Principal Propulsion Engineer, Engine Systems & Test

At Relativity Space, we’re building rockets to serve today’s needs and tomorrow’s breakthroughs. Our Terran R vehicle will deliver customer payloads to orbit, meeting the growing demand for launch capacity. But that’s just the start. Achieving commercial success with Terran R will unlock new opportunities to advance science, exploration, and innovation, pioneering progress that reaches beyond the known.

Joining Relativity means becoming part of something where autonomy, ownership, and impact exist at every level. Here, you're not just executing tasks; you're solving problems that haven’t been solved before, helping develop a rocket, a factory, and a business from the ground up. Whether you’re in propulsion, manufacturing, software, avionics, or a corporate function, you’ll collaborate across teams, shape decisions, and see your work come to life in record time. Relativity is a place where creativity and technical rigor go hand in hand, and your voice will help define the stories we’re writing together. Now is a unique moment in time where it’s early enough to leave your mark on the product, the process, and the culture, but far enough along that Terran R is tangible and picking up momentum. The most meaningful work of your career is waiting. Join us.

About the Team:

The Propulsion team at Relativity is focused on developing and delivering highly performant and manufacturable engines for Terran R. Engineers are responsible for the entire lifecycle of their parts, from initial design through production to qualification and flight. The team fosters a culture of bottoms-up decision-making, free from technical gatekeeping, where ownership and accountability are key at all levels. But designing engines with a quarter million pounds of thrust is just the beginning. As the flight configuration enters qualification, the team is now exploring modifications for future engines, including thrust upgrades, new cycles, and design for mass production.

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:

• Working knowledge of fluid components such as valves and instrumentation

• Working knowledge of engine subsystems such as combustion devices and turbomachinery

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:

$185,000—$277,000 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.

If you need a reasonable accommodation, please contact us at accommodations@relativityspace.com.

Please note: Relativity Space does not accept unsolicited resumes, candidate profiles, or referrals from recruitment agencies or search firms. Any unsolicited submission - via email, our website, social media, or directly to an employee - will be deemed the property of Relativity Space, and no fee will be owed absent a current, fully executed agreement with Talent Acquisition that specifically authorizes submissions for the applicable role.