SR-72?

[sferrin]

For discriminating decoys, I can think of several things.  The most basic is to look for different thermal signatures.  A second approach, if you've got the equipment, is to hit evrything with a laser impulse sufficient to cause a reaction in decoys but not in heavier warheads.  Of course, the optimum approach, one the ABL is being developed at, is boost phase intercept, before the warhead bus has even separated from the missile.  Obviously, there are other ways of doing this, such as UAVs over the launch area with AMRAAMs or such to catch ballistic missiles early in flight when they're comparatively slow.

A couple others are:

"The Firepond Laser Radar.
One of the most sign ficant experiments in
space-based strategic defense related systems was
the Firepond system launched early in 1991 on a
Delta rocket. In the experiment, a laser was
aimed a t various vehicles deployed by the payload
of the rocket and it was demonstrated that the
laser could discriminate between simulated
warheads and simulated decoys. The important
point about this systems test  is that  t provides
strong evidence that the discrimination problem
can eventually be solved using laser radars.
Figure 10 shows the arrangement of the Firepond
laser radar experiment.  I do not want t o imply that this is a
complete list of successful systems tests that
can.be attributed to work done under the
Strategic Defense Initiative . What is important
is that they are systems tests which go beyond
simple concepts and the development of
components. It is , of course, systems tests of
this kind that will eventually give people the
necessary confidence that strategic defense can
have important military values. The success of
these experiments and many others like them have
made it possible to evolve an ABM system
architecture such as the one shown i n Figure 11.
This i s a much less complex system than Safeguard
was twenty years ago" 

(that was 16 years ago)

Another concept being kicked around back then was using neutral particle beams.  Zap them all with subatomic particles and compare how they react.

[sferrin]

If any of you experts can actually explain how these new decoy detection systems work, that would be very helpful. Or how the mass of a opaque decoy in free fall in a vacuum can be determined remotely, since it would follow a ballistic trajectory regardless.

Certainly not an expert but I can think of several.  If you can image the RVs across a broad spectrum there's no way a decoy is going to look the same as the RV even if only because it effects background radiation differently.  Also a lightweight decoy is going to cool in space at a different rate than an RV.  And an RV isn't necessarily going to cool uniformly and depending on the resolution of the imager it could be damn hard to get the IR signiture of the decoy to look EXACTLY like an RV.  Consider that even NASA can image tiles on the shuttle from Earth and the liklihood that military stuff is better.  Now you could try floating the RV INSIDE another decoy and insulate it so heat doesn't leak out but then you still have to make sure that doesn't effect how radiation bleeds through.  If someone sets off a nuke up high and it sets up a field of charged particles that the RVs and decoys have to move through they'd likely effect the particles differently. 







 Also I'm interested to know more about this Polaris Chevaline Update as one failed program doesn't necessarily invalidate an entire concept but it might explain a lot.

Back to the Mach 6 plane and why, if it is so easy to shoot down ballistic missiles (traveling at Mach 10+?), is it so hard to shoot down a hot plane (no quotes please)? Personally I think they'd both be pretty tricky but Chinese allegedly shot down a D-21 Mach 3 drone more than 30 years ago. Not meaning to be disparaging or inflammatory it would be quite shocking for a Mach 6 plane program to exist given the US military's declared funding situation and the existence of a now cancelled X-43 program. But please convince me otherwise, I crave enlightenment, It would be great, honestly.

Cheers, Woody
[/quote]

[sferrin]

Back to the Mach 6 plane and why, if it is so easy to shoot down ballistic missiles (traveling at Mach 10+?), is it so hard to shoot down a hot plane (no quotes please)?

Planes can manuever a lot more than a dumb RV.  Even a manuevering RV is just doing canned manuevers, it's not reacting to the SAM.

Personally I think they'd both be pretty tricky but Chinese allegedly shot down a D-21 Mach 3 drone more than 30 years ago.

Not trying to be a smarta$$ but the USAF allegedly disected aliens at Area 51.  The USAF lost a number of D-21s over China and the general concensus was "hmm. . .".  No hard facts of anything other than the one that flew OVER China and crashed in the USSR.

Not meaning to be disparaging or inflammatory it would be quite shocking for a Mach 6 plane program to exist given the US military's declared funding situation and the existence of a now cancelled X-43 program. But please convince me otherwise, I crave enlightenment, It would be great, honestly.

