I remember an anecdote our robotics lecturer told our university class in 1995, which was about how in the west we try to make expensive things that are the absolute best of technology and how the other side didn't have that luxury and relied on ingenuity.
He described a cold war Russian missile they had somehow obtained and were tasked with trying to reverse engineer. Ostensibly, it was thought to be a heat seeking missile, but there seemed to be no control or guidance circuitry at all. There was a single LDR (light dependent resistor) attached to a coil which moved a fin. That was it. Total cost for the guidance system maybe a couple of dollars, compared to hundreds of thousands for the cheapest guidance systems we had at the time.
The key insight was that if you shined a light at it, the fin moved one way and if there was no light the fin moved the opposite way. That still didn't explain how this was able to guide a missile, but the next realisation was that the other fins were angled so when this was flying (propelled by burning rocket fuel), the missile was inherently unstable - rotating around the axis of thrust and wobbling slightly. With the moveable fin in place, it was enough to straighten it up when it was facing a bright light, and wobble more when there was no bright light. Because it was constantly rotating, you could think of it as defaulting to exploring a cone around its current direction, and when it could see a light it aimed towards the centre of that cone. It was then able to "explore the sky" and latch on to the brightest thing it could see, which would hopefully be the exhaust from a plane, and so it would be able to lock on, and adjust course on a moving target with no "brain" at all.
That's roughly how the original Sidewinder worked.
The original concept was to reduce near-misses. If the pilot could get on the target's tail and aim at the engines, it usually got a hit. That was the same task as getting into firing position for guns. Hit rate about 8% in combat.
Later versions allowed launches from longer ranges and from off-angles.
I believe there was a similar weapon being developed in the west, only recently, which involved a missile with contra rotating halves joined by a clutch. The fixed fins caused it to always steer one way. It flew straight by releasing the clutch to spin up the front half, negating the steering effect. Grabbing the clutch caused it to stop spinning and veer off in one direction.
Presto! Two axis continuous flight control with a 1-bit input.
35-ish years ago there was a pitch for cheap, high velocity, spin-stabilized rockets that were deployed in dense pods on the A-10. The rocket's seeker could divert some small amount of thrust at an angle for guidance, but otherwise that was it. I can't recall if it ever made it out of the pilot phase, but obviously nothing new under the sun.
I think the Ukrainian Stugna & other ATGMs (not only with soviet heritage) use the rotation trick - you get some stabilization for free, might need less control surfaces and maybe even simpler sensors.
IIRC in the Stugna case, they even use solid fuel micro motors - they have a couple dozen of them in a rignt near the nose and fire them as the missile rotates in flight providing a kick in the right direction to hit the target. Given the missile usually flies for <30 seconds, this is perfectly adequate versus a complex set of aerodynamic actuators.
Strike a light in front of a parked but otherwise active fin guided heat-seeker and its freaky to watch it come alive like a lazy beagle eyeing a treat.
This is an interesting thought, as if I remember correctly, there was this theory that once something is known to be possible to discover, it only takes dedication to achieve it (George Dantzig as an example)
Also wouldn't it only work for aircraft that are flying away from the launcher? IR & light signatures are much weaker from the front. At best I think this guidance system would only be economical for ground-based launchers, as the cost of aircraft and their limited payloads mean you want the most effective weapons onboard, not the cheapest.
Annoyingly, I can't find any information online about such a simple guidance system. The earliest homing missile fielded by the Soviets was the K-13[1], which used technology reversed-engineered from the AIM-9 Sidewinder[2]. Later systems seem to be improvements upon that technology, not simplifications.
I'm impressed by the kid's engineering and gumption, but I think he's a bit.. misguided, if you'll pardon the pun. The video ends with shots of Russian drone war, and, bizarrely, photos of David Koresh.
In the two test launches shown in the video, the "missile" doesn't fly straight nor does it demonstrate ability to be "guided" by the launcher towards any particular target.
It's also incredibly slow. There are children's rocket kits that fly significantly faster than this.
The engineering is genuinely impressive for $96, but naming the repo "MANPADS-System-Launcher-and-Rocket" on GitHub is going to attract exactly the kind of attention you don't want. ITAR implications aside, the interesting part is the mid-flight trajectory recalculation on a $5 sensor. That's the same basic problem military guidance systems solve with hardware that costs thousands.
The gap between consumer electronics and mil-spec capability keeps shrinking and this is a pretty stark demonstration of where that trend leads. A few years ago this would have required an IMU that cost more than this entire build. The democratization angle cuts both ways though - the same accessibility that makes this cool for hobbyists makes it genuinely concerning from a proliferation standpoint.
When everyone started working on 3D-printed guns, I was sitting here thinking that if it comes to actual revolution, one is going to need anti-tank/anti-air a whole lot more than (relatively easy to acquire) small arms... Nice to see movement on this front
There are 2 short segments in the video showing the actual performance and thus far it is a complete [1] failure [2].
