BEL
Liquid Propulsion Research Project
Vertical Static Fire System
About BEL
BEL (Bulls Experimental Liquids Team) is developing the Stoic I liquid bi-propellant engine and its vertical static fire test stand for the Society of Aeronautics and Rocketry at the University of South Florida.
The system uses nitrous oxide and ethanol to target 4.9 kN (1,100 lbf) of nominal thrust for at least 16 seconds at a 4 MPa chamber pressure. Its fuel-rich 3.5 O/F mixture ratio is designed to reduce combustion instability and flame temperature while preserving performance.
Hot-Fire Testing & Propulsion Validation
On October 18th, the Bulls Experimental Liquids Team conducted its most recent static fire test, marking a major milestone in SOAR's liquid propulsion campaign. The test verified ignition sequence timing, chamber pressure, and propellant feed dynamics on the test stand as the team advances toward integrated vehicle flight operations.
Bulls Experimental Liquids Team Liquid Propulsion Static Fire
Project Objectives
The CDR-defined objectives cover the Stoic I engine, propellant feed system, vertical test stand, and controls architecture required for safe, repeatable hot-fire testing.
Stoic I Engine Performance
Develop a nitrous oxide and ethanol engine targeting 4.9 kN nominal thrust, at least 16 seconds of continuous burn, and a 4 MPa chamber pressure.
Injector, Chamber & Nozzle Integration
Validate the triple-impinging injector, C-C ablative liner and nozzle, 15° conical nozzle, and 7.013 expansion ratio for efficient and thermally protected combustion.
Pressurized Feed System
Integrate the concentric nitrous oxide and ethanol tanks, EPDM pistons, Valworx solenoid valves, stainless tubing, pneumatic actuators, and fill, vent, and run-line quick disconnects.
Vertical Test Stand & EECS
Build a 17-foot guided-sled stand rated above 1,100 lbf and operate it with LabJack T7 data acquisition, Teensy 4.1 controls, fiber or Ethernet UDP communication, and redundant ignition.
Safe, Repeatable Test Operations
Use FMEA, SOPs, emergency action plans, pre-test checklists, pressure relief, dual-operator verification, software arming controls, and an emergency stop sequence.
Technical Teams
Propulsion Team
Engine design, injector development, and combustion analysis
Ground Station EE/CS Team
Electrical, electronic, and computer systems design
Ground Station Mechanical Team
Mechanical aspects of the ground station, including structural integrity, mechanical systems, and maintenance
Avionics Team
Design, development, and maintenance of avionics systems for the rocket, including navigation, communication, and control systems
Aerostructures Team
Design, development, and maintenance of the rocket's aerostructures, including structural integrity, aerodynamic performance, and material selection
Current Development Phase
Critical Design Review completeAs of the October 23, 2026 Critical Design Review, BEL has defined the Stoic I engine and Vertical Static Fire System architecture. Current work is focused on finalizing the 17-foot test stand, validating the concentric tank and valve network, and integrating the EECS controls and data pipeline ahead of hot-fire testing.
The control interface is being developed around a LabJack T7 with at least 50 Hz sampling and a Teensy 4.1 controller for six solenoid valves and dual-redundant ignition. The operator GUI will provide P&ID visualization, 10-second rolling charts, look-but-don't-touch safeguards, dual-key confirmations, and a spacebar emergency stop.