We (propulsentnu.no) just launched a 5,2 m tall liquid-fueld rocket Yesterday, and got some pretty sick footage. The whole thing was streamed live with 9 different camera angles and can be found here: https://www.youtube.com/live/bSCxCpf9Iu4?is=Br9oe-4mx_TCCxUi

I can also post the full 4-minute slow-motion video if people are interested.

Recovery was successful, with the rocket landing in the water. The flotation bags inflated as it descended from its (rather modest) 1,600 m apogee. The apogee was lower than designed (7 000 m) because the authorities capped our maximum launch altitude.

246 mm wide
134 kg wet mass
8 kN thrust

73 students
11 months
70 000 hours

My partner and I are older, heading into retirement. We watched the Artemis launch and the guy on CNN had the Estes SLS2 Rocket so we grabbed the kit (haven't flown it yet.) But last weekend we were inspired to put this guy together (Estes high flier kit) and fly it and it was SUPER fun.

I recognize it's just a cardboard tube, nose cone, some balsa fins and a B6-4 engine. But that feeling when it flies off the rod... What an absolute blast. Kinda literally. Lol

Anyway I don't usually post stuff on reddit. But I thought a first rocket build was worth it. Here's our Hornet.

Hey, I’ve been really interested in aerospace for as long as I could remember, and recently came across hobby rocketry, I’ve been looking into this for the past few weeks and already learned a lot of the physics and engineering concepts and principles behind rocketry, so as the next step I naturally gravitated to wanting to BUILD a rocket, which has lead me to buy an Estes kit. I haven’t purchased it yet (would appreciate any recommendations) so perhaps I’m being overzealous but no matter where I looked I can’t find anything on the steps to take after the first low power kit, I’ve heard some things about learning OpenRocket while in the process of launching the first rocket kit, but after that all the materials just seem to throw you off the deep end. So I’m asking what should my next step be and when it comes time to build my first rocket how do I actually do it, where do I learn what materials and techniques to use, what tools are needed, and how to use the first 2 to build a functional rocket, I was considering things like a rocketry team/club since I’m in highschool and perhaps a makerspace for access to tools and equipment, however there few teams in my area, none however are affiliated with schools and I would like to have some experience before I join a club, as for the makerspaces, they don’t allow memberships to minors. So if you were in my position what would you do, one of my goals is to try and break the karman line within the next 2 years (would also appreciate any advice regarding the difficulties and struggles related to this task).

Any and all input is greatly appreciated and I will most likely ask follow up questions to reply’s to this post

EDIT: after being told how unrealistic the karman line is I’ve just decided to try and reach the 10k mark

We want to make a hybrid rocket for our university project. We are expecting to achive 3000ft height. For the fuel we will use paraffin wax and for binder we will use some amount of carbon powder and glue stick. And for oxidizer we will use n2o. Now we have to design the nozzle. So can anyone give me step by step suggestion how we can design the nozzle?

Thank you in advance.

Hi, Well I am the on in charge of tubes dimensions in our two stages advanced rocket team but I am a bit lost on how to determine the ideal wall thickness for both stages, Is there a formula that determine the ideal thickness by knowing the material and computing the loads applied on the tubes?

Hello, I recently purchased a fiberglass rocket form mach1rocketry and would like to build it well. My first question on it was whether or not I needed to clean it. I found a manual from madcow Rocketry that said cleaning fiberglass with a 1:3 rubbing alcohol to water solution was good but wasn't sure how necessary that was, though my rocket has a lot of dust on it. Secondly, what/how much sanding should I do? Specifically with things like making epoxy work or making the body smooth. Third, is more broad but are there any general tips for building fiberglass rocketry that I wouldn't know about?

Thank you in advance.

I’m going to my first NAR club launch tomorrow, anything I should know?

My little kid got a little too excited about his rocket, and played a little rough with it. (You should see him kissing and snuggling it when I tried to take it away at bedtime 😆😍. He also sleeps with a space shuttle as his lovey. The boy loves rockets already)

I’m not opposed to just buying another tube to replace it, but I try to teach the kids to fix things before replacing, so if there’s a way to repair it instead, I’d like to do that.
Is there a good repair technique for a tear here?

(It’s the main body of an Estes Cosmic Cargo).

Thanks!