The "White" world rarely reflects the "Black" world.  For example one of the biggest reasons for the stink about the Hubble's flawed mirror was due to the fact that the USAF had essentially been flying Hubbles for years- pointed at Earth.  Also read of instances where things that had been solved years prior on military projects were kicking NASA's butt trying to figure out. (Not the mirror specifically but in general). The X-43B & C were cancelled because the technology had some key limitations, namely it's reliance on hydrogen as a fuel (not to mention the miniscule NASA budget).  You'll note that the USAF already has a couple hydrocarbon-fueled designs in the works to test, the X-51 and HyFly.  (Although there seems to be a bit of confusion as to EXACTLY what HyFly is using.  I've heard a scramjet, a dual-combustion ramjet, and having it operate in BOTH modes depending on the speed at the time.)

[Simon666]

Planes can manuever a lot more than a dumb RV.  Even a manuevering RV is just doing canned manuevers, it's not reacting to the SAM.

At that speed, turn radius would be enormous and it also bleeds energy. Missiles can still take a lot more g's than humans and probably a hell of a lot more than planes designed for hypersonic speeds.

A couple others are:

"The Firepond Laser Radar.

As discriminating technology advances, so does disguising technology. You could think of counteracting that with having the warheads bounce inside inflatable balloons and having decoy masses bounce as well in inflatable balloons. Your doppler readings will show varying speeds of the balloons but will probably have trouble discriminating. Regarding spectral emissions, you could just put different IR and light emitters inside warhead and decoy balloons or cool them differently. Sure you'd find differences, but how to know which is which?

An interesting read is the executive summary from the April 2000 UCS/MIT report "Countermeasures: A Technical Evaluation of the Operational Effectiveness of the Planned US National Missile Defense System"

Overall Findings and Recommendations
(1)
Any country capable of deploying a long-range missile would also be able to deploy countermeasures that would defeat the planned NMD system.
Biological or chemical weapons can be divided into many small warheads called "submunitions." Such submunitions, released shortly after boost phase, would overwhelm the planned defense. Moreover, there are no significant technical barriers to their deployment or use. Because submunitions allow for more effective dispersal of biological and chemical agents, an attacker would have a strong incentive to use them even in the absence of missile defenses. The United States should recognize that any long-range missile attack with biological or chemical agents would almost certainly be delivered by submunitions, and that the NMD system could not defend against such an attack.

An attacker using nuclear weapons could also defeat the planned system. An attacker could overwhelm the system by using "anti-simulation balloon decoys," that is, by deploying its nuclear weapons inside balloons and releasing numerous empty balloons along with them. Or an attacker could cover its nuclear warheads with cooled shrouds, which would prevent the kill vehicles from detecting and therefore from homing on the warhead.
http://www.ucsusa.org/global_security/missile_defense/countermeasures.html

[elmayerle]

If you increase the mass of the decoys to each match the mass of a warhead, you've managed to either reduce the number of warheads you can launch - leading to many more being needed for the same number of warheads deliverd -  or drastically increased the size of your boost vehicle - making it easier to detect and much harder to use a mobile launcher.  This whole arguement, though, can be completely terminated by the use of BPI, Boost Phase Intercept; you simply get the entire missile before the warhead bus even separates.  This is one of the main drivers behind the ABL effort.

[sferrin]

Planes can manuever a lot more than a dumb RV.  Even a manuevering RV is just doing canned manuevers, it's not reacting to the SAM.

At that speed, turn radius would be enormous and it also bleeds energy. Missiles can still take a lot more g's than humans and probably a hell of a lot more than planes designed for hypersonic speeds.

And that's the common mistake many make.  Lots of G's and sharp turns are not necessarily synonomous.  If applied to aircraft you'd see the problem.  Which is going to turn sharper, an F-104 at Mach 2 or an F-16 at Mach .8?  Now take the wings off the F-104.  How sharp is it going to turn now?  Now take it to 100,000 feet where there's hardly any air.  How sharp will it turn now?  See the problem?  Missiles work to get around it by going really fast and using body lift (and they aren't pulling those 40 or 50 Gs at anywhere NEAR 100,000ft BTW).  Nike Hercules and the SA-5 are the two best examples of SAMs designed with fast, high altitude aircraft in mind and they have/had huge wings for exactly that reason.  By the time Patriot, SA-10, and SA-12 came on the scene Mach 3 aircraft were an oddity rather than the perceived future of things.  No need for big wings when your targets are going to be at less than 50,000 ft (and usually much less than that) so why lug the weight around?  In a nut shell the current generation of SAMs aren't going to be making sharp turns at high altitudes.  Now if they gave the SAM wings and a scramjet and ditched the rocket engine that's another story.

