October 9, 2024 Wisconsin Space Program Achieves a Hot Fire Ignition Written By: Kassi Akers Departments: Electrical & Computer Engineering|Mechanical Engineering Categories: Students Combustion exhaust gases exiting the nozzle of the torch igniter. After 3 years of hard work designing, analyzing, and building a torch igniter from scratch, the Wisconsin Space Program (WiSP) propulsion sub-team is ecstatic to share they successfully completed a hot fire and achieved ignition. WiSP, formerly AIAA UW-Madison, is a student organization that focuses on getting members experience and knowledge necessary to start their careers in the aerospace industry. They compete in national solid and liquid competitions and plan to use all they’ve learned from the torch igniter success in future endeavors. WiSP’s Torch Igniter In general, a torch igniter is a pyrotechnic device used to ignite the propellants in orbital-scale rocket engines, such as SpaceX’s Raptor engine. The torch igniter developed by the propulsion sub-team uses gaseous methane (CH4) and gaseous oxygen (O2), as well as nitrogen (N2) to purge and vent the system. Keeping safety in mind, the team controls the system using an Arduino located a safe distance away. The Arduino communicates via Bluetooth with a laptop running a control software made with Python. This allows the team to actuate every valve, record data from the sensors, and execute various pre-programmed sequences, such as firing and venting. Through research, testing, and trial and error, the team developed a variety of custom circuit boards. Some examples of the boards’ functions include, distributing power, powering/actuating valves, and driving a spark plug. Test set up for nitrogen cold flow tests. Prepping for Ignition The team conducted a variety of tests and consulted professionals in the field in hopes of achieving a successful ignition. A few weeks prior to the hot fire, they completed cold flow tests with nitrogen. This process included, testing the control mechanisms, developing a checklist procedure, and verifying expected pressures, temperatures, and flow rates. The team took the information and experience from the tests to speak with club alumni and propulsion engineers Brandon Wilson at Sierra Space and Will DeVerter at Purdue HAMTC to facilitate a Test Readiness Review (TRR). The TRR allowed the group to present their design and discuss their plan with professionals to gain valuable feedback and understand future improvements they can make. Hot Fire Test Success On the day of the hot fire test, the team was excited to see their hard work put to action. Little did they know, they would quickly have to apply all they had learned over the years to fix a leaky hose and failed solenoid valve to prevent a delayed launch. When the issue presented, the team quickly began diagnosing and fixing the leak. After 30-minutes of walking back and forth from the igniter, trying various pressure and flow rates, they finally heard a pop! This release in pressure signified the hot fire ignition the team had been working so hard to achieve. John Krueger, Jack Gronseth, Kyle Adler, and Jordan Gardipee holding the torch igniter after the successful test. Jackson Cyvas not pictured. Kyle Adler, 5th year Engineering Mechanics + Aerospace student, commented on the experience, “The torch igniter project has been a long time in development, so we were all extremely excited to finally see a flame after years of design and various setbacks along the way.” Jordan Gardipee, an Engineering Mechanics master’s student, further contributed, “Overall, this project proved to be a great way for many students to get valuable hands-on experience with propulsion systems and learn a ton along the way. Everything I learned in my time in WiSP will be carried with me in my career. I obtained key knowledge and forged friendships that I will not soon forget.” Collaboration and Support WiSP would like to thank: Brandon Wilson at Sierra Space for taking the time to review their design and run the test; Will DeVerter at Purdue for offering input along the entire design process; and their club mentor Frank Nobile for facilitating the launch site and providing safety equipment. They would also like to thank UW-Madison Departments of Mechanical Engineering and Electrical and Computer Engineering, as well as all of their industry sponsors for the funding that made this project possible. Future Plans Moving forward, the WISP propulsion sub-team plans to incorporate everything they’ve learned from this project into their future projects, including improving the torch igniter. Their main project for 2024-2025 is building two liquid bi-propellant rockets using isopropanol and nitrous oxide, one of them of a completely custom design. They also plan to rebuild and fire a hybrid rocket engine designed by a previous senior design team. Special thank you to Kyle Adler for sharing all photos, igniter information, and recap details. View a video of the torch igniter test fire.