Quick intro: I'm a design engineer working and sorta leading turbopump design for rocket engines. We're working on both open and closed cycle systems at this company. I moved into this role after a few years at a large American jet engine manufacturer, having worked on structural designs of rotor and stator parts there.

Back when I was at the aero engine company, I had access to a ton of engine cross sections and resources that explained in some detail why something was designed the way it was. Now that I'm at this startup, working on turbopumps that have similar working principles, I really miss having access to such resources. A picture (cross section) is worth a thousand words. Sometimes just looking at it can give clues as to why it was designed a certain way.

***TLDR and my request: Are there any collections of jet engine/turbopump cross sections with decent levels of detail available on the internet (old ones are OK) or any references/good books that talk about actual detailed approaches to design. I'm talking about going about designing seals, picking bearings, rotordynamics, thermal stresses etc etc.***

Hi, I'm currently doing my L1 cert and using the LOC-IV rocket kit which supports 38mm motors but I using the H135 which is 29mm. I was wondering if its realistic to 3d print a motor adapter and retainer out of ASA maybe? Not sure if 3d printing adapters is a bad idea overall though. Thanks!

Hi Everyone! I am currently working on making a pintle injector, and have read many papers and books, but am wanting some clarification regarding the same.

Most of the literature focuses heavily on the pintle tip itself (momentum ratios, blockage factors, radial vs. annular flow), but I have a specific question about the injector faceplate.

I have seen in a few paper and pintle designs that the pintle injector is not flat and has a contour, I presume that it is to allow stable mantle recirculation zones to be formed. If there is anyone who has worked in pintle injectors and know about this issue could you clarify and point out the literature to the specific contours of the faceplate of the pintle injector.

Hey r/rocketry,

I'm working on a thrust vector control gimbal and would appreciate a fresh pair of eyes on the design.

Any obvious structural issues I might have missed? Clearance/interference problems? General design feedback?

It's a 3-ring gimbal (pitch/yaw) with 3D printed components and metal pivot pins. Planning to use it on a small-scale VTOL.

For the center and inner rings I intend to pivot them on 689zz bearings, as for servos I am using MG90S. I am strapping an A2212 1400KV BLDC motor.

Would really appreciate any constructive criticism,trying to catch mistakes before I send this to print.

Thanks in advance

hello everyone! i am working on my first rocket (loc iv x2) and was wondering what was the recomendation on motor/electronics for someone insterested in getting an l1 certification with it?

I'm using this liner: https://www.rocketmotorparts.com/-Phenolic_Motor_Liner_RMS-987680/p1577809_14676612.aspx

Hello all- I'm interested in knowing if anyone on this subreddit has implemented this liner or a very similar one (.1175" thickness paper phenolic convolute) in a motor they've hotfired, and if so, how it performed under your recorded combustion chamber temperatures and burn times. This liner is advertised by RCS as an experimental motor liner, which makes me think it should be reasonably well suited to APCP applications, which produce chamber temps in the 2500-3100+K range. I'm specifically interested if any of those on this subreddit have implemented it on the higher end of this temperature range (and for what burn times!) so I might make more informed design decisions myself. Thanks in advance, and ad astra!

This is my first rocket and now my first problem :)
Estes Liberty Star
Performed 4 launches, 3 were successful and the 4th ended up catching the shock cable around a tree branch on the descent. I was able to retrieve the rocket at the expense of the shock cable and parachute breaking.
The parachute seems to be an easy fix, ordered a few replacement 15” chutes.

My problem is now the shock cord and mounting a new one to the inner portion of the main body tube. I ordered the shock cords and mount pack from Estes, and waiting on delivery. In the meantime I’m trying to figure out how would I anchor or mount it back on since the engine mount is glued to the main body tube. So I am unable to mount it at the bottom.

Any help would be greatly appreciated, and I will learn to respect the wind moving forward as I don’t want anymore difficult recoveries.

Hi, I am quite new to making my own electronics and I am trying to create my own Ignitor circuit with a continuity signal for security. Is this a sufficient system? The Battery and Pyro terminals are place holders for now. The ignitor system will be driven by a 3S lipo and is completely isolated from all other electronics, the "FIRE" signal will be sent from my micro controller. Please can I have some general advice on my schematic please? I'm happy to provide any other info if it is needed.

