Mechanical Engineer II

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 Stennis Test team designs, builds, and operates Relativity's propulsion and stage test stands. Team members are hands-on with large-scale, complex systems including fully integrated engines and stage assemblies, pushing hardware to the limits and directly contributing to flight readiness. The work is fast-paced and highly operational, ideal for those with backgrounds in aviation, automotive, manufacturing, offshore operations, industrial systems, construction, or adjacent industries. You'll work in a close-knit, dynamic environment where collaboration between technicians, operators, and engineers is not only encouraged, but expected. As the company scales, the Stennis Test team becomes even more critical to unlocking our next phase of growth: proving out full-stage systems and paving the way for routine, reliable flights of Terran R.

About the Role:

As a Mechanical Engineer II, you will be responsible for designing and operating rocket engine test stands for our Terran R engines and stages. Engineers at our Stennis facility work within a team of engineers and technicians to build and modify test facilities, as well as participate in test campaigns to flight qualify our hardware. You will be directly engaged in daily test operations, maintenance, construction, and commissioning activities in the field. The engineer II role may include aspects of both designing ground systems [Design focus] and conducting test operations [Operations focus], possibly both. This position will be titled Propulsion Test Engineer II within the organization.

[Design focus]

• Design advanced propulsion test stands including 3D modeling, fluids, structural, and thermal analysis, fabrication drawings, fluids P&IDs, component lists, and detailed work instructions
• Supervise the construction, commissioning, and initial operations of these facilities
• Solve a variety of technical problems, across broad ranges of timeframe, complexity, cost, and long-term impact
• Support operations on and perform related improvements to existing test stands

[Operations focus]

• Create, modify, and optimize test sequences, procedures, and data review processes
• Conduct complex propulsion test operations to assess performance of rocket engines and stages
• Directly control and receive telemetry from the test stand and test articles through GUIs and an integrated software suite for control, automation, and data visualization
• Help develop new rocket engine propulsion designs based on real test data
• Potentially travel to production and launch locations, up to 25%

About You:

• Bachelor's degree in mechanical engineering, aerospace engineering, or a related field
  • Prior experience in aerospace is not required
  • Varied perspectives & backgrounds strengthen our team
• Minimum of 2 years of engineering experience in a related field
• Demonstrated engineering fundamentals in thermal, structural, and fluids analysis
• Demonstrated drive to deliver on tight schedules, especially when unconventional & creative solutions are necessary
• Hands-on fabrication experience using common power tools for projects at work/home/school
• Ability to work occasional night shifts
• This position requires a valid driver's license in order to operate vehicles on the test site

Nice to haves but not required:

• Proficiency in 3D modeling and drafting, including GD&T
• Hands-on experience with metalworking, welding, hydraulics, manufacturing, etc.
• Working knowledge of fluid components such as valves, regulators, and instrumentation
• Ability to understand and develop fluid P&IDs (Plumbing and Instrumentation Diagrams) for large-scale test stands and supporting ground equipment
• Experience safely operating complex fluid systems, including high pressure gas, cryogenic fluids, flammables, and hydraulics
• Ability to work occasional night shifts

Successful candidates must clear a background check administered by the US government to obtain clearance for on-site work at our government partner location in Stennis, Mississippi.

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:

$112,000-$143,000 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.

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