Mechanical Propulsion Engineer

OUR COMPANY

As an early mover in the in-space transportation and infrastructure services, Momentus is at the forefront of the commercialization of space. With an experienced team of aerospace, propulsion, and robotics engineers, Momentus has developed a cost-effective and energy-efficient in-space transport system. 

OUR PEOPLE

Daring problems require daring solutions.  We boldly charge into uncharted territory knowing that no matter the outcome we will benefit from the journey and move closer to our goals no matter what. Our teams know that working at Momentus means more than building innovative technology, it means creating entirely new markets in the space economy. We are level-headed, business-minded strategic thinkers intent on providing immediate value to our customers today while simultaneously preparing for the vast possibilities of the future. If this sounds like you, we should talk.

JOB SUMMARY

We are seeking a Mechanical / Propulsion Engineer with a strong hands-on background in spacecraft hardware and propulsion system development. This hybrid role blends mechanical design, propulsion assembly and testing, spacecraft layout/architecture, and cross-functional collaboration across thermal, structural analysis, and manufacturing teams—with a strong emphasis on AIT execution and spacecraft hardware integration. The ideal candidate thrives in fast-paced, hardware-focused environments and enjoys working from concept through fabrication, test, and flight. 

Key Responsibilities 

• Execute hands-on assembly and testing of propulsion systems, including tubing, heaters, sensors, valves, and other fluid-system hardware. 

• Develop 3D CAD models, detailed part/assembly drawings, tolerance analyses, and integrated layouts optimized for tightly constrained spacecraft environments. 

• Design spacecraft hardware such as brackets, enclosures, fluid-routing solutions, thermal/mechanical interfaces, and structural components. 

• Generate models, documentation packages, and work instructions to support AIT (Assembly, Integration & Test) for propulsion and spacecraft mechanical hardware. 

• Collaborate closely with structural, thermal, analysis, and manufacturing teams to iterate designs through the full engineering lifecycle—from early concepts to flight-ready hardware. 

• Support propulsion and mechanical test campaigns, including setup, execution, data review, troubleshooting, and documentation. 

• Apply aerospace standards—including range safety guidelines and RPUG requirements—to ensure compliance, safety, and mission success. 

• Contribute to process development, continuous improvement, and flight-readiness maturation for mechanical and propulsion subsystems. 

Desired Skills & Experience 

• Hands-on experience with propulsion system build-up and testing, including fluid systems, heaters, wiring/sensors, or valve integration. 

• Mechanical design proficiency using modern CAD tools; experience with GD&T, tolerance stack-ups, and drawing release workflows. 

• Familiarity with spacecraft packaging constraints, tight-tolerance interfaces, and multidisciplinary integration challenges. 

• Working understanding of propulsion-system fundamentals, thermal behavior, or fluid dynamics is a plus. 

• Knowledge of aerospace standards (range safety, RPUG, etc.) or prior experience working with flight hardware. 

• Strong documentation skills and the ability to produce clear, concise technical communication. 

• Effective collaborator in hands-on, cross-functional engineering environments; capable of taking hardware from bench to flight. 

Education & Work Experience 

• BS in Mechanical Engineering, Aerospace Engineering, or related field. 3+ years relevant experience. 

• 3 to 5 years of on-the-job engineering experience. 

• Desire to contribute to a highly hands-on engineering setting involving design, integration, testing, and flight hardware ownership. 

Compensation: 

Annual Base Salary Range: $125,000 - $150,000/per year 

Base pay is one part of our total compensation package (base+bonus+equity) and is determined within a range. Your actual base salary will be determined on job-related knowledge and skills, education, and experience.  Our benefit plans include medical, dental, and vision insurance, 401k retirement plan, short and long term disability and life insurance. We also offer flexible PTO, along with 11 paid holidays, sick time and paid parental leave.

This is a full-time position in San Jose, California. This position requires access to export-controlled commodities, technical data, technology, software, and services. U.S. citizenship, U.S. legal permanent resident status, or protected person status under 8 U.S.C. § 1324b(a)(3) is required. 

All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, or status as a protected veteran.

To all recruitment agencies: Momentus does not accept agency resumes. Please do not forward resumes to our employees or any company email. Momentus will not be responsible for any fees related to unsolicited resumes.