r/rocketry Jun 21 '20

Announcement r/rocketry now has a Discord server!

81 Upvotes

Feel free to join the r/rocketry Discord server! Click here for invitation link.

We intend this to be a place where any user can get a quick response from knowledgeable rocketeers, as well as a more appropriate place for content related to rocketry, but that doesn't quite fit the sub. Any and all discussion is welcome and there are appropriate channels for many relevant topics.

Please suggest server improvements in the #server-suggestions channel or in the comments below.


r/rocketry Dec 20 '25

Minor subreddit update- all posts require manual mod approval

58 Upvotes

Several months ago, this subreddit was inundated with repeated off-topic posts from a well known troll/spammer. Bans did not work because the user just came back with a new account.

To combat this, it was decided to implement a rule where all posts require manual approval from a moderator. If you noticed the spammer hasn't posted here in a while, that's why.

Unfortunately, this means posts will only go live when a moderator is online and checks the mod queue, so there may be a delay of many hours before posts show up. Mods have jobs and lives outside of reddit. You are not shadow banned.

Several users have been sending mod mail after every post, thinking this will help their post be approved faster. This is unhelpful- we will see the mod mail the same time we see the post in the mod queue. Please stop messaging moderators about this.

If your post is not approved, that means it violated some rule. You may have also noticed there are fewer posts recently with low effort questions about unsafe ways to make motors (violating rule 2)- this is why.


r/rocketry 7h ago

Showcase Our new rocket

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10 Upvotes

Our new rocket is full ready to launch with 100 N-s motor, 540m apogee


r/rocketry 5h ago

Tube arrived slightly crumpled on one side, is this salvageable or not worth risking?

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2 Upvotes

Just got in an LOC goblin, and ups wasn’t very nice.


r/rocketry 17h ago

Question How to know how will Mt model rocket fly, which engine will be best for it and is it aerodynamic?

2 Upvotes

I'm 3d printing a model rocket (medium size) and I wanna know how will it perform before 3d printing it


r/rocketry 1d ago

Gibt es deutsche hier?

5 Upvotes

Hallu ich suche deutsche mit denen man sich austauschen kann einfach Kommentar schrieben vielleicht kann man ja einen discord machen


r/rocketry 2d ago

Question Model rocket design review

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51 Upvotes

Hi, I've been designing a small model rocket powered by a Klima B4-4 engine.

This is the first rocket I am making from scratch so I would be grateful if someone could review the project. I am open to all corrections and advice.


r/rocketry 2d ago

Coming up soon Oct. 3 -4, 2026 Louisiana Rocketry Fall Launch

10 Upvotes

Louisiana Rocketry

Fall Launch Dates

Oct. 3 -4, 2026

Oct. 31 – Nov. 1, 2026

Time: 9:00AM – 5:00PM Saturday 9:00AM – 3:00PM Sunday

Club Membership: (Join At The Launch Site) $30.00 per Year

Launch Fees:

High Power: $20 / Members $10 for the weekend

Mid Power: $10 / Members $5 for the weekend

Low Power: FREE for ALL AGES

(Chris’ Rocket Supply is our ON-SITE vendor) [csrocketry.com]()

Launch Site Location: Goldmine Plantation

https://maps.app.goo.gl/46BLZhvHvrk3TspcA

NOTE: We do NOT allow Sparky, Skid Mark, Metal Storm, Dark Matter or any other sparking propellants!

If we cancel a launch due to weather, we will announce it no later than 9:00 PM on the Thursday before the launch.

There is a 10,000′ FAA waiver for our field and flights can be made to 14,000′ with a call in.

NOTE: We do NOT allow Sparky, Skid Mark, Metal Storm, Dark Matter or any other sparking propellants to be flown or burned at our launches!

Motors allowed are 1/2A through M impulse. If you plan on flying L or M motors please contact Paul Sansoucie to arrange for pad placement or if you require the large rail (1515 rail).

We do not have ground support for hybrid motors, If you plan to fly hybrid motors you need your own GSE, please contact in advance.

