Scramjet Passes Milestone

[spacelifejunkie]

<br />http://www.space-travel.com/reports/Successful_Design_Review_And_Engine_Test_Bring_Boeing_X_51A_Closer_To_Flight_999.html<br /><br />I hated to see the X-43 program get shut down by NASA but it's good to see the research continue elsewhere. <br /><br /><br />SLJ<br /><br />

 

[wdobner]

Very cool, there may be hope for an X-30 spaceplane-like vehicle yet. <img src="/images/icons/smile.gif" /> <br /><br />With any luck we'll get the mix right this time.

 

[docm]

I posted on this in SB&T. Pictures pending with one being the engine under test. <div class="Discussion_UserSignature"> </div>

 

[holmec]

DITTO!! <div class="Discussion_UserSignature"> <p> </p><p><font color="#0000ff"><em>"SCE to AUX" - John Aaron, curiosity pays off</em></font></p> </div>

 

[christine16]

why to name it Scramjet?

 

[lampblack]

Scramjets. <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[drwayne]

Christine,<br /><br />That was an ideal question to google on.<br /><br />I don't point that out to complain about you asking, merely to encourage you to engage your curiosity to do what I call free form googling.<br /><br />A question pops up because of something you see or hear, you google, you find out some things, but it raises more questions, so you google some more - and in the end, you will be surprised how much you can learn.<br /><br />A notebook of information and links is easy to start, a log of your explorations - it can be a valuable history for you.<br /><br />(I use google as a generic term here, insert your favorite search engine)<br /><br />Its a miraculous time - use that power!<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[christine16]

thanks drwayne

 

[rocketman5000]

exciting stuff!!

 

[spacelifejunkie]

I know that timelines at early stages of development like this are fuzzy at best but what are the first applications of this technology going to be? And when? If funding continues, I'm guessing the first applications will be scramjet cruise missles with 10,000+ mile ranges able to hit anywhere in the world in under an hour. The war on terror demands this kind of quick strike capability. How long before we see hypersonic military or passenger planes? Space planes? Using scramjets for orbital access? Can it be done in under 10 years?<br /><br /><br />SLJ

 

[qso1]

Scramjet is short for supersonic combustion ramjet. A ramjet will not ignite until sufficient air pressure is rammed into the intake. On ramjets this occurs around 300-400 mph. As the name implies, a supersonic combustion ramjet must go supersonic before ignition can occur. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[docm]

I see 2 main uses;<br /><br />1. hypersonic cruise missiles<br /><br />2. hypersonic rapid-deployment UAV recon = unpredictable, unlike satellites. <br /><br />probably submarine launched versions too.<br /><br />Unless we're seeing a developmental stage 10-15 years behind what's going on in black projects (more likely than not) I don't see manned or orbital applications anytime soon. <div class="Discussion_UserSignature"> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>Scramjet is short for supersonic combustion ramjet. A ramjet will not ignite until sufficient air pressure is rammed into the intake. On ramjets this occurs around 300-400 mph. As the name implies, a supersonic combustion ramjet must go supersonic before ignition can occur. <p><hr /></p></p></blockquote><br /><br />Generally a ramjet is operational at the speed greater than the speed of sound (Mach 1), and scramjet starts around Mach 5 but a better performance is usually around Mach 6 or higher. <br /><br />If you ride the regular commercial airplanes, you'd notice its engines have "fan blades". The fan blades are used to "compress" air to a higher pressure so it can produce thrust (much like when you blow air into a baloon and then let it go). Also, if you ride in a car going about 50 mph and you roll down the window & stick your hand out of window, you'll feel a "ram" of air pushing against your hand. Well, that "ram-air" is much much stronger at 750 mph (equivalent speed of sound), so if you can design an inlet to capture & "shape" how the air flow goes into your engine without lossing much of its high pressure, then you could use the "natural" air pressure to power your engine instead of using fan blades. That's the principal of how a ramjet works. <br /><br />A ramjet will slow the captured air from supersonic to subsonic (below the speed of sound) by the time it reaches to its combustor, injet fuel, burn, and push out to the back with a nozzle. This is where one gets thrust as the exit gases pushes against the funnel shape nozzle forward. But at some air speed, mainly above Mach 5~6, there's too much pressure losses by slowing the incoming air down to below the speed of sound, making a ramjet less efficient. So the approach is to let the incoming air to stay supersonic as it enters the combustor, inject fuel, burn and pushes the gases back out of its nozzle. They called this "<font color="yellow">S</font> <div class="Discussion_UserSignature"> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>I see 2 main uses; <br /><br />1. hypersonic cruise missiles <br /><br />2. hypersonic rapid-deployment UAV recon = unpredictable, unlike satellites. <br /><br />probably submarine launched versions too. <p><hr /></p></p></blockquote><br /><br />OK, this is an amusing topic <img src="/images/icons/smile.gif" /><br /><br />1. Why does one needs a hypersonic cruise missle? <br />What's wrong with the current cruise missle now? It's stealthy flying at low altitude and not detectable by radar. It flies slow enough so the guidance & navigational system can follow the terrain, recognize the building, or the specific window on the 2nd floor, to enter. Who cares when you fire off the missile?<br /><br />Now a supersonic missile is going to come in like a fire-ball from the sky. It's nose will glow red hot from the aerodynamic heating and it ain't Rudolph the red nose raindeer. People can see it coming from 20~30 miles away (on a sunny day). What is the advantage of these "fireballs from the sky"?<br /><br />2. An UAV main purpose is to loiter (fly around slowly) and circle above a particular area to gather info (intelligence). So the slow speed is actually an advantage and hypersonic speed would be a disadvantage.<br /><br />3. Submarine launch? <br />You'll need a solid motor booster, taking away the advantages of a scramjet again. <div class="Discussion_UserSignature"> </div>

