Articles: "Nuclear Warfare 101".

[SilverHawk]

Also, B-2 says hi.



Also, the Falcon E's IFTS can be used as an IRST. Whoops, opening your mouth before checking your facts, you think you'd learn considered how much I've been burned in this very thread for failing to do the same thing!

http://www.defenseindustrydaily.com/the ... eet-04538/

Also, I forgot to include the Super Hornet, it's getting IRST packages as well. Though it has to settle for it's IRST being integrated into a reduced capacity fuel tank.

[SilverHawk]

http://www.es.northropgrumman.com/solut ... index.html

The IFTS provides the Block 60 F-16 with 24-hour precision strike and navigation capabilities. It allows the Block 60 F-16 to detect and identify both ground and airborne targets, even at night or in adverse weather, for highly accurate weapons delivery.

Hmmm. It can detect, track and identify airborne targets and the use that data to fire a weapon at it. If I didn't know any better, that's exactly what an IRST does.

My mind...is blown.

[Sea Skimmer]

Also, the Falcon E's IFTS can be used as an IRST. Whoops, opening your mouth before checking your facts, you think you'd learn considered how much I've been burned in this very thread for failing to do the same thing!

An IRST automatically scans the sky and automatically tracks targets. The targeting system on the F-16 Block 60 is a internal carry version of the LITENING targeting pod which is aimed by the pilot or auto points at grid coordinates. Any FLIR system could be used to look at a plane sure, but that doesn't make it an IRST. Any air to air capability is incidental. You could use the FLIR on a helicopter to track a plane too but that doesn't make it an IRST that can do hemispheric searches. You might notice the F-35 has an internal LITENING pod too, and six actual IRST sensors even though coverage is redundant.

All the stuff I mentioned is public knowledge. So no, I didn't go to
a stealth school, though if it was a real thing, it'd be pretty cool to go to.

I love how you just try to deny that you claimed to know secrets about the F-117 and then ran and hid from the comment when we called you on it. Its funny. And no, we aren't going to let that drop like you'd like us too just by ignoring it. We've ran into way too many bullshitters already.

[SilverHawk]

What "secrets" did I claim to know, exactly? I don't recall any claims to knowing classified information. But you are more then welcome to show me.

An IRST automatically scans the sky and automatically tracks targets. The targeting system on the F-16 Block 60 is a internal carry version of the LITENING targeting pod which is aimed by the pilot or auto points at grid coordinates. Any FLIR system could be used to look at a plane sure, but that doesn't make it an IRST. Any air to air capability is incidental. You could use the FLIR on a helicopter to track a plane too but that doesn't make it an IRST that can do hemispheric searches. You might notice the F-35 has an internal LITENING pod too, and six actual IRST sensors even though coverage is redundant.

So it operates like the old 1-D IRSTs on the Voodoo and Dagger (Or the AN/ALR-23 on the early Tomcats), it's still an IRST. (Being able to locate, track, lock and fire upon airborne targets.)

Unless you're calling Nothrop Grumman, liers.

[Shroom Man 777]

http://www.es.northropgrumman.com/solut ... index.html

The IFTS provides the Block 60 F-16 with 24-hour precision strike and navigation capabilities. It allows the Block 60 F-16 to detect and identify both ground and airborne targets, even at night or in adverse weather, for highly accurate weapons delivery.

Hmmm. It can detect, track and identify airborne targets and the use that data to fire a weapon at it. If I didn't know any better, that's exactly what an IRST does.

My mind...is blown.

An IRST automatically scans the sky and automatically tracks targets. The targeting system on the F-16 Block 60 is a internal carry version of the LITENING targeting pod which is aimed by the pilot or auto points at grid coordinates. Any FLIR system could be used to look at a plane sure, but that doesn't make it an IRST. Any air to air capability is incidental. You could use the FLIR on a helicopter to track a plane too but that doesn't make it an IRST that can do hemispheric searches. You might notice the F-35 has an internal LITENING pod too, and six actual IRST sensors even though coverage is redundant.

