Senior Fluid Systems Engineer

Relativity; Long Beach (CA); On-site; USD 132,000 - 198,000; Full time

Job summary

Relativity Space is seeking a Vehicle Fluid Systems Engineer to own the fluid subsystem architecture for a space vehicle, applying system design and thermodynamics to guide hardware, analysis, and manufacturing.

You will conduct fluid and thermal analyses, lead design and manufacturing reviews, and define test objectives to validate system performance, with on-site work at our factory and collaboration across teams to accelerate Terran R.

Qualifications

• Bachelor's degree in Mechanical Engineering or relevant field.
• 4+ years of experience with fluid systems.
• Strong fundamentals in thermodynamics, fluid dynamics, and heat transfer.
• Experience with fluid or thermal modeling tools and Python for analysis.

Responsibilities

• Own the vehicle fluid subsystem architecture and schematics, including system control and sizing.
• Perform fluid and thermal analyses (1D steady-state, fluid networks).
• Lead system and hardware design and manufacturing reviews.
• Define and support test objectives and campaigns to validate design and performance.

Skills

Fluid systems

Thermodynamics

Python

System design

Education

Bachelor's degree in Mechanical Engineering

Tools

Fluid/thermal modeling tools

Job description

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 Stage Fluids team designs and delivers the propellant, pressurant, pneumatics, and other fluid systems that turn structures into functioning rockets. The team has full ownership across design, production, test, and flight, maintaining a holistic view of Terran R, focused not on isolated parts but integrated functionality. Working on-site at the factory means you're never far from the hardware, enabling rapid iteration and tight feedback loops across design and manufacturing. You won't just be handed requirements: you'll be expected to ask the right questions, collaborate with partners across the company, and ultimately find the best solutions for Terran R.

About the Role:

As a Vehicle Fluid Systems Engineer, you will be responsible for the fluid system architecture and function for a given vehicle fluid subsystem. You will apply expertise in system architecture, systems operations, and fluid thermodynamics applications to guide hardware design, system analysis, manufacturing, validation and operations.

• Own the vehicle fluid subsystem architecture and schematics, including system control scheme, system and component selection and sizing
• Conducting fluid and thermal analyses, including system sizing and characterization using a variety of base analytical methods (1D steady-state, fluid networks, etc.)
• Leading and participating in system and hardware design and manufacturing reviews
• Defining and supporting test objectives and test campaigns to validate system design, system models and overall system performance including supporting integrated vehicle testing and launch

About You:

• Bachelor's degree (Mechanical Engineering or relevant)
• 4+ years of experience working with fluids systems
• Experience applying engineering fundamentals in system design, thermodynamics, fluid dynamics, and heat transfer
• Experience with one or more fluid or thermal modeling tools for internal compressible and incompressible analysis
• Proficiency in Python or a similar programing language for scientific computing and automated test/simulation data analysis

Nice to haves, but not required:

• Experience with launch vehicles and spacecraft

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: $132,000 - $198,000 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 [e-mail].

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.