 

[no_way]

also sometimes called "scamjets". applicability to orbital launchers: little to none.<br />interesting tech none the less, and has its own ( mostly military ) niche applications

 

[spacelifejunkie]

"1. Why does one needs a hypersonic cruise missle?"<br /><br />Propforce, I realize that Popular Mechanics is not the best source for information but there is a quote in a recent article that is interesting.<br /><br />"The goal, according to the U.S. Strategic Command's deputy commander Lt. Gen. C. Robert Kehler, is "to strike virtually anywhere on the face of the Earth within 60 minutes." <br /><br />Their argument is simply time and flexibility. Submarines aren't always in the right place. If you see or hear the X-51 coming from 20 miles away, you have less than 30 seconds to get the hell out there! The kinetic energy alone is enough, no warhead needed. <br /><br />I agree with you about the UAV's, though. They will become more and more capable as time goes on. Robotics and AI will transform warfare in the next 25 years.<br /><br />http://www.popularmechanics.com/technology/military_law/4203874.html?page=1<br /><br /><br />SLJ

 

[docm]

<font color="yellow">1. Why does one needs a hypersonic cruise missle? What's wrong with the current cruise missle now?<br /> /><br />People can see it coming from 20~30 miles away (on a sunny day)</font><br /><br />As SLJ said the reason is rapid attack anywhere within 30 minutes. In todays world this is a <i>necessity</i>.<br /><br />Ex: before 9/11 Bin Laden was located in an Afghan camp and a submarine launched cruise missile strike ordered, but it took too long to get it there and he was missed. Bureaucracy was part of the problem, but the slow speed of the Tomahawk (550 mph - 880 km/h) was just as much at fault.<br /><br />If we had a hypersonic cruise missile in the inventory back then they'd still be picking up OBL's pieces.<br /><br /><font color="yellow">2. An UAV main purpose is to loiter (fly around slowly) and circle above a particular area to gather info (intelligence). </font><br /><br />Inteligence can be garnered by loitering, but thats useless in areas where there are heavy air defenses. Not a few Predators have been lost this way and not necessarily to advanced systems.<br /><br />Satellites are not so vulnerable, but have the disadvantage of being predictable; when the birds go over it's easy enough to mask many activities, especially in tactical situations. Remember the Libyan desert scene in Patriot Games where they disguise the camp before a satellite flyover? Same idea.<br /><br />Hypersonic recon UAV's would return the immediacy of the SR-71 but much enhanced; it would have the element of surprise plus higher altitude and blistering speed making it virtually invulnerable to conventional SAM's.<br /><br /><font color="yellow">3. Submarine launch? You'll need a solid motor booster, taking away the advantages of a scramjet again. </font><br /><br />So does the Tomahawk SLCM but that doesn't eliminate their utility, does it? The difference is that a scramjet would need to go faster/higher to "light". <div class="Discussion_UserSignature"> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>"1. Why does one needs a hypersonic cruise missle?" <br /><br />Propforce, I realize that Popular Mechanics is not the best source for information but there is a quote in a recent article that is interesting. <br /><br />"The goal, according to the U.S. Strategic Command's deputy commander Lt. Gen. C. Robert Kehler, is "to strike virtually anywhere on the face of the Earth within 60 minutes." <br /><br />Their argument is simply time and flexibility. Submarines aren't always in the right place. If you see or hear the X-51 coming from 20 miles away, you have less than 30 seconds to get the hell out there! The kinetic energy alone is enough, no warhead needed. <p><hr /></p></p></blockquote><br /><br />I realize these arguments are philosophical at best, and this segment of Air Force certainly put out one argument for hypersonic cruise missile. <img src="/images/icons/wink.gif" /><br /><br />But the same "global reach, global strike" capability that the Air Force needs can also be argued, that it can be met by other means. For example, the current ground launch ballistic missile re-entry profile can reach anywhere on face of earth far less than 60 minute <img src="/images/icons/cool.gif" />. <br /><br />Now let's see how much time we'll need to launch this hypersonic cruise missile...<br /><br />1) Load the missile under the wing of aircraft, e.g., the B-52 <br />(I doubt this thing will be small enough to go under the belly of X-35, the JSF).<br /><br />2) Hopefully we'll have a good weather to launch the B-52 <img src="/images/icons/laugh.gif" /><br /><br />3). Taxi the B-52 to runway and launch<br /><br />4) Cruise to destination, now that could be 20 miles or 2,000 miles. <br />In the case of the hunt for Osama Bin Ladin in Afghanistgan, the nearest U.S. base for B-52 is in Diego Garcia in the middle of Indian ocean which is at least 1,000 miles away. This alone would take 2~3 hours just to reach the edge of India/ Pakistan/ Afganistan. <div class="Discussion_UserSignature"> </div>

