Materials Engineer - High Temperature Composites

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 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.

Materials Engineer – High Temperature Composites

Castelion is seeking a highly motivated recent graduate or early-career engineer to support R&D development and scale-up of our ceramic matrix composite (CMC) fabrication processes. This role will support composite layup and densification operations which are part of the production workflow for high-performance thermal protection system (TPS) materials.

The position is ideal for a recent graduate with an interest in ceramic matrix composite material process development and scaling large-scale production systems of high-performance aerospace parts. It will involve hands-on composite fabrication work with analytical and process engineering responsibilities. The engineer will support prepreg layup and part shaping operations compression, curing, resin infiltration, and high-temperature pyrolysis processes. In addition, the engineer will characterize fabricated materials, develop drive data collection and analysis of the different sub-processes, and contribute to improving process repeatability and manufacturing readiness across the pilot line.

Responsibilities

• Support composite layup, shaping, and densification operations to deliver a completed TPS demonstrator part set by the end of the year.

• Own all process QA data collection activities and database management.

• Conduct characterization activities of all finished C/SiC goods to assess performance and inform development strategies.
• Assist with prepreg layup, compression molding, filament winding, curing, resin infiltration, and pyrolysis operations for CMC components.
• Perform characterization and inspection of composite materials using standard laboratory techniques.
• Collect, organize, and analyze process and material performance data to support process optimization.
• Develop and maintain process documentation, work instructions, and standardized operating procedures.
• Support installation, maintenance, and scale-up of pilot-line manufacturing hardware.

Basic Qualifications

• Bachelor's or Master's degree in Materials Science, Mechanical Engineering, Chemical Engineering, Aerospace Engineering, or related field.

• Familiarity with materials characterization techniques (mechanical testing, metallographic mounting and polishing, SEM).

• Must be willing to work weekends when necessary.

• Ability to work independently in a hands-on engineering environment.

Benefits And Perks

• Employee Equity: Meaningful equity for all full-time employees - share value has increased 150x in three years
• Personal Time Off: Four (4) weeks of paid time off to unplug, reset, and come back sharp—velocity matters, burnout doesn't
• Company Paid Holidays: Ten (10) company paid holidays
• Medical: We offer plans at 100% employee covered and 80% of dependent coverage
• Dental & Vision: We cover 90% employees and 80% for dependents to ensure you and your family have access to quality preventive and ongoing care
• FSA/HSA: To support long-term health and financial resilience, we offer FSA and HSA options that allow employees to set aside pre-tax dollars for eligible medical and dependent care expenses
• Retirement: 401k plan offered to support long term financial growth along side high-impact, high-velocity work
• Paid Parental Leave: We support growing families with meaningful time to bond and recover. Birthing parents are eligible for up to 10 weeks of paid leave, while non-birthing parents may take up to 4 weeks of paid leave. This time can be used for pre-natal care, pregnancy, childbirth, and related medical needs—ensuring every parent has the support they need during this important life moment.8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees
• Meals & Catering: Frequently catered lunches and team meals, plus company-covered meals when extra time or effort is required
• Snacks & Beverages: Fully stocked kitchen with