Using Model Rockets for Research

Written by Vimal Velu

Edited by Firdavs Mirzoev

I originally launched model rockets for fun. I enjoyed building them, launching them, and  watching them soar off into the sky, but I never really considered the amount of data  contained in those few seconds of flight. Eventually, I became more interested in what was actually happening to the rocket while it was in the air. This led me to start experimenting with ways to obtain such data. Additionally, I spoke to Varun Nagaraj, who wrote his own research paper on the optimal fin shape for a model rocket, and it inspired me to do the same. In fact, he said that this is an area of science in which not many people pay much attention to. Furthermore, my conversation with Aditya Vinod, an IIT graduate who later completed his PhD at the University of Texas at Austin, reinforced this idea from a different perspective. Despite describing aerospace as an incredibly exciting field, he mentioned that not enough people care about it. This is why I believe that researching model rocketry is the perfect bridge for those who love aerospace and want to learn and experiment, but do not have access to world-class labs.  

To conduct my experiments, I used the BMP280, a small pressure sensor that measures atmospheric pressure and temperature. Since atmospheric pressure decreases with altitude, changes in pressure can be used to calculate the rocket's approximate altitude throughout its flight. I also experimented with an MPU-6050, which uses an accelerometer and gyroscope to measure the rocket's motion and rotation. Together, these sensors transformed the rocket from a toy into a data lab. These sensors are incredibly cheap and relatively easy to code and put into the rocket to collect data.  

However, collecting meaningful data was much easier said than done. A sensor producing a number does not necessarily mean that the number is accurate. When I tested the BMP280 while it was sitting completely still, I noticed that the calculated altitude could drift by around half a meter even though the sensor itself had not moved. During an actual flight, there were even more variables to consider, including temperature, atmospheric  pressure, vibration, sensor noise, and changes in the rocket's movement. I therefore had to consider not only how to collect data, but also whether I could trust the data I was collecting. Once the measurements had been processed, they could reveal much more about the flight. I could plot how altitude and other variables changed throughout the flight, identify the rocket's maximum altitude, compare different launches, and investigate how changes to the rocket's design affected its performance. I could also compare my  experimental results with simulations from OpenRocket, creating a direct connection  between what a computer model predicted and what actually happened in the real world.

This entire process was incredibly interesting. For example, I investigated how changing  the size of the rocket's fins affected its maximum apogee. Larger fins can improve stability, but they can also increase aerodynamic drag, meaning that changing a seemingly simple component can create competing effects on a rocket's performance. By using repeated launches and collecting measurements from the rocket itself, I could investigate these effects using experimental evidence rather than relying only on observation. This is one of the reasons I find model rockets useful for research: they provide a relatively accessible way of testing concepts that are also important in larger aerospace systems. The scale is different, but many of the engineering principles remain relevant. 

In the end, the importance and value of these experiments go far beyond rocketry itself. This is because, regardless of the outcome, the process itself is the prize. When you are designing, improving, and fixing your ideas, it forces you to think and opens many pathways, many of which seem long and scary at first, but once you come out the other side, you realize that those challenges are no longer barriers but opportunities. I truly believe that these sorts of projects are 100% worth doing because they force you to fail. They change your mindset from treating failure as an endpoint to a learning point. 

The OpenRocket software application.

An example of Altimeter I designed using the Cirkit Designer website and put in the rocket.