[HN Gopher] OpenRocket
___________________________________________________________________
OpenRocket
Author : zeristor
Score : 345 points
Date : 2026-03-15 12:20 UTC (3 days ago)
(HTM) web link (openrocket.info)
(TXT) w3m dump (openrocket.info)
| mitchbob wrote:
| The miracle of 3D printing. First ghost guns, and now ghost
| rockets. Will be curious to see what prediction markets will have
| for these.
| Onavo wrote:
| Need itar to be defanged first.
| altruios wrote:
| you get some good, you get some bad.
|
| Building a rocket shell is probably just fine: you need to fuel
| yet - that you can't 3D print. probably fine...
|
| Overall 3d printing is a lot more than ghost guns and ghost
| rockets. That the conversation dominates this small sub-section
| reeks of 'think-of-the-children' screeching that hides explicit
| power grabs in regulation and surveillance with the main intent
| seemingly to be 'enforce copywrite' (of only the big players
| that can afford to throw their weight around).
|
| Fear pushes people's buttons.
| rmvt wrote:
| i've recently had youtube randomly suggest me a video where
| this dude was building his own opensource manpads, with a
| single rocket costing under $100 in parts (there was no
| explosive payload so that makes it just a rocket and not a
| missile, i guess). not long after, someone posted it here on hn
| but i think it's been removed (by the mods, i imagine) since.
|
| i find these projects both fascinating and terrifying. seeing a
| single person building what normally involves huge defense
| corporations and government contracts, these things in their
| bedroom is amazing. it shows how information wants to be free
| and how ingenious people can get with whatever motivates them.
| mandeepj wrote:
| > with a single rocket costing under $100 in parts
|
| Is there a parts list?
| nbernard wrote:
| I believe it is the same project that was discussed here a
| few days ago: https://news.ycombinator.com/item?id=47385935
| mandeepj wrote:
| I know; I thought they'd have a handy parts list on their
| new site. But you are right; I should have looked in
| their Google Drive docs. There's a section - "Bill of
| materials and cost breakdown", but details are buried
| somewhere. Thanks, though.
| _trampeltier wrote:
| It was here on HN (441 points)
|
| https://news.ycombinator.com/item?id=47385935
| embedding-shape wrote:
| > someone posted it here on hn but i think it's been removed
| (by the mods, i imagine) since.
|
| The submission: https://news.ycombinator.com/item?id=47425297
| "Tech hobbyist makes shoulder-mounted guided missile
| prototype with $96 in parts" -
| https://github.com/novatic14/MANPADS-System-Launcher-and-
| Roc...
|
| Seems to have almost as many comments as points, so guessing
| it got pushed down the frontpage list because of the "anti-
| flame-war" thingy HN has.
| chasd00 wrote:
| The knowledge and skill in the HPR (high power rocketry)
| hobby is definitely there to build basic weapon systems.
| Active stabilization using movable fins is a thing, onboard
| gps and flight controllers are also a thing. Nobody puts it
| together end to end though because it gives the whole hobby a
| bad look and the hobby governing organizations strongly
| discourage it too. Also, fortunately, most people have no
| interest in mass murder either. Much of the hobby is old
| engineers who are retired but still want to work on
| engineering projects in their garage.
| SilentM68 wrote:
| Bookmarked :)
| aliljet wrote:
| I wonder how crazy the scale here can get. How far can I go? The
| bps.space guy is heading into space. Can the community hit the
| moon? Literally.
| EvanAnderson wrote:
| Amateur rocketry achieving orbit would be significant. Reaching
| the moon would be substantially more difficult.
| rigrassm wrote:
| Might be worth checking out the "Copenhagen Suborbitals" group
| (they have a YouTube channel) and see if they're still active!
| It's been years but I think I recall they were trying to build
| something capable of getting a person into space (not sure if
| orbit was a goal).
| lovlar wrote:
| Space Concordia, a Canadian university space-oriented student
| group, which is sort of amateur-level given that it's driven by
| students and donations, attempted to reach space not that long
| ago with a liquid fueled single staged rocket. Here is a video
| of the launch
| https://www.youtube.com/live/610YciEs8qg?t=4594&is=aAWo8Y7vi...
| p-o wrote:
| Thank you so much for sharing this video, it's just amazing
| to see a bunch of young amateurs getting so excited about
| things that would have been virtually inaccessible 20 years
| ago.
| showerst wrote:
| "Space" is 100km. The moon at its closest is about 350,000km.
|
| So the jump from the former to the latter is... significant.
