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Chinese Researchers Reveal Active Stealthy Material (popsci.com)

hackingbear writes: Even after billions and billions of dollars spent on the stealthy skin used on F-22, F-35 and B-2, the material has weaknesses, and one of those is ultra-high-frequency (UHF) radar, which can pick up traces of the plane that other radar misses. Chinese researchers came to the rescue and created a material just 5/16 of an inch thick that can safeguard stealth planes against UHF detection. The material tunes itself to a range of detection frequencies, protecting against a large swath of radar scans. What's even more amazing? They published this seemingly top secret invention wide open in the Journal of Applied Physics .

13 of 138 comments (clear)

  1. Doesn't work by Calydor · · Score: 4, Funny

    If this thing works, how did anyone notice it?

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  2. So... by Etherwalk · · Score: 5, Interesting

    Are they publishing it because (1) they have something better, (2) they have figured out a way to beat it and hope we will use it, or (3) they were simply incompetent?

    1. Re:So... by Zocalo · · Score: 4, Interesting

      I'm going with 1 *and* 2. Based on discussions I have had with Chinese tech companies the days of China having to steal all of its tech and being incapable of developing its own are long since past and they are now quite capable of developing stuff on their own, from scratch if need be. Any industrial espionage is more than likely just to save them time and effort so they can take a shortcut and compare notes.

      I'm also reminded of how the US once published spy satellite pictures of the Nile delta showing all of the subterranean waterways as a means of informing the Russian military that they could, by inference, also see all of the missile silos and other underground facilities the Soviets had build in Siberia, etc.; so this is probably also about sending a similar message. Quite nicely done too, unlike the Russian's ham fisted efforts with their "leak" of nuclear torpedo schematics via state TV over the weekend. Yeah right, like the Ra-Ra-Putin Channel doesn't have an official censor to vet everything it airs...

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    2. Re:So... by gtall · · Score: 5, Insightful

      Oh, which country has the U.S. stolen since WWII, Tibet? Which sea is the U.S. claiming to entirely own, the S. China Sea? And them missiles aimed at Taiwan, the U.S. is claiming to own that as well?

    3. Re:So... by DarkOx · · Score: 4, Interesting

      They just set up the puppet governments that do the US bidding.

      Friendly yes puppets no. Its true that the governments we helped stand up after or during various conflicts are usually friendly to us. That is beneficial yes its good to have friends. Its good for them to keep us as friends too, in almost all those cases those governments could not resist the various threats to them without an umbrella of US Military protection or at least apparent protection.

      The are not puppets though, their self interesting in survival, not causing us to have to sever ties with them is a requirement for that. Even with that said most of those governments very much have at times resisted our policies in favor of their other interests. We have permitted them to do that as well. Its not colonialism and its not expansionism its something certainly but its neither of those things.

      I am not saying its all good either, just trying to be fair.

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    4. Re:So... by SharpFang · · Score: 5, Insightful

      Yep, the first free elections in Iraq. The Nation spoke. They wanted islamist fundamentalist party at the helm. The USA choose to simply disregard the results of the elections and set up a government of their choice. "Democracy."

      "Puppet government" and "government friendly to us" is just two different names for the same thing, depending on which side you're sitting.

      "self-interest in survival" is a very interesting way to put their motivations behind remaining friendly to the USA.

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    5. Re:So... by Gim+Tom · · Score: 5, Informative

      The Russian physics paper was very theoretical and derived the equations needed to show that this technology was possible. The equations could not, and probably still can not, be directly solved. However, this paper was translated by the US Air Force as were many such technical publications and circulated through channels to aircraft manufacturers, and others. It was an engineer at Lockheed who realized that you could implement this technology without solving the equations if you were willing to devote huge amounts of computer resources to doing numerical solutions, which, are great for engineers, but frowned upon by theorists. We had the computer power to do this and the USSR did not. Even then the F117, sometimes called the wobbly goblin, had to sacrifice much in terms of aerodynamics and flight characteristics to implement the first true stealth aircraft.