[Woody]

Hi guys, other searching I've done would seam to cooberate that Polaris Chevaline was is so far the only ICBM to deploy decoys, though the reasons I've found are less than satisfactory.

http://www.fas.org/nuke/guide/uk/slbm/chevaline.html

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

It never occurred to me that an attacker would wait until the re-entry phase to launch their decoys. I assumed that they be released as soon as the vehicle was clear of the atmosphere - agreed they be potentially observable for longer but more dispersed preventing them all being destroyed in one shot. At greater ranges they'd be more difficult to identify accurately. A defender hoping to destroy MIRV buses before they deployed would then have a real problem.

I'm still concerned about the significances you all attach to mass - it doesn't affect how a object moves in a vacuum in ballistic flight and there's not much else you can tell from normal radar. And cryogenic gas could cool decoy and warhead alike as soon as they were out of the attmosphere I would have thought. Re. the Fire pond If you have a laser system so infallible and powerful that can probe every object at massive range wouldn't that be a basis for a killer laser instead of an ABM?, I don't hear anyone seriously suggesting this. Please tell me more.

Obviously it's better to try and kill an ICBM in its launch phase and I quite like the Boeing ABL-1 but to have enough of them permanently on station a few hundred kilometers from an enemy is got to be expensive and to have laser weapons aimed at the entire country is a trifle provocative. Also an attacker could launch a bunch of scud style cheap rockets at the same time to further make life difficult for defenders. If your in a position to hit your enemies ICBMs at launch with missiles haven't you already won?

If nuclear tipped ABMs are used (this is apparently what the Russians have) wouldn't these blind the defensive systems? An attacker could stagger their assaults to take advantage of this. Further to this they could detonate their own nuclear explosions at various points along the flight path to blind the defenders sensors.

But the biggest problem with whole game is that it's never been tested for real and a lot of the stuff is only experimental. The best demonstration so far was against primitive scuds during the first Gulf war and that didn't go so well. I hope we never find out.

Cheers, Woody

[elmayerle]

The reasoning on the mass is that a push from a laser will impart an impulse to what it hits, if the decoy doesn't have the same mass as the warhead+re-entry vehicle, it won't respond the same to that impulse.  With accurate tracking, that's sufficient to discriminate.  That wsa the theory demonstrated by Fire Pond.

Of course, if you mass produce small KKVs (Kinetic Kill Vehicles), you can take a "shotgun" approach to taking out incoming RVs and decoys because you can get the unit cost down to where it's affordable.  Besides the ABL, there've been proposals for some years now for armed UAVs to go near known or suspected missile launch sites and catch them early in boost.

It's really not practical to have warhead and decoy separation until well into the post-boost phase, ensuring that the delivery bus is on the proper trajectory.

[flateric]

BTW, fresh news on C-400 from Bill Sweetman's Defense Technology Magazine
http://www.nxtbook.com/nxtbooks/aw/dti0607/index.php?startpage=36
"...it may be even possible to hit hypersonic targets flying at 3000 meters per sec., at endoatmospheric altitudes to 150 km" - Col.-Gen. Yuri Soloviev

[Woody]

Hi Sferrin,

Which is going to turn sharper, an F-104 at Mach 2 or an F-16 at Mach .8?  Now take the wings off the F-104.  How sharp is it going to turn now?  Now take it to 100,000 feet where there's hardly any air.  How sharp will it turn now?  See the problem?  Missiles work to get around it by going really fast and using body lift (and they aren't pulling those 40 or 50 Gs at anywhere NEAR 100,000ft BTW).  Nike Hercules and the SA-5 are the two best examples of SAMs designed with fast, high altitude aircraft in mind and they have/had huge wings for exactly that reason.  By the time Patriot, SA-10, and SA-12 came on the scene Mach 3 aircraft were an oddity rather than the perceived future of things.

