Top Secret Teardown Reveals Soviet Missile Secrets

Technology has moved at such a furious pace that what would have been most secret military technology a few decades ago is now surplus on eBay. Case in point: [msylvain59] picked up a Soviet-era K-13 IR seeker used to guide air-to-air missiles to their targets. Inside is a mechanical gyroscope turning at over 4,000 RPM, a filter made of germanium to block visible light, and a photoresistor. It’s sobering to think you can get all of this in a few small packages these days, if not integrated into one IC.

Fitting on top of a missile, the device isn’t that large anyway, but it is nothing like what a modern device would look like. A complex set of electronics processes the signal and moves steering actuators that control fins and other controls to guide the missile’s flight. You can see a video of the device giving up its secrets, below.

It isn’t just the IR sensor that looks different from a modern design. The actuators, the control logic — everything, really — we would do in a much easier way today. Of course, you’d still have to make sure the equipment met shock requirements of the launch, although perhaps not the impact. But if anything, that would be easier with fewer smaller components.

Honestly, we got winded just watching him remove the outer housing. Then there was plenty of potting material — probably to help with shock resistance and environmental requirements.

We will agree you probably won’t ever design an IR tracker for a warhead. If you did, it wouldn’t look at all like this. But it is illustrative to look at how designers made things work without the host of microcontrollers and miniature devices we have today.

If you want to understand more about how all gyros work, start here. We don’t know what the K-13 cost new, but we know this much less complex gyro cost about $15,000 in today’s dollars.

46 thoughts on “Top Secret Teardown Reveals Soviet Missile Secrets

    1. Les Frènch, ze Germanz, and many many European countries dub their TV programs. Which means they don’t even hear english. Northern countries do not, except for kids’ shows, but the original version is still available too. That is obviously not the same as talking yourself, but it helps a lot.

    2. I see it all the time in Europe where researchers or other cohorts will speak English with each other but have no one to ape a good accent from. For example in scientific research areas where english is a good universal language, or even gaming.

  1. I was surprised to see the D-connectors on the top photo.
    I guess I was expecting the Soviets to use something that was totally unfamiliar with me.
    And then I thought, if it was a military application, why weren’t Cannon connectors used?

      1. DA15 is very common and easy to get. It’s only the never got a letter code 19 pin ones that are hard to find because they were only used on later apple // series and early macintosh floppy drives, and some odd music and test equipment.

  2. ” Inside is a mechanical gyroscope turning at over 4,000 RPM, a filter made of germanium to block visible light, and a photoresistor. It sobering to think you can get all of this in a few small packages these days, if not integrated into one IC.”

    Wow! A mechanical gyroscope running at 4,000 RPM…IN AN IC! I know I’m sold.

    1. MEMS gyroscopes are mechanical and available, with electronic parts, in an IC. They might not do a full circular rotation, but their back-and-forth rate is well past 4,000whateversPM.

      There’s also ICs in germanium, and probably a photoresistor somewhere if you really looked, perhaps one of those precision colour ref chips.

      1. Amazed me when I first read about MEMS IC’s and that there are even MEMS Michelson Interferometers. Would be something to have an array of those and even a matrix of those at the tip of a ???… I’d think aircraft more likely. Might not be bad for satellites and tracking junk also… might not be a bad idea for a space fence that is actually in space. Seems there would be less stuff in the atmosphere in the way.

  3. The gyro is an extended revision from the German V-2 rocket gyro.

    The V-2 had two gyros, both spinning at speeds between 10,000 (ref: The V2 and the German, Russian and American Rocket Program) and 30,000 rpm (ref:

    The Russians initially made a clone of the V-2 with the help of captured engineers, the R-1, and their own extended versions (R-2 and R-5)

    Looks like they refined it down to a single gyro at a far lower speed.

  4. Interesting. Not finding a trace of another classified surplus item that was on eBay at the moment… though was on eBay a few years back and was a mini dish radome unit that had card modules where some of the card modules weren’t included since the system was U.S. Top Secret. Came out of Texas if I recall correctly… I think was an U.S. Army unit… though I don’t recall and was noted that they were portable and placed around highly secured areas perimeter. The outer shell didn’t come with it… though I think that was one of the first units I saw that got me thinking a portable array of marine radars would be interesting to see what could be higher res imaged.

    Anyone know what I am referring to? I didn’t document anywhere unfortunately.

    1. There is a company that (extensively) modifies modern marine radars into weather radars, making them significantly cheaper then purpose-built weather radars, so…a weather radar is probably the best use for something like this ;-)

      1. All the military related I could find have large like DirectTV looking or huge dishes. Do you know which company does the modifications? I’m still surprised no one has done an almost real time 3D radar with marine radars yet. They are super HD now too and seems there are sonar 3D systems that I’ve wondered about hacking to use the hardware.

        I’ve seen where they can image bugs and this when doing a recent search:

  5. The Russkis stole this seeker design from the AIM-9 Sidewinder. I did a series of tests on one and had to get it running. I used a pilot light bulb with a low current on it (invisible) as a target.

    1. Actually you gave it to them, sort of.

      “The 24 September 1958 Chinese acquisition of an American AIM-9B Sidewinder missile marked the beginning of a breakthrough in the development of Soviet air-to-air missiles. The missile, fired from a Taiwanese F-86 Sabre aircraft, lodged without exploding in a Chinese MiG-17. The missile was sent to Toropov’s engineering office to be copied, and the product the K-13, long the most popular Soviet air-to-air missile. The Sidewinder had a number of valuable features, not least of which was the modular construction that facilitated ease in production and operation. The simplicity of the AIM-9 was in marked contrast to the complexity of contemporary Soviet missiles. The Sidewinder’s infrared-guided homing head contained a free-running gyroscope and was much smaller than Soviet counterparts, and the steering and in-flight stabilization system were equally superior. Gennadiy Sokolovskiy, later chief engineer at the Vympel team, said that “the Sidewinder missile was to us a university offering a course in missile construction technology which has upgraded our engineering education and updated our approach to production of future missiles.””

  6. Near the end, he seems surprised that the mirror assembly doesn’t turn exactly straight, and guesses that maybe this is secured by the magnetic field. Which tells me he doesn’t understand how it works. This is a conical scanning sensor; the only reason it rotates is to scan, so that the direction of the hot spot it’s aimed at can be determined.

    1. In fact, now that I think about it, where is this so-called gyroscope? The online reference he finds calls the rotating mirror/sensor assembly a “gyroscopic rotor optical assembly”. This is NOT a gyroscope, in the sense that word is used around here; it’s just an optical scanner.

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