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.

Senior Propulsion & Ordnance Engineer

We are seeking a Senior Propulsion & Ordnance Engineer to design and deliver ignition and energetic systems for Castelion's long-range hypersonic strike vehicles. This role is critical to enabling reliable motor ignition, flight termination, and stage separation through robust, high-performance energetic devices. You will work hands-on with multidisciplinary engineering teams to design, analyze, build, and validate ignitors, detonators, destruct charges, linear shaped charges, and related systems in a fast-paced, hardware-driven environment.

Responsibilities

• Design and develop energetic systems, including rocket motor ignitors, detonators, AFTS destruct charges, and linear shaped charges for stage separation
• Lead the architecture and detailed design of ignition and ordnance hardware, including initiation chains, packaging, and integration with vehicle systems
• Perform thermal, structural, and energetic performance analyses to ensure reliable initiation, propagation, and output under extreme environments
• Develop and optimize ignition systems for consistent, repeatable motor start across a range of operating conditions
• Work closely with propulsion, AFTS, structures, avionics, and safety teams to ensure seamless integration of ordnance systems with vehicle architecture
• Support energetic material selection, handling, and processing in collaboration with materials and manufacturing teams
• Plan and execute ground test campaigns, including component-level and integrated system testing, and analyze results to drive design improvements
• Conduct failure analysis and root cause investigations related to ignition performance, initiation reliability, or ordnance function
• Ensure compliance with safety, handling, and mission assurance requirements for energetic systems
• Mentor junior engineers and contribute to best practices in propulsion and ordnance system design
• 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 propulsion, ignition systems, or ordnance/energetics design for aerospace or defense applications
• Strong background in rocket motor ignitors, detonators, initiation systems, and/or explosive devices such as shaped charges or destruct systems
• Experience with energetic materials, initiation chains, and safe handling practices
• Familiarity with AFTS or flight termination systems and associated hardware
• Experience with ground testing of energetic systems, including instrumentation and data analysis
• Proficiency in analysis and modeling tools (e.g., MATLAB, ANSYS, or equivalent)
• Experience with hardware build, integration, and troubleshooting in a lab or test environment
• Strong problem-solving mindset, thriving in a fast-paced, hardware-rich, high test cadence environment

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.

Benefits And Perks

All 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 Statement

Employment 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.