The guy has a talent, and he put together a nice prototype based on OpenRocket [3], but with all due respect, this is not a rocket, and you are not going to win any war with this toy, even if all your enemy has are rocks thrown at you from pretty much similar distance.
The remix of computer games / Ukraine / Martin Luther King / Vietnam / David Koresh just adding more to the amateur spirit and confusion.
A certain kind of mind deals with stress by devising solutions, even if one cannot put them into action.
Seeing people in Israel, Iran, the general Middle East as well as the Ukraine live in fear of drone strikes might have incentivised this person to come up with a potential way to deal with these threats.
Cheap air defense would equilibrate drone warfare again:
Currently drones are much cheaper that the systems that take them down.
> This project manifesto declares a fundamental shift: advanced air-defense capabilities—once locked behind billion-dollar state arsenals and classified labs—are now within reach of determined individuals using consumer electronics, open-source software, and rapid prototyping.
I guess a lot of people will not be happy with this xD
I think this violates ITAR. You aren't allowed put a guidance system on a rocket. And even if you were allowed to do it for your own fun/education, you certainly aren't allowed to provide instructions to foreign entities about how it do it.
Many mention ITAR or some other issue, nothing about this project is even close to ITAR (as far I understand), connecting camera to rocket using it as guidance will get in trouble most likely, if not mistake only thing allowed is using camera to AIM at sun.
Straight up admitting that it's meant to implement MANPADS is certainly a choice, I hope the author doesn't get himself in hot water.. ITAR or something..
Check out his code. It’s a joke. His control loop is a naive proportional response that doesnt even account for error let alone interpolate trajectory. Look at rocket.txt and launcher.tx. Especially the “fusion” function. lol. Stay in school kid.
This provides a distributed camera network to provide realtime updatable telemetry for target acquisition.
Only thing missing is he should have used LoRa as the backend comms. Meshtastic devices provide encryption and full comms with mesh for cheap.
Thankfully ive already downloaded everything. I suggest you all do the same, cause this repo is getting purged and the student Alisher Khojayev at Los Angeles Valley College is likely going to get black bagged.
This is obviously a missile, and I'm not well-versed in weapons tech, but won't this need a camera to actually track and take out a flying object? So far I just see gps and barometric sensing...
Also 3D printing and some electronics, ok fine, but where do you get the rocket propellant? That seems at least as critical as the software and sensing side of things...
I would suggest using a more modern IMU, the MPU6050 has been long obsoleted both in cost and capability by newer IMUs. I used the ST LSM6DSOX in my rocket flight computers, for example it has a way better rate noise density of 110ug/Sqrt[Hz] at 16g fs compared to the awful 400 ug/Sqrt[Hz] of the MPU6050 and is cheaper than the MPU6050 on LCSC last time I bought some. If you go newer to the LSM6DSV you can get 60ug/Sqrt[Hz] but these aren't as cheap. There was an interesting Sony project which used a synchronized array of these consumer IMUs to achieve lower noise (apparently they became export controlled despite just fusing a bunch of consumer IMUs on one PCB!)
Nowadays you can even use the LSM6DSV320X which has both a low-g and high-g integrated which basically obsoletes the high-g ADXL375 and saves some space, but it's not quite at the price and supply reliability of the LSM6DSOX since it is less than a year old.
I think with the proliferation and effectiveness of countermeasures passive target acquisition and first shot accuracy with traditional ballistic methods might be a better place to focus but I understand that's very hard to do nonprofessionally as an individual thanks to the rules and laws.
On the other hand, there is a lot to be said for making them blow their $1k active countermeasures on your $500 missiles before sending a real one in to finish the job. Heck, even just forcing your adversary to treat every sky like it's hostile is worth a lot.
Both approaches are clearly worthy of development.
531 comments
He described a cold war Russian missile they had somehow obtained and were tasked with trying to reverse engineer. Ostensibly, it was thought to be a heat seeking missile, but there seemed to be no control or guidance circuitry at all. There was a single LDR (light dependent resistor) attached to a coil which moved a fin. That was it. Total cost for the guidance system maybe a couple of dollars, compared to hundreds of thousands for the cheapest guidance systems we had at the time.
The key insight was that if you shined a light at it, the fin moved one way and if there was no light the fin moved the opposite way. That still didn't explain how this was able to guide a missile, but the next realisation was that the other fins were angled so when this was flying (propelled by burning rocket fuel), the missile was inherently unstable - rotating around the axis of thrust and wobbling slightly. With the moveable fin in place, it was enough to straighten it up when it was facing a bright light, and wobble more when there was no bright light. Because it was constantly rotating, you could think of it as defaulting to exploring a cone around its current direction, and when it could see a light it aimed towards the centre of that cone. It was then able to "explore the sky" and latch on to the brightest thing it could see, which would hopefully be the exhaust from a plane, and so it would be able to lock on, and adjust course on a moving target with no "brain" at all.
