Sr. Mechanism Engineer

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.

As a Sr.

Mechanisms Engineer, you will own a critical vehicle mechanism subsystem from concept through flight.

Depending on your background and team priorities, your assignment may include separation systems, landing gear, aero control surfaces, or electromechanical actuation.

This is a hands-on role at the center of vehicle hardware development, working closely with propulsion, structures, avionics, GNC, and launch operations to design integrated systems, build hardware, and validate through test.

You'll be expected to move quickly, iterate often, and take full ownership of mechanisms that directly impact mission success.

• Own the complete lifecycle of moving mechanical assemblies — from requirements and interface definition through conceptual/detailed design, development, assembly, verification, qualification testing, operation, manufacturing support, and post-flight analysis
• Drive structural and kinematic design for minimum mass while meeting strength, stiffness, fatigue, and operational-life requirements across ascent, entry, landing, and reuse environments
• Apply first-order hand calculations and empirical formulas to assess and iterate on designs rapidly
• Build finite element models and perform detailed analysis — including tolerance stack-ups — to prove designs meet vehicle requirements
• Create detailed component and assembly drawings incorporating GD&T (ASME Y14.5) and tolerance stack-up analysis
• Own the design, development, and implementation of custom tooling in support of programs
• Define and execute qualification and acceptance test campaigns; author test plans, procedures, acceptance criteria, and anomaly dispositions; validate predictions with test and flight data
• Balance performance, manufacturability, cost, and schedule in every design decision
• Work directly on the factory floor with manufacturing to iterate quickly and resolve build issues in real time
• Troubleshoot hardware anomalies, perform root cause analysis, and implement design improvements
• Work with suppliers and manufacturing to bring designs to reality, including managing schedule/budget for owned hardware and tracking/dispositioning non-conformances
• Support launch operations, post-flight inspection, and refurbishment planning
• Be the reliable expert of your system — from concept to mission control console

• Bachelor's degree in Mechanical Engineering, Aerospace Engineering, or related field or equivalent experience.
• 5 + years of professional experience designing mechanisms or complex mechanical systems for spacecraft, launch vehicles, missile systems, or other high-reliability aerospace hardware.
• Demonstrated ownership of complex hardware projects from concept through design, manufacturing, integration, and test.
• Working knowledge of launch and space environments, including vibration, shock, vacuum, thermal cycling, and temperature extremes.
• Experience applying engineering analysis to mechanism performance, structural integrity, functional margins, and tolerance management.

• Experience with motion/kinematic simulations
• Strong fundamentals in structural mechanics, kinematics, materials, and manufacturing processes
• Experience writing and executing structural test plans
• Experience with aerospace standard structural analysis methods (Bruhn, Niu, Roark, Shigley's, etc.)
• Proficiency with CAD packages (Siemens NX preferred; SolidWorks, CATIA, or Creo also acceptable)
• Proficiency with industry FEA/FEM tools (Nastran, ANSYS, FEMAP, Abaqus, etc.)
• Strong understanding and application of drafting standards and GD&T (ASME Y14.5)
• Direct experience with separation systems, landing gear, aero control surfaces, or flight electromechanical actuators
• Experience with docking/berthing systems
• Experience with pyrotechnic or low-shock separation devices
• Hands-on prototyping and machining experience
• Familiarity with reusable vehicle design
• A proven history of mentoring junior engineers
• Experience at a fast-moving, hardware-focused startup or early-stage program