Staff Fluid Systems Engineer

Relativity Space; Long Beach (CA); On-site; USD 164,000 - 246,000; Full time

Benefits offered by this job

Salary & equity

PTO & sick leave

Parental leave

Learning stipend

Job summary

Relativity Space is seeking a Vehicle Fluid Systems Engineer to own the fluid subsystem architecture and its integration across design, analysis, and flight operations. You will apply fluid thermodynamics, system operations, and hardware experience to guide validation and manufacturing decisions.

You will collaborate with propulsion, manufacturing, and software teams on-site at our Long Beach factory in California.

Qualifications

• Bachelor's degree in Mechanical Engineering is required.
• 8+ years of experience with fluid systems.
• Strong fundamentals in system design, thermodynamics, and fluid dynamics.
• Experience with one or more modeling tools for internal compressible/incompressible analyses.
• Proficiency in Python for scientific computing and data analysis.

Responsibilities

• Own the vehicle fluid subsystem architecture and schematics, including system control scheme and sizing.
• Conduct fluid and thermal analyses and system sizing.
• Lead design and manufacturing reviews for systems and hardware.
• Define and support test objectives and campaigns to validate design and system performance.

Skills

Python programming

Fluid systems engineering

Thermodynamics

Education

Bachelor's degree in Mechanical Engineering

Tools

Fluid modeling tools

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)
• 8+ years of experience working with fluid 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 programming 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: $164,000 — $246,000 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].