November 28 2007, @09:09PM (#21513229) Journal
      The YF-12was a high altitude and high speed interceptor. It fired Air Intercept Missiles (AIM-7's)which are already aircraft in their own right. It did not drop free fall munitions at high speed.

      This current little trick is probably a proof of concept for a change to the F-22, which carries free fall bombs such as the JADM in a recessed bomb bay. The B-1b can only do about Mach 1.25 at altitude where the air is thinner. The B-1b was designed as low level penetrator to sneak under Soviet radars. With the end of the cold war, the B-1b started taking over as a high altitude bomber with GPS guided weapons, and not risk itself to ground fire to drop.

      The F-22 can cruise at Mach 2 without using afterburners, and I believe it can only carry two Mk-82 JADM weapons. The ability to fly in at Mach 2 while being practically invisible to radar, AND not having to slow down to deploy weapons would be a huge advantage.

      • Re: (Score:3, Informative)

        by Brett Buck (811747)
        One of the weapons devised for the YF-12/proposed B-12 was the original "kinetic energy" weapon - effectively, just a mass that acted much like a meteorite strike. It got to the point of successful testing but the program was cancelled. I will dig up a reference, but it was probably Ben Rich's book.

                  Brett

        • Re:Very very incorrect. (Score:5, Interesting)

          by jafiwam (310805) on Wednesday November 28 2007, @10:34PM (#21513791) Homepage Journal
          Rumor has it some laser guided bombs were filled with cement and used as k-kill devices during the last Iraq war to take out tanks next to civilian targets.

          At sub-orbital re-entry speeds, you don't need an explosive to fark up a tank. And if you can hit it reliably you don't need to go boom, it just shatters because a big block of stuff just came through the top, out the bottom and into the dirt below.

          • Re:Very very incorrect. (Score:5, Informative)

            by YrWrstNtmr (564987) on Wednesday November 28 2007, @10:57PM (#21513965)
            Rumor has it some laser guided bombs were filled with cement

            Not rumor, fact [nytimes.com].

            A 2000lb guided rock hitting a particular vehicle/tank is just as effective as a 2000lb MK-84.

              • Re: (Score:3, Insightful)

                by Brett Buck (811747)
                The (very substantial) energy has to go somewhere. At some point the yield from the kinetic energy alone exceeds the yield from any explosive. And to get a high terminal velocity, you need to make the projectile as dense as possible - and high explosive is not nearly as dense as tungsten, tantalum, DU, etc. So putting in explosives is actually a loss.

                That meteorite that killed the dinosaurs didn't explode in the sense you mean, either, yet it managed to vaporize a fair bit of th

          • Re: (Score:3, Informative)

            by Calinous (985536)
            Also, tanks are built to fight tanks. Their top armour is shamefully thin (this goes for russian AND american tanks). This is the reason recent anti-tank rockets are fired upward, and will attack the tank in a descending trajectory (hitting the top armour, not the front or side armour).
      • That's what I was thinking; the drop would be at high speed, but since the bomb is leaving the bay at much higher than its terminal velocity the fact that it is going mach 2 at drop really isn't going to add to the impact the device has (for example if you read Heinlein's The Moon is a Harsh Mistress they dropped "rocks" from the moon onto Earth. If big enough to not disintegrate in the atmosphere you didn't need an explosive payload for an impressive destructive force). With this though, the bomb would be

      • Re:Very very incorrect. (Score:5, Informative)

        by TopSpin (753) * on Wednesday November 28 2007, @09:25PM (#21513355) Journal

        The F-22 can cruise at Mach 2 without using afterburners
        The F-22 can not 'cruise' at Mach 2. That would be even more buck rogers than the aircraft is already. Exceeding Mach 2 in an F-22 requires afterburners and this, in the parlance of military aircraft, is not 'cruise.' What an F-22 can do is supercruise (exceed Mach 1 without afterburners, thus high fuel efficiencies which means good range and therefore viable in bombing missions) at about Mach 1.7.

        The F-22 can dogfight (maneuver at high-G and operate weapons) above Mach 1 which is a major advantage as most of it's contemporaries must be below Mach 1 to do much more than cover ground. Dropping JDAMS at high speed and altitude is another huge advantage which is, as you speculate, what this is probably intended to validate.

        • Re:Very very incorrect. (Score:5, Interesting)

          by tjstork (137384) <tbandrowsky@might y w a re.com> on Wednesday November 28 2007, @09:32PM (#21513401) Homepage Journal
          The F-22 can not 'cruise' at Mach 2. That would be even more buck rogers than the aircraft is already.

          Actually, the big poop is that, in fact, it probably can. I've read that the engines on that thing are so powerful that with afterburner the aircraft would be capable of Mach 3 but the airframe simply isn't strong enough to take it, so the flight control software intentionally limits the speed so the plane doesn't break up. It's a very aerodynamic design coupled to a fantastically powerful engine, and the result is that the F-22 is quite a burner. One has to wonder if there might be a covert block with a stronger airframe for reconaissance.