(Being able to locate, track, lock and fire upon airborne targets.)

Unless you're calling Nothrop Grumman, liers.

Detect and identify =/= automatically scans the sky and automatically tracks targets?

The Northrop-Grumman description didn't describe what Sea Skimmer was describing. They might be talking about different things. The Northrop-Grumman description just said "detect and identify", but didn't really specify "automatic scanning/tracking" which is what Skimmer was talking about. I think Northrop-Grumman and Sea Skimmer are talking about different things. The Northrop-Grumman quote of yours wasn't too specific in describing it, anyway.

[Stuart]

It says FLIR, not IRST. Though I have no idea what's the difference between the two. What IS the difference between FLIR and IRST?

There are three basic categories of infra-red system. They are:

FLIR. This stands for Forward Looking Infra Red. Essentially this is just a camera that points forward and produces a picture in the cockpit that shows the field of view as an expression of heat differentials in that view. These have been in use for a surprisingly long time. German nightfighters in WW2 had a very simple, elementary system called "Spanner" that worked much along these lines. It was used to detect the hot exhausts on night-flying bombers. Some versions of Spanner used an infra-red searchlight to illuminate the target. Neither worked very well. At the same time, allied ASW aircraft were experimenting with very elementary forward-looking infra-red to detect submarines. In that case, the introduction of the snort caused serious problems in detecting subs. Radar was reduced to minimal value (now it had to pick up a snort head rather than a whole sub). That change reduced ASW aircraft search ability for swaths of sea hundreds of miles across to much lower levels. The idea of using IR was that the exhaust gases from a snorting sub were very hot and could be detected at range. This idea worked very well and is still used today - until quite recently, ASW aircraft were the major users of FLIRs. The introduction of FLIRs also led to a scientific revolution is oceanography since it revealed that the sea was not uniform in termperature. Up to that point it had been assumed that the sea was largely uniform with temperature differences being a gross characteristic only. ASW aircraft returning from flights using their new FLIRs reported that the sea was actually an amazingly complex pattern of different termperature bands and zones.

More recently FLIRs have been used for ground attack missions. They negate the effectiveness of some types of camoflage and make targets like tanks (with warm engines) and people (hearts still beating - matter to be soon rectified) stand out clearly. They allowed the aircraft to distinguise between buildings that were occupied and those that were not. All sorts of goodies like that. With the development of laser-guided bombs, it wasn't long before FLIRs were hooked to laser designators so the designator could be placed on the right target. These were usually two-pod systems with the FLIR carried on one pylon and the designator carried on the other. These had a lot of disadvantages because the target would pass out of the field of view of the FLIR and be lost. That would break the laser lock and the bomb would go astray. The answer was to stabilize the FLIR and allow the pilot to lock it and the laser onto a specific target. That would allow him to maneuver within limitations without losing the target. That's an IRTS. There are loads of these systems now, everybody and his brother offers one. The Turks offer ASELPOD, the French Atlis, the US Lightening, Lantirn and Sniper, the British TIALD (although the British replaced it with Lightening for reasons they are reluctant to elaborate on. The Saudis replaced their TIALDs with Sniper). Lots of others. They are available as one-pod and two-pod systems although the two-pod is usually preferred. They can also be mounted internally.