A Porta-Potty will be on site. No Camping allowed on the field. No BBQ or cooking allowed on the field

 


r/rocketry 2d ago

L1 rocket "Tiny Tim"

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196 Upvotes

Decided I wanted to do a scratch build for my level 1 and made a ~1:3 scale model of the ww2 naval rocket Tiny Tim. It took a lot of learning and I had to leave some details out, but I'm overall very happy with how it turned out.


r/rocketry 2d ago

First launch

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92 Upvotes

Had a small error with the ignition at first 😅, smooth from there.


r/rocketry 2d ago

Question Please help me with a water rocket designed using OpenRocket

5 Upvotes

\I’m currently using a translator, so I apologize in advance for any awkward wording or misunderstandings.*

Hello. I’m a high school student, and I don’t know much about rocket design, but I need to build a water rocket for a school project. I’m planning to launch it vertically. I’ve made a rough design using OpenRocket, and I have a few questions:

  1. Could you give me some feedback on this design? I’m planning to make it by connecting two 1.5 L PET bottles together, so it’s difficult for me to change the diameter. I’m also planning to attach an Arduino sensor to the front.
  2. I wanted to find the optimal design through simulation, but I couldn’t find a motor for water rockets in OpenRocket. I also looked into generating a thrust curve using other simulation software, but I couldn’t get it to work because I don’t know the drag coefficient. Is there any way I could run a simulation for a water rocket?

r/rocketry 2d ago

Question AeroTech 38/480 RMS

9 Upvotes

Hey yall
I’m looking to purchase a 38/480 complete set. Given AeroTech has a 16-30 week lead time I wanted to see if anyone can point me in the right direction for vendors who have any stock of complete rms motors.

Thanks!


r/rocketry 3d ago

Showcase Using a vacuumed centrifugal mixer for mixing AP propellant

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212 Upvotes

r/rocketry 2d ago

🚀 Redmond/Bellevue parents: kids can build & launch their own model rocket

7 Upvotes

If you have a kid ages 6-11 who loves science, engineering, or space, I’m running a small hands-on model rocketry camp in the Redmond/Bellevue area.

This isn't a sit-and-watch science class. Students will:

🚀 Build their own model rocket
🧪 Learn the science behind how rockets fly
🎨 Customize their rocket
🔥 Learn how the propulsion/recovery systems work
🚀 Launch the rocket themselves

I’m keeping the group small so every student gets a genuinely hands-on experience.

The camp will be held every Sunday 1-3PM from Sept. 13th to Oct. 4th at 60 Acres. There will be indoor spaces in case it's raining.

Registration: https://pci.jotform.com/form/262297609462163

If you have questions about the camp, location, safety, or what the kids actually do, feel free to email me at liftofflab@icloud.com.


r/rocketry 3d ago

Discussion Any thoughts on "Full flow Segregated Cooling Cycle"

1 Upvotes

The Indian space-startup "Ethereal Exploration Guild" just put out a video (linked below) explaining what they call the Full-flow Segregated Cooling Cycle for their future fully reusable vehicle design. Most of the video is just marketing but the idea of the cycle itself seemed interesting.

According to the limited information from the video, it seems to be a variation on an expander cycle but with multiple phases. Idk what the exact plumbing is (maybe one could work it out based on the renderings in the vid) but apparently, during the ascent stage it's pretty much a closed expander cycle, with one (or both?) of the propellants heating up through the combustion chamber cooling, being used to drive the turbine.

The interesting bit imo is the reentry phase, where they want to use one of the propellants (ig RP-1 from the vid) as a heat sink for the reentry heating to avoid having extra reentry shielding/reentry burns. The heated RP-1 then transfers its energy to the LOX which is used for driving the turbine. My guess as to why they're using RP-1 to absorb reentry heat but LOX to drive the turbines is that the respective properties are better suited for the job and outweigh whatever loss of energy there is due to the heat transfer.

The engine is supposed to provide 80 kN of thrust with an Isp of 323 sec in vacuum and 293 sec at sea level, so nowhere near to the Isp of engines like the RL-10. Are there actually benefits to this cycle or is it just something to generate hype?

