Propulsion Engineer, Structures (Mid)

Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases, more companies launching payloads to space continue to emerge.

For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles.

Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more.

We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.

About the Role

Apex is seeking a Propulsion Engineer with experience in structures and hardware integration to design the propulsion modules that bolt onto Apex spacecraft at scale. You will own mechanical designs across the module, including the structure, mounting and installation of flow controllers, PPUs, and thrusters, and the packaging that turns a set of components into a single, buildable, flight-ready assembly.

What makes this role distinctive is that the propulsion components you're integrating are designed and built in-house at Apex. You'll work directly with the engineers who own our thrusters, cathodes, flow controllers, and PPUs, helping shape their mechanical, thermal, and interface design so the components and module are optimized together from the start.

You'll also work closely with our manufacturing team throughout the design cycle, supporting first builds and incorporating feedback from the production floor as we scale. This role offers significant hands-on design ownership and the opportunity to take hardware from concept through build, test, and production.

Responsibilities:

• Own mechanical designs for propulsion modules, including module structures, mounting interfaces, and the installation of flow controllers, PPUs, thrusters, and other propulsion hardware.

• Design module structures to meet vehicle-level structural and environmental requirements, including launch loads, vibration, shock, and thermal environments, while conforming to vehicle ICDs.

• Define mechanical, thermal, and structural interfaces between propulsion components and the module, and between the module and spacecraft.

• Partner with Apex's in-house thruster, cathode, flow controller, and PPU teams to optimize component mounting, packaging, and interfaces.

• Perform structural analysis, including hand calculations and FEA, to verify strength, stiffness, and margins.

• Design against mass, cost, and power budgets and support engineering trades across competing requirements.

• Design for manufacturing and assembly to ensure modules are buildable, repeatable, and installable at rate.

• Work directly with manufacturing and production teams during first builds and resolve design and integration issues on the floor.

• Incorporate manufacturing feedback into design iterations to improve producibility, yield, and build time.

• Create and own component and assembly drawings, tolerance stack-ups, fastening and torque specifications, and installation work instructions.

• Support the build, integration, and test of flight hardware and contribute to anomaly resolution and root-cause investigations.

• Contribute to continuous design improvements across module generations as production scales.

Qualifications:

• Bachelor's degree in mechanical, aerospace, or a related engineering field.

• 3+ years of relevant mechanical or aerospace engineering experience, with experience in structural design and hardware installation/integration.

• Strong understanding of structural design and analysis, including load paths, strength and stiffness, fasteners and joints, tolerance stack-ups, hand calculations, and FEA.

• Experience designing aerospace or other complex hardware to structural and environmental requirements, including vibration, shock, and thermal environments.

• Experience integrating discrete components, such as propulsion, avionics, fluidic, or other hardware, into structural assemblies.

• Proficiency with CAD, engineering drawings, and GD&T, with experience taking designs through release, build, and test.

• Experience working with manufacturing or production teams to transition designs into hardware and resolve build and integration issues.

• Ability to make sound engineering trades across performance, mass, cost, manufacturability, and schedule.

• Ability to communicate clearly and work cross-functionally across engineering, manufacturing, and production teams.

• Must be a U.S. Person (U.S. citizen, lawful permanent resident, or protected individual) as defined by ITAR (22 CFR §120.15).

Nice to Have:

• Direct experience with spacecraft propulsion modules, feed systems, or propulsion component integration.

• Experience designing spacecraft or aerospace hardware for serial or high-rate production, including design-for-manufacturing and design-for-assembly.

• Familiarity with electric propulsion components, including thrusters, flow controllers, PPUs, and their mechanical, thermal, fluidic, and electrical interfaces.

• Experience with propellant feed-system routing, fluidic components, and cleanliness/contamination control.

• Experience collaborating with component design teams to optimize hardware and system-level integration.

• Experience supporting environmental qualification testing, including vibration, shock, and TVAC.

• Experience supporting flight hardware through integration, qualification, launch, and/or on-orbit operations.

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Why Join Apex?

Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup that has raised more than $500M in funding, and we invest heavily in our people from day one.

What We Offer For Full-time Employees:

• Shared upside: Receive equity in Apex, letting you benefit from the work you create

• Best-in-class healthcare: 100% company-paid medical, dental, and vision for you and your dependents, plus $100k life insurance at no cost

• Comprehensive PTO package to reset and recharge - starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays

• Competitive 401(k) plan with generous matching - 100% match on first 3%, 50% on next 2%

• 8 weeks paid parental leave plus childcare reimbursement up to $350/day for work-related travel

• Daily catered lunch and unlimited snacks to keep you fueled throughout the day

• Vibrant community: Monthly office socials, pickleball tournaments, run club, and gatherings for you and your family

• Your dream desk setup and all the tools you need to be your most productive self

• World-class Playa Vista office with the benefit of in-person collaboration with amazing coworkers and flexibility to integrate work and life