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 Senior Mechanical Engineer at Relativity, you will be responsible for design, fabrication, and modification of test stands for our Terran 1 and Terran R engines and stages. Engineers at our Stennis facility are engaged directly with construction and maintenance activities in the field, across a variety of hours to years-long project scales. This position will be titled Senior Propulsion Test Engineer within the organization.

• Design advanced propulsion test stands, including 3D modeling, fluids and structural 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

• Ability to work occasional night shifts

About You:

Bachelor's degree in mechanical engineering, aerospace engineering, or a related field and 5+ years of combined engineering experience is required

• Prior experience in aerospace is not required

• Varied perspectives & backgrounds strengthen our team

• Ownership of propulsion or structural test related projects including design, analysis, construction, and commissioning from beginning to end as well as proficiency in 3D modeling and drafting, including GD&T

• Demonstrated engineering fundamentals in thermal, structural, and fluids analysis as well as a 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

• Knowledge of fluid components such as valves, regulators, and instrumentation as well as experience designing, fabricating, and operating complex fluid systems

• This position requires a valid driver's license in order to operate vehicles on the test site

Nice to have but not required:

• Experience with FEA or CFD

• Hands-on experience with metalworking, welding, hydraulics, manufacturing, etc.

• In depth knowledge of manufacturing processes, material selection, inspection, precision measurement, and non-destructive testing

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:$139,500—$170,500 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 accommodations@relativityspace.com.