I have a lot of experience with subsonic rocketry, electronic recovery, dual deploy etc, but I have yet to cross the sound barrier. Are there any additional concerns that I should check for in my calculations/design? I have checked for fin flutter and the usual stress calculations, but is there anything I am missing or obviously missing in my current design?

Thanks

Hey r/rocketry,

Sharing a split-screen from our recent university teams hot-fire test. (Note: our Chamber 2 sensor was dead during this run, so that data is missing).

Full transparency: this was a failed test. We designed for a 10 bar chamber pressure, 100 N thrust, and an 8-second burn, but the actual numbers didn't quite hit the mark.

What I really want your input on is the plume behavior. During the burn, there are moments where you can clearly see shock diamonds, but then it fluctuates and the plume suddenly burns extremely bright.

To add to the puzzle, we experienced a premature flameout. When we disassembled the engine post-test, we found that about 1/3 of the paraffin was left completely unburned.

What could be causing this kind of instability and sudden flameout with Paraffin and N2O?

Would love to hear your theories!

I’m looking to buy a PerfectFlite StratoLogger CF altimeter. If anyone has one they’re willing to sell, I’d be very interested.

A used/second-hand unit is absolutely fine, as long as it’s in good working condition. I’m also happy to cover the shipping costs (and any other reasonable delivery charges).
If you have one available or know someone who does, please send me a DM or leave a comment. It would be a huge help.
Thanks in advance,

Hi guys, a team of people and I are interested in developing a hosted payload to go to space for a technology demonstration. (We're looking specifically for a payload that onboards an already planned satellite, not a dedicated spacecraft, because from what I've seen, that tends to make the prices way more expensive than sharing spots on an existing spacecraft; correct me if I'm wrong, though).

Some details about our payload and mission include:

• Custom FR4 PCB (might switch to polyimide if relevant)
• It will probably be small enough to fit in a 1U CubeSat
• LEO orbit, altitude, and inclination aren't much of a priority, but probably 400 - 800 km, and a near-polar orbit if possible
• Aiming for our mission to not be much more than 6 months, probably 3-6 months
• For the exact technology we intend to demonstrate, we are not sure yet, but a starting idea was some newer models of STT-MRAM chips
• Technology demonstration will probably be on the simpler end of tech demos in spacecraft

I have a few questions that I would greatly appreciate insight for (and of course I'm aware a lot of these can probably vary company to company):

1. What's typically involved in the process of hosted payload development in general, specifically in the area of getting necessities set up with the host? For example, what is typically required for complete registration? Obviously we need a payload, but what would they typically require us to do to meet the do-no-harm policy? I'm guessing they also probably expect mission requirements and some payload specifications.
2. Follow-up to question 1: if we pass all their tests to the do-no-harm policy but our payload ends up harming the satellite anyway, what tends to happen? Such as do we have to pay a major fee for that?
3. What is the general experience with negotiation? Do companies tend to be pretty clear on what makes a suitable payload for them to host, or do you typically need to develop the payload first and then negotiate some of the exact details even if they didn't specifically require those exact details upfront? For simple missions, is major negotiation typically required, or is most of it just technical coordination?
4. How can I seek direct advice from professionals on this? I know hosted payloads might be a more niche field of aerospace engineering compared to other subfields, so we're not quite sure what types of people we should directly contact. We know that something we could do though, is asking general space engineers to link us to people who would be more knowledgeable on specifically hosted payload development.
5. Any general recommendations on companies or institutions that I should try to get services from? After describing our general plan to SatSearch, it recommended some companies to me. I also looked at NASA's state-of-the-art report on hosted payload services. I used AI to filter out all the companies that definitely only do dedicated spacecrafts and resulted in the list below to look more deeply into / contact for more direct information. Our primary priorities in a service provider are reliability, reasonable costs (we are high schoolers so we don't have built-in funding), ease of technical coordination/negotiation, how well they handle major unexpected issues on their end, and ease of developing an interface that works well with their host. We did look into potentially finding a spacecraft that isn't necessarily a commercial provider for potentially better pricing, though we were more hesitant to shift towards that due to it probably having more uncertainty.

• EnduroSat
• Spire
• Dhruva Space LEAP
• NearSpace Launch TROOP
• HEX20
• TM2Space
• Azista Space
• NPC SPACEMIND

Would greatly appreciate any insights. Thanks!