IRST. This stands for Infra Red Search and Track. It's quite a different animal from the FLIR. What this system does is scan an area in front of the platform aircraft for an infra-red signature. That's the search bit. When it detects one, it then tracks that contact (yes, that's the track bit) and feeds the data into the fire control system of the aircraft. The fire control system then processes the data from the IRST in exactly the same way as it would the information from the aircraft's radar. After all, a track is a track is a track. The aircraft FCS can then key an air-to-air weapon in on that designated target and let fly. Now, here's the useful bit. When the USAF started using IRST systems back in the very late 1950s and 1960s, their primary air-to-air system was the AIR-2 Genie nuclear rocket and its predecessor, a salvo of 2.75 inch Might Mouse rockets. These were both unguided systems. Other weapons (cannon and later AIM-4 Falcons) were intended to finish of cripples and so on. However, using an unguided weapon meant that it was helpful if the target neglected the opportunity to get out of the way. Most bombers had radar detectors that could locate and isolate search radars and those detectors would allow the bomber to take evasive action. The IRST was totally passive so the target got no warning until somebody visually sighted the rocket coming in. One can plot the aircraft intended to carry the AIR-2 by the presence of an IRST (yes, the F-4 had one. Interesting that. More later) Later, missiles became much more agile and reliable, the AIR-47 and its descendents/cousins were intended to carry a nuclear warhead (most never did) and the need for an IRST faded away.

Then came the obsession with stealth. That brought IRSTs back into favor with a vengeance. Thermal signature was the first big chink in the low observability fad's armor. The Soviets hopped on to it with enormous enthusiasm and they learned a lot very quickly. One is that thermal signature is a big chink and there's not much that can be done about it. Engine exhausts can be masked and their effects reduced by cold air dilution but they can't be eliminated completely. And so on. It also turned out that data processing made the IRST much more productive than had been possible thirty years earlier. Even faint thermal signatures could be detected at relatively long range. Black hole detection was also possible. In other words, detecting where thermal signatures were not. For example, if there was a very warm background, an aircraft flying over it would record as a shadow of easily-defined shape and size. Now, if that shadow had no radar signature, there are only a limited number of possibilities as to what it could be. So, one locks one's radar onto the position of the shadow by using the IRST system, cranks emission power up to maximum and sees what happens. Or just fire a missile at it. Even a tiny amount of damage will dramatically increase the RCS of a low-observable aircraft.

IRSTs aren't the be-all and end-all of air defense. They aren't much use against targets flying in cloud etc. However, they are very useful systems indeed. Their presence on Russian-built fighters is a big sales point in their favor.

IRSCAN. IRSCAN stands for Infra Red Scanner. These are fascinating systems; I've actually worked with them in a naval context. An IRSCAN is a fixed installation (it may be on a ship, on a land element or fitted to an aircraft. Essentially it consists of a capable IR system linked to a scanning head that has 360 degree rotation. The speed at which the head rotates can be anothing from 30 to 240 rpm. That scanning head is quite small so spinning it at high speed is possible in applications where spinning a radar antenna at the same speed would cause it to take off. That scanning head works exactly like a radar; it has a deliberately limited field of vision so that as it spins, that field of vision effectively forms a "beam" that sweeps the search area. Just like a radar in fact (an IRSCAN is really an infra-red radar). What it does is that it then produces a display that has the bearing and altitude of every contact it makes per scan. The narrower the field of vision, the more accurate the date; the faster the scan rate, the more data points per track. Just like a radar. The IRSCAN has two big advantages though. One is that it is totally passive so it doesn't give the system's position away. (CAVEAT, that isn't strictly true. In fact, or actually in theory, another IRSCAN can pick up the first by spotting a small flashing black dot that is the scanning head on the opposing system. That's because the head is cooled to increase sensitivity). Another big advantage of the IRSCAN is that it can see things no radar can. Like things that are over the horizon. You see, said things over the horizon produce heat plumes, sometimes very big and distinctive ones. The IRSCAN can see those plumes. Anti-ship missiles are a good example. The big, fast ones produce enormous heat plumes that can be picked up for minutes (don't ask) before the missile actually crosses the radar horizon. That heat plume can be tracked and used for targeting data. One way an AEGIS ship can take pot-shots at targets that are far over the nominal horizon.

