Second Week: Problems (!) & Solutions (?)

Post date 8/25/25

Welp, its been almost a week and I have done a considerable amount of thinking on these problems, even with my participation in a tennis tournament Friday-Monday. Crazy busy. School starts in two days too, but enough of the irrelevancy, back to the rocketry. I came up with some operational definitions of my goals as well as the conditions that I will be using to simulate the rocket’s performance before I fire it. First off, I live in Seattle Washington, which is very close to sea level, so air pressure is very close to the baseline of 14.7 psi. Weather in the fall and winter is mostly ~50 F, and humidity is often quite high >50%. Launch windows will be when the skies are clear and no wind, so precipitation and retrieval shouldn’t be much of a problem. With those out of the way, we can now get into my goals. I want my rockets to go as far up as possible with the same propellant in order to collect a data point for my comparison. Similarly, speed and acceleration will also be recorded, as that can often indicate drag factors. Lastly, cant and erraticism of flight are also important metrics to see how modifications impact the flight of the rocket. With those in mind, I once again set upon the task of building my rocket.

I met with my advisor again to talk about my new goals and the environmental factors, and then we began upon the problems that I had encountered before. For one, I had started my rocket design completely wrong. I had tried to pick a motor based on my design, when in reality I should have based my design around the motor. I came to terms with the fact that I should buy the motor from a retailer. Because these motors are mass-produced, they are more consistent, and I would be able to fly the rockets multiple times by just replacing the spent motors, another upside for data collection. I came to the decision that I would use a G-class motor, the G80T-10. This meant that I had to redesign my rocket, as it needs to be light and aerodynamic. My old design was if I had a large motor (think 58mm); however, those are all high-powered and are thus restricted to L1+ holders from TRC or NAR. Thus, I need to make the chassis skinnier, way skinnier.

I then had the conversation of parts. Because I am using lower-powered rocketry motors, I cannot just use weight willy-nilly. Everything has to be light and have a purpose. That essentially rules out 3d printing for everything except mockups, so back to the drawing board. Darn.

Also, measurements must be taken. For that, I picked the LSM9DS1. However, electronics is something I will figure out in one of the future blog posts. Even a cursory glance at Reddit and the rest of the internet tells me this is another rabbit hole I can fall into. Probably will take up the whole blog post.

This blog post was fraught with failures, but each failure is a step in the right direction, as I now know what NOT to do. I am sure there will be more of these kinds of posts in the future, but for now, I am hopeful that it won’t come in the near future. I am also second-guessing my motor choice. Too much power is a thing in rocketry.