GNC Engineer

About Poseidon Aerospace:

Poseidon Aerospace is reimagining how the world moves goods. We build and operate full-size autonomous cargo aircraft - capable of carrying two tons of payload over a thousand nautical miles. From remote communities to contested logistics operations, our platforms unlock a new cost curve for air freight, making it faster, cheaper, and accessible anywhere it's needed. Headquartered in the San Francisco Bay Area with locations in Washington DC, Oregon, and Maine; we're building something consequential.

About the role

GNC is how our cargo aircraft knows where it is, decides where to go, and flies there with no pilot on board. As a GNC Engineer you will design guidance, navigation, and control algorithms, prove them in simulation, and work with flight software to get them onto the aircraft. You will then support flight test and use the data to improve both the models and the algorithms.

Responsibilities

• Design and tune flight control laws for all phases of flight, including takeoff and landing
• Develop navigation and state estimation algorithms that fuse GNSS, inertial, and air data sensors
• Develop guidance algorithms for trajectory following and autonomous takeoff and landing
• Design sensor and actuator fault detection and the control response to failures
• Build and maintain 6-DOF simulation models of the aircraft, sensors, actuators, and environment
• Analyze stability, control margins, and performance across the flight envelope, including Monte Carlo analysis
• Work with flight software to implement algorithms in flight code and verify the implementation against the design
• Verify algorithms in software-in-the-loop and hardware-in-the-loop testing
• Support flight test planning and execution, including travel to our flight test site
• Analyze flight data to validate models, identify aircraft dynamics, and refine gains

Required Qualifications

• B.S. in aerospace engineering, mechanical engineering, electrical engineering, or a related field, or equivalent experience
• 2+ years designing guidance, navigation, or control algorithms for aircraft, spacecraft, or comparable vehicles
• Strong grounding in flight dynamics and classical and modern control theory
• Experience building or using 6-DOF simulation to design and verify algorithms
• Proficiency in MATLAB/Simulink or Python, and working knowledge of C++

Preferred Qualifications

• GNC experience on fixed-wing aircraft, crewed or uncrewed
• Algorithms you designed have flown on a real vehicle
• Experience with Kalman filtering and GNSS/INS integration
• Experience with autonomous takeoff and landing
• Experience with hardware-in-the-loop testing
• Experience with system identification from flight test data
• M.S. or Ph.D. in controls, dynamics, or a related field

Why this role

There is no pilot to fall back on. The algorithms you design fly the aircraft from takeoff to landing. You will work from the math through simulation to flight test, and watch your control laws fly an aircraft that carries two tons.

What you get from us

• Competitive salary and meaningful early-stage equity
• Relocation support if applicable
• Employee Health Benefit Plans
• 6% Retirement matching
• Flexible PTO
• Free lunches, snacks, and a stocked fridge at our offices
• AI tools and subscriptions