They also mention a supercritical Brayton cycle (ig for the LOX) so maybe they want to keep the Ox supercritical for the expansion section? Anyways, there's not much info out there about this design so I was wondering if anyone had more info on it or any thoughts?

Here's the video (from the important part)


r/rocketry 4d ago

Question How necessary is CFD for predicting drag on a ~Mach 1.1 high-power rocket with deployable airbrakes vs using OpenRocket?

22 Upvotes

I’m part of a university rocketry team currently developing a high-power rocket targeting roughly 3 km AGL, and I’m trying to decide how far we need to go with aerodynamic modelling.

The rocket is approximately 150 mm diameter, uses 4 clipped-delta fins, and is expected to reach around Mach 1.0–1.1. We are also using 4 deployable airbrake petals during coast to control apogee. The airbrakes deploy radially from the body, with their large exposed face approximately perpendicular to the freestream, so their drag behaviour is quite different from that of a normal fin.

At the moment our trajectory model is in RocketPy, with the clean-rocket drag curve obtained from OpenRocket as a function of Mach.

For the airbrakes, OpenRocket does not natively model this geometry, so I have been experimenting with representing the fully deployed brakes as an equivalent fin set with approximately the same projected frontal area. This gives me a second C_D vs-Mach curve for the fully deployed configuration.

Our current simplified RocketPy airbrake model assumes four paddles with about 1156 mm² projected area each and uses an approximate flat-plate C_D = 1.2..

My concern is that this becomes increasingly approximate near the transonic region, particularly because the deployed airbrakes will generate separation, wakes and potentially local shock interactions that OpenRocket’s equivalent-fin approach obviously isn’t designed to reproduce.

I am therefore considering doing a full ANSYS Fluent CFD campaign on the actual rocket CAD. My plan would be to analyse both:

●airbrakes fully retracted and fully deployed;

●Mach numbers roughly 0.3, 0.5, 0.7, 0.8, 0.9, 0.95,\ 1.0, 1.05, 1.1;

●angles of attack around 0,2.5,5.

The main outputs would be C_D(M,angle of attack), normal-force coefficient / pitching moment where useful, and the loads on the individual airbrake petals. I could then feed the CFD-derived drag curves back into RocketPy/OpenRocket for trajectory simulations.

My questions are mainly:

1)How much confidence would you place in OpenRocket/RocketPy-style drag modelling for a rocket only slightly above Mach 1?

2)More importantly, would you trust an equivalent-fin/projected-area model for deployable airbrakes for apogee-control predictions, or is this a case where CFD is genuinely justified?

I’m not expecting CFD itself to be automatically “more accurate” — I’m aware that turbulence model, domain size, mesh independence, atmospheric conditions and transonic convergence all need to be handled properly. I would likely use 3D compressible RANS with k-w SST, ideal-gas air, inflation layers and mesh/domain-independence studies.

If anyone has done CFD validation of high-power rockets, transonic rockets, or deployable airbrakes, I’d really appreciate hearing how closely your CFD agreed with OpenRocket/RASAero/flight data and what level of modelling was actually necessary.

Thanks for your time :D


r/rocketry 4d ago

Raptor Engine Fluid Model

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138 Upvotes

Hi everyone! A few weeks ago, I released my open-source lumped-parameter dynamic fluid system solver, FullFlow, and mentioned that it could be used to model steady-state and transient flow in real rocket engines. So, I decided to showcase those abilities with my favorite rocket engine, SpaceX's Raptor Engine.

Raptor is a full-flow staged combustion engine, so it's particularly hard to model correctly, especially with the multiple combustion preburners, regen channels, turbopumps, etc. With the public data I had available, I was able to construct and validate (to the best of my ability) a steady-state model of Raptor 2. I used FullFlow to model the fluid pathways and components and ThermoProp to model the fluid/material properties and combustion.