Later versions allowed launches from longer ranges and from off-angles.
Presto! Two axis continuous flight control with a 1-bit input.
Edit: my memory wasn’t far off. It’s Starstreak: https://en.wikipedia.org/wiki/Starstreak
IIRC in the Stugna case, they even use solid fuel micro motors - they have a couple dozen of them in a rignt near the nose and fire them as the missile rotates in flight providing a kick in the right direction to hit the target. Given the missile usually flies for <30 seconds, this is perfectly adequate versus a complex set of aerodynamic actuators.
https://youtube.com/shorts/6fYM4OlkIgk?si=NFMgNKGWz7rCJm2B
Annoyingly, I can't find any information online about such a simple guidance system. The earliest homing missile fielded by the Soviets was the K-13[1], which used technology reversed-engineered from the AIM-9 Sidewinder[2]. Later systems seem to be improvements upon that technology, not simplifications.
1. https://en.wikipedia.org/wiki/K-13_(missile)
2. https://en.wikipedia.org/wiki/AIM-9_Sidewinder
> That still didn't explain how this was able to guide a missile
That does explain why it lands on civilian areas tho
> with no "brain" at all
It seems this is how Russia moves in general. Hopefully, this will end at some point.
* https://github.com/NawfalMotii79/PLFM_RADAR
I'm impressed by the kid's engineering and gumption, but I think he's a bit.. misguided, if you'll pardon the pun. The video ends with shots of Russian drone war, and, bizarrely, photos of David Koresh.
I don't think this ends well.
It's also incredibly slow. There are children's rocket kits that fly significantly faster than this.
The gap between consumer electronics and mil-spec capability keeps shrinking and this is a pretty stark demonstration of where that trend leads. A few years ago this would have required an IMU that cost more than this entire build. The democratization angle cuts both ways though - the same accessibility that makes this cool for hobbyists makes it genuinely concerning from a proliferation standpoint.
The guy has a talent, and he put together a nice prototype based on OpenRocket [3], but with all due respect, this is not a rocket, and you are not going to win any war with this toy, even if all your enemy has are rocks thrown at you from pretty much similar distance.
The remix of computer games / Ukraine / Martin Luther King / Vietnam / David Koresh just adding more to the amateur spirit and confusion.
[1] https://youtu.be/DDO2EvXyncE [2] https://youtu.be/DDO2EvXyncE?t=280 [3] https://openrocket.info/
Seeing people in Israel, Iran, the general Middle East as well as the Ukraine live in fear of drone strikes might have incentivised this person to come up with a potential way to deal with these threats.
Cheap air defense would equilibrate drone warfare again:
Currently drones are much cheaper that the systems that take them down.
> This project manifesto declares a fundamental shift: advanced air-defense capabilities—once locked behind billion-dollar state arsenals and classified labs—are now within reach of determined individuals using consumer electronics, open-source software, and rapid prototyping.
I guess a lot of people will not be happy with this xD
https://www.youtube.com/watch?v=DDO2EvXyncE
This appears to be flight stabilized and guided via direct command coming from the launcher. It is not an autonomous guided missile.
https://www.youtube.com/@LafayetteSystems is similar project, also by actual defense contractor, and less opensource.
> Despite the tech-cool factor of the project, Tom's Hardware does not condone making your own weapons system at home.
Not that this matters for the topic, but I don't see why people have started saying "weapons system" instead of "weapon".
(Would be cool to see an ATGM variant too!)
> This guy really wants that defense contract.
This provides a distributed camera network to provide realtime updatable telemetry for target acquisition.
Only thing missing is he should have used LoRa as the backend comms. Meshtastic devices provide encryption and full comms with mesh for cheap.
Thankfully ive already downloaded everything. I suggest you all do the same, cause this repo is getting purged and the student Alisher Khojayev at Los Angeles Valley College is likely going to get black bagged.
Also 3D printing and some electronics, ok fine, but where do you get the rocket propellant? That seems at least as critical as the software and sensing side of things...
Nowadays you can even use the LSM6DSV320X which has both a low-g and high-g integrated which basically obsoletes the high-g ADXL375 and saves some space, but it's not quite at the price and supply reliability of the LSM6DSOX since it is less than a year old.
The future is scary
https://github.com/novatic14/Distributed-Camera-Node-Trackin...
On the other hand, there is a lot to be said for making them blow their $1k active countermeasures on your $500 missiles before sending a real one in to finish the job. Heck, even just forcing your adversary to treat every sky like it's hostile is worth a lot.
Both approaches are clearly worthy of development.