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.

Position Overview: Castelion is seeking motivated and talented engineering interns for Summer 2025. This internship offers a dynamic, hands-on experience working on cutting-edge missile systems, including SW, guidance, navigation and control (GNC), propulsion, power electronics, manufacturing, mechanical/structures, avionics, system integration, etc. You will contribute directly to the development, testing, and integration of advanced defense systems, while working in a highly collaborative startup environment.

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:

• Gain hands-on experience in aerospace engineering, working on cutting-edge hypersonic missile systems.
• Develop your technical skills by working with high-performance teams and state-of-the-art tools.
• Learn about the full lifecycle of missile development, from design and prototyping to testing and final integration.
• Receive mentorship from experienced engineers and leaders in the aerospace and defense industry.
• Be a part of a fast-paced startup culture where innovation, teamwork, and rapid development are at the forefront.

Qualifications:

• Currently pursuing a Bachelor's or Master's degree in Aerospace Engineering, Mechanical Engineering, Electrical Engineering, Computer Science, or a related field.
• Rising junior, senior, or graduate-level student preferred.
• Strong academic record with relevant coursework in areas such as propulsion, GNC, power systems, or related fields.
• Familiarity with engineering software (e.g., MATLAB, Simulink, SolidWorks, ANSYS, or similar).
• Hands-on experience through lab work, projects, or internships is a plus.
• Passion for aerospace, defense technology, and innovative engineering solutions.
• Excellent problem-solving, analytical, and communication skills.
• Ability to work collaboratively in a fast-paced, team-oriented environment.

Preferred Qualifications:

• Experience with hardware testing, data acquisition, and analysis.
• Familiarity with missile systems, defense technology, or aerospace components.
• Strong interest in working in a startup environment with high-impact projects.

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:

• Bias to Action and Creative Problem Solving:
• Demonstrated ability to question assumptions and propose breakthrough ideas that lead to successful implementation. Capable of bringing in processes, materials, or concepts from other industries to achieve efficiency gains.
• High Commitment, High Initiative:
• A genuine passion for Castelion’s mission and a strong sense of accountability. Consistently seeks ways to contribute to technical goals and resolve blockers in the development process.
• Clear Communicator:
• Proactively communicates challenges and solutions. Trusted to represent the company with key stakeholders such as suppliers, customers, and regulators. Capable of delivering clear, logical communications that drive clarity and eliminate ambiguity.

ITAR Requirements:

• To conform to U.S. Government export regulations, the applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (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.

Castelion is an equal-opportunity employer. Employment decisions are based on qualifications, experience, and merit, regardless of race, color, religion, gender, national origin, veteran status, disability status, sexual orientation, or any other protected class.