Portfolio Careers

Senior Satellite Guidance, Navigation, and Control (GNC) Engineer

Portal Space Systems

Portal Space Systems

Bothell, WA, USA
Posted on Jul 10, 2025

We are seeking a highly experienced Senior Satellite Guidance, Navigation, and Control (GNC) Engineer with significant experience in spacecraft and satellite development, including hands-on expertise in avionics integration and mission planning. This role requires a deep understanding of control theory, sensor fusion, and high-fidelity simulation for real-time aerospace applications.

Responsibilities

  • Design, develop, and validate GNC algorithms with a focus on precise pointing and stability control using linear control methods.
  • Perform high-fidelity simulations, modeling, and analysis of guidance, navigation, and control systems.
  • Lead avionics integration efforts, including sensor calibration, hardware-in-the-loop testing, and flight software validation.
  • Support mission planning, trajectory design, and optimization of spacecraft pointing performance.
  • Collaborate with multidisciplinary teams, including software engineers, avionics specialists, and mission planners.
  • Conduct system performance assessments, stability analysis, and develop risk mitigation strategies.
  • Develop and document technical specifications, interface control documents, and system architecture designs.
  • Provide hands-on support for integration and testing of flight hardware and software.
  • Collaborate with partner organizations on satellite development.
  • Mentor junior GNC engineers.

Basic Qualifications

  • Bachelor's, Master’s, or PhD in Aerospace Engineering, Electrical Engineering, Mechanical Engineering, or a related field.
  • Minimum of 5 years of experience in spacecraft and satellite GNC development.
  • Expertise in precise pointing control using linear control methods.
  • Proficiency in MATLAB, Simulink, Python, or C/C++ for simulation and algorithm development.
  • Experience with avionics integration, including working with IMUs, star trackers, sun sensors, magnetorquers, GPS receivers, and reaction wheels.
  • Deep understanding of spacecraft dynamics, orbital mechanics, and trajectory optimization.
  • Experience with high-fidelity simulation, hardware-in-the-loop (HIL), and software-in-the-loop (SIL) testing.
  • Familiarity with aerospace industry standards and regulations.
  • Strong problem-solving skills and ability to work in a fast-paced, collaborative environment.

Preferred skills & Experience

  • Experience with real-time embedded software development and flight software implementation.
  • Familiarity with Kalman filtering, guidance laws, and autonomous navigation techniques.
  • Previous experience in mission operations and post-launch analysis.
  • Knowledge of spacecraft communication protocols and fault detection systems.
  • Hands-on experience with integration and test campaigns for space missions.

Compensation & Benefits

Base salary is just one part of your total rewards package at Portal. You may also be eligible for long-term incentives in the form of company stock, stock options, or long-term cash awards, as well as potential discretionary bonuses and the ability to purchase additional stock at a discount through an Employee Stock Purchase Plan. You will also receive access to comprehensive medical, vision, and dental coverage. Portal is planning to establish future access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks. Employees typically have 2-3 weeks of paid vacation per year plus company holidays.

ITAR Requirements

To conform to U.S. Government export regulations, the applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.