Senior Propulsion Engineer, Fluids

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 Senior Propulsion Engineer with deep experience in pressurized fluid systems to own the feed-system design of the propulsion modules that fly on Apex spacecraft. You will be the fluidics authority on the propulsion module team — designing the wet side of the module from the tank through the routing to the thruster and cathode, defining and running the test campaigns that qualify it, and carrying the hardware through range safety and into space.

This is a senior individual contributor role with technical leadership scope. You'll own pressurized fluid architecture, component selection, and routing; the proof, burst, and leak testing that verifies it; and the range-safety and pressure-systems compliance that lets it fly. You'll also work directly with Apex's in-house propulsion component teams (thrusters, cathodes, flow controllers, PPUs) and with manufacturing to design feed systems that are safe, verifiable, and buildable ponsibilities Own the propellant feed-system design for Apex's propulsion modules — architecture, schematic, component selection (tanks, regulators, valves, filters, transducers, service valves), and end-to-end fluidic routing.

Design pressurized fluid systems to appropriate factors of safety, defining MEOP, proof, and burst requirements and the design margins that satisfy them.

Perform the fluids analysis that drives the design — flow and pressure-drop budgets, transient/water-hammer, feed-pressure and blowdown behavior, filtration, and thermal effects on the fluid.

Design tubing, fitting, weld, and braze joints and routing that survive launch and space environments and conform to vehicle ICDs.Define and execute feed-system test campaigns — leak (including helium/mass-spec), proof, burst, functional, and acceptance testing — and author the procedures and GSE requirements to run them.

Own range safety and pressure-systems compliance for the module (e.g., SSCMAN/AFSPCMAN 91-710), including fracture control for pressurized hardware and COPVs, hazard analyses, and the documentation and approvals needed to fly.

Support propellant servicing — fill/drain and hazardous operations — from a fluids-design and safety standpoint.

Partner with Apex's in-house thruster, cathode, flow controller, and PPU teams to define fluidic interfaces and co-optimize the feed system with the components it serves.

Work with the manufacturing team to ensure a smooth handoff to the floor, and fold their feedback back into the design to improve producibility, cleanliness, and build time ve design-for-manufacturing and cleanliness/contamination control so feed systems are buildable, cleanable, and testable in serial production.

Support build, integration, test, launch campaigns, on-orbit performance evaluation, and anomaly resolution, and lead root-cause investigations on fluidic issues.

Provide technical mentorship to…