WATER ROCKET

• — BMP390 and BNO-055 flight sensors
• — Servo-driven parachute deployment at apogee
• — Stability optimized in OpenRocket
• — 3D-printed fins and nose cone
• — Apogee: 100+ ft

DETAILS

Fire hazard was a major problem where I lived, so using a water rocket eliminated that risk. It also meant no certifications were required, meaning I had more time to dedicate to the rocket design itself.

I began by programming a microcontroller to detect the flight stage the rocket was in, such as pre-launch, ascent, apogee, and descent so it could control a servo and deploy the parachute once the rocket had reached its max altitude. This was determined using data from BMP390 and BNO-055 sensors. I then designed and 3D printed a frame to hold the electronics and cut large plastic water bottles to hold all the internal components as well as the water for launch. I had to be really careful in this process, especially for the bottles that would actually hold the water and be pressurized since any small crease could cause the bottle to burst under pressure. Luckily, no defects were found when I pressure tested all the bottle assemblies.

Once I had all the parts sorted, I hand-calculated where center of gravity and center of pressure pressure would be, and along with the measurements of my parts, I used OpenRocket to optimize stability by experimenting with fin geometry. In the end, the fins and nose cone were 3D printed.

The launch resulted in an apogee of over 100 ft and a successful recovery with no damage on the rocket.