Senior Thermal & TPS Integration 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 Thermal & TPS Integration Engineer We are seeking multiple Senior Thermal & TPS Integration Engineers to design and deliver thermal protection solutions for Castelion's long-range hypersonic strike vehicles. These roles are critical to ensuring vehicle survivability and performance in extreme aerothermal environments. You will work hands-on with multidisciplinary engineering teams to design, analyze, build, and validate TPS across the vehicle, including heat shields, control surface protection, and internal thermal insulation systems in a fast-paced, hardware-driven environment. Responsibilities • Design and develop TPS across the vehicle, including heat shields, acreage TPS, and leading-edge protection systems • Design TPS for control surfaces, including elevons, seals, and moving interface solutions that maintain performance under thermal and mechanical loads • Develop internal thermal protection solutions, including insulators, blankets, and standoff systems to protect avionics and structures • Lead the architecture and integration of TPS with primary structure, mechanisms, and subsystems, including attachment methods, gaps, and strain isolation • Perform thermal and thermal-structural analyses to ensure performance under extreme aerothermal heating and transient environments • Work closely with structures, materials, aerothermal, GNC, and manufacturing teams to ensure seamless system integration • Develop and evaluate materials and configurations, including ceramics, carbon-carbon, ablatives, and insulating materials • Conduct tolerance analysis and assess thermal expansion, deformation, and interface behavior • Support prototyping, assembly, and hardware bring-up, including troubleshooting and root cause analysis of TPS performance issues • Define and execute qualification and environmental test plans, including arc-jet, furnace, and flight testing • Optimize designs for mass, thermal performance, durability, and manufacturability • Mentor junior engineers and contribute to best practices in TPS design and integration • Partner closely with program leadership to make technical trades aligned with mission success Basic Qualifications • Bachelor's, Master's, or PhD in Aerospace Engineering, Mechanical Engineering, Materials Science, or related field • 5+ years of experience in thermal protection system design, analysis, and validation for aerospace or high-temperature applications • Strong background in aerothermal environments, heat transfer, and high-temperature materials • Experience designing TPS for flight vehicles, including heat shields, control surfaces, or internal insulation systems • Familiarity with TPS materials such as ceramics, carbon-carbon, ablatives, and insulating blankets • Experience with seals, gaps, and interface design in high-temperature, moving or constrained systems • Proficiency in thermal and structural analysis tools (e.g., ANSYS, MATLAB, or equivalent) • Experience with high-temperature testing methods (e.g., arc-jet, furnace, or similar) • Experience with hardware build, test, and troubleshooting in a lab or flight hardware environment • 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.