Propulsion Engineer - Build Advanced Propulsion Systems for Next-Generation Defense Platforms El Segundo, California | On-site Opportunity Summary Join a well-funded, early-stage defense technology company developing advanced aerospace systems designed to solve some of today's most demanding national security challenges. As a Propulsion Engineer, you will lead the development of high-performance propulsion hardware that enables rapid response, extreme acceleration, and reliable operation in challenging environments. This is a highly hands-on engineering role with ownership across the complete development lifecycle. You will design, analyze, prototype, test, and refine propulsion systems while working closely with founders and a multidisciplinary engineering team. The role spans propulsion architecture, high-pressure hardware, combustion analysis, testing, and system integration, giving you direct influence over both the product and the company's technical direction. About Us We are a venture-backed aerospace and defense startup building advanced hardware for next-generation defense applications. Our team is focused on developing high-performance systems that combine innovative engineering with rapid product development. Engineers are empowered with broad ownership, work closely across disciplines, and play a direct role in taking complex hardware from concept through operational deployment. Job Duties Lead the design, development, and testing of advanced propulsion systems for high-performance aerospace applications. Design propulsion architectures including solid rocket motors, gas generators, cold gas systems, and other compact impulse devices. Perform combustion, internal ballistics, mass flow, chamber pressure, and thermal analyses to optimize system performance. Develop propellant grain geometries and thrust profiles to meet mission-specific performance requirements. Evaluate propulsion trade studies across solid, liquid, hybrid, and alternative architectures. Design high-pressure hardware including motor cases, pressure vessels, regulators, valves, burst disks, and related mechanical components. Analyze structural performance under high-pressure and high-acceleration loading conditions. Develop propulsion test articles, fixtures, instrumentation, and data acquisition systems. Plan and execute static fire tests, pressure testing, thermal testing, and system qualification campaigns. Analyze test data and rapidly iterate designs through hardware development cycles. Model propulsion performance using analytical and numerical simulation tools including CFD, FEA, combustion, and thermal analysis. Collaborate closely with mechanical, electrical, and controls engineers to integrate propulsion hardware into complete systems. Support ignition system development, actuator integration, safety systems, and propulsion sequencing. Maintain safe operating procedures when working with energetic materials and high-pressure systems. Qualifications Bachelor's degree in Aerospace Engineering, Mechanical Engineering, Chemical Engineering, or a related technical discipline. Demonstrated experience designing propulsion, combustion, or high-pressure fluid systems. Hands-on experience developing propulsion hardware from concept through testing. Experience with solid rocket motors, propulsion test stands, ignition systems, pressure vessels, or related aerospace hardware. Strong understanding of combustion, fluid mechanics, heat transfer, structural mechanics, and internal flow behavior. Experience designing propulsion systems for aerospace, missile, launch vehicle, or other high-performance platforms. Ability to work hands-on through design, fabrication, testing, troubleshooting, and iteration. U.S. Person or Lawful Permanent Resident status required. Preferred Experience Experience designing solid propellant grain geometries and internal ballistics. Familiarity with solid propellant formulations, insulation materials, and nozzle thermal protection. Experience working with propulsion analysis tools such as NASA CEA, CFD, FEA, MATLAB, Python, ANSYS, OpenFOAM, COMSOL, or similar software. Knowledge of propulsion instrumentation including pressure transducers, thermocouples, strain gauges, high-speed cameras, and data acquisition systems. Experience with MIL-STD environmental or qualification testing. Hands-on experience with machining, pressure plumbing, fixture design, or propulsion hardware assembly. Familiarity with energetic materials, ignition systems, or pyrotechnic hardware. Why Join Us Build critical propulsion hardware with ownership from initial concept through full-scale testing. Work alongside experienced founders and a small, highly technical engineering team. Help shape the design of both the product and the engineering organization during a pivotal stage of company growth. Gain meaningful equity ownership and significant opportunities for technical and leadership advancement. See your work rapidly transition from design into real hardware through fast development and test cycles. Compensation Details $$130,000 - $180,000 #LI-AV