York Space Systems is looking for a talented Propulsion Engineer, Senior that will contribute to the growth and development of our core products. This individual will work across a variety of programs, apply different propulsion technologies, and have a direct influence on both commercial and national security missions. They will lead the design and qualification of complex propulsion systems, ensuring technical excellence from concept through flight. They will also be expected to mentor junior engineers, drive technical decision-making, and serve as primary subject matter expert for cross-functional teams.   Responsibilities Lead the full life cycle of propulsion systems, providing technical oversight from vendor selection and AI&T through to on-orbit operations and anomaly resolution. Manage technical relationships with propulsion hardware suppliers, collaborating with internal supply chain teams to drive procurement, resolve critical non-conformances, and ensure mission success. Perform delta-v calculations based on mission requirements and subsystem performance Own the validation of propulsion interfaces, working cross-functionally with spacecraft systems engineers to proactively identify and resolve complex, multidisciplinary technical issues. Generate and release system-level specifications and ICDs, support design and engineering reviews Oversee and execute high-risk testing, fueling, and verification of flight and ground hardware, ensuring strict adherence to safety and quality standards. Drive the development of internal engineering standards, design tools, and best practices to optimize the propulsion department's efficiency and capabilities. Mentor and provide technical guidance to junior and mid-level propulsion engineers, fostering a culture of continuous learning and engineering excellence. Other Duties as Assigned   Required Qualifications Bachelor’s degree in engineering, science or a related technical field required 4 - 8+ years experience in propulsion, spacecraft, launch vehicle, or related experience Deep technical expertise in both electric and chemical propulsion systems, including a comprehensive understanding of subcomponents Proven hands-on experience qualifying, testing, and troubleshooting flight-qualification propulsion hardware and ground support equipment Demonstrates self-initiated work in a team environment Excellent communicator with a desire to strengthen the entire team Ability to obtain a security clearance Willingness to work full-time in our Greenwood Village, CO office   Preferred Qualifications Active security clearance Ability to provide ownership of the full life cycle of propulsion systems, including vendor selection, AI&T, and on-orbit operations. Experience in the design, testing, or operations of satellite propulsion systems