Mechanical Engineer Fall 2026 Co-Op

About the role

Fall 2026 Mechanical Engineering Co‑Op at Castelion offers a dynamic, hands‑on experience developing next‑generation missile systems. Interns contribute directly to the design, testing, and integration of advanced defense technologies in a fast‑paced, collaborative startup environment where work has immediate impact.

At Castelion you'll be part of a mission‑driven company where every project matters. Interns don't just observe – they contribute meaningfully to the success of our programs, working at the cutting edge of aerospace engineering while developing skills for future leadership.

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.

Qualifications

• Currently pursuing a Bachelor's or Master's degree in Mechanical Engineering, Aerospace Engineering, or a related field.
• Rising junior, senior, or graduate‑level student preferred.
• Strong academic record with relevant coursework in areas such as mechanical design, propulsion, power systems, or related fields.
• 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.
• Leadership qualities: bias to action and creative problem solving; desire to question assumptions; ability to bring in processes from other industries; high commitment and initiative; clear communication; accountability and integrity.

Benefits

• For non‑local interns, housing or relocation stipends may be available to help offset temporary living expenses.

Pay

This internship is paid at an hourly rate of $30 per hour. Compensation may vary based on experience and education level.