Senior Propulsion Engineer, Hall-Effect Thrusters Verified today

About the Role

Apex is seeking a Senior Electric Propulsion Engineer with deep expertise in Hall-effect thrusters to own the design, development, qualification, and production of Hall thruster technology for our electric propulsion systems. Building on Apex's in-house Hall-effect thruster capability, you will drive thruster development from plasma physics and discharge channel design through qualification, flight integration, and design-for-manufacturing at rate.

This is a senior individual contributor role with significant technical ownership and leadership scope. You will drive key Hall thruster design decisions, lead test and life-qualification campaigns, and work alongside propulsion engineers as we scale electric propulsion production.

Responsibilities

• Own the end-to-end design and development of Apex's Hall-effect thrusters, including discharge channel geometry, magnetic circuit design, anode and gas distributor design, and thermal-mechanical packaging.
• Develop plasma physics and performance models to drive thruster design, including ionization and acceleration behavior, magnetic field topology, efficiency, thrust-to-power, and specific impulse across the operating envelope.
• Define and execute thruster test and life-qualification campaigns, including performance mapping, plume characterization, thermal testing, oscillation and stability characterization, wear testing, and long-duration life testing in vacuum facilities.
• Develop erosion, degradation, and life models for the discharge channel and pole pieces and demonstrate compliance with mission life and propulsion budgets.
• Drive cathode-thruster coupling and overall electric propulsion system integration in partnership with cathode, propellant feed-system, and power processing unit owners.
• Select materials and processes, including ceramics, magnetic materials, and refractory metals, and qualify them for spaceflight and scalable production.
• Optimize thruster designs for performance, mass, cost, manufacturability, and repeatability, and develop the work instructions, process flows, and assembly and integration procedures required to build them at rate.
• Partner with systems, power electronics, thermal, structures, and avionics teams to define interfaces and verify requirements.
• Support the build, integration, and test of flight hardware, as well as launch campaigns, on-orbit performance evaluation, and anomaly resolution.
• Lead and contribute to failure analysis, root-cause investigations, and continuous design improvements.
• Provide technical mentorship to propulsion engineers and contribute to the continued development of Apex's Hall thruster capability.

Required Qualifications

• Bachelor's degree in aerospace, mechanical, electrical, plasma or propulsion engineering, applied physics, or a related field.
• 6+ years of relevant electric propulsion experience with a Bachelor's or Master's degree, OR a Ph.D. in electric propulsion, plasma physics, applied physics, or a closely related field with 3+ years of relevant industry experience, with substantial and demonstrable focus on Hall-effect thruster design, development, and testing.
• Deep, hands-on knowledge of Hall thruster physics and design, including discharge channel design, magnetic circuit layout, anode and gas distribution, cathode coupling, and thermal management.
• Experience planning and executing Hall thruster or electric propulsion test campaigns in vacuum facilities, including plasma and plume diagnostics, performance measurement, and life and wear testing.
• Strong understanding of the failure and degradation mechanisms that drive Hall thruster life, including channel and pole erosion, thermal limits, and discharge instabilities.
• Working knowledge of spacecraft propulsion system architecture, propellant feed systems, and power processing unit interaction.
• Experience owning hardware through design, development, build, and test.
• Ability to decompose requirements and interface control documents and communicate clearly across engineering disciplines.
• Must be a U.S. Person as defined by ITAR (22 CFR §120.15): U.S. citizen, national, lawful permanent resident, refugee, or individual granted asylum.

Nice to Have

• Direct experience taking a Hall thruster from development through flight qualification and on-orbit operation.
• Experience with magnetically shielded, wall-less, or unshielded Hall thruster architectures.
• Experience with alternative propellants, including krypton and non-xenon electric propulsion propellants, and their effects on thruster performance and life.
• Familiarity with Hall thruster plasma simulation tools, including particle-in-cell and hybrid codes, and magnetic finite element analysis.
• Familiarity with power processing unit and thruster drive electronics and power interface definition.
• Design-for-manufacturing experience bringing propulsion hardware into serial or high-rate production.
• Experience with electric propulsion environmental qualification, including vibration, thermal vacuum, and electromagnetic interference testing of flight propulsion hardware.
• Experience supporting failure investigations and resolving issues on flight or qualification hardware.

Employment Details

Full-time position based in Los Angeles. Compensation ranges are set by role, level, location, and market data. A candidate's specific level and base pay are determined case by case and may vary with job-related skills, education, experience, technical capabilities, and internal equity. Full-time hires are also eligible for long-term incentives in the form of stock options, medical, dental, and vision coverage, and a 401(k) retirement plan with 100% match on first 3% and 50% match on next 2%.

ITAR Requirements

Apex's work is governed by U.S. export control laws, including the International Traffic in Arms Regulations (ITAR) and the Export Administration Regulations (EAR). Applicants must either qualify as a U.S. Person or be able to obtain required export authorizations from the U.S. Department of State, U.S. Department of Commerce, or another applicable U.S. government agency.