Staff Vehicle Fluid Systems Engineer (Product)

Segment (Twilio); Long Beach (CA); On-site; USD 164,000 - 225,500; Full time

Benefits offered by this job

Equity

PTO

Sick leave

Parental leave

Learning stipend

Job summary

Relativity Space seeks a Vehicle Fluids Product Responsible Engineer to own the fluid system architecture for a vehicle product line. You will apply deep expertise in system architecture, fluid thermodynamics, and modeling to guide hardware design, analysis, and operations.

You will lead cross‑functional interfaces with Propulsion, Structures, GNC, and Avionics, perform 1D thermofluids sizing, and define test scopes to reduce risk before full vehicle testing.

Qualifications

• Bachelor’s degree in Mechanical Engineering or relevant.
• 7+ years of experience with complex fluids systems.
• Strong background in fluid system architecture, operations and application of engineering fundamentals in system design, thermodynamics, fluid dynamics, and heat transfer.
• Proficient with fluid/thermal modeling tools for internal compressible and incompressible fluid analysis.
• Experience with programming languages such as MATLAB, Python, or C++ for data analysis or modeling.
• Direct experience designing or operating launch vehicle or spacecraft fluid or propulsion systems.
• Nice to have: experience with certification of a vehicle fluid system for NSSL and/or range certification.

Responsibilities

• Own the integrated stage‑level fluid architecture and schematics, ensuring seamless functionality across all propellant, pressurant, and pneumatic subsystems.
• Lead cross‑functional interface definitions and negotiations with partner vehicle teams to ensure flawless system integration.
• Assist with sizing and fluid 1D steady‑state thermofluids analysis at both the system and component levels when necessary.
• Define development, qualification, and acceptance testing scopes to buy down technical risk prior to vehicle‑level integrated testing.
• Participate in CONOPS development and operation data review to take ultimate ownership of the successful operational philosophy and testing execution of the fluid systems at the integrated vehicle level.

Skills

Fluid systems

Thermodynamics

Fluid modeling

Launch vehicles

Education

Bachelor’s degree in Mechanical Engineering or relevant

Tools

MATLAB

Python

C++

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 Fluids Product Responsible Engineer, you will be responsible for the fluid system architecture and function for a given vehicle product line. You will apply deep expertise in system architecture, complex systems operations, and fluid thermodynamics applications to guide hardware design, system analysis, manufacturing, validation and operations.

You Will:

• Own the integrated stage‑level fluid architecture and schematics, ensuring seamless functionality across all propellant, pressurant, and pneumatic subsystems
• Lead cross‑functional interface definitions and negotiations with partner vehicle teams (Propulsion/Engine, Structures, GNC, and Avionics) to ensure flawless system integration
• Assist with sizing and fluid 1D steady‑state thermofluids analysis at both the system and component levels when necessary
• Define development, qualification, and acceptance testing scopes to buy down technical risk prior to vehicle‑level integrated testing
• Participate in concept of Operations (CONOPS) development and operation data review to take ultimate ownership of the successful operational philosophy and testing execution of the fluid systems at the integrated vehicle level

About You:

• Bachelor’s degree (Mechanical Engineering or relevant)
• 7+ years of experience working with complex fluids systems
• Strong background in fluid system architecture, operations and application of engineering fundamentals in system design, thermodynamics, fluid dynamics, and heat transfer
• Proficient with one or more fluid or thermal modeling tools for internal compressible and incompressible fluid analysis
• Experience using programming languages such as Matlab, Python, or C++ for data analysis or modeling
• Direct experience designing or operating launch vehicle or spacecraft fluid or propulsion systems

Nice to haves but not required:

• Experience with certification of a vehicle fluid system for NSSL and/or range certification

Compensation and Benefits:

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—$225,500 USD

Equal Opportunity Employer Statement:

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].