Senior GNC Engineer

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. Senior GNC Engineer We are seeking a Senior GNC Engineer to develop guidance, navigation, and control solutions for Castelion’s long-range hypersonic strike vehicles. This role is critical to enabling stable, precise, and adaptive flight performance across all mission phases. You will work hands-on with multidisciplinary engineering teams to design, analyze, implement, and validate control and autopilot algorithms in a fast-paced, hardware-driven environment. Responsibilities • Design and develop flight control and autopilot algorithms for high-speed flight vehicles across atmospheric and exo-atmospheric regimes • Develop and implement advanced control strategies, including adaptive and robust control methods, to ensure performance under uncertain and dynamic conditions • Conduct modeling, simulation, and analysis (3DOF/6DOF) to evaluate control system performance, stability, and robustness • Work closely with avionics, flight sciences, mechanisms, and flight software teams to integrate control algorithms into real-time embedded systems • Support hardware-in-the-loop (HIL) testing, flight testing, and post-flight analysis, translating results into system-level improvements • Analyze vehicle dynamics, actuator behavior, and sensor characteristics to inform control system design and tuning • Develop tools and frameworks for control system design, verification, and validation • Mentor junior engineers and contribute to best practices in GNC and control system development • Partner closely with program leadership to make technical trades aligned with mission success Basic Qualifications • Bachelor’s, Master’s, or PhD in Aerospace Engineering, Electrical Engineering, or related field • 5+ years of experience in control system design, analysis, and validation for aerospace or high-performance dynamic systems • Strong background in classical and modern control theory, including adaptive, nonlinear, and robust control methods • Experience developing autopilot algorithms for missiles, rockets, hypersonic vehicles, or similar systems • Proficiency in modeling and simulation tools such as MATLAB/Simulink or equivalent • Experience with 3DOF and 6DOF simulation environments and real-time control implementation • Familiarity with flight software integration and real-time embedded systems • Strong problem-solving mindset, thriving in a fast-paced, hardware-rich, high flight cadence environment Castelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details. Other Duties Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice. Additional Eligibility Requirements This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government authorization, and to satisfy any citizenship or other eligibility requirements imposed by applicable law, regulation, executive order, or government contract requirements. You will be notified if and when such requirements apply. Affirmative Action/EEO Statement Castelion is an Equal Opportunity Employer. We are committed to providing equal employment opportunities to all applicants and employees without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, age, disability, genetic information, protected veteran status, or any other characteristic protected by applicable federal, state, or local law. Castelion is committed to providing reasonable accommodations to qualified individuals with disabilities throughout the application and hiring process. If you require a reasonable accommodation to complete an application, participate in the interview process, or otherwise participate in the hiring process, please contact hr@castelion.com. Requests for accommodation will be considered on an individual basis and handled in accordance with applicable law. Castelion is committed to fostering a workplace where employment decisions are based on qualifications, business needs, and the ability to perform the essential functions of the role, with or without reasonable accommodation. EAR/ITAR Requirements This position requires access to export-controlled information, and as such, employment (or hiring of a contractor) is contingent upon the candidate’s ability to access all applicable export-controlled information without additional export licensing being required by the Bureau of Industry and Security and/or the Directorate of Defense Trade Controls.