How could we calculate the dimensions of injector hole ,combustion chamber length and mass flow rate for Hybrid Combustion Chamber

I friend of mine’s husband recently passed a way, and she “inherited” my son and I his extensive collection of rocket kits. Does anyone have the pdf directions for Boyce’s discontinued version of the 1:100 Saturn V fin can? https://boyceaerospacehobbies.com/collections/upgrades-more-1/products/saturn-v-fin-can?variant=15497657450541

If you could share a copy it would be much appreciated!

Hi, I'm currently starting of a physics project at my high school, we will progress onto more advanced designs with more stages, as more people join us and we have more funding from the school, but for now for a low powered rocket with a D9 motor do, would PVC or PC do?

Would you recommend me some other material with a density close around 1g/cm3 up or down?

I have heard many people discouraging others from using these materials, but only saw that on posts with more advanced and with higher power rockets, so I just wanted to make sure I'm safe with getting these as my rocket body.

Also do these materials have any problem when using epoxy on them? (I will need to attach my fins as well..)

I'm pretty new to this, just started out ~2 months ago, so I would appreciate the biggest amount of opinions and recommendations possible.

Thx!

PS. if there is anyone here from Poland I would appreciate some info on regulations and laws regarding rockets, at least low-middle power ones.

Really interested to see if this actually works out, but wanted to see if a convergent-divergent 3D printed nozzle would work on a BP motor. Wasn’t expecting the math to say that a PLA nozzle would last longer than a polycarbonate one. Gonna do a couple static fire tests tomorrow.

(Noob Aerospace student just getting into rocketry trying out random stuff)

Ok, this might be a dumb question, but, why do vacuum engines in space need pumps. Shouldn’t the vacuum of space be able to suck the propellants out? And, there could just be a valve to control the flow of propellants and throttle the engine. I might be missing something though, so please correct me if it’s wrong.

I just joined a student liquid engine team. We're making an Ethanol / GOX (gaseous oxygen) engine, pretty small scale, small budget ($1000-$1500).

I'm the only person on the team with an interest in controls and avionics, and I'm new to this. I have some great professors who can help me if I need it, but I want to at least get a good understanding of where to start. I have taken some controls classes (optimal control, nonlinear controls, multivariable controls) and worked as an avionics engineer in my last internship on cube sats, but other than that, have no experience. My degree is in Mechanical Engineering.

Any advice on where to start learning would be greatly appreciated. Thanks in advance!

Hi everyone, I´m 18 years old and started my Physics B.Sc. this semester. I joined the Rocketry group at my University, as I am very interested in Rockets, Space, etc. Most of the people in the club are studying aerospace engineering and already know how to use CAD Modelling, FEM, etc. I on the other hand know absolutely nothing about rockets compared to them. It´s kinda a ruff start when your teamlead asks what you want to do and you can´t tell them anything because well - you don´t know what you CAN do at all. As part of the onboarding we are supposed to model a two stage rocket in which we will put fireworks, until next week. I have no idea how to start. Am currently trying to figure out how rockets work in the first place, then which parts I need to think about creating. But then I still have to model the whole thing, having never used CAD before. I´m super lost and a bit scared that others and especially my teamlead rather see me as someone who constantly needs help. I don´t think I´ll be able to make even a half-ass design until next week. What should I do?

Hello everyone,

I'm a 15 years old student from India, passionate about rocket science and engineering. I’ve been working on an educational project to design and build a small electric-pump-fed rocket engine for last 2-3 years. The engine is designed to produce a thrust of 1 kN. I want to emphasize that this is purely for educational purposes, and no fire tests will be conducted until I turn 18 and obtain all the necessary legal permissions.

Recently, I’ve been trying to seek permission from local authorities to begin constructing the engine. I’ve sent emails to the District Magistrate and the Commissioner in my area but haven’t received any responses. Today, I visited the DM’s office in person with my father, but unfortunately, the DM wasn’t available. I met the City Magistrate instead, who dismissed my request and returned my letter without much consideration.

To be honest, the experience left me feeling defeated. I’ve put so much effort into researching and designing this project, and I believe it’s an important step for my education and passion for aerospace.

what i am looking for now?

1. Has anyone faced similar challenges in pursuing a project like this? if yes please tell how you got permit?
2. Are there alternative avenues I can explore for support, such as ISRO or other scientific institutions?

I’d be grateful for any advice or encouragement. This project means a lot to me, and I don’t want to give up on it.

Thank you for reading.

this post was originally posted on r/AerospaceEngineering 1 day ago. I am posting here to get some more advice. (https://www.reddit.com/r/AerospaceEngineering/comments/1gusk8j/im\_a\_15yearold\_working\_on\_a\_rocket\_engine\_project/?utm\_source=share&utm\_medium=web3x&utm\_name=web3xcss&utm\_term=1&utm\_content=share\_button)

Thank You!

Hey guys,I am from a Rocketry company in India.Recently we had this requirement forwarded from a team participating in Spaceport competition.They need someone who is a L3 certificate holder and would be interested in helping them out.

