Summer 2026 Mechanical Engineering Internship

Job description

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. Summer 2026 Mechanical Engineering Internships: Join us for a dynamic, hands-on experience developing next-generation missile systems. As an intern, you'll contribute directly to the design, testing, and integration of advanced defense technologies all within a fast-paced, collaborative startup environment where your work has immediate impact. Key Responsibilities: - Assist in the design, analysis, and testing of components for missile subsystems, including propulsion, guidance systems, power electronics, and more. - Support engineering teams with simulations, modeling, and prototyping of critical hardware components. - Conduct research and development tasks, gathering and analyzing data to inform design decisions. - Participate in system integration efforts, helping to assembl...