Mechanical Engineer jobs in California

Astranis

Internship · San Francisco, CA · $29 / hour

Astranis is seeking a mechanical engineering intern to spend twelve weeks designing, building, and testing satellite hardware and structures for spacecraft that will launch to orbit. This role suits current undergraduates pursuing degrees in mechanical or aerospace engineering who enjoy hands-on work and are ready to tackle real engineering problems with immediate impact.

Listed on Astranis’s careers site · Apply there ↗

KLA-Tencor

Full-time · Milpitas, CA · $141,300 – $240,200

KLA is seeking a senior mechanical design engineer to develop next-generation opto-mechanical assemblies for broadband plasma wafer inspection systems used in semiconductor manufacturing. This role is ideal for someone with a strong track record in optical and thermal design who enjoys collaborating across engineering disciplines to bring innovative inspection products from concept to production.

Listed on KLA-Tencor’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $132,000 – $198,000

This role involves designing and testing critical mechanisms for a commercial rocket, including stage separation systems, landing gear, and deployment mechanisms. It's suitable for experienced mechanical engineers who thrive in fast-paced hardware development and want hands-on ownership of flight-critical systems.

Listed on Relativity Space’s careers site · Apply there ↗

Astranis

Internship · San Francisco, CA · $29 / hour

Astranis seeks an undergraduate mechanical engineering student for a 12-week summer internship designing and testing spacecraft hardware and mechanisms. This role suits students eager to contribute to real satellite projects that will launch to orbit, with hands-on experience in CAD, structural analysis, and assembly processes.

Listed on Astranis’s careers site · Apply there ↗

KLA-Tencor

Full-time · Milpitas, CA · $181,000 – $307,700

This role leads a mechanical engineering team developing precision hardware for next-generation EUV light sources in semiconductor reticle inspection equipment, operating in extreme vacuum and thermal environments. It suits an experienced engineering manager who has built capital equipment at high complexity and wants to own subsystem architecture across vacuum, optics, and thermal-mechanical integration.

Listed on KLA-Tencor’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $132,000 – $198,000

Relativity Space seeks a mechanical engineer to design and develop flight mechanisms for their Terran R rocket, including stage separation systems, landing gear, and control actuators. This role suits someone with aerospace design experience who thrives owning complex hardware projects from concept through testing and manufacturing.

Listed on Relativity Space’s careers site · Apply there ↗

Astranis

Internship · San Francisco, CA · $29 / hour

This is a 12-week paid internship for mechanical engineers working on real satellite hardware and systems at a space technology company. It suits current undergraduates eager to contribute to flight-bound projects in a hands-on engineering environment.

Listed on Astranis’s careers site · Apply there ↗

KLA-Tencor

Milpitas, CA · $141,300 – $240,200

KLA seeks a mechanical engineer to design and architect the gas, water, cryogenic, and vacuum distribution systems for advanced semiconductor manufacturing equipment. This role combines system-level architecture work with hands-on CAD design, P&ID documentation, and cross-functional leadership of a critical subsystem.

Listed on KLA-Tencor’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $132,000 – $198,000

Senior engineer guiding the design and testing of rocket mechanisms like stage separation and landing gear systems, working across structures, avionics, and manufacturing teams to deliver flight-ready hardware. Suits someone with aerospace or complex product development experience who thrives in fast-paced environments and wants hands-on ownership of critical subsystems.

Listed on Relativity Space’s careers site · Apply there ↗

Astranis

Full-time · San Francisco, CA · $145,000 – $225,000

Astranis is seeking a seasoned mechanical engineer to lead the design and lifecycle management of spacecraft subsystems, from concept through on-orbit operation. The role combines individual technical expertise in structures and mechanisms with mentorship of junior engineers, suited for someone with deep aerospace hardware experience who thrives in a fast-paced development environment.

Listed on Astranis’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $150,000 – $226,000

You'll design and deliver mechanical systems for advanced avionics platforms destined for space science missions, working hands-on from concept through flight qualification. This role suits experienced aerospace engineers comfortable owning complex thermal and structural challenges in a fast-moving environment where your decisions directly shape the next generation of interplanetary exploration hardware.

Listed on Relativity Space’s careers site · Apply there ↗

Astranis

Full-time · San Francisco, CA · $110,000 – $160,000

This role designs and develops mechanical systems for satellites operating in high orbits, working with structure, mechanisms, and thermal components from concept through assembly and test. It suits engineers with 2-4 years of mechanical design experience who want hands-on involvement in spaceflight hardware and can thrive in a fast-paced environment.

