Project Northstar

Project Northstar is a variable-impulse hybrid rocket engine under development at Saint Louis University’s Rocket Propulsion Lab (SLURPL) for use in sounding rocket research. The engine is designed for seamless integration with rockets for the International Rocketry and Engineering Challenge (IREC). Northstar is classified as an O4200 hybrid engine, utilizing solid PMMA fuel and liquid nitrous oxide as the oxidizer. It is designed to deliver a total impulse of 5,000 lbf·s with an average thrust of 1,000 lbf. Hybrids allow for throttleable engines which allow for better flight control and safety. The project focuses on two objectives which are to provide the experience and infrastructure for SLURPL’s hybrid program and to have altitude control enabled by a throttleable hybrid engine. Additionally, the program is structured into two iterative development cycles: Northstar V1, emphasizing foundational hybrid engine capabilities, and Northstar V2, which serves as the final flight article for the 2026 IREC.