Senior Structures & Composites Engineer (Rocket Motor Cases)

Why Castelion, Why NowCastelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts.This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.Senior Structures & Composites Engineer (Rocket Motor Cases)We are seeking a Senior Structures & Composites Engineer to design and deliver high-performance rocket motor cases for Castelion’s long-range hypersonic strike vehicles. This role is critical to enabling lightweight, high-strength propulsion structures capable of withstanding extreme pressure and thermal environments. You will work hands-on with multidisciplinary engineering teams to design, analyze, build, and validate composite and metallic motor case structures in a fast-paced, hardware-driven environment.ResponsibilitiesDesign and develop rocket motor case structures, including composite overwrapped pressure vessels (COPVs) and filament-wound composite casesLead the architecture and detailed design of motor cases, including load paths, interfaces, domes, bosses, and attachment featuresPerform structural analysis of pressure vessels under internal pressure, thermal loads, and dynamic environments to ensure performance and reliabilityDevelop and analyze composite layups, fiber orientations, and manufacturing approaches to optimize strength, stiffness, and massWork closely with propulsion, materials, manufacturing, and test teams to ensure seamless integration of motor cases with propulsion systemsSupport material selection, processing, and characterization for composite and high-temperature materialsConduct failure analysis and root cause investigations, driving design improvements and risk reductionDefine and execute qualification and environmental test plans, including pressure testing, proof/burst testing, and vibration testingSupport prototyping, fabrication, and hardware bring-up, including troubleshooting manufacturing and structural performance issuesOptimize designs for mass efficiency, manufacturability, and operational reliabilityMentor junior engineers and contribute to best practices in composite and pressure vessel designPartner closely with program leadership to make technical trades aligned with mission successBasic QualificationsBachelor’s, Master’s, or PhD in Aerospace Engineering, Mechanical Engineering, or related field5+ years of experience in structural and composite design for aerospace or high-performance pressure vessel applicationsStrong background in composite materials, including filament winding, laminate theory, and failure criteria (e.g., Tsai-Wu, Hashin)Experience designing pressure vessels, COPVs, or rocket motor cases for high-pressure applicationsProficiency in structural analysis tools (e.g., ANSYS, Abaqus, NASTRAN, or equivalent)Familiarity with manufacturing processes for composites, including winding, curing, and inspection methods (e.g., NDI/NDT)Experience with proof/burst testing and structural validation of pressure vesselsExperience with hardware build, test, and troubleshooting in a lab or production environmentStrong problem-solving mindset, thriving in a fast-paced, hardware-rich, high test cadence environmentOther DutiesPlease 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.Benefits 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.