Principal Engine Systems Development Engineer

At Relativity Space, we have two audacious goals : to build the next great commercial launch company with Terran R and to become America's leading force in additive manufacturing innovation. Both contribute to our long-term vision of creating humanity’s industrial base on Mars, paving the way for interplanetary life to expand the possibilities of the human experience. This journey begins right here on Earth – where we design, build, and fly rockets to deliver customer payloads to orbit. Terran R, our medium-to-heavy lift reusable rocket, fulfills the growing demand for launch capacity, thanks to our iterative approach that accelerates design, testing, and development while minimizing costs. While our groundbreaking research and development in 3D printing pushes the boundaries of large-scale additive manufacturing.

Your journey with us is more than just a job – it’s an opportunity to shape the future of aerospace technology, additive manufacturing, and the human experience alongside a community of passionate, creative individuals. Join us on this extraordinary journey, as we work together to transform our vision into reality.

About the Team :

The propulsion team at Relativity is responsible for the successful development of the engines that will power the Terran R vehicle. We own their design from concept through to launch and reuse. Our team partners heavily with manufacturing, test, launch, and integration teams, striving to develop our engines in record time and to support Terran R's first launch in 2026. As part of this team, you will help build, test, and iterate on the full product lifecycle of our Aeon-R engine systems, seeing them mature and eventually bring Terran R into space.

About the Role :

This role may span several areas of our team depending on your skillset and the team’s needs at the time. The core responsibilities are driving engine system (architecture CONOPS) trades, managing engine interfaces & negotiating requirements to optimize for the vehicle, and supporting engine system development overall. You may additionally support engine system analysis and simulation, engine testing, tool development, and more. In engineering at the system level, you will be expected not just to coordinate & facilitate amongst other technical teams, but to bring your own deep technical acumen to bear on problems in this highly technical role.

At the principal level, you will have significant impact on the development trajectory of the current engine, as well as on the architecture of future engine iterations. Depending on your background & where you want to grow, you may work across multiple teams & technical disciplines in propulsion. You will serve as a mentor to guide the team, but will also learn from mentors of your own within propulsion and the broader company. And in addition to learning from each other, we all learn from the engine – Aeon R is a novel engine that’s never been built before, and with every engine test it gives us new mysteries to solve and challenges to grow from.

In order to be successful in this role, you should be capable of leading collaborative projects to completion with minimal oversight. You should also be a self-starter who is always looking for ways to improve yourself & learn more about the systems that interface with yours. Along with these high expectations comes the opportunity to have a significant influence on a fast-growing startup company and to make rapid professional gains in an environment that encourages growth and risk.

This role requires an average of 15% travel to our test & launch sites and may occasionally require shifted schedules or weekend work for critical milestones.

About you :

• Experience applying engineering fundamentals in fluid mechanics & thermodynamics
• Clear evidence of ownership, problem-solving skills, and effective team collaboration from school or work experience
• Demonstrated drive to deliver on ambitious schedules, even and especially if unconventional & creative solutions are necessary to do so
• Bachelor’s degree in a science, engineering, technology, or mathematics field
• Working knowledge of liquid-propellant rocket engines
• 11 years of relevant experience, preferably in complex engineering system development and / or test environment

Nice to haves, but not required :

At Relativity Space, we are committed to transparency and fairness in our compensation practices. Actual compensation will be determined based on experience, qualifications, and other job-related factors.

Compensation is only one part of our total rewards package. Relativity Space offers competitive salary and equity, a generous PTO and sick leave policy, parental leave, an annual learning and development stipend, and more! To see some of the benefits & perks we offer, please visit here.

Hiring Range : $196,000—$253,000 USD

We are an equal opportunity employer and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

Salary : $196,000 - $253,000