| hermitcrab wrote:
| And you need a serious amount of money, effort and expertise
| to each 100km with a rocket.
| zamadatix wrote:
| Distance is usually the wrong measure in space. Something
| like delta-v will give you a much better scaling as once you
| manage to get something to orbit the rest is actually a lot
| closer than it would seem on the ground.
|
| Not to say the effort somehow becomes peanuts, cheap, or
| easy... but the jump in delta-v needed to go from "100 km
| vertical ascent" to "hit the moon 350,000 km away" is more
| like a ~6-7x increase than a 3,500x one. If the moon were
| instead 700,000 km away the factor would still be ~6-7x.
|
| Cool site for delta-v estimates https://deltavmap.github.io/
| showerst wrote:
| Wow even as a bit of a rocket nerd i'd never thought about
| it that way, that's pretty cool!
| chasd00 wrote:
| Amateurs have reached the karman line, orbit is still pretty
| much out of reach. The people who get close to the karman line
| use two stage passive stabilized airframes and solid fuel
| motors. The airframes are basically works of art and it takes a
| lot of luck because of passive stabilization and Mach 3+
| speeds. Many pictures of these rockets have their paint and
| leading fin edges burned off when they're recovered. Propellent
| is expensive and an attempt at > 100k feet is about $5-6k an
| attempt in propellent alone.
|
| This guy is widely respected in the hobby and this flight made
| it to 293k feet https://www.youtube.com/watch?v=gmv7G6Rf5WE
|
| Check out the liquid bi-prop engines the halfcat guys have,
| apparently they were just certified by the HPR hobby governing
| organization Tripoli which means they can be insured at
| sponsored launches. With a liquid fueled engine you can do
| thrust vectoring (nozzle gymbaling) easier than solid fuel
| motors so active stabilization is more feasible. If you have
| active stabilization then all you need is thrust to weight > 1,
| enough fuel, and you'll eventually get to whatever altitude you
| want. Orbit means orbital velocity and that's just a whole
| other ball game.
|
| https://www.halfcatrocketry.com/
| p0w3n3d wrote:
| I hope this is for students' project and for sending a gopro to
| the stratosphere?
| dzink wrote:
| With the current wars this will only gain more interest.
| joelshep wrote:
| But hopefully not that kind of interest.
|
| Model rocketry, as a hobby, enjoys a limited amount of
| regulation, at least in the US. In large part, that is because
| the community has been very good about self-policing. Most
| folks who are serious about the hobby closely follow the safety
| guidelines published by the two national organizations (Tripoli
| and NAR), and steer newcomers to as well. Serious accidents are
| few and far between, intentional damage even more so. Compare
| this to, say, drones, which seem to be more widely embraced by
| the public, but are much more closely regulated and have been
| implicated in a number of serious incidents like
| https://abcnews.com/US/drone-operator-charged-hitting-super-...
| . Model and amateur rockets are cool. Folks mis-using them are
| going to run into a lot of pushback from pretty much every
| direction, because it'd only take an incident or two to ruin
| the hobby for everyone.
| hermitcrab wrote:
| similar situation in the UK. It would only take 1 or 2 idiots
| to ruin it for everyone.
| stackedinserter wrote:
| Hobby rockets fall into the same regulations as drones.
| hermitcrab wrote:
| Not in the UK (may be true in other countries).
| EvanAnderson wrote:
| This is pretty cool. I remember having fun simulating my rockets
| using the BASIC programs from G. Harry Stine's "Handbook of Model
| Rocketry" when I was a kid. This looks like a way to recreate
| some of that fun.
| swalsh wrote:
| Oh i've been looking for a project for my 11 year old... he's a
| very project oriented learner, which schools don't seem to do
| anymore.
| hermitcrab wrote:
| What country are you in?
| evanwolf wrote:
| Is there a similar drone design simulator?
| gabrielcsapo wrote:
| Have you seen https://store.steampowered.com/app/2060160/The_Fa
| rmer_Was_Re...? It is not a drone simulator more like a problem
| solving game using a drone.
| chasd00 wrote:
| idk off hand but i'm sure there's something like OpenRocket for
| R/C airplanes. Where you put in the dimensions, wing type, mass
| distribution, and other stuff and it tells you if it's
| aerodynamically stable or not. After that you put in an
| ardupilot autopilot+gps+airspeed sensor and there's your drone.
| iirc, with ardupilot you can do automated flight planning like
| "fly to this gps coordinate, orbit for 10 minutes, fly home"
| etc.
