Spaceport America Cup 2023
Blue Reaper
As the Avionics Team Lead for the 2022/2023 academic year, I worked on a number of projects that guided our Spaceport rocket to a successful flight in June 2023.
Leading the Avionics team was a great experience, and I initiated a number of new projects for the team…
We worked on several different projects throughout the year, combining engineers from diverse backgrounds and skill sets to create something incredible. Our rocket, Blue Reaper, flew successfully at both our test launch and the Spaceport America Cup, tageting 10,000 feet. Though we ended up a bit below our target altitude, the rocket performed well and placed 36th out of over 150 teams at the competition.
Avionics Bay and Separation Mechanism
Two fundamental goals exist at the core of the avionics team: house all onboard electronics in an efficient manner and accurately separate the rocket for parachute deployment. Our avionics bay emphsized adaptability while probiding ample space for all components, and separation was achieved using a CO2 ejection mechanism.
Mounting Structure Design
The 3D printed mounting structure provides a place for all sensors, computers, and batteries to reside within the rocket. Primarily designed by William Kim and I, along with the rest of the Avionics team, it represents a lightweight and efficient mount. Many hexagonal holes were built into the design for weight-saving, and battery caps were added to keep them in place while flying. Four 1/4”-20 threaded rods run between the aluminum bulkheads to transfer the forces of flight safely through the avionics bay. Large U-bolts are attached to either end to connect to parachute equipment for recovery.
Wiring and Separation
Wires were run throughout the mounting structure, held in designated places with zipties. At each bulkhead, WAGO lever nuts were used to provide strong solder-free connections for tension control, adaptability, and wire management. The actual separation mechanism used in the rocket was the Tinder Rocketry Raptor. This system utilizes a tiny amount of blackpower ignited by an electronic match to fire a spike into a compressed gas canister. This gas is released into the adjacent section of the rocket, separating it into two parts and deploying the parachute. The carbon dioxide canisters fit snuggly within the mounting structure, running through the center of the avionics bay.
Custom Flight Computer
Coming into the year, one of my primary goals was to introduce student-developed electronics into the club. Designing a flight computer became the primary goal, and necessary if we wanted to control the airbrake mechanism on board. The ERIS Beta flight computer became the product of that effort, a PCB design spearheaded by Quinn Edwards, Luke Andresen, and myself. The rest of the avionics team provided lots of support through the ideation and design process. Eventually, this computer was able to successfully detect all stages of flight accurately, trigger separation events, actuate the airbrakes, and provide power to other systems within the rocket!
Microcontroller and Sensors
After debating various microcontrollers, the team settled on utilizing a Teensy 4.1 as the central brain for the flight computer. It has the ability to run Arduino code (which is easy to test) at better performance rates compared to ATMega chips. A suite of onboard sensors complimented this controller, including accelerometers, IMUs, barometers, GPS, and more. All of the incoming data was logged to flash memory for later downloading via SD card, though a every 10th data point was also sent back to our computers via telemetry.
Programming
Having never developed a flight computer before, over 1000 lines of code needed to be generated to implement all of the necessary functions. Luke Andresen and I tackled the majority of this Arduino code (a modified version of C++). We attempted to utilize pre-written sensor libraries whenever possible for well-known chips, but Luke spent time adapting these to our needs. I worked on developing the flight logic systems and checks that monitor states of flight, in addition to servo actuation and control for airbrake functionality, while he handled data structure, collection, transfer, and storage.
Variable Drag Airbrake System
Work beyond avionics…
Throughout the year, I attended many other subteam meetings and tried to contribute in as many ways as I could. As a former Structures team member, I still regularly attended meetings and assisted with many aspects of ideation, design, and construction of the rocket. I spent time in the machine shop working on both stuctures and avionics parts, using the Wire EDM, CNC mills, lathes, and more. The club’s composites also made a huge leap this year thanks to Strucures team lead Vinnessa Van, so I helped with a number of prepreg composite layups and other structural builds. All in all, I had a fantastic time working on many different parts of the rocket, and it was a blast to see a successful launch at Spaceport!
Watch Blue Reaper take flight!
A compilation of our onboard camera and the Spaceport America Cup livestream, edited by Grant Weerts.