In April 2022, Dr. Enrique Gomez, Nathan Eckhoff, and Ian Green met with the engineering faculty members in charge of establishing capstone projects. We discussed evolving the research Nathan and Ian were completing in to a capstone project for the 2022 - 2023 school year. The Twiggs Space Labs CanSat and QB2 were used as examples of stepping stones to assist in learning the basics of satellite design. Starting in August 2022, Drew Britt, Austin Caudle, and Jared Holland joined our team. We began by researching common probelms encountered by spacecraft in deep space environments: radiation that can disrupt electronics and experiments, thermal loads, micrometeorite impacts, vibrations experienced during rocket powered flight and more.
At the end of September, we met with Destination SPACE LLC and Twiggs Space Labs to discuss our progress and gather recommendations on our path forwards. We were told that while the reserach of the systems listed above were important, our it would be best for our fledgling program to take a more itertive approach and create a more rapid prototype so we can start testing on high altitude balloons. The electrical engineers also began designing circuts for our CPU, PSU, and Communications boards at this time.
Our electrical engineers began working on a Computer Processing Unit, Power Supply Unit, and Communications custom Printed Circuit Boards. The mechanical engineers began iterating through a 6U CubeSat frame designed based on the 6U CubeSat specifications found via Rocket Lab documentation. We wanted to keep the footprint of the interior components of the CubeSat small so future teams didn't need to resdiesgn the internal layout fo fit more complex components. After a few iterations, we converted the design into a 3D printable version so we didn't need to pay for replacement metal incase we lost the payload duriing a balloon flight. 3D printing a frame takes less cost and time to manufacture and assemble versus mutiple sheet metal frames. At the end of the Fall 2022 semester, we had the 3D printed frame manufactured and partially assembled and components ordered for the custom printed circuit boards.
Before the Spring 2023 semester started, we were planning on launching a tethered balloon to test the thermal loads on the eight corners of the 3D printed frame. Unfortunately, due to high winds throughout the week, we were not comfortable enough to perform a tethered balloon flight with limited resources available in case the tether broke. On January 17th, 2023, when the semester started, Nathan Eckhoff retrieved the supplies that had arrived over Winter Break from the College of Engineering and Technology storeroom for printed circuit board assembly in the lab space. On January 23rd, 2023 the Computer Processing Unit, Power Supply Unit, and Communications custom printed circuit boards were completed but untested. Around this time, Ian Green began redesigning the High Energy Particle Detector, which included testing of the MIT CosmicWatch Muon Detector against an oscilloscope to further refine the design. Jared Holland started developping hte firmware and software that was used in testing the Teensy Microcontroller and Communication boards.
We decided to perform a benchtop test of all subsystems on March 6th, 2023, however, in troubleshooting an communication error between the Teensy Microcontroller and the Long Range Radio Module, a short killed the Microcontroller. The team decided to meet on March 6th, despite no benchtop test taking place to discuss next steps and the final deliverables for the project. It was decided that communication between the existing subsystems, a High Energy Particle Detector that could detect and log particle events, and integration of all electrical components into a 2U CubeSat frame would suffice as final deliverables for this Capstone project. After returning from Spring Break Jared Holland updated the software of the Teensy Microcontroller and designed a 2U CubeSat frame that would be integrated with the printed circuit boards. Drew Britt designed a sensor board with ports for external sensors that could be mounted to the CubeSat and align with the Teensy's Analog output pins. Additionally, the sensor board had a MicroSD card port integrated with it to overcome the datalogging issues we were facing.
By the beginning of April, the final revision of all boards and components had been ordered, including the new sensor board and particle dectector board. Assembly of these boards began, but some key components were intentionally left off to minimize their chance of shorting during testing. Nathan Eckhoff and Jared Holland worked in the College of Engineering and Technology's Machine Shop to manufacture the panels needed for the 2U grame out of 6061 Aluminum Sheet Metal. A WaterJet was used to cut out the panels, a CNC machine to precisely drill holes, and a wheel grinder to grind the welding edges down to 45 degrees. Jared Holland and Rapid Center Engineer Shawn Lyvers then worked to weld the manufacutered panels together into the final assembly of the 2U CubeSat. Jared Holland and Ian Green then worked together to test and troubleshoot the problems with the boards. Upon project completion, Nathan had assembled the completed Printed Circuit Boards onto a PETG Circuit Sled and mounted the Sled into the completed 2U CubeSat Frame. While the Teensy Microcontroller worked by itself and power was drawn from the Iron Phosphate Batteries, the external SD card port on the Sensor board did not work due to incorrect trace routings to the pins, the Communications chip was shorted, and the High Energy Particle Detector recieved incorrect compontents and couldn't physically work. However, the theoretical design of the High Energy Particle Detector does work as intended as provided by the following link https://tinyurl.com/2dkj5y7h.