Senior Mechanical Engineer - Lithium

Marathon Fusion•San Francisco, CA

About The Position

As a Senior Mechanical Engineer on the Lithium Team, you’ll work closely with electrical and mechanical engineers, physicists, and scientists to prototype, test, and deploy solutions in the pursuit of advancing the development of the fusion fuel cycle. With your hands-on experience designing and testing electromechanical systems, you’ll play a pivotal role in the development and iteration of a first of kind isotope separation device.

Requirements

B.S. or higher in Mechanical or Aerospace Engineering or related field.
5+ years of experience in designing, prototyping, and testing of electromechanical systems.
Demonstrated experience with high vacuum, high temperature, and/or with reactive material systems (e.g lithium, liquid metals, or molten salts).
Strong experimental skills and ability to draw insights from physical systems. Bonus if you’ve led large scale or complex designs and experiments.
Proficiency in mechanical design, including CAD, GD&T, and DFM best practices.

Nice To Haves

Experience in electric propulsion systems (Hall thrusters) and developing in an experimental R&D setting.
Experience with handling, containment, or processing of reactive materials.
Success in mentoring interns and new grads.
Experience in a start up or a similarly fast paced environment.

Responsibilities

Lead the iterative design and improvement of an isotope separation system, driving toward robust, scalable deployment.
Prototype, test, and troubleshoot components and integrated systems in close collaboration with other engineers, physicists, and technicians.
Develop first-principles understanding of key physical processes and guide improvements based on experimental data and literature.
Document experimental results and decisions clearly to inform design iterations and process development.
Mentor and support junior engineers, fostering technical growth and strong engineering judgment on the team.