Thermal Engineer I

Relativity; Long Beach (CA); On-site; USD 90,000 - 136,000; Full time

Benefits offered by this job

Competitive salary and equity

PTO & sick leave

Parental leave

Learning & development stipend

Job summary

Relativity Space is seeking a Thermal Systems Engineer to drive architecture, sizing, and development of thermal systems for Terran R. You will conduct analyses, guide design teams, and develop tests to ensure robust thermal performance across subsystems and the vehicle.

The role emphasizes hands-on data analysis, scripting in MATLAB/Python, and collaboration with propulsion, manufacturing, and avionics teams to deliver reliable thermal solutions for launch operations.

Qualifications

• Bachelor's degree in Engineering or related field.
• Industry experience via internships or university collaborations is preferred.
• Strong fundamentals in heat transfer and thermal analysis.
• Hands-on experience writing test plans, instrumentation, and data analysis at component/system level.
• Experience with engineering scripting language like MATLAB or Python.

Responsibilities

• Drive the architecture, sizing, and development of thermal systems (insulation, heaters, thermal protection, environmental conditioning).
• Build, execute, and validate thermal analyses at component, sub-system, and vehicle levels; support tool development and automation.
• Guide design and development engineers in applying thermal sciences to meet requirements.
• Develop and execute tests to support thermal systems development and qualification; instrument and process data.
• Support vehicle/engine thermal system development, stage testing, and flight operations.

Skills

Heat transfer

Thermal analysis

Test planning

Data analysis

Python

MATLAB

Education

Bachelor's degree in Engineering or related field

Tools

Sinda

Fluint

Thermal Desktop

FEM/FDM/FVM solvers

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:

Relativity's Integrated Performance teams ensure that our products work across all systems and disciplines, from trajectory design to aerodynamics to reliability analysis and beyond. Our groups size the Terran R rocket, design its missions for customer success, reliability, and reusability, and ensure that every system on the rocket and ground is engineered correctly for the demanding environments of launch and entry. Recently, we completed the preliminary design and analysis of Terran R including Relativity's first-ever work on launch vehicle reusability, spanning advanced trajectory simulations, wind tunnel testing, and structures analysis, among many other projects.

The Thermal team is responsible for predicting temperatures, designing thermal architectures, and guiding designs for the structures, fluids, components, and avionics of our launch vehicles. With a strong grasp of thermodynamics and all methods of heat transfer, the team addresses a vast number of thermal challenges across ground and flight phases. The team leverages first-principle hand calculations, reduced order modeling, and coupled system detailed thermal modeling to drive cross disciplinary vehicle designs. Our collaboration with hardware engineers and all other teams further enables us to overcome design and integration hurdles, ensuring a seamless and efficient development process from concept through launch.

About the Role:

• Drive the architecture, sizing, and development of thermal systems like insulation, heaters, thermal protection, and environmental conditioning in collaboration with peer technical teams
• Build, execute, and validate thermal analyses at the component, sub-system, and vehicle level, including supporting tool development and automation
• Guide design and development engineers in the successful application of thermal sciences to achieve system and component requirements
• Develop and execute tests to support thermal systems development and qualification, including test article integration, instrumentation setup, and data processing
• Support vehicle and engine thermal system development and stage testing, as well as flight operations

About You:

• Bachelor's degree in Engineering or related field
• Experience in industry via internships or university collaborations
• Strong fundamentals in heat transfer and thermal analysis
• Hands‑on experience with writing test plans and performing testing, instrumentation, and data analysis at the component and system level
• Experience with an engineering scripting language like MATLAB or Python

Nice to haves, but not required:

• Graduate degree in engineering or related field
• Experience solving complex problems on integrated vehicles with design teams
• Experience in component and system level thermal and fluids analysis, using relevant toolsets like Sinda/Fluint/Thermal Desktop or other commercial FEM/FDM/FVM solvers
• Familiarity with cryogenic liquid rocket stage architecture, engine architecture, and operations
• Understanding of aerodynamics and external flight related heating, including thermal protection system materials and thermal protection system sizing

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:

$90,000 - $136,000 USD

We are an equal opportunity emplo