Of course, there are some deviations from reality, especially since there is only so much public data available. I had to estimate many data points like turbomachinery curves or valve geometries. I also didn't have the proper tools to model supercritical combustion flow for the preburners or hot-gas manifolds. Also, I didn't have access to empirical efficiency values for components like the nozzle or pumps.

Eventually, given enough data, I hope to make a transient simulation of Raptor using FullFlow. I also hope that I can eventually apply these tools and skills to the actual Raptor engine or other industry engines!

Raptor 2 FullFlow Model: github.com/saakethramoju/Raptor

FullFlow: github.com/saakethramoju/FullFlow

ThermoProp: github.com/saakethramoju/ThermoProp


r/rocketry 4d ago

Question Launchcontroll Curcuit

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10 Upvotes

Hey Guys,

I am currently trying to build this curcuit for my Launch controll case.

I have been trying for the past two days to figure out how this curcuit works, where to get the parts and more importantly which parts to get.

Moreover I want to avoid as many wires as humanly possible and therefore want to make this curcuit a PCB but suprise.. I do not got any experience designing PCBs.

I am hoping you guys might be able to help me out with which parts to order and where to order them so they won`t break the bank (I`m from the EU) aswell as what I have to consider when designing the PCB.

Thank you guys in advance :)


r/rocketry 4d ago

Question I'm beginner

6 Upvotes

I'm currently a 10th grader, and I'm thinking of spending the next year building model rockets with my friends. So, I'm planning to buy an Estes kit that includes a launch system and a rocket, along with a C motor and recovery wadding. Do you have any rocket recommendations? Based on experience, what size rocket motor should I buy? (I live in Asia, so I'd like to buy everything in one order if possible).


r/rocketry 5d ago

Showcase first 3d printed rocket

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116 Upvotes

r/rocketry 4d ago

Quizz L2 Tripoli

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0 Upvotes

Hi, here's a useful link to practice for your L2 Tripoli exam! (in French for now)


r/rocketry 5d ago

Question Building Thrust Vector Control mount

8 Upvotes

So I wanted to purchase the 3D print files for a Thrust Vector Control mount by BPS Space, but Joe is no longer selling the "Signal R2 kit" which I believe included the flight computers and whatnot. My knowledge in coding, PCBs and arduino is honestly very limited, and I'm not sure if I'd be able to figure out how to make my own breadboard, much less a custom PCB for the flight computer.

If anyone has experience or any tips on what I should do, please let me know.

https://bps.space/products/thrust-vector-control


r/rocketry 6d ago

Question Launch location?

9 Upvotes

so ive been wanting to get into rocketry for a while now and i've finally finished building my first model rocket (estes journey). the only problem is that i have no idea where im supposed to launch it. are there any good launch spots in the indianapolis area that you guys know of? thanks


r/rocketry 6d ago

Question Looking to get started as an ABSOLUTE beginner in rocketry

19 Upvotes

Hi! I'm a rising junior in high school and I'm hoping to learn rocketry as a long term passion project. My goal is to understand enough to design, simulate, and build my own model rockets for a rocketry club.

Over the past couple days, I've watched a bunch of youtube videos on how to build DIY rockets/get started on rocketry, but I've been struggling to figure out what to learn, and in what order. Please keep in mind that I'm a COMPLETE beginner😭. I have some background in general physics and Calc II, but I essentially know nothing about fluid dynamics, aerodynamics, and CAD. Also, I'm not in the U.S., so its very difficult for me to find a mentor/rocketry program :(

What theory should I learn before designing/building? How much fluid dynamics, electronics, etc should I know?

and how should I learn simulation, CAD and rocket design? please tell me programs/websites you found to be helpful.

ANY advice would be very helpful. I'm feeling very lost as of now. If anyone has been in the same situation & managed to learn rocketry from scratch, please tell me how. 🙏🙏🙏


r/rocketry 7d ago

Showcase Launch control circuit

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31 Upvotes

I built a little launch control circuit, 12v with a battery voltage level indicator, continuity and firing indicator. When installed in its housing it will have a master power switch, locking arm switch and the momentary for firing.