Why us? POLARIS Raumflugzeuge GmbH develops innovative transportation systems that redefine access to space for payloads and passengers. As we expand our operations, we are seeking a skilled and driven individual to join us at our headquarters in Bremen as Senior Rocket Propulsion Systems Engineer. Join our dynamic and fast-growing startup and be part of our exciting journey to revolutionize space transportation and hypersonics. We are a passionate team dedicated to pushing boundaries, fostering innovation, and creating impactful solutions that make a difference. Your mission Design and analysis of conventional and linear aerospike rocket propulsion systems Design and analysis of liquid rocket engine components, including injector, combustion chamber, nozzle, and igniter Thermodynamic, fluid dynamic, and thermostructural analysis using tools such as CEA, Ansys Mechanical & Fluent, MATLAB or Ecosimpro Material selection, component sizing, and thermal protection strategies Optimisation of the engine performance and efficiency Collaboration with test and DAQ engineers to define test plans and analyse test data Contribute to system-level propulsion architecture decisions Your profile Successfully completed aerospace engineering degree (M.Sc./M.Eng.) Strong understanding of thermodynamics, fluid mechanics, heat transfer, and combustion Several years of working experience in the field of rocket propulsion Experience with rocket propulsion system analysis tools (e.g. CEA, Ecosimpro, Ansys) Programming skills would be an advantage (e.g. Python, Matlab) Experience with CAD and CFD software would be an advantage Work experience in a start-up environment is an advantage Proactive thinking, high level of motivation, flexibility, and team-working skills Proficiency in both German and English Join us in shaping the future of space transportation and making a positive impact. Apply now by sending your complete application portfolio, including CV, certificates and a cover letter outlining your relevant experience and why you are the ideal candidate for this role. We look forward to welcoming you to our team! About us The German aerospace start-up POLARIS Raumflugzeuge GmbH is developing a revolutionary reusable space launch and hypersonic transport system that operates like an aircraft. Based on more than 30 years of German and European spaceplane research, the development of the spaceplane AURORA began at the German Aerospace Center DLR. Aurora combines aircraft and rocket launcher technologies with a unique vehicle design, and offers a game-changing economic viability as well as opening the door for routine low-cost and safe access to space. In order to validate the technology and accelerate the spaceplane development, POLARIS has been developing a series of scaled flight demonstrators.