A DoD Mechanical Engineer is responsible for designing, analyzing, testing, and maintaining mechanical systems used in defense applications. They work on a variety of projects, including military vehicles, aircraft, ships, and weapon systems, ensuring they meet strict performance and safety standards. These engineers collaborate with interdisciplinary teams, follow government regulations, and may be involved in research and development for new defense technologies. The role often requires security clearance and expertise in areas such as thermodynamics, materials science, and structural analysis.