Mechanical Engineering Intern (Summer 2027) at Castelion in Allen, TX

Job description

Why Castelion, Why Now Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we're building a world-class team to turn bold ideas into real capability. This is a rare opportunity to join at an early stage, where you'll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function. Summer 2027 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 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 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. Preferred Qualifications: Experience with hardware design, 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. Castelion offers a generous benefits package. Please refer to the bottom of our Careers page for more details. Other Duties Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or responsibilities that are required of the employee for this job. Duties, responsibilities and activities may change at any time with or without notice. Additional Eligibility Requirements This position may require access to classified information or restricted U.S. Government sites, systems, or information, as determined by the Company and/or applicable U.S. Government requirements. If the position is so designated, your employment in the role may be contingent upon your ability to obtain and maintain the required U.S. Government security clearance or other government