I think Greg's beaten me to it but the unlike Patriot, S-300P (SA-10) and S-300V (SA-12) etc. feature gas dynamic control and are not limited to aerodynamic maneouvering so potentially could still pull those high G turns. And what relevance does a Mach 0.8 F-16 have to our hypersonic mystery plane? I know it's hard to shoot down a high flying fast object but the old Gary Powers experience would still appear to hold true, that it's cheaper to improve missile systems than planes to out fly them. This new S-400 just makes it that much harder.

Cheers, Woody

[sferrin]

BTW, fresh news on C-400 from Bill Sweetman's Defense Technology Magazine
http://www.nxtbook.com/nxtbooks/aw/dti0607/index.php?startpage=36
"...it may be even possible to hit hypersonic targets flying at 3000 meters per sec., at endoatmospheric altitudes to 150 km" - Col.-Gen. Yuri Soloviev

Yeah THAAD and SM-3 are already doing that.  BALLISTIC targets or RVs.  Neither of which can turn like something with wings.

[sferrin]

Hi Sferrin,

Which is going to turn sharper, an F-104 at Mach 2 or an F-16 at Mach .8?  Now take the wings off the F-104.  How sharp is it going to turn now?  Now take it to 100,000 feet where there's hardly any air.  How sharp will it turn now?  See the problem?  Missiles work to get around it by going really fast and using body lift (and they aren't pulling those 40 or 50 Gs at anywhere NEAR 100,000ft BTW).  Nike Hercules and the SA-5 are the two best examples of SAMs designed with fast, high altitude aircraft in mind and they have/had huge wings for exactly that reason.  By the time Patriot, SA-10, and SA-12 came on the scene Mach 3 aircraft were an oddity rather than the perceived future of things.

I think Greg's beaten me to it but the unlike Patriot, S-300P (SA-10) and S-300V (SA-12) etc. feature gas dynamic control and are not limited to aerodynamic maneouvering so potentially could still pull those high G turns.

Nope, the only ones with gas dynamic control are the small missiles in the S-300PMU/S-400 system.  And gas dynamic systems help you point the airframe faster but you're still relying on body lift to actually change direction.  And again, high G and sharp turn are not necessarily synonamous.

And what relevance does a Mach 0.8 F-16 have to our hypersonic mystery plane?

Sounds like you should go back and read it again and let it sink in.

I know it's hard to shoot down a high flying fast object but the old Gary Powers experience would still appear to hold true, that it's cheaper to improve missile systems than planes to out fly them. This new S-400 just makes it that much harder.

Cheers, Woody

The S-400s high altitude capacity is against MISSILES.  Also this mysterious large missile someone mentioned is like THAAD and SM-3 (in theory) in that it's pretty much worthless against aircraft.

[flateric]

So then SR-72 flight will look like a zigzag...you are talking of high Gs here, maneuvers...it's not gonna be a fighter, it's a recce plane - and what, if one of 48N96 will miss this doesn't mean other will do the same. Ideology behind A-12/SR-71 is push the envelope beyond reach of Soviet SAMs, not making daredevil moves among SAMs fireblasts.

[Sundog]

I think people here are confusing what kind of turns a hypersonic plane has to make to force a missile to miss it. It isn't like a fighter "jinking."  Just a slight turn of one degree changes the missiles intercept course by miles. As such, they wouldn't need to perform "high G" maneuvers to avoid missiles. Not to mention, I'm sure it would possess some very sophisticated ECM/IRCM systems on board.

[sferrin]

I think people here are confusing what kind of turns a hypersonic plane has to make to force a missile to miss it. It isn't like a fighter "jinking."  Just a slight turn of one degree changes the missiles intercept course by miles. As such, they wouldn't need to perform "high G" maneuvers to avoid missiles. Not to mention, I'm sure it would possess some very sophisticated ECM/IRCM systems on board.

That's exactly the point.  At a mile a second you don't have to make much of a turn to put you way out of the kill envelope.  Something like a scramjet powered Bomarc or D-21 (not those specific airframes but you get my meaning) might have a chance but the current and near-future generation of SAMs can forget it unless the pilots are dumb enough to try a direct over flight of the site.