Listed on Astranis’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $129,000 – $193,000

This role involves designing and delivering the mechanical systems that support advanced avionics platforms for space science missions, including enclosures, thermal solutions, and structural components that must survive launch and space environments. It suits an experienced mechanical engineer comfortable working hands-on in a fast-paced aerospace setting, iterating rapidly from concept through flight qualification.

Listed on Relativity Space’s careers site · Apply there ↗

KLA-Tencor

Milpitas, CA · $117,800 – $200,300

KLA seeks a mechanical design engineer to lead the development of ultra-clean vacuum subsystems for semiconductor inspection equipment, working across optics, electrical, and controls teams to deliver precision chambers and integrated platforms. This role suits someone with strong CAD and analysis skills who thrives on complex multi-disciplinary systems and can mentor junior engineers through detailed design cycles.

Listed on KLA-Tencor’s careers site · Apply there ↗

Astranis

San Francisco, CA · $110,000 – $160,000

Design and develop mechanical enclosures for spacecraft electronics and RF components, managing the complete lifecycle from requirements through testing while solving complex challenges in thermal management, EMI isolation, and launch survivability. This role suits engineers with hands-on hardware experience who enjoy bridging mechanical and RF engineering disciplines in a fast-paced space technology environment.

Listed on Astranis’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $132,000 – $198,000

Relativity Space seeks a hands-on mechanical engineer to design, analyze, and test primary and secondary structures for their Terran R rocket, working across the full development cycle from concept through manufacturing support. This role suits someone with 5+ years of structural design experience who thrives in a fast-paced startup environment, owns projects end-to-end, and balances creative innovation with rigorous engineering discipline.

Listed on Relativity Space’s careers site · Apply there ↗

Astranis

Full-time · San Francisco, CA · $145,000 – $225,000

You'll design and test mechanical enclosures for satellite electronics and RF components, solving complex problems in thermal management, EMI shielding, and structural survivability for space. This role suits experienced mechanical engineers who enjoy hands-on hardware work and thrive at the intersection of mechanical, thermal, and RF engineering challenges.

Listed on Astranis’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $132,000 – $198,000

This role designs structural components and assemblies for Relativity's Terran R rocket, from concept through manufacturing support, working with metals, composites, and sheet metal across all vehicle stages. It suits experienced mechanical engineers who thrive in fast-paced environments, enjoy hands-on hardware ownership, and can balance creative problem-solving with rigorous technical discipline.

Listed on Relativity Space’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $136,000 – $204,000

Lead the design and integration of rocket engine assemblies at a commercial space company, owning the complete lifecycle from layout through flight qualification. This role suits an experienced mechanical or aerospace engineer with fluid systems and structural design expertise who can mentor a small team while navigating the technical complexity of high-performance propulsion systems.

Listed on Relativity Space’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $164,000 – $246,000

You'll lead the mechanical design of rocket mechanisms like stage separation and landing gear systems, working through the complete engineering lifecycle from concept to flight test. This role suits experienced mechanical engineers who thrive in fast-paced aerospace environments and want hands-on ownership of hardware that reaches orbit.

Listed on Relativity Space’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $185,000 – $277,000

Relativity Space seeks a principal mechanical engineer to design and oversee manufacturing tooling and factory automation equipment for rocket production. This role suits experienced engineers who thrive on autonomy, enjoy solving novel problems in hardware development, and want to shape how rockets are built at scale.

Listed on Relativity Space’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $143,000 – $215,000

This role designs and engineers tooling, fixtures, and factory automation equipment that enables the production of Relativity's Terran R rockets and Aeon engines. It suits experienced mechanical engineers who thrive in fast-paced manufacturing environments and want to see their designs impact real production at scale.

Listed on Relativity Space’s careers site · Apply there ↗

Relativity Space

Long Beach, CA · $122,000 – $182,000

This role designs and develops tooling, fixtures, and factory automation equipment that supports manufacturing of Terran R rockets and Aeon engines. It suits experienced mechanical engineers who enjoy solving novel production problems, working across teams, and seeing their designs built and deployed on the factory floor within weeks or months.

Listed on Relativity Space’s careers site · Apply there ↗