 

[propforce]

<blockquote><font class="small">In reply to:</font><hr /><p>As SLJ said the reason is rapid attack anywhere within 30 minutes. In todays world this is a necessity. <br /><br />If we had a hypersonic cruise missile in the inventory back then they'd still be picking up OBL's pieces.<p><hr /></p></p></blockquote><br /><br />See post above.<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>Inteligence can be garnered by loitering, but thats useless in areas where there are heavy air defenses. Not a few Predators have been lost this way and not necessarily to advanced systems. <br /><br />Hypersonic recon UAV's would return the immediacy of the SR-71 but much enhanced; it would have the element of surprise plus higher altitude and blistering speed making it virtually invulnerable to conventional SAM's. <p><hr /></p></p></blockquote><br /><br />Hypersonic is not very useful if your camera can not focus when you go by so fast ! <img src="/images/icons/wink.gif" />. OK, just kidding, but think about this... how big of a radius do you have to turn the UAV around for a 2nd look when you're going at Mach 6??? !!! I think the end result is that you can a fraction of a second for the area of interests and spend the next 30 minutes to an hour to turn the vehicle around, making a "U-turn" for another 1-second look. Not a very practical "recon" approach <img src="/images/icons/smile.gif" /><br /><br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>So does the Tomahawk SLCM but that doesn't eliminate their utility, does it? The difference is that a scramjet would need to go faster/higher to "light".<p><hr /></p></p></blockquote><br /><br />True, but since the existing submarine launch "box" is only so big, and scramjet needs to go Mach 5 before operational (as oppose the current turbojet can start right after it surfaces from the water; edit: after only a short boost from SRM), this means a bigger & bigger portion of launch box goes to the solid motor booster, making the scramjet smaller <div class="Discussion_UserSignature"> </div>

 

[docm]

Your launch scenario is making assumptions not in evidence. <br /><br />Many planes other than the BUFF can carry the ALCM, are much faster and can be in the air double-quick. In fact the F-35 can carry the JASSM and Storm Shadow cruise missiles, so the new bird is likely to be made to fit.<br /><br />As for cameras; even at MACH 6 the angular motion will be small because of the altitude. Add that todays cameras can image faster than a flea can fart and I see no problem. <br /><br />Wide field sensors let the SR-71 do it in 1 pass, so why not this bird?<br /><br />Standard torpedo tubes are 21" wide with bow tubes being 252 inches (21 feet) and stern tubes 276 inches (23 feet). That's big enough for a pretty long bird.<br /><br />That said there is another another obvious option; the subs ballistic missile tubes. Designed for the 3 stage Trident (83 x 528 inches) they are certainly big enough and have been equipped with Tomahawks on several boats.<br /><br />Why not use an ICBM? It's been thought of in the form of the "Conventional Trident Modification" program. I think it's a risky idea.<br /><br />Why? Tridents have a distinctive flight profile and IR signature detectable by satellite. For arguments sake say we launch a Trident on a tactical mission; how do the Russians or Chinese know our intentions or the target in boost phase? They can't, which is why they would have to go on alert and who knows what happens if Comrade Lt. Boris sees it on his display while drinking his lunch? <br /><br />Russian units have been given launch-on-warning authority before, and given the way Putin's talking....<br /><br />That's why this option has been criticized by people in both parties and will probably be rejected by Congress.<br /><br />On the other hand a boosted scramjet cruise missile would heel over and obviously not be an ICBM, but reach the target nearly as fast. <div class="Discussion_UserSignature"> </div>

