Staff Propulsion Engineer (Test)

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.

The Test-focused Propulsion Engineer leads propulsion test capability and practices, using their hands-on test expertise to advance thruster, feed system, and pressurant system development. The role is responsible for developing and commissioning propulsion test stands and facilities, including a large vacuum chamber, and for defining and executing hazardous test operations involving high pressure, vacuum, ammonia, and high power optical and induction systems. This position establishes propulsion test standards with the team, mentors fellow Propulsion Engineers, and partners with hardware owners and suppliers to plan test campaigns, stand up sufficient test capability quickly, generate trustworthy data, and drive hardware development from early development testing through qualification.

Core Responsibilities

Overarching Responsibility – Propulsion Test Leadership

Lead propulsion test planning across thruster, feed system, and pressurant system development, partnering with hardware owners and propulsion leadership on test priorities, schedule, and resourcing

Establish and maintain propulsion test standards with the team, including test procedures, hazardous operations practices, test readiness reviews, data quality, and test reporting

Mentor fellow Propulsion Engineers in test planning, test execution, and hazardous operations

Facilitate test readiness and post-test reviews, helping hardware owners clearly document and communicate results to inform hardware decisions

Guide test capability investments across the propulsion roadmap, balancing fast, sufficient capability now against longer-term infrastructure needs

Primary Responsibility – Thruster Test

Own HEX Thruster test campaigns from test planning and procedure definition through execution, data review, and reporting

Stand up and commission a large vacuum chamber facility, bringing up sufficient test capability first and iterating toward the full facility (pumping, feedthroughs, instrumentation, and safety systems)

Integrate and safely operate the high power optical and induction systems that drive the thruster

Define thruster test instrumentation and diagnostics to measure performance (e.g., thrust, propellant flow, temperatures, and pressures)

Define and execute hazardous operations procedures for ammonia, high pressure, vacuum, and high power systems

Secondary Responsibility – Feed & Pressurant System Test

Develop and commission test stands for feed system and pressurant system component and system-level testing, favoring fast, sufficient setups that generate data early over building final-state infrastructure up front

Support development and qualification testing of valves, regulators, tanks, and flow control hardware, partnering with hardware owners on test requirements and execution

Partner with Fluid/Thermal analysis to define pre-test predictions and correlate models with test data

Define test stand DAQ and control architectures and develop AI-assisted automation and data processing to rapidly turn test data into hardware decisions

What You Bring To Portal

Strong foundation in fluid systems, vacuum systems, and high energy test hardware with the ability to apply first principles reasoning to test design, test safety, and anomaly resolution

Ability to lead a test scope, prioritizing the tests that most effectively reduce risk and accelerate hardware decisions, and establishing safe, repeatable test practices for the team

Ability to mentor engineers, establish test standards, and lead collaboratively with hardware owners to deliver propulsion test campaigns

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

Propensity to solicit and provide peer review, clearly and concisely document procedures and results, and communicate implications for the associated hardware

Basic Qualifications

Bachelor’s or Master’s degree in Mechanical Engineering, Aerospace Engineering, or related field

6+ years of experience in hands-on propulsion or fluid system hardware testing

Experience developing and commissioning test stands or test facilities

Experience defining and executing high pressure, vacuum, and hazardous test operations

Experience leading test campaigns and mentoring engineers

Preferred Qualifications

Proficiency with NI DAQ hardware and software

Experience using AI-assisted tools for test automation and data processing

Experience with ammonia or other toxic propellants

Experience with high power optical or induction systems

Experience standing up large vacuum chambers or thruster test facilities

Pay Range $165K to $215K

Compensation and Benefits:

Your actual level and base salary will be determined on a case-by-case basis and may vary based on the following considerations: job-related knowledge and skills, education, and experience.

At Portal, your base salary is just one part of your total rewards package. You may also be eligible for long-term incentives, in the form of company equity at an exciting time of company growth as well as potential bonuses. You will also receive access to comprehensive medical, vision, and dental coverage (premiums paid by Portal 100%), access to a 401(k)-retirement plan, paid parental leave, you may also accrue 3 weeks of paid vacation and will be eligible for 12 or more paid holidays per year as well as sick time.

ITAR Statement

This position may involve access to technical data and defense-related materials controlled under the International Traffic in Arms Regulations (ITAR). Eligibility to access ITAR-controlled items requires that candidates be U.S. persons , which includes U.S. citizens, lawful permanent residents, and other protected individuals as defined by U.S. law. Employment is contingent upon verification of ITAR eligibility and, where applicable, obtaining any required export authorization or license.

Equal Opportunity Statement

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.