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redgridtactical | on: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor
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.

tclancy | parent | next
> The gap between consumer electronics and mil-spec capability keeps shrinking

My friend's brother works in munitions and had, in his spare time, designed and prototyped a missile that could be built for about 10k. He pretty much was ignored by the contractor he works for.

Shockingly, as of a couple weeks ago, they are all hot and bothered to talk.

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hrmtst93837 | parent | next
Cheap sensors look impressive in demos but drift and calibration wreck repeatability unless you babysit launches so nobody in defense is sweating this yet.
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mikkupikku | parent | next
It's not really terribly new actually, in the past, rapid advances in consumer technology have enabled other sort of weapon guidance systems. For instance, the development of extremely compact television cameras available to consumers directly lead to the development of the Walleye television bomb. It happened when one nerdy guy was fucking around with his new camera and realized that he could automatically track track features in an analogue television signal using some quite basic analogue electronics. Point the camera into the general direction of the target and you can then "lock on" to some target feature and based on contrast it could tell how that feature was moving around in the image.

He implemented a 1D tracker in his garage, took it to work and showed people. A few years later these bombs are taking out bridges and even sometimes hitting moving trucks.

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shrubble | parent | next
Consumer GPS chips are specifically nerfed for using them in rockets; they give erroneous readings on purpose if altitude is above a certain height and/or if speeds exceed a certain speed. That’s likely why the mid-course correction software uses other methods.
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the__alchemist | parent | next
> A few years ago this would have required an IMU that cost more than this entire build.

Are you sure about this? MEMS IMUs have been popular and cheap for ~10-15 years.

danmaz74 | parent | next
More than the electronics, I would be curious about the performance of 3d-printed plastic parts on a rocket. Are they strong enough?
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mothballed | parent
Owning a system designed for surface to air weapon carries life imprisonment any USA, without any intent for violence, just simple possession or conspiracy to possess[]. Doesn't even matter if you have an NFA stamp, there is no exception except if it's done with authorization and behalf of the government.

Merely having a device intended to guide the rocket is also the same penalty.

[] https://www.law.cornell.edu/uscode/text/18/2332g

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