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.  

Sr. Materials & Process Engineer, Energetic Materials 

Job Title: Sr. Materials & Process Engineer, Polymer Materials 
Reports To: Director of Materials Engineering 
Location: Torrance, CA / Rio Rancho, NM 

About the Role  

Castelion is seeking an experienced Materials & Process Engineer to lead the characterization, qualification, and failure analysis of solid rocket motor propellants and related material systems. This individual will be responsible for developing a fundamental understanding of propellant material behavior, establishing characterization and qualification methodologies, and investigating material and process-related failures to support reliable propulsion hardware. 

The successful candidate will bring strong expertise in the characterization of polymers, elastomers, or other viscoelastic materials, with experience translating material behavior into engineering requirements, specifications, and qualification programs. Prior experience with energetic materials or solid propellants is preferred but not required. 

Key Outcomes for 2026  

• Establish test methods to characterize the mechanical, viscoelastic, thermal, and environmental behavior of propellant materials, including the effects of temperature, strain rate, aging, and processing conditions. 

• Establish qualification and acceptance testing for raw materials and cast propellant, including material specifications, test plans, acceptance criteria, and environmental qualification requirements. 

• Develop a systematic approach to investigating material and process-related failures using mechanical testing, microscopy, thermal analysis, and other characterization techniques to identify root causes and drive corrective actions. 

Key Responsibilities  

• Lead characterization of propellant and related polymeric material systems using mechanical testing, DMA, rheometry, DSC/TGA, microscopy, and other relevant techniques. 

• Develop test methods to understand material behavior across relevant temperatures, strain rates, aging conditions, and operational environments. 

• Develop and execute material qualification and acceptance testing programs for raw materials and cast propellant. 

• Lead failure analysis and root-cause investigations related to material performance, processing, and manufacturing defects. 

• Develop and maintain material specifications, process controls, test plans, and acceptance criteria. 

• Partner with Propulsion and Manufacturing Engineering to translate characterization results into material selection, processing requirements, and design inputs. 

• Support manufacturing scale-up by identifying relationships between processing conditions, material structure, and resulting properties and performance. 

• Ensure material testing and qualification activities comply with applicable material, handling, and safety requirements. 

Basic Qualifications  

• Bachelor’s degree in materials science/engineering, chemistry or a related discipline.  

• 5+ years of experience working with polymer characterization, preferably within the aerospace industry.  

• Prior experience with propellant characterization techniques including mechanical testing, impact, static, burn-rate, and impulse testing. 

• Excellent written and verbal communication skills.  

• Must be authorized to work in the U.S. and comply with ITAR eligibility requirements.  

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.