Hi, I’m a high school junior, and I’ve been trying to come up with a research question in Aerospace Engineering for the past few weeks. As you can imagine, I have very little experience in this field, so everything feels new and overwhelming, making it difficult to even get started. I've attempted to formulate a few questions on my own, but none of them feel strong enough. These challenges have made me question myself, and I’ve even considered switching to a more familiar research area or quitting altogether. But my passion for aerospace engineering is what keeps me moving forward.

This isn’t my first time posting on this forum, and I’m extremely grateful for all the helpful advice and insights I’ve received. One piece of advice that’s come up consistently is to first choose an area within aerospace engineering that interests me. After doing some background research in that area, I should expect to see certain topics stand out to me. The final step would be to develop a research question around one of these topics, making sure it addresses an existing issue in the field.

I’d love to hear if others, especially those with more experience, agree with this strategy or if they have additional tips. Also, if you have any suggestions on specific issues or topics I could explore, that would be greatly appreciated.

So I got the idea of creating a flight controlled rocket with a flight computer and have already designed my rocket as well as the material that it will need to ignite for it to fly. I am quite skilled in programming using hmtl,css, duckyscript, lua, and python as well as cybersecurity, and have started learning electronics around 2 years ago. Any tips to creating a flight computer using raspberry pi zero w or raspberry pi pico? Where should I start? im not much of an arduino fan.

I'm looking to develop a calculator similar to this one, to help me tweak a rocket's rough characteristics and determine its maximum payload. The rocket is accelerated inside an evacuated launch ring to Mach 7 then ejected at ~6000 m, destined for orbit at ~400 km.

I'd like to tweak most of the input values (below) to determine whether a small rocket could make it into a given orbit, and how much of a payload the rocket could carry. (This is for a near-future, hard sci-fi novel, so I'm looking for reasonable accuracy, rather than perfection. Being off by 10 kg won't make any difference.)

Some assumptions:

• The nosecone can withstand the heat.
• The air is sufficiently thin that the rocket can survive initial contact with the air when transitioning out of the vacuum unscathed.
• The fuel is solid metallic hydrogen (1.15 g/cm^(3)). Don't get hung up on this aspect: it is simply an input value to the calculator (e.g., fuel mass).

To get a decent estimate for the maximum payload, the calculator needs at least the following inputs:

• a starting elevation (6212 m)
• a starting velocity (Mach 7)
• an orbital altitude (400 km)
• surface temperature (25 C) (to derive air density at elevation)
• specific impulse (1700 s)
• wet mass (250 kg)
• dimensions (e.g., length [4 m?], diameter [0.5 m])
• drag coefficient (0.75)
• latitude (1.469167)

Here are some equations that may be needed:

Equations

I'm wondering:

• What other equations are necessary to make a calculator that can help compute the maximum payload mass that such a small-sized rocket could include while still reaching the desired orbital altitude?
• What other inputs may be needed (e.g., inclination at orbital altitude)?
• What needs to be added to accommodate drag decreasing as the elevation increases?

Thank you!

This is purely a theoretical question, and I have no intention of ever doing this.

Could you theoretically use a small BP motor (b/c sized) to ignite a large BATES grain motor? Similar to the AJ-260 with a smaller rocket motor in it that ignites? This is an interesting concept to me and I was wondering how feasible it would be.

Attached is the AJ-260 ignition with the exhaust of the smaller rocket flying away

I have mostly completed my boosted Bertha however I went to apply the water decals and they were unlike any water decals I’ve ever used before. They were incredibly thin, could not be repositioned at all, and tore as soon as I went to put them on. Estes was incredibly unhelpful, with the first time contacting them they just completely stopped responding and closed the ticket and the second time saying they don’t provide replacement decals. Is there anywhere I can get decals or am I sol and will have to find someone to hand letter everything in paint? I’m a little ticked off over the whole thing as there was a couple misprints in the directions about measurements for the engine mounts and spending 35 dollars on a kit to not have it come out nice but oh well

Edit: While his school's shop is properly equipped, his teacher has decided this deviates too far from the planned curriculum. We may proceed with this outside of school (he's very bummed out!) but for the time being, there's a pin being put in this one.

My son has decided to take on a rather (okay, very) ambitious school project, combing his mechanics class with his science class. He wants to make a rocket. In the past we have some pretty neat projects under our belt, including a pumpkin trebuchet, so the school tends to Ok the projects and I do my best to help him see them through because encouraging his passions is a huge passion of mine.

