About Castelion

Castelion is bringing a new approach to defense development and production: one that focuses on short, iterative design cycles, rapid testing in development, and modern commercial manufacturing strategies for production at scale. We’re designing, building, and testing next generation long range strike weapons systems to give America and its Allies a definitive edge and deter future conflicts.

Senior Ordnance Engineer

Castelion is designing and building next-generation hypersonic weapon systems that restore stability through credible deterrence. We are seeking a hands-on, mission-driven Senior Ordnance Engineer to lead the design, development, and integration of ordnance systems across our hypersonic vehicles.

This is a high-impact role for someone with deep expertise in energetic devices and safe & arm mechanisms, who thrives in a fast-paced, hardware-rich development environment.

Responsibilities

• Own the design, development, and qualification of ordnance systems, including:
• Initiators, detonators, transfer charges, explosive bolts, safe & arm devices.
• Mechanically or electronically actuated flight termination systems (FTS).
• Define requirements and interface specifications across mechanical, electrical, and software boundaries.
• Lead supplier engagement, component selection, and build-to-print efforts with a focus on manufacturability, cost, and performance.
• Drive development test planning, execution, and analysis for ordnance systems (including arena testing, function testing, and environmental qualification).
• Work closely with systems, propulsion, and GNC teams to ensure ordnance components integrate safely and effectively into the full weapon system.
• Support FMEA, fault-tree analysis, and safety case development.
• Own documentation and compliance to MIL-STD-1901A, AFSPCMAN 91-710, and other relevant standards.

Requirements

• B.S. or M.S. in Mechanical Engineering, Aerospace Engineering, or related field.
• 5+ years of experience in ordnance or energetics design, analysis, and test.
• Deep understanding of flight termination systems, safe & arm devices, and energetic component integration.
• Familiarity with relevant DoD and NASA standards (e.g., MIL-STD-1901A, RCC 319, etc.).
• Hands-on test experience in high-consequence environments.
• Strong communication and documentation skills.
• Active or eligible for a U.S. security clearance.

Preferred Experience

• Experience working with DoD customers and navigating military qualification processes.
• Background in hypersonics, missile systems, or space launch vehicles.
• CAD and mechanical analysis experience (e.g., SolidWorks, FEA tools).
• Prior experience working at a defense startup or fast-moving development organization.

All employees are granted long-term stock incentives as part of their employment as Castelion. All employees receive access to comprehensive medial, vision, and dental insurance, and the company offers three weeks of paid time off per year.

Leadership Qualities

Bias to Action and Creative Problem Solving. Desire and experience questioning assumptions in ways that lead to break through ideas that are ultimately implemented. Successfully bring in applicable processes/concepts/materials from other industries to achieve efficiency gains. Ability to personally resolve minor issues in development without requiring significant support.

High Commitment, High Initiative. A successful candidate will have a genuine passion for Castelion’s mission and consistently look for ways to contribute to the company’s technical goals and prevent hardware blockers. Ability to work in a fast paced, autonomously driven, and demanding atmosphere. Strong sense of accountability and integrity.

Clear Communicator. Proactively communicates blockers. Trusted in previous roles to be voice of company with regulators, suppliers, gate keepers and customers. Capable of tactfully managing relationships with stakeholders to achieve company-desired outcomes without compromising relationships. Emails, IMs and verbal interactions are logical, drive clarity, and detailed enough to eliminate ambiguity.

ITAR Requirements:

• To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.

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.