IRSCAN equipment made its big impact in missile defense. The system can give one a huge amount of data and, once it is tracking a specific target, it can be set to give a huge wealth of information on that target. Heat patterns are very distinctive, almost as individual as a type-specific fingerprint. Aircraft are one case; it's possible to tell the difference between an Indian MiG-21 and a Pakistani F-7 (Chinese-built MiG-21) by their thermal signature (assuming the Indian MiG-21 doesn't crash first). Missiles are another. An IRSCAN is also capable of telling one things like the internal structure of a ship by the differences in thermal signature of her hull plating. Plating with a bulkhead behind it will be cooler due to heat-sink effect than palting over an open compartment. We can also tell you which compartments are occupied at any given time. FLIRs will do some of that but the combination of a very narrow beam and scanning will give a lot more. IRSCAN is also used on aircraft to warn of inbound missiles. You've all heard of missile launch detectors? There are a few different types but the most capable are the IRSCANs.

Obviously the situation isn't quite as neat as this. The division between the three types gets a little cloudy sometimes (the latest IRSTs are pretty close to being IRSCANs while the IRSTs carried on the F-101 etc were basically only elaborate FLIRs) but the basic divisions do hold good. Also, we've been talking about IR but there are other similar systems around that use different technologies. For example, there is a growing family of ultra-violet search and detection systems. They have their own capabilities and uses. False color is another adjunct. Take visible light and chop out a small section of the spectrum. Say, take all the green light. Now, "green" is actually a band of light frequencies. So, we take that band and chop it up into new "colors" This means that what we see is now a new colored picture that at first glance is quite normal. Only that picture only shows what is reflecting green light. Now, suddenly we can see a whole load of things we couldn't see before. Like a green-painted tank sitting in a bunch of trees (because, for example, the green leaves still look green but the green paint now looks red). These days we can do that in real time and it's a great help. It makes camoflage almost impossible; one has to match reflectance as well as color.

[Shroom Man 777]

So FLIR is just basically infrared vision, that allows targeters to point laser designators at targets they are seeing in infrared, that they otherwise wouldn't see if not for infrared? Whereas IRST isn't infrared vision, and doesn't require laser designators, but instead it guides missiles to heat signatures?

So FLIR is using infrared vision to see, and using lasers (or other things) to guide bombs/missiles at targets. Whereas IRST is really "heatseeking"?

[D.Turtle]

False color is another adjunct. Take visible light and chop out a small section of the spectrum. Say, take all the green light. Now, "green" is actually a band of light frequencies. So, we take that band and chop it up into new "colors" This means that what we see is now a new colored picture that at first glance is quite normal. Only that picture only shows what is reflecting green light. Now, suddenly we can see a whole load of things we couldn't see before. Like a green-painted tank sitting in a bunch of trees (because, for example, the green leaves still look green but the green paint now looks red). These days we can do that in real time and it's a great help. It makes camoflage almost impossible; one has to match reflectance as well as color.

Now, THAT is interesting.

I'm guessing the problem with all these possible information sources is being able to interpret the data fast enough in order to be able to act on it quickly. It wouldn't surprise me if that were a possible major application of AI.

It really is scary how much is theoretically possible, and we (humans) just aren't capable enough to make use of it.

[Shroom Man 777]

I think they are already using it. For UAVs and satellites, I think, I'm not sure but I think I've seen some overhead photos with weirdo funny colors. Not only for military purposes, but also agricultural ones (and other civilian/scientific stuff) IIRC.

[Stuart]

So FLIR is just basically infrared vision, that allows targeters to point laser designators at targets they are seeing in infrared, that they otherwise wouldn't see if not for infrared? Whereas IRST isn't infrared vision, and doesn't require laser designators, but instead it guides missiles to heat signatures? So FLIR is using infrared vision to see, and using lasers (or other things) to guide bombs/missiles at targets. Whereas IRST is really "heatseeking"?

Essentially yes; An IRST doesn't usually give the pilot a pure picture but relays its data directly to the aircraft fire control system that then integrates it with data from other sources and gives the pilot a composite picture of what is going on. For example, the IRST might give the FCS a target track which is then compared with the radar picture from an AWACS. If that track isn't on the radar picture, then there is something interesting going on. Then, that data is compared with data from IFF and if there is still no match, then life gets even more curious.

