Hercules

Fall 2024 - Current

"Hercules" is the name of the engine that I intend to use as a medium to learn the not-so-basics of propulsion, liquid biprop engine / rocket design, project management, and more. I like to keep myself engaged in projects outside of work, and this is the latest one.

Fig. 1. Exploded view of the Hercules Engine. Parts include: Chamber, Jacket, Saddle, Test Cover Plate, Injector Plate Top, and Injector Plate Bottom.

Abstract:

"Hercules" is a liquid bipropellant engine that I conceptualized with a colleague of mine on 10/30/24. This engine will run on 2-Propanol (C3H8O) and Nitrous Oxide (N2O). We have yet to determine its theoretical thrust, Isp, etc. and are working towards our goal of cold firing this rocket the week of June 8th, 2025. Our hot fire is loosely planned for 4th of July 2025 (how fun!). I'll be using this page as a journal and updating it as the project progresses (at the very least for my own record-keeping) so welcome, and feel free to skim through!

If this page has not been updated recently, feel free to skim through our notes. We update this document as we work in real time, so it will be our most up-to-date research on this rocket.

Last Updated: 11/15/24

Real-time Notes

Introduction:

My experience with aerospace engineering concepts started in my freshman year at BU in 2019 and took me through 2021. I worked on two projects with Boston University Rocket Propulsion Group (BURPG) that taught me a lot but admittedly, I left a lot on the table. I put more effort into other commitments, and COVID didn't help either. Unfortunately, I have to start from scratch on Hercules because as a collegiate engineer, I let the upperclassmen handle the more complex concepts, and only worked on what systems I understood. Now I'm returning to rockets and engine design with a fresh mind and a matured skillset that will enable me to see a complex, independent project like this all the way through. I called a friend one day to see if he would join me, if nothing else but to be each others' sounding board and keep each other accountable, and Hercules was born.

I'm excited to exercise things I've learned as a professional like project management, test engineering (principles of Six Sigma and DOE), electrical design, controls, DFM, etc., and implement them into a high-caliber project like Hercules. Of cource I'm excited to learn and implement technical skills, but I'm equally if not more excited to lead a team and feel like I have a hand in getting us to where we want to be. Over time I plan to grow this amateur team and hopefully be a mentor to others down the line.

My work on Boston University Rocket Propulsion Group (BURPG) is linked below, though I anticipate that Hercules will be a far more comprehensive showcase of my current skillset, so I urge you to read on.

Airframe

Heat Exchanger

Below is our full project schedule (Last updated for portfolio: 11/15/24). This schedule is not perfect, especially having been made with what bare minimum knowledge about rocketry I've gained over the last couple weeks. This schedule is intended to be semi-malleable, and will solidify as we progress.

Week 1

Week 1 started with trying to learn what I don't know. After a week or so of skimming textbooks and watching whatever videos I could find on the basics of propulsion and engine design, I had a semblance of an understanding of liquid biprop rockets and had enough to build a schedule. This would be the foundation of the entire project.

Project Schedule

One big hurdle of this project is that it will be highly asynchronous. My co-founder and I live about 2500 miles away (MA & CA), so we needed to implement a robust project framework to keep up-to-date with each other, stay organized, share files, etc. We meet about once a week, but continue to talk throughout the week in spurts.

I've built a schedule that will take us from ground zero (i.e., knowing absolutely nothing) to a cold flow / cold fire, and built a weekly task structure resembling Agile. Agile has been a vital tool of our workflow at my current job at Fedorka Enterprises, especially in the early days. As Thomas Fedorka would say it, "big R, little D". This is highly similar to how this project has started, where Hercules is more Research than it is Development, at least for now.

Between the kickoff of this project (10/30/24) and our first cold fire makes about 7-8 months. This is an incredibly short time to learn these concepts from scratch while both working a full time jobs, but this is our challenge and successful completion will be a testament to our goalsetting and work-ethic.

Initial System Requirements

Generally, my philosophy towards problem-solving is to "just do something". I think the worst thing anyone could do is get paralyzed by fear, or sit around waiting for genius to strike -- I've done this enough to know that you will blink, and time will have passed with no progress made, so you might as well have just started. So with this mindset, we set a few initial requirements without knowing how those might drive our later decisions. Those will be for discovering later. In this mindset, we submit to and own up to future mistakes, and that is part of this process.

The first few things we decided early were:

1) Engine type (solid, hybrid, monoprop, or biprop)

2) Propellant(s)

As two post-grad engineers, we took it upon ourselves to push our limits and opted for a liquid biprop rocket using 2-Propanol (C3H8O) and Nitrous Oxide (N2O). Compared to the other types of engines we looked at, this was on the more complex side. With the industry knowledge that we did have, we noticed that pretty much all rockets being developed by aerospace companies are liquid biprop, so choosing this kind of engine would have directly translatable skill.

I'd also read up on some amateur rocket teams working with IPA and N2O and knew how easy they would be to get (compared to say LOX). We agreed on just picking a fuel / ox combination that has enough literature to learn from and is easy to get our hands on.

With the groundwork laid out, all that was left to do was to dive straight into liquid biprop engine design and brush up on our high level thermochemistry.