 

[spacelifejunkie]

"Sounds tedius and time consuming to me, as oppose to push a button with a ground launch RV with multiple warheads for re-entry (MRV), each one with "terminal kinetic energy accelerator". When your cargo needs to be absolutely positively have to be there in 30 minutes or less, involves far less operational complexity, and a much shorter time to target which leads to a faster mission scenario, IMO"<br /><br />The situation you describe above is certainly the ideal. The Trident missile system on our submarines might be outfitted precisely in this way you describe. However, convincing China and Russia that those Tridents are conventional and not nuclear would be a tough sell and would be asking a lot of them to comply. Tactically, though they would have superior range and impact force. <br /><br />The X-51 missle is slated to be about 14 feet long. Would it have to go under a B-52 or B-2? What about the JSF? Or F-22? There are some 2000 lb bunker busters that are that are roughly 14 feet in length which are dropped by F-15's today. I'm not an Air Force General or a member of the Joint Chiefs of Staff so, no I'm not an expert. I may be wrong. But if they can have a better chance to kill OBL and everyone like him with this technology, then let's do it. Besides, it helps pave the way toward the next step, hypersonic planes, space planes and orbital access.<br /><br /><br />SLJ<br /><br />

 

[spacelifejunkie]

Thanks for the detail, docm. You beat me to the reply by a few minutes! <br /><br /><br />SLJ<br />

 

[docm]

Expanding on my comments about subs launching Tomahawks vertically;<br /><br />SSGN: SS = "submersible ship"; G = "guided missile"; N = "nuclear"<br /><br />The oldest of the Trident subs (Ohio Class) have been modded into pure SSGN boats because under the START I treaty they represent "excess capacity." <br /><br />Boats: USS Florida (SSGN-728), USS Georgia (SSGN-729), USS Michigan (SSGN-727) and USS Ohio (SSGN-726). <br /> <br />Each boat carries 154 Tomahawks; 7 in each of its 22 vertical launch tubes.<br /><br />My guess is that these boats will get a compliment of whatever hypersonic cruise missiles are brought into the inventory. <div class="Discussion_UserSignature"> </div>

 

[josh_simonson]

These would be ground or ship launched, not air launched. The whole purpose of the hypersonic missile is that you do not need it to be staged on an aircraft in the vicinity of the target for rapid strike capability.<br /><br />They hope that the cost of a scramjet missile will cost somewhere between a conventional cruise missile and all-rocket powered missile of the same capability. Tridents are EXPENSIVE at $30m+ per shot.

 

[propforce]

<font color="yellow">Many planes other than the BUFF can carry the ALCM, are much faster and can be in the air double-quick. In fact the F-35 can carry the JASSM and Storm Shadow cruise missiles, so the new bird is likely to be made to fit. </font><br /><br />Have you size this hypersonic cruise missle? SLI quote the X-51 is approx 14 feet, I don't know if that includes the SRM to boost it to Mach 6, but irregardlessly; the X-51 is very small, flight experiment, and have virtually no payload carrying capacity whatsoever. An operational version would definitely be longer, bigger, and more gnarly to fit in the internal launch tube of an X-35.<br /><br />PS- forget about the traditional pylon attachment underwing configuration like the current AAM or ALCM. The drag alone will kill ya.<br /><br /><font color="yellow">As for cameras; even at MACH 6 the angular motion will be small because of the altitude. Add that todays cameras can image faster than a flea can fart and I see no problem. </font><br /><br />It's not the angular motion of camera that is the issue. The heated boundary layer that will cause distortion to your camera lense. Also, the limited time available for ISR at that speed, easily detected by radar, etc., makes it non-ideal for recon at hypersonic speed.<br /><br /><font color="yellow">Wide field sensors let the SR-71 do it in 1 pass, so why not this bird? </font><br /><br />You are comparing minor league (SR-71) to the majors (hypersonic speed) as far as the sensor technologies <img src="/images/icons/smile.gif" />. Whole different set of issues at work here.<br /><br /><font color="yellow">Standard torpedo tubes are 21" wide with bow tubes being 252 inches (21 feet) and stern tubes 276 inches (23 feet). That's big enough for a pretty long bird. </font><br /><br />You think? I think some sizing exercise is in order to realize the magnititude of problem <img src="/images/icons/wink.gif" /><br /><br /><font color="yellow"> Tride</font> <div class="Discussion_UserSignature"> </div>