I'd have to get into an Su-27 or Su-30 with the system up and running to tell you exactly what the display looks like (at the moment I have no need to know that so nobody is prepared to pay the bill the Russians would charge for showing me) but I've seen similar British and French systems up and running and the results are impressive. An IRST is a very different animal from a FLIR or FLIR-based targeting pod.

[Simon_Jester]

I think they are already using it. For UAVs and satellites, I think, I'm not sure but I think I've seen some overhead photos with weirdo funny colors. Not only for military purposes, but also agricultural ones (and other civilian/scientific stuff) IIRC.

Oh yes. NASA loves false color, for example.

It would be cool enough if all you could do was take a narrow range of the visual spectrum (say, the "greens" between 500 and 550 nm or so) and balloon it out into a whole rainbow, thus making the 500 nm greens appear violet and the 550 nm ones appear red. That's what Stuart seems to be talking about. But you can also use a color map for things that aren't in the visible range at all (say, create an infrared picture where hot objects are red and cold objects are violet). Or as a way to represent data over a surface (say, a map of the surface of Mars where high spots are red and low spots are blue, or a map of Mercury where different kinds of rock on the surface are shown in different colors).

It's a great tool for both studying planets, and generating trippy psychedelic pictures of those planets to share with the media.

[Stuart]

Now, THAT is interesting. I'm guessing the problem with all these possible information sources is being able to interpret the data fast enough in order to be able to act on it quickly. It wouldn't surprise me if that were a possible major application of AI. It really is scary how much is theoretically possible, and we (humans) just aren't capable enough to make use of it.

Lord yes. The big problem is information overload; there is simply too much data around for a single person to interpret. Most people select a few sources they are happy with and simply don't use the rest. There was a big question about the time when color displays became available as to whether they were a good idea or not. The counter argument was that the use of color presented so much data that it would overwhelm the pilot. That was dismissed as being luddite, reactionary etc. Guess what, it turned out to be a serious problem Aircraft displays have to be very carefully designed so they don't overwhelm the pilot with data.

On a domestic front drivers have much the same problem with GPS and other "advanced" systems. Accidents happen because the GPS says "Go straight on" and the driver does so - straight through a red light. Or the GPS says "turn left" and the driver does so - straight through a tree or into a lake. My car has a head-up display fitted. When they were first fitted, they caused a lot of parking accidents because people had their eyes focussed on their HUD, not on the rear end of the car in front. The HUD had to be greatly simplified and its focus changed to solve that problem. I drove a Cadillac for a week once that was fitted with a thermal imager (essentially a very cheap FLIR). I loved it and got a lot of good use out of it. Most other drivers found it useless at best. Reason was simple; I'm familiar with FLIRs and know how to use them. Most civilians don't and thelearning curve is very, very steep.

Another problem is that people using false color systems forget that they are using a generated image. They're seeing what the computer tells them is there, not what is there. For example, they forget they are seeing a green-based false color image. They never see the fighter that kills them because it was silver.

False-color imagery is a massively useful tool. I believe that its being used in cancer diagnosis now and can pick up cancer cells long before they can be detected by any other system (biologists here please confirm?).

[Simon_Jester]

A caveat: false color is only as good as the sensor that the false color data came from. The advantage isn't so much the false color itself as that it lets a human user take full advantage of the resolution of the sensor. We can tell which of two colors is "more red" or "more blue" with much greater precision than we can tell which of two light sources is "more bright."

So the advantage of false color is that it lets us take raw data from a machine (any machine) and translate it into a form a human can use more efficiently than they could use a black and white image or a huge mass of numbers.

