Mechanical Design, Structural Analysis, and Static Fire Testing of a Jet Vanes System for Thrust Vectoring

Jet vanes are a method for active control in rocket propulsion systems that involve actuating control surfaces (vanes) inside exhaust flow. By redirecting the flow, these vanes induce control forces on the rocket. This work addresses the key challenges of integrating a jet vane structural system with commercial-off-the-shelf (COTS) solid rocket motors, particularly in (1) withstanding extreme thermal and erosive conditions, (2) retaining structural integrity under high loads, and (3) minimizing mechanical packaging within space constraints of COTS airframes. This study presents the design of a jet vane assembly (JVA) capable of withstanding thrust forces up to 2.2 kN while maintaining precise vane control. The initial assembly featured a sandwich-design structural assembly for its low weight, a two-stage drivetrain to distance vane-driving actuators from motor exhaust, and copper-tungsten control vanes for their manufacturability. This design was structurally verified by finite element analyses (FEA), and initial static fire results validated the structural assembly and control vane drivetrain. However, results also revealed excessive erosion of control vanes and unprecedented exhaust backflow. Consequently, the current iteration of the JVA employs a pure tungsten control vane for its superior hardness, a thermal protection system to further isolate actuators from exhaust backflow exposure, and structural and drivetrain assemblies identical to the first iteration, all of which will be verified by an upcoming final static fire before rocket integration and launch. This work establishes that a jet vanes active control system can be developed within the constraints of collegiate rocketry environments.