|
| to relate to OpenRocket, some people are into rocket powered
| gliders and use autopilots to make flying them after launch
| easier. It's basically a fly by wire setup so controlling the
| glider is on easy-mode with the autopilot doing most of the
| work keeping things stable while the human with the controller
| just focuses on making the slow circles back to the launch
| area. These autopilots are how typical quadcopter drones can be
| flown easily without the wind and 4 motors causing havoc
| constantly.
| chuckreynolds wrote:
| Well THAT's cool. I was just talking about getting back into
| model rocketry... I'm not sure my 6yo daughter will like it as
| much as I did/do but I want to get back into it and launch a few
| and see if she's into it. Timing here is great as I need to start
| looking at starting from scratch with kits etc.
| hermitcrab wrote:
| I bought my son a Estes kit about 10 years ago. He's now at
| University studying aerospace engineering as a direct result.
| So you never know!
| sandrello wrote:
| I read the name and the first logical thought that came to mind
| was that of a platform to have AI agents iterating on rockets
| design. How doomed am I?
| CarVac wrote:
| OpenRocket has a little optimizer built in but of course it
| neglects structural integrity which it knows nothing of...
| daemonologist wrote:
| Just reading the name I wouldn't have been surprised if it had
| nothing to do with rockets whatsoever - I was half expecting it
| to be some kind of "agentic platform to accelerate your product
| development" etc.
|
| I think I need to go for a walk.
| MoonWalk wrote:
| I figured it was a typical no-info HN title; I was happy to
| discover it actually conveyed some meaning.
| entropicdrifter wrote:
| Why would you put that evil thought into other people's heads?
| Now someone might do that
| CarVac wrote:
| I helped out with a user interface redesign of OR many years ago.
| It was pretty incredibly unintuitive back then, and many hobby
| rocketeers paid for Rocksim instead.
| pm90 wrote:
| Im guessing that all the sudden interest in rocketry and drones
| is related to the war in the middle east? Because I have found
| that very interesting too, that a country as poor and as heavily
| sanctioned as Iran is managing to hold out the mightiest human
| forces the world has ever seen.
| hermitcrab wrote:
| Model rocketry has long been a gateway drug to get kids
| interested in STEM subjects.
| QuantumFunnel wrote:
| Helps to have terrain around your country that makes it one
| giant fort
| stackedinserter wrote:
| What do they hold, exactly? Leaders are dead and keeps dying,
| good chunk of their military is defunkt, while "mightiest human
| forces" don't even have boots on ground.
| scronkfinkle wrote:
| The strait of hormuz is still closed, and a new government
| has not been installed.
|
| From a conventional perspective Iran is by all means "losing"
| the war. However, the United States and the majority of the
| world desperately want the strait to be opened and have so
| far been unsuccessful in preventing Iran from blocking it.
| The US is also greatly interested in regime change, which has
| also been unsuccessful.
| lm28469 wrote:
| I highly recommend you to open a few foreign newspaper and
| lurk in foreign forums, groups, &c. you're either misinformed
| or blind
|
| > don't even have boots on ground
|
| Anyone with half a brain cell knows this would be the biggest
| strategic, tactical and political blunder of the century
|
| > What do they hold, exactly?
|
| What they hold exactly is:
|
| - middle eastern countries who've been greasing Washington's
| palms for influence and protection received 0 protection,
| it'll take decades to rebuild any trust here
|
| - Americans deserted their bases in the region instantly,
| they are now damaged or destroyed, the US conveniently ask
| satellite image providers to delay the release of new data
|
| - Lost a bunch (most?) of radars from their early warning
| system in the region
|
| - US sailors seemingly set their own ship on fire to avoid
| deployment
|
| - Depleted israel interceptor stocks, more and more things
| are passing through the dome
|
| - the US spent 12b so far to fuck up Iran, Russia made 6b
| from the gas price increase in the meantime, big brain move
|
| - the US pulling out of asia to send more shit to the middle
| east, eroding trust of countries like South Korea
|
| - Israel support in the US is falling fast, in the EU it's
| gone
|
| - the price of everything will slowly rise, because
| everything we use rely on gas one way or another, they've
| been sanctioned for 50 years they don't give a shit anymore.
|
| - the US showing their complete lack of strategical vision,
| saying something on monday, the opposite on tuesday and
| denying they even said either things by wednesday
| cheema33 wrote:
| Agree with what others have said. And will add that under
| Trump US was losing soft power around the world. But
| attacking Iran accelerated that process significantly.