After some chatting, we came up with This. Yes, it's a (very) crude diagram and it's going to need some clarifications:

1. He's in grade 8, we're not trying to get to orbit. 3-4 seconds of good thrust is plenty.
2. He'll be working in steel. Too heavy, but eh we work with what we have, not what we wish we had.
3. Buffer gas will be nitrogen, compressed and released via electronic control, likely with a welding pressure regulator.
4. Since the rocket is round and we want to leverage that as a feature, the Kerosene will run between the outer skin and the gas O2 tank.
5. The gas O2 with a welding regulator will feed into a circular area (to equalize the output around the circumference), and down into a mixing "ring", which will then expel into the combustion area, with a disposable igniter to trigger the combustion.
6. Where used, will likely use welding regulators. Valves will likely be solenoids.
7. We have a safe (privately owned) launch area where we can ensure failed parachute turning this into a lawn dart does not represent a safety risk. A smoke system is intended to help aid visual tracking as well.
8. Structurally, the skin attaches to the mixer, which attaches to the spike. The spike holds the O2 tank with some un-pictured standoffs.
9. The kerosene doesn't have a dedicated tank, it just sits between the O2 tank and the buffer gas, the latter being mounted to the skin as well

I'm comfortable with figuring out the F/O ratios, and believe we can produce those ratios using the regulators. I'm more than comfortable with programming and controlling the solenoids with an Arduino or similar.

What I don't want to do is make a pipe bomb. Incremental testing of fuel and O2 mixing, etc, will be done, but the experience of other people who've already done it is invaluable.

Hello, I have been learning math, physics, and rocketry related topics through textbooks and online for the past several years. I have done some work with solid rocket motors but am interested in constructing a monopropellant thruster. I’ve been searching around for information but would appreciate if anyone could give me links or book suggestions to help me learn about monopropellants. The only thing right now I’m not quite sure how to do is construct some sort of catalyst bed. Any help would be appreciated!

Hi guys,

I'm currently working on some simulations in RocketPy, specifically now the Monte Carlo Sims, and I am getting no apogee and impact data found, which is why it cant output the landing elipses. Idk if anyone has experience in Rocketpy, but I could really use some help if you know something about this.

Thanks!

sometimes when im bored, i draw my own rocket engines. what do you guys think of this one i made today?

https://preview.redd.it/qg4f6k7imv1e1.jpg?width=4032&format=pjpg&auto=webp&s=9e83147779226559df9da8f031050ed18e5d1f59

Starship’s 6th flight is today, and I’m hyped! Meanwhile, I’m gonna build a functional Starship model rocket—with a catch system too! Documenting the journey on YouTube. First video is live,let’s make it fly!

YouTube video link - https://youtu.be/fNpWa66T6PE?si=-wam1JFDDy7zK4sG

A hypothetical question! I know why liquid hydrogen/oxygen is better than gas, but I can't seem to find the answer as to whether it would even work. If you were to feed a liquid hydrolox engine (RS-25, etc) with gases, would it still ignite? Just with a lower Isp/thrust?

Im considering putting a camera into my rocket by cutting a little hole onto the side of the body tube and putting the camera inside. Will this work? Does anyone have any suggestions on what camera to use?

I am an avionics lead on a university rocketry team, and we are trying to design a radio system that can provide us downlink telemetry while our rocket is in flight. Our rocket has an apogee of 30,000ft.

Our team has been designing our radio systems around the RN2483 LoRa chip, using the 433.05MHz frequency band at a 13.6dBm transmit power, spread factor of 7, 500kHz bandwidth, 4/7 coding rate and preamble length of 6. With these parameters we've never experienced range beyond 1.5km with line of sight, which is what Semtech's LoRa calculator also tells us should be true. In order to get up to 10km range with this chip we're basically cranking the spread factor to 12 and sacrificing our data rate down to ~18bps, which is far too low bandwidth for any meaningful telemetry (we want to send ~100 bytes at 10Hz).

What is confusing our team is that the RN2483's underlying radio chip is the SX1276, which is also the same underlying chip used by Featherweight GPS modules which claim up to 262,000ft of range (that chip is inside the CMWX1ZZABZ). Even taking this with a grain of salt, we've definitely received Featherweight GPS transmitter signals much farther than the RN2483 can transmit during our flights, including at apogee. The manual claims they use a spread factor of 7, and they are not sending an insignificant amount of data either. Nothing about their antennas is very different from the rubber ducky antennas we are using on our radio systems from what we can tell, and there is nothing between the SMA connector and their CMWX1ZZABZ module, just a single RF trace.

Has anyone had success with live telemetry from their rockets up to around 30,000ft? We've investigated a non-LoRa solution (the RFD 900x), but it pulls about 1.2A at max transmit power which is a bit hefty. Any success stories with LoRa chips? Which ones did you use, and what settings? Any ideas how Featherweight has such great range on their GPS transmitters with just whip antennas and 50mW of output power?

Olá, estou participando de uma equipe recém criada de foguete, e estamos com a proposta de trabalho com propelente sólido. Gostaria de saber se a comunidade possuiria algum link com os relatórios técnicos de outras equipes a respeito de motores SRAD, neste caso de autoria da equipe?

Hi all,

I wanted to share a project that I've been working on. It uses three different AI technologies to setup, run and analyze fluid simulations. I'm curious what level of interest yall would have in a project like this? Would love to hear your thoughts!

matrixseven.ai