Summer 2026 Engineering Internship

About the job Summer 2026 Engineering Internship

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 Engineering Internships

Join us for a dynamic, hands-on experience developing next-generation missile systems across disciplines such as software, guidance / navigation / control (GNC), propulsion, power electronics, manufacturing, mechanical and structural design, avionics, and system integration. 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 assemble and test subsystems in real-world test environments.
• Collaborate cross-functionally with engineering, manufacturing, and test teams to ensure project success.
• Document design processes, test results, and project progress, contributing to the continuous improvement of our systems.
• Attend technical reviews, design meetings, and team briefings to stay engaged with project developments and learn from industry experts.

Learning Opportunities :

Qualifications :

Preferred Qualifications :

Why Castelion?

At Castelion, you'll be part of a mission-driven company where every project matters. Our interns don't just observe - they contribute meaningfully to the success of our programs. This is a unique opportunity to work at the cutting edge of aerospace engineering while developing the skills and experience that will help you grow into a future leader in the field.

Leadership Qualities :

ITAR Requirements :

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.

This internship is paid at an hourly rate of $30 per hour. Compensation may vary based on experience and education level. For non-local interns, housing or relocation stipends may be available to help offset temporary living expenses.