|
| Most of our allies feel that they can give us the middle
| finger when we ask for help. More people around the world
| than ever before now think that US and Israel are the biggest
| threat to world peace.
|
| This is new and uncharted territory for us. We will pay a
| bigger price for this over the coming years and decades than
| whatever we did to Iran.
| lm28469 wrote:
| Only someone coming out of the US education system can have
| both the power to start such a war and the complete lack of
| knowledge needed to think it would go well...
|
| > a country as poor and as heavily sanctioned as Iran
|
| It's one of the oldest civilization in the world
|
| It's not poor by any means, it's the 20th economy in the world
|
| They produce as many engineers per year as the US, and they're
| not financial engineers or saas coders, fyi:
|
| > mid-14c. enginour, "constructor of military engines," from
| Old French engigneor "engineer, architect, maker of war-
| engines; schemer"
|
| Sanctioned for half a century means they developed other ways
| to live and survive
| hermitcrab wrote:
| We used OpenRocket for designing our rocket for UK youth rocketry
| competition UKROC[1].
|
| It is great for getting a 'spherical cow in a vaccuum' idea of
| likely altitude with different motors, centre of pressure, center
| of mass etc. But it obviously doesn't take account of detailed
| aerodynamics etc and we found the maximum altitude estimates were
| about 15% too high. But it was still very useful.
|
| [1] UKROC is an amazing competition for UK school kids. And there
| are equivalent competitions in the US, France and Japan, with an
| International competition for the 4 country winners. If you know
| any kids interested in engineering I recommend you look into it.
|
| https://www.ukroc.com/
| chasd00 wrote:
| This application gets used a lot in the High Power Rocketry
| hobby. Most of the parts/manufactures are included as well as
| motor manufactures. The simulations are very good and accurate, I
| would sim my larger builds at the location where i was launching
| to get an idea of altitude and it was always pretty close (
| within 5-10% i'd say ).
|
| I use to have a website where you could upload an openrocket file
| and get back 2d drawings for your fins that could then be sent to
| my lasercutting service. The idea was design the rocket in
| openrocket, send me the file, and get back the wooden pieces you
| need cut per the design. Similar to sendcutsend but for the
| rocketry hobby.
|
| Really cool seeing it show up on HN.
| 0dayman wrote:
| you gonna need them!
| darkteflon wrote:
| Does anyone know of something similar, but for aircraft and/or
| drones? I've been 3D printing model aircraft with my 8-year old
| but would be great to take it to the next level.
| hermitcrab wrote:
| There is a game on Steam where you can design and fly your own
| aircraft. Would be fun to then try to 3d print the successful
| ones. But I can't remember the name of the game, sorry.
| looperhacks wrote:
| Kerbal Space Program?
| hermitcrab wrote:
| No, its more aircraft oriented.
| hermitcrab wrote:
| I think it was:
|
| https://store.steampowered.com/app/397340/SimplePlanes/
| svag wrote:
| [Ardupilot|https://ardupilot.org/] maybe? It's for controlling
| the drones, but I think it has simulators as well.
| cyanydeez wrote:
| Love to play "Useful program or random startup" with these
| titles.
| ahd94 wrote:
| There should be an agent for this :D . What kind of tooling do
| you folks use for simulation ? Maybe there is something to be
| done there. ?
| mclau153 wrote:
| or an integration with a 3D game engine
| jonwinstanley wrote:
| Hahah - you'd have made Kerbal Space Program :-)
| _moof wrote:
| Software developers: I am begging you to put representative
| screenshots on the home page. This has become a real widespread
| problem.
|
| I know you want to tell us all about the amazing (sincerely!)
| stuff under the hood, but to users, the interface is the product.
| jdjdjdjdjd wrote:
| Yes!!
| deadbunny wrote:
| https://openrocket.info/features.html
| _moof wrote:
| I said
|
| _> on the home page_
|
| and I meant it
| andai wrote:
| Here's how this page looks on my phone:
|
| https://files.catbox.moe/2idw98.jpg
| andai wrote:
| I also like it when there's a short video that shows how the
| thing works and what it can do.
| nytrox wrote:
| Its a nice project !
| perryprog wrote:
| Tangentially related is NASA's open source GMAT[0] software which
| is more focused for calculating orbital transfers and the like.
| It's pretty fun to play around in.
|
| [0] https://software.nasa.gov/software/GSC-18094-1
___________________________________________________________________
(page generated 2026-03-18 23:00 UTC)