Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

$96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

github.com

Post reply on HN
Print view View original

151–160 of 561 posts

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#151

Post by redgridtactical »

hrmtst93837 wrote: post #46
redgridtactical wrote: post #13

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 electronic…

[flagged]

For a sub-minute flight the drift budget is actually pretty forgiving — a MEMS gyro drifts maybe 1-3 deg/sec, and if you're fusing with accelerometer data you really just need "which way is up" and "am I still pointed at the target." A $5 IMU can hold that for tens of seconds.

Where you're right is repeatability. Mil-spec works the same on launch 1 and launch 500 across temperature extremes. Consumer MEMS you'd need to characterize each unit individually — fine for a demo, impractical at any scale.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#152

Post by vidarh »

tzury wrote: post #88

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 / Uk…

You don't need to win any wars with it if you can use them to sow confusion, obscure the firing of more serious rockets, and/or trigger a sufficiently more expensive response.

It clearly needs more work, but if an amateur can get this far at this low cost, odds are you'll see attempts at overwhelming attackers or defense systems by sheer volume with cheap decoys like this long before they become an actual threat in and of themselves.

Get the rocket a bit more stable, and force an attack to try to take out dozens of these because one of them might be a real threat, and you'll have created a problem.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#153

Post by mikkupikku »

make3 wrote: post #138
mikkupikku wrote: post #94

Earlier quoted context omitted.

Yes, I don't think this project is a serious threat as a weapon, it's more interesting if viewed as a politically provocative stunt, to get people thinking about the relationship between technology and war.

I always wonder why rockets are millions of dollars each, that seems insane to me.

Check out Joe Barnard's youtube channel BPS.Space where he's documenting his development of "high power" (hobby) rockets. Those are relatively small rockets still but nonetheless he's getting into performance regimes where the engineering starts to be tricky and the details really matter. The more extreme your rocket gets, the difficulty really ramps up quick.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#154

Post by redgridtactical »

mosura wrote: post #74
hrmtst93837 wrote: post #46

Earlier quoted context omitted.

[flagged]

For different definitions of cheap though. While the pure gyro/accelerometer stuff does suffer from major problems the improvements in SLAM using just cameras in the last 15 years are insane.

Visual SLAM on a rocket would be wild. The frame rates you'd need at those velocities are brutal though — feature tracking falls apart fast when your entire visual field is changing at hundreds of m/s. Drones are the sweet spot where camera-based nav really shines.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#155

Post by kotaKat »

firesteelrain wrote: post #114
rancar2 wrote: post #98

Earlier quoted context omitted.

Taking a quick look at the BOM, it lacks the correct sensor selection.

Even if the correct sensor could be chosen (whatever it is), unlikely is attainable by consumers and the technology would definitely be export controlled in the US.

You'd be AMAZED what you can find on eBay.

I saw this pop up alongside its video thumbnail and nearly shit myself watching it and going "damn, that looks exactly like what's on those RU/UA drones going at each other"... https://www.ebay.com/itm/197224214645

"HS AI Vision Cube For Ultra-long-range Target Recognition tracking & Thermal" for as low as $175. I am feeling the potential ITAR violations straight through my screen.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#156

Post by vidarh »

roysting wrote: post #142
einpoklum wrote: post #48

Earlier quoted context omitted.

I am completely against the US-Israeli war on Iran. That said, they are not carpet-bombing Iran. That is, they appear to be selecting individual targets rather than engaging in carpet bombing entire areas: https://en.wikipedia.org/wiki/Carpet_bombing The choice of targets is not legally legitimate (and the entire campaign is illegal AFAICT), and sometimes they used old/invalid intel, like what happened with that girl…

I understand your compulsion to rationalize things, make excuses for your abusers, but I ask you to contemplate for a moment what you are defending. One, hopefully we have all seen the genocidal bombing of Gaza turning whole regions of large apartment blocks into an hell-scape of rubble with tens of thousands of people buried underneath them; people, not animals, not “just brown people”, not “terrorists”… people like…

They did not defend it or make excuses for it. They argued about the very specific claim of carpet bombing in Iran, before pointing out the entire campaign is illlegal and calling the choice of targets "not legally legitimate".

They also said nothing about Gaza.

I share your concern about both Gaza and Iran, but criticising people for calling out an exaggeration is not helping anyone.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#157

Post by jacquesm »

vidarh wrote: post #152
tzury wrote: post #88

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 / Uk…

You don't need to win any wars with it if you can use them to sow confusion, obscure the firing of more serious rockets, and/or trigger a sufficiently more expensive response. It clearly needs more work, but if an amateur can get this far at this low cost, odds are you'll see attempts at overwhelming attackers or defense systems by sheer volume with cheap decoys like this long before they become an actual threat in a…

With a 3D printer and some 'ordinary household chemicals' to quote a certain movie you can do pretty scary stuff.

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#159

Post by charcircuit »

mothballed wrote: post #150
mikkupikku wrote: post #77

Earlier quoted context omitted.

MANPADS are certainly covered by ITAR. It could probably be effectively argued by his lawyers that what he has created isn't truly MANPADS but rather just an edgy toy that superficially resembles a weapon system but isn't actually capable of performing as one. Maybe that would work, but I think his chance of getting dragged into the legal system for this or for some chickenshit like weed possession are very high, par…

https://www.law.cornell.edu/uscode/text/18/2332g states that just having a system "intended to launch or guide a rocked or missile described in... [description of MANPAD type rocket]" carries life imprisonment. He calls it a manpad and then shows a system intended to launch it. There is no consideration in the law whether he actually plans to use it or ever meant any violence, nor any consideration of whether it viol…

So design a system for launching test vehicles?

Re: $96 3D-printed rocket that recalculates its mid-air trajectory using a $5 sensor

#160

Post by simonh »

daymanstep wrote: post #101
tzury wrote: post #88

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 / Uk…

I'm surprised nobody else has pointed this out. The entire YouTube video has only two short clips of the actual rocket being fired, and in both cases the clips are very short and only show the rocket being fired and then following an erratic flight path, and then get cut before showing the rocket hitting anything. For all the technical info given in the video, there is a curious lack of any data regarding the actual…

I suspect a major problem is the quality and consistency of the propellant and getting a symmetric burn.
Post reply on HN