          • Re:Very very incorrect. (Score:5, Insightful)

            by twiddlingbits (707452) on Wednesday November 28 2007, @09:51PM (#21513515)
            I seriously doubt that. F22 airframe is mostly titanium and it's got to take 9G turns which are much more stressful then Mach3 level flight. The PW119 engines are very powerful but only about 25% more than what is on the F16 and the plane is much bigger. The benefit of these engines in their high efficency which allows supercruise w/o afterburners which saves 40% on fuel consumption. Go look at http://www.f22fighter.com/ [f22fighter.com]

            • Re:Very very incorrect. (Score:5, Informative)

              by tjstork (137384) <tbandrowsky@might y w a re.com> on Wednesday November 28 2007, @10:38PM (#21513809) Homepage Journal
              I've been to the F-22 web site, its really nice. But you should check out this:

              http://www.airplanes.com/forums/military-aircraft/1411-mach-2-0-supercruise-60-000ft-altitude.html [airplanes.com]

              There, you have a claim by a Major Robert Garland to have flown the F-22 at Mach 2 in level flight.

              If you google around, you'll find Air Force guys saying that this plane will do Mach 2.5, and, more than a few people have pointed out that the F-22 has a better thrust to weight ratio than the SR-71... thus, all things being equal, this ought to be one fast bird.

            • Re: (Score:3, Interesting)

              by Runefox (905204)
              Actually, it's not structural, it's more the fact that the air inlets are fixed rather than variable, so the engines can't get the optimal amount of air intake at different flight envelopes. Because of this, pushing the aircraft beyond mach 2.0 for any extended period of time will cause structural failures in the air intake. Presumably, this is a feature designed either to increase stealthiness or decrease overall weight and/or surface area, or perhaps to optimize air intake for supercruise. I'm not a fligh

              • Fixed geometry inlets (Score:5, Informative)

                by calidoscope (312571) on Thursday November 29 2007, @01:26AM (#21514983)

                Actually, it's not structural, it's more the fact that the air inlets are fixed rather than variable, so the engines can't get the optimal amount of air intake at different flight envelopes. Because of this, pushing the aircraft beyond mach 2.0 for any extended period of time will cause structural failures in the air intake.


                The first sentence is correct, the second is not.


                The problem with a fixed geometry inlet is that it is inefficient. At Mach 2.0 and above, a significant portion of the thrust from a properly designed inlet is coming from the inlet itself. The A-12/F-12/SR-71 cruising at Mach 3.0 gets between 55 and 60% of the total thrust from the inlet - this is accomplished by the positioning the shock wave just inside the inlet (the cons on the front of the engine can be moved in and out specifically for this purpose). One of the early issues with the Blackbirds was figuring out how to handle "unstarts" where the shock wave pops out of the inlet - and gives the crew a wild ride in the process - this was also a problem with the B-58.


                The F-16 was also limited to Mach 2.0 because of the fixed geometry wing. OTOH, the F-104 was rated top speed was Mach 2.2, but it could easily achieve Mach 2.4, but at the cost of weakening the aluminum alloy in the airframe.

            • Re:Very very incorrect. (Score:4, Informative)

              by Cornelius the Great (555189) on Thursday November 29 2007, @10:06AM (#21518031)

              The PW119 engines are very powerful but only about 25% more than what is on the F16 and the plane is much bigger.

              First off, you're forgetting that the F-22 has two of them. The F-16 only has one, capable of about 29,000 lbs of thrust. Each Pratt&Whitney power plant puts out over 35,000 lbs each (w/ afterburner), so that means 70,000+ lbs total thrust.

              Second, they're completely different aircraft with completely different goals. So don't compare the two. The F-22 was designed to be an air-superiority fighter to replace the F-15 (they're about the same size). The F-16 is light multi-role fighter with shorter range and payload. Have you ever seen an F-16 next to an F-15? BIG difference... the F-15 is a mammoth, the F-16 is a lawn dart.

              Despite this difference, the F-22 has a much larger thrust-weight ratio due to having 2 powerplants (~1.26) compared to the F-16 (~1.1, with updated engine). Fascinating fact: the YF-23 (the ATF competitor to the F-22) had a thrust/weight ratio of over 1.36, which could theoretically push the bird into Mach 3 at altitude (though its top speed is still classified).
        • The F-22 can not 'cruise' at Mach 2. That would be even more buck rogers than the aircraft is already. Exceeding Mach 2 in an F-22 requires afterburners and this, in the parlance of military aircraft, is not 'cruise.' What an F-22 can do is supercruise (exceed Mach 1 without afterburners, thus high fuel efficiencies which means good range and therefore viable in bombing missions) at about Mach 1.7.

          A less than 20% error is fine for government work...

