Propulsion Engineer II (Design)

About Portal

Portal Space Systems is on a mission to expand humanity’s freedom of movement in space. We’re building the spacecraft that makes that mission possible. From our Bothell, WA headquarters, we design vehicles with the maneuverability, resilience, and adaptability needed for the next era of orbital operations. Every system we build is in service of a simple idea: space should be more accessible, responsive, and capable. Joining Portal means stepping into a team that believes in bold engineering, fast iteration, and the power of small groups to change what’s possible. If you want your work to directly shape the future of in-space mobility, join us.

Position Summary

The Design-focused Propulsion Engineer uses their mechanical design skills to advance pressurant system, propellant management device (PMD), feed system, and reaction control system (RCS) flight hardware. With guidance from senior Propulsion Engineers, the role contributes to mechanical design and drawings, supplier engagement, and development, qualification, and acceptance testing, while collaborating on build, vehicle integration, and functional testing. This position works closely with fellow Propulsion Engineers and suppliers to get sufficient hardware built and tested quickly, learn from it, and drive designs from early development through qualified flight hardware.

Core ResponsibilitiesFlight Hardware Design & Development – Pressurant, PMD, & Feed Systems

• Develop mechanical designs and drawings for propulsion flight hardware (pressurant system, PMD, feed system, and/or RCS) with available mentorship from senior Propulsion Engineers, starting with fast, sufficient development hardware to learn quickly before converging on flight designs

• Engage with suppliers to help bring components from specification through delivery, including interface definition and verification

• Develop test requirements, test articles, and success criteria for assigned hardware, reviewed by senior Propulsion Engineers, and interpret results to inform design decisions

• Execute tests as needed, partnering with fellow Propulsion Engineers on test stands and hazardous operations

• Collaborate on build plans and execution to ensure designs are buildable and built as intended

• Support vehicle integration and functional testing of propulsion hardware

What You Bring To Portal

• Solid foundation in mechanical design, fluid systems, and structures with the ability to apply first principles reasoning and quickly learn unfamiliar hardware, processes, and disciplines

• Ability to perform first-order structural and fluid hand calcs (e.g., stress margins, pressure drop)

• Bias toward fast and sufficient solutions first, getting useful hardware and test data in hand and iterating toward the intended final state rather than aiming for it out of the gate