Propulsion - Lead Propulsion Engineer

At Orbital Paradigm, we design, develop, manufacture, and operate reusable orbital logistics systems. Our spacecraft perform multiple orbital mission profiles and return safely to Earth through hypersonic atmospheric reentry and landing with pinpoint accuracy for rapid refurbishment and reuse. Role Description We are looking for a Lead Propulsion Engineer to establish and lead the propulsion function at Orbital Paradigm, with responsibility for the architecture, design, development, integration, and testing of chemical propulsion systems for reusable orbital logistics vehicles. The role focuses on HTP-based propulsion systems, including propulsion architecture, thrusters, tanks, feed systems, valves, regulators, pressurization systems, fluidic components, additive manufacturing, test hardware, and propulsion test campaigns. The engineer will work closely with systems, GNC, avionics, software, mechanical, thermal, manufacturing, AIT, quality, and program teams to develop reliable propulsion systems from early design through testing. This is a technical and team leadership role requiring strong propulsion engineering judgment, direct experience with HTP systems, hands-on test experience, and the ability to build the processes, team, suppliers, and infrastructure required to deliver spacecraft propulsion capability. Key Responsibilities Establish the company’s propulsion function, including technical processes, design practices, supplier interfaces, test logic, team structure, and development workflows. Define propulsion system architecture for reusable spacecraft, including thrusters, tanks, feed systems, pressurization systems, valves, regulators, lines, and interfaces. Lead design and development of HTP-based chemical propulsion systems from early concept through detailed design, manufacturing, integration, and testing. Perform propulsion system sizing, trade studies, performance analysis, pressure drop analysis, thermal assessments, and operational scenario analysis. Define propulsion requirements, interfaces, verification logic, and test plans. Lead development and testing of propulsion components, assemblies, and integrated systems. Support additive manufacturing approaches for propulsion hardware, including design-for-manufacturing, supplier coordination, inspection, and test validation. Plan and execute propulsion test campaigns, including component tests, subsystem tests, hot-fire tests, pressure tests, leak tests, and functional tests. Define test infrastructure, instrumentation, procedures, safety controls, and readiness criteria for propulsion testing. Manage technical risks related to HTP compatibility, materials, contamination, pressure systems, thermal behavior, ignition, decomposition, and hazardous operations. Lead anomaly investigation, root-cause analysis, corrective actions, and design iterations based on test results. Coordinate with suppliers, manufacturing partners, test facilities, and external technical partners. Build, guide, and mentor propulsion engineers and technicians as the team grows. Prepare and maintain technical documentation, design reports, test procedures, verification reports, and review material. Contribute to design reviews, test readiness reviews, qualification reviews, and flight readiness reviews. Required Qualifications 5-10 years of relevant professional experience in propulsion in aerospace, automotive, or other high-performance industries. Degree in Aerospace Engineering, Mechanical Engineering, Chemical Engineering, Propulsion Engineering, or a related technical field. Significant professional experience in chemical propulsion systems for spacecraft, launch vehicles, missiles, or equivalent high-performance systems. Direct experience with HTP-based propulsion systems, including design, materials compatibility, handling, testing, or operations. Experience taking propulsion hardware or systems from design through manufacturing, integration, and testing. Experience defining, designing, developing, manufacturing and testing propulsion architecture for spacecraft or aerospace systems, and in particular for spacecraft, reentry vehicles, launch vehicles, landers, or orbital maneuvering vehicles. Experience with propulsion design and analysis tools for CAD, CFD, FEA, system simulation, performance modelling, and test data analysis, such as CATIA, Siemens NX, ANSYS, STAR-CCM+, OpenFOAM, EcosimPro/ESPSS, NASA CEA, Python, MATLAB, or equivalent. Experience with propulsion test campaigns, including planning, procedures, instrumentation, execution, data analysis, and anomaly resolution. Experience with pressure systems, tanks, valves, regulators, feed systems, lines, fittings, seals, and fluidic components. Experience with additive manufacturing for propulsion or high-performance fluidic/thermal hardware. Strong understanding of propulsion fundamentals, fluid dynamics, thermodynamics, combustion or decomposition processes, heat transfer, materials, and system-level trade-offs. Ability to lead technical work, coordinate multidisciplinary teams, and make sound engineering decisions under development and test constraints. Ability to manage suppliers, test partners, manufacturing partners, and technical interfaces. Ability to write clear technical documentation, test procedures, analysis reports, verification reports, and review material. Full proficiency in English, written and spoken. Preferred Qualifications Familiarity with aerospace industry standards such as ECSS, NASA, or MIL. Basic proficiency with one or more programming languages such as Python and MATLAB. Experience in a startup or small-company environment with fast design iterations. Experience with monopropellant, bipropellant, RCS, OMS, reaction control, or main propulsion systems. Experience with propulsion qualification, environmental testing, acceptance testing, and flight readiness logic. Experience with hazardous operations, clean fluid systems, contamination control, propellant loading, or test facility operations. Experience with sensors, instrumentation, DAQ systems, test automation, and post-test data analysis. Familiarity with CAD, CFD, FEA, system simulation, or propulsion performance modelling tools. Experience building or scaling a propulsion team, laboratory, or test capability. Good proficiency in Spanish. What We Value Excellence in technical work, execution, and professional conduct Strong ownership mindset, with the ability to drive activities to clear outcomes through accountability, proactivity, and resourcefulness Clear, efficient, direct, and constructive communication Team-first attitude with low ego and strong cross-functional collaboration What We Offer Location: Madrid, Spain (office-first) Flexible hybrid work (2 days/week from home + 2 fully remote weeks/year) 30 vacation days (23 flexible, +7 during holidays). Salary depending on experience and profile Relocation package depending on seniority and profile Flexible compensation (meal vouchers, health insurance, public transport) Company shares plan