[Fingolfin_Noldor]

A caveat: false color is only as good as the sensor that the false color data came from. The advantage isn't so much the false color itself as that it lets a human user take full advantage of the resolution of the sensor. We can tell which of two colors is "more red" or "more blue" with much greater precision than we can tell which of two light sources is "more bright."

So the advantage of false color is that it lets us take raw data from a machine (any machine) and translate it into a form a human can use more efficiently than they could use a black and white image or a huge mass of numbers.

These days, the rage with hyperspectral imaging, which include using interferometers as a kind of fourier transform device, might just be able to give existing devices better dynamic range and resolution.

[phongn]

False-color imagery is a massively useful tool. I believe that its being used in cancer diagnosis now and can pick up cancer cells long before they can be detected by any other system (biologists here please confirm?).

I'm not sure about "any other system" but it is used hugely in the field. It's particularly useful because it's easier for eyes to pick out changes in colors rather than just grey levels - or because no monitor can display the intensities otherwise.

[Simon_Jester]

A caveat: false color is only as good as the sensor that the false color data came from. The advantage isn't so much the false color itself as that it lets a human user take full advantage of the resolution of the sensor. We can tell which of two colors is "more red" or "more blue" with much greater precision than we can tell which of two light sources is "more bright."

So the advantage of false color is that it lets us take raw data from a machine (any machine) and translate it into a form a human can use more efficiently than they could use a black and white image or a huge mass of numbers.

These days, the rage with hyperspectral imaging, which include using interferometers as a kind of fourier transform device, might just be able to give existing devices better dynamic range and resolution.

Well, again, it's not a question of what the sensors are capable of; it's question of what the human eye is capable of. Intelligent use of color lets us enormously increase the amount of information the eye can take in at any one time through a given format.

Improving the sensors does no good if the human operator can't use the improved resolution effectively. False color is good because it makes you better at using the information encoded by the false color image, not because it makes the equipment you're using better.

[Fingolfin_Noldor]

]Well, again, it's not a question of what the sensors are capable of; it's question of what the human eye is capable of. Intelligent use of color lets us enormously increase the amount of information the eye can take in at any one time through a given format.

Improving the sensors does no good if the human operator can't use the improved resolution effectively. False color is good because it makes you better at using the information encoded by the false color image, not because it makes the equipment you're using better.

They have been working on sensor fusion for years. This isn't quite a new problem, ye know? One of the delays in the F-35 programme happen to be the issue of sensor fusion, incidentally.

[Stuart]

Not just the F-35; every major defense program that uses sensors is hitting the same problems. It's one of the reasons why costs and development times are going skywards. What it's doing is cutting more and more countries out of the systems development business. It's not expertise per se it's simply money. The U.S. gets less defense per dollar spent that any other country with the possible excpetion of Japan and the reason why is sensor and data fusion problems. We're about five to ten years further down that road than anybody else but other countries can look at us and see what is coming. They have a choice, they can pony up the readies or leave the game entirely.

[Starglider]

Part of the problem with that is that software engineering as a discipline still hasn't solved the scaling problem for large projects. Large commercial projects are massively less efficient in terms of lines of code produced per dollar spent than small ones; from my experience, comparing say a web search/aggregation start-up to a high-street bank the ratio is somewhere between 100 and 1000 times. Which is to say that for the money the start-up spends (on its small team of expert coders) to get 1000 lines of code, the bank (with its massive over-managed teams of almost tenured staff spread out over the globe) gets a handful. Both projects are highly likely (>50%) to fail, but the former is likely to fail for market/business reasons while the later is likely to fail for technical/cost escalation reasons. Government funded IT projects are even worse than this, due to even less competent and more numerous management, and even more random specification changes mid-project. While I have virtually no personal exposure to military projects, I suspect they are similar.

[MKSheppard]

So FLIR is using infrared vision to see, and using lasers (or other things) to guide bombs/missiles at targets. Whereas IRST is really "heatseeking"?

Gets better.