  3. 5/16 Inch = 8mm by Anonymous Coward · · Score: 5, Informative

    Translation: 5/16 Inch = 8mm

    1. Re:5/16 Inch = 8mm by Buchenskjoll · · Score: 4, Informative

      Thank you. 8mm actually sounds like a lot. And by the way: The world is metric, learn to live with it.

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  4. Re:Turned absorption by SharpFang · · Score: 4, Insightful

    It's still better than nothing. A passive broadband radar will take milliseconds to adapt the coating to any single radar frequency. With more than one it will run into trouble, but again, multiple blips at predictable intervals are quite easy to program, so the airplane would be able to hide from multiple radars.

    This can be thwarted relatively easily with a radar that constantly shift frequencies randomly, but... you need to build one. The old infrastructure becomes obsolete, necessitating costly upgrades. It may provide exactly zero battlefield advantage in the long run but if it forces the opponent to suffer costs of performing upgrades of their infrastructure which would be otherwise not needed, it's already a win. And by publishing the paper (instead of costly building air force exploiting the new tech, which *might* leak through the opponent spies (and become obsolete fast), or might remain secret and become obsolete much slower) they are simply running the costs up for the USA.

    "Upgrade all your radars to frequency-hopping right now, before anyone builds a plane that will be invisible to them". And the plane *will* be built somewhere, because there are many countries that just can't afford upgrading their radar infrastructure, and their opponents would benefit greatly from planes invisible against them - even if they are useless against the (upgraded) USA radars. And the USA will definitely dislike the option of having 3rd party airplanes in the air which they can't see, even if they don't mean a direct threat currently.

    Economical warfare: at relatively low cost for yourself force the enemy to spend a bunch of money on defenses they will probably never need. (but will never need them only if they build them... if they don't, they'll regret they didn't.)

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  5. Re:Gamble? by gtall · · Score: 4, Interesting

    The future of air warfare (neglecting space) is pilotless aircraft. They can pull much higher Gs and no pilot means you don't have to put up with propaganda showing captured pilots. Just about all of the U.S. military knows this except a few spaghetti splattered uniformed Air Force generals.

  6. Re:Gamble? by Z00L00K · · Score: 5, Insightful

    Dodging in the form of guerrilla warfare where you move around all the time seems to work still. It's why it was so hard to find Bin Laden and that there's still ongoing work trying to locate IS leaders.

    Bunkers are outdated when it comes to serious assault stuff, but such weapons are expensive and limited in supply so if you can trick your opponent into wasting bunker busters and missiles by fake bunkers and similar then you can at least let things play in your favor.

    During WWI it was not unusual to have the "disappearing guns" in fixed artillery fortress locations protecting harbors. They became obsolete with the advent of the bomber aircraft, which resulted in a ceiling on the fortresses to protect against incoming bombs, which was pretty common during WWII. When the battleships got gyro-stabilized guns with high precision and aircraft able to do precision attacks on bunkers they became obsolete too since they now were essentially death traps.

    That's why most artillery units (both coastal and land) today are highly mobile. They can be operated by 1-2 men, stop and fire several rounds in under a minute and then be on their way again. (Bofors Archer)

    When you look at aircraft today it's a lot of stealth, but the downside with that technology is that it limits the punch it can carry. The A10 is non-stealth, and carries over 1000 30mm rounds, carries rockets externally to the level that it looks like a porcupine while the F-35 has a few hundred 20mm rounds and have to hide every rocket inside the hull. The stealth capabilities are also constraining the aerodynamics so that maneuverability suffers.

    However the advantage with stealth is that the first strike may appear with little warning, but after that the advantage is lower - and since the carried payload is lower it takes more missions to get the job done. A war zone is also highly fluid - the weapons you brought with you at the beginning of the mission may not be the right weapons when you arrive in the strike zone.

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  7. this compound is worthless by WindBourne · · Score: 4, Interesting

    first, UHF does not detect American stealth. China just claims it in hopes that fools will buy their radar.
    China is giving up nothing. They have a compound that will absorb UHF, but all others are reflected. IOW, it is worthless.
    So, why not publish it?

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