      • [arm chair general] It'll be just like the Aurora Supersonic Bomber from Command and Conquer:Generals, except you can drop two and your desperate, last minute airstrikes on Iran's superweapon won't have to be suicide missions! How long until we have the Air Fuel bomb version from the Zero Hour's turtler General? That'll show those Al Quaeda tunnel/stinger-missile sites: lets see you rebuild your hole now! [/arm chair general]

    • Re: (Score:2, Insightful)

      by Gerhardius (446265)
      The B-58 could drop at supersonic speeds, and the A-5 Vigilante may also have had this capability. During the 50's the USAF had a serious hard-on for all things supersonic. Given the generally limited supersonic capabilities of aircraft from that era the ultimate utility of the concept must have been called into question. The supersonic cruise ability of the new generation of aircraft has simply re-awakened a dormant idea. Much like the fashion industry, the institutional memory is so limited that many folk

      • Re: (Score:3, Insightful)

        by Somegeek (624100)
        The B-58 had no internal bomb bay to launch bombs out of, which is the whole point of TFA. It's one thing to detach a weapon on a pylon that is already in a supersonic airstream, it's another to try to force one out of a stagnant weapons bay into a supersonic airstream.

    • Re:This is very handy (Score:5, Informative)

      by gujo-odori (473191) on Wednesday November 28 2007, @09:07PM (#21513219)
      It's not a matter of how fast a target on the ground may move. It's a matter of how fast:

      A) SAMs move
      B) Enemy fighters aircraft move

      If a bomber can fly by at Mach 2 at a high altitude and kick out its load of smart bombs, it becomes much harder to hit it with either a SAM or an air-launched missile. Let's say you make your bombing run at 40,000 feet going Mach 2 and a SAM battery a few miles away takes a shot at you. You kick out the bombs and firewall the throttle for any more speed you can get, and punch out chaff. The SAM is going maybe Mach 5 and you're maybe now at Mach 2.5. At a closure rate of only Mach 2.5, the SAM may run out of fuel before it reaches you, even if it doesn't get fooled by the chaff. If you'd had to slow down to sub-sonic speeds to make your bombing run, the SAM would have a much better chance of catching you.

      If there is a CAP up, it's going to have a lot more trouble catching and firing on a bomber going Mach 2 than a bomber going Mach .7.

      While these have not been particularly great threats recently (I believe the Viet Nam War was the last time an American heavy bomber was brought down by enemy fire), it wouldn't be wise to assume that the situation will always remain this way, so it's good to have that technology in our back pockets.

      Even at lower altitudes, that would take a lot of light anti-aircraft systems off the table, and at least make it harder even for large SAM systems. Imagine being a guy with a shoulder-fired AA missile trying to get a bead on something going at Mach 2. Even if you get a successful lock on it and fire, it's unlikely your missile will be able to catch it even if it's on a low-level bombing run (something I wouldn't expect a B-2 to do, anyway).

    • Re:Anyone know (Score:4, Informative)

      by Tmack (593755) on Wednesday November 28 2007, @09:27PM (#21513365) Homepage Journal

      Can powered munitions (stuff with a rocket motivating it instead of just gravity) be fired without this new technology? ie. Is the new research just applicable to iron bombs?

      I think most supersonic fighters already have that capability, since the missiles they fire tend to travel much faster than the jets they are chasing down (even the old AIM-9 sidewinder hit mach2.5+), and when launched, are already under power and moving forward in the supersonic flow relative to the aircraft and can thus navigate themselves clear. See Here [army.mil], scroll to SRAM, and that was 1969.

      The challenge with dropping bombs at supersonic speed is to get them to clear the bomb bay or wing pylon without the shock of the surrounding air flow blasting it back into the aircraft or otherwise tossing it about or ripping it apart. Not to mention designing a bomb bay and aircraft that can withstand the supersonic shock when the doors are opened.

      Tm

    • Re: (Score:3, Informative)

      by nrgy (835451)
      Well the one thing you never hear talked about with the whole "Drones are the future" topic is what about jamming technology in the future? Your over sized RC plane with some bombs on it isn't gonna do much if it cant relay its data link back to base or a satellite.

      If I remember correctly during the beginning of the war in Iraq, some cruise missiles were thrown off target when they were jammed by GPS jamming devices. What is to say that technology in the future wont advance to also include jamming the dro

      • Re: (Score:3, Informative)

        by tsotha (720379)
        This is just wrong for a lot of reasons. First, jamming is spectacularly ineffective. Not only is the other responder correct in pointing out antennas can be designed to reject signals coming from the wrong direction, but also spread spectrum communications operate over such wide bands it's impractical to jam them - it takes too much power. Finally, any source of a jamming signal has a big bullseye on it, since the signal can be used for homing. No jammer will last more than a few minutes after the enga

    • Re:*sigh* (Score:5, Informative)

      by Blakey Rat (99501) on Thursday November 29 2007, @12:56AM (#21514807)
      Why do you assume that investing in defense technology does *not* help the people of the US?

      As I see it, any enemy we'd have to use this against would be throwing ICBMs with nukes at us. Why the fuck are we building bigger and better and more expensive bombs when all of our operations are counter-terrorist ops?

      You're right, we should be like France before WWII and just invest all our military spending on a single type of defense because it made sense when we started building it. How stupid of us to diversify!

      (When France started building the Maginot Line, it was actually impossible for tanks at that time to cross through the forested regions they decided to leave undefended; by the time war actually broke out, tanks could do it with ease and the entire installation was useless.)

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