The posting
Hop Aero is a venture-backed startup building rockets that deliver cargo. Our mission is to enable resilient global logistics to protect and improve our way of life. Our founding team has prior experience founding a satellite startup and taking it to orbit, launching 20+ Falcon 9 missions at SpaceX, and leading engineering teams at some of the world’s most advanced aerospace organizations. The company is well-capitalized through venture funding and government contracts.
About the role We’re hiring a Senior Turbopump Engineer (Electric Pumps) to lead the development of electric propellant pumps for Hop Aero’s liquid rocket engines. You will report directly to the CTO and be a key member of Hop Aero's propulsion team. You will own our e-pumps end-to-end, from initial sizing and analysis through detailed mechanical design, manufacturing, component testing, engine integration, and flight hardware. We’re specifically looking for someone who has worked directly on cryogenic rocket propellant pumps before. Ideally, you have developed electric pumps, but experience developing conventional rocket-engine turbopumps is highly relevant as well. The perfect candidate has prior experience in the mechanical and electrical engineering required to take a pump from whiteboard to hot fire. This is a deeply hands-on engineering role. You should be comfortable moving between pump performance analysis, CAD, rotordynamics, bearings and seals, manufacturing drawings, supplier conversations, hardware assembly, and the test stand. We want someone who can turn analysis into hardware and hardware into a working propulsion system.
Job Description Lead the design and development of Hop Aero’s electric propellant pumps (e-pumps) Own pump hardware from initial architecture and sizing through manufacturing, testing, integration, and flight Design centrifugal pump components including impellers, inducers, volutes, housings, shafts, bearings, and seals Perform rotordynamic, structural, and thermal analysis of high-speed rotating assemblies Define pump operating conditions, performance requirements, margins, and interfaces with the engine Integrate electric motors, shafts, bearings, seals, and pump assemblies into a complete e-pump system Work directly with manufacturing engineers, machine shops, and suppliers to produce development and flight hardware Develop drawings, tolerances, material selections, and manufacturing processes for precision rotating hardware Plan and execute pump component and system-level test campaigns Instrument hardware and interpret pressure, flow, vibration, temperature, torque, current, voltage, and rotational-speed data Diagnose test failures and performance discrepancies and rapidly iterate the design Support integration of the pump into complete rocket engines and propulsion systems Own pump technical risks through design reviews and test-readiness reviews Work in person with the team at our shop in Orange, CA
Requirements 3+ years of direct experience developing rocket-engine cryogenic propellant pumps, turbopumps, or closely related high-speed pump machinery Strong understanding of centrifugal pump design, and high-speed rotating machinery, including shafts, bearings, seals, balancing, and rotordynamics Demonstrated experience taking pump hardware from analysis through detailed design, manufacturing, assembly, and test Experience designing precision mechanical hardware using CAD (ideally Siemens NX) and an understanding of relevant power electronics. Must be a US Person under ITAR - Hop Aero will not sponsor visas for this role.
Nice to have Experience taking an e-pump from initial design through engine hot-fire Experience with LOX pumps Experience with high-power-density electric motors and motor controllers Experience with cryogenic bearings and seals Experience with additively manufactured impellers, inducers, volutes, or pump housings Experience designing pumps for deep-throttling rocket engines Experience transitioning development hardware into repeatable flight hardware Experience in a fast-moving aerospace or hardware startup
What we offer Competitive salary and meaningful stock options Healthcare, office meals & snacks Direct collaboration with founders & engineers with rich flight heritage Significant technical ownership from day one The opportunity to own and build a core rocket-engine technology from the ground up Fast upward mobility as the company grows
Even if you don’t meet every single requirement, we’d still love to hear from you. Greatness looks different in every one of us - and we need the best tackling this problem.