A year or so ago; I was talking with the senior account manager here http://www.inputsolutions.com/index.htm, to price scanning the roll of microfilm I got from the USAHR -- all four volumes of aircraft armament development for fighters and bombers from 1917 to 1962.

When he asked me what it was, etc; I told him, and he then says his dad was command pilot of a B-17 in WW2 -- 384th BG, out of grafton underwood -- did 35 missions.

(sidenote; when he said that; I asked - 1944-45?; and scored it right out the gate! I mentioned that's because early in the war it was 25; then it got raised).

He was also the combat trainer for his group; took guys out on milk runs for their first mission.

But this is where it gets real awesome.

After the war, he stayed in the USAF, and became a optical physicist.

So around the 1950s, he has an idea about using IR imagery to compute the yield of a nuke -- he writes a support paper; submits it, and gets support from the Pentagon. He basically went on to act as the program manager, lead engineer, etc all rolled into one for it -- it was a pretty small, tight program.

So they set up their equipment in an observatory in hawaii; and they set up the IR film, and wait for a Soviet nuke test. Well, when it happened, he was able to phone back to the Pentagon the yield of that test before the radiological sampling ships and airplanes could get and analyze their samples.

That got attention fast -- and the USAF quickly expanded the idea to a formal program, and now applications of this principle are found on satellites etc; and it can discriminate between a fission and TN device -- probably due to the slight time lag as each stage ignites.

So -- now imagine E/O IIR systems doing real time nuclear BDA

[SilverHawk]

Speaking of False Color, it it possible that NASA or some other space program creates False Sound? We all know that there is no sound in space because of a lack of medium, it would seem that a good use of computing power would be to generate sound for the Crew/Pilot to increase situational awareness.

Also, concerning skin friction giving away stealth aircraft to IRSTs/FLIRs. Composites help a little, but is there any research being done into active cooling systems to counter that issue? (Sort of like how the F-4 used engine exhaust forced over flaps to increase their effectiveness.)

[Simon_Jester]

There's not much in space for sound to increase operational awareness of. Your ears are better used to communicate with ground control.

[SilverHawk]

There's not much in space for sound to increase operational awareness of. Your ears are better used to communicate with ground control.

True, but I'm speaking more future tense.

[PeZook]

Also, concerning skin friction giving away stealth aircraft to IRSTs/FLIRs. Composites help a little, but is there any research being done into active cooling systems to counter that issue? (Sort of like how the F-4 used engine exhaust forced over flaps to increase their effectiveness.)

I don't think it can physically be done. The heat has to come out somewhere ; You can shuffle it around, but you have to dump it eventually. You can radiate it through the skin, or use tricks and heat pumps to move it somewhere else, like a radiator in a specific place, maybe the exhaust, etc, which means the enemy will have to release a programming patch for their infrared sensors to recognize the new B2 heat signature.

Spacecraft do it a lot, actually, but it doesn't mean the Space Shuttle is invisible on infrared ; It just has huge glowing radiator flaps.

[SilverHawk]

Also, concerning skin friction giving away stealth aircraft to IRSTs/FLIRs. Composites help a little, but is there any research being done into active cooling systems to counter that issue? (Sort of like how the F-4 used engine exhaust forced over flaps to increase their effectiveness.)

I don't think it can physically be done. The heat has to come out somewhere ; You can shuffle it around, but you have to dump it eventually. You can radiate it through the skin, or use tricks and heat pumps to move it somewhere else, like a radiator in a specific place, maybe the exhaust, etc, which means the enemy will have to release a programming patch for their infrared sensors to recognize the new B2 heat signature.

Spacecraft do it a lot, actually, but it doesn't mean the Space Shuttle is invisible on infrared ; It just has huge glowing radiator flaps.

I was thinking perhaps having the waste heat be vented through the turbine exhaust, that way it can be cooled again as the platypus nozzles absorb some of the heat. I'm not expecting total stealth from IR, but any range you can shave off an enemy fighter's effective IRST range is progress.