GNC Engineer - Actuation Systems

As a GNC Engineer focused on actuation systems at Castelion, you will build the control algorithms, models, and software that turn vehicle commands into precise physical motion.

You will own problems across actuator modeling, closed-loop control, system identification, hardware characterization, simulation, and flight integration. Depending on your experience, you may contribute to individual control loops or take ownership of complete actuation systems from requirements and architecture through hardware testing and flight.

This role is a strong fit for engineers who enjoy controls, electromechanical systems, hands-on testing, and seeing algorithms directly affect hardware performance.

Responsibilities

• Design, implement, and tune closed-loop control systems for flight vehicle actuators
• Develop position, velocity, force, torque, and current control architectures as required by the actuator system
• Model electromechanical actuator dynamics, including motors, transmissions, ball screws, control surfaces, sensors, structural loads, friction, backlash, saturation, and other nonlinear effects
• Develop actuator performance requirements and support motor, gearing, sensor, and mechanical hardware sizing
• Perform stability, bandwidth, robustness, disturbance rejection, and tracking performance analysis
• Develop feedforward, filtering, compensation, anti-windup, command shaping, and other control features to improve actuator performance
• Perform system identification and parameter estimation using component, bench, and integrated test data
• Build actuator models for high-fidelity vehicle and 6-DOF simulations
• Implement control algorithms in embedded flight software and support real-time execution constraints
• Develop Software-in-the-Loop (SITL) and Hardware-in-the-Loop (HITL) test environments for actuator validation
• Plan and execute hardware characterization and closed-loop actuator testing
• Analyze test and flight data to validate models, identify performance limitations, and improve control designs
• Work closely with GNC, avionics, embedded software, mechanical, electrical, and test engineers to deliver integrated flight-ready actuation systems

Systems Engineering, Systems Engineering, Algorithms, Hardware Quality Assurance, Hardware Simulation, Hardware Architecture, Testing, Electromechanical Systems, Performance Management, Control Systems, * Bachelor’s degree in Aerospace Engineering, Mechanical Engineering, Electrical Engineering, Computer Engineering, or a related technical field

• Strong fundamentals in feedback controls, dynamics, or electromechanical systems
• Experience programming in Python, Rust, C/C++, Julia, or a similar technical computing language
• Experience analyzing dynamic systems through coursework, research, internships, projects, or professional work
• Ability to work effectively across software, electrical, mechanical, and controls disciplines

Preferred Skills and Experience

• Experience designing and tuning closed-loop control systems for electromechanical or aerospace hardware
• Experience with motor control, servo systems, position control, velocity control, force control, or torque control
• Experience modeling DC, BLDC, or PMSM motors and their associated drive electronics
• Experience with mechanical transmission systems such as gearboxes, ball screws, linkages, or rotary-to-linear mechanisms
• Strong understanding of classical control techniques, including loop shaping, gain and phase margin, bandwidth, and frequency-domain analysis
• Experience with state-space controls, observers, feedforward control, or disturbance estimation
• Experience with nonlinearities including saturation, rate limits, deadband, backlash, friction, hysteresis, and compliance
• Experience with system identification and correlation of analytical models against hardware test data
• Experience with embedded or real-time control software
• Experience with sensors such as encoders, resolvers, current sensors, load cells, or position transducers
• Experience with actuator sizing, power requirements, thermal constraints, structural loads, or performance trades
• Experience developing simulation models for actuator dynamics and integrating them into larger vehicle simulations
• Experience with Monte Carlo analysis, uncertainty analysis, or robustness assessment
• Experience with Software-in-the-Loop (SITL) or Hardware-in-the-Loop (HITL) testing
• Experience designing or operating test stands and working directly with flight-like hardware
• Experience supporting aerospace, robotics, automotive, industrial automation, or other high-performance motion-control systems

Why Castelion, Why Now

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we’re building a world-class team to turn bold ideas into real capability.

This is a rare opportunity to join at an early stage, where you’ll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function.