Senior Mechanical Design Engineer (Structures & Thermal Protection Integration)We are seeking a Senior Mechanical Design Engineer to design and deliver critical flight vehicle structures for Castelion's long-range hypersonic strike vehicles. This role is focused on structural systems that interface with and enable the thermal protection system (TPS), including separating nose tip architectures and other high‑temperature structural components. You will work hands‑on with multidisciplinary engineering teams to design, analyze, build, and validate flight‑critical structures in a fast‑paced, hardware‑driven environment.ResponsibilitiesDesign and develop flight vehicle structures, including separating nose tip systems and other components critical to thermal protection system (TPS) performanceLead the architecture and detailed design of high‑temperature structural assemblies, including joints, interfaces, and load paths across TPS and primary structurePerform structural and thermal analyses to ensure performance and reliability under extreme aerothermal, pressure, and dynamic environmentsWork closely with materials, TPS, aerothermal, GNC, and manufacturing teams to ensure seamless integration of structures with vehicle systemsDevelop and analyze separation mechanisms and interfaces, ensuring reliable and repeatable operation under flight conditionsConduct tolerance analysis and assess thermal expansion, material compatibility, and interface behavior at elevated temperaturesSupport prototyping, assembly, and hardware bring‑up, including troubleshooting and root cause analysis of structural and interface performance issuesDefine and execute qualification and environmental test plans, including thermal, vibration, and shock testingOptimize designs for mass, thermal performance, structural integrity, and manufacturabilityMentor junior engineers and contribute to best practices in high‑temperature structural designPartner closely with program leadership to make technical trades aligned with mission successBasic QualificationsBachelor's, Master's, or PhD in Mechanical Engineering or related field5+ years of experience in structural design and analysis for aerospace or high‑performance systemsStrong background in high‑temperature structures and materials, particularly in TPS‑adjacent or aerothermal environmentsExperience designing separation systems, joints, and structural interfaces for flight hardwareProficiency in CAD and analysis tools (e.g., NX, SolidWorks, ANSYS, or equivalent)Experience with structural and thermal analysis, including thermal‑structural coupling and tolerance stack‑upFamiliarity with materials used in high‑temperature environments (e.g., ceramics, carbon‑carbon, refractory metals, or similar)Experience with hardware build, test, and troubleshooting in a lab or flight hardware environmentStrong problem‑solving mindset, thriving in a fast‑paced, hardware‑rich, high flight cadence environmentBenefits And PerksAll full‑time employees are granted meaningful long‑term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company‑paid holidays, and comprehensive health benefits—including 100% employee‑covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy perks like catered meals, company‑covered food during high‑demand periods, and a fully stocked kitchen to stay fueled throughout the day.While this position does not currently require a U.S government‑issued security clearance, it may in the near future. Therefore, the ability to obtain and maintain a U.S. government–issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance.Affirmative Action/EEO StatementEmployment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.#J-18808-Ljbffr