Senior GNC Engineer

At Vast, our mission is to contribute to a future where billions of people are living and thriving in space. Vast is developing next-generation space stations to ensure a continuous human presence in space for America and its allies, enabling advanced microgravity research and manufacturing, and unlocking a new space economy for government, corporate, and private customers. Using an incremental, hardware-rich and low-cost approach, Vast is rapidly developing its multi-module Haven Station. Haven Demo’s 2025 success made Vast the only operational commercial space station company to fly and operate its own spacecraft. Next, Haven-1 is expected to become the world’s first commercial space station when it launches, followed by additional Haven modules to enable permanent human presence by 2030. Our team is all-in, committed to executing our mission safely and on time. If you want to work with the most talented people on Earth furthering space exploration for humanity, come join us. Vast is seeking a Senior GNC Engineer to own guidance, navigation, and control for a new constellation-ready spacecraft bus — a product line designed to scale to hundreds of spacecraft per year. The satellite bus uses a CMG-based attitude control system — four Vast Mini CMGs in a pyramid configuration. ADCS performance is a defining capability of the bus — it's what enables high-power payloads that demand precise pointing and rapid slew. You'll own the GNC algorithms, simulation environment, sensor suite definition, and pointing performance for the satellite. This is end-to-end ADCS ownership: from architecture trades and algorithm development through 6DOF simulation, hardware-in-the-loop testing, and on-orbit commissioning. You'll engage directly with payload customers on pointing and stability requirements, and you'll define the CMG and sensor performance specs that drive hardware development and procurement across the program. This will be a full-time, exempt position located in our Long Beach location. Responsibilities: * Define the ADCS architecture — CMG pyramid configuration, sensor suite selection, pointing modes (nadir+yaw steer, LVLH fixed, 3-axis sun tracking) * Develop GNC algorithms — attitude determination, CMG steering law (including singularity avoidance), momentum management, desaturation strategy * Own the pointing budget — pointing accuracy, stability, jitter, and smear allocation across the sensor and actuator chain * Define the simulation strategy — determine how the spacecraft design, simulation, and digital twin tool and Vast’s flight-validated 6DOF physics sim (GTsim) work together, what fidelity is needed for upfront system design vs flight readiness

• Build and validate the 6DOF simulation environment
• Define CMG performance requirements — momentum capacity, gimbal rate, gimbal

limits, pyramid angle — feeding the electronics lead for box design * Define sensor performance requirements — star tracker, IMU, sun sensor, magnetometer, GNSS receiver accuracy and noise specs (feeding the procurement lead for vendor selection)

• Support CMG Rev 1 bring-up with closed-loop testing
• Define and commission the HITL (hardware-in-the-loop) lab — flight processor,

spoofed I/O, real-time simulation

• Magnetic field modeling for torque rod sizing
• Run Monte Carlo analysis campaigns to demonstrate pointing performance and

flight readiness * Assess flexible body dynamics — structural mode coupling with large solar arrays and cantilevered payloads, define appendage first-mode frequency requirements for structures * Engage directly with payload customers on pointing and stability requirements — assess feasibility on the bus, define GNC data interfaces, and negotiate what we can support * Ensure controllability during electric propulsion maneuvers — coordinate with the EP team on thrust vector, disturbance torques, and momentum impact * Build a GNC team as the program scales — define roles and hire as complexity demands * Support on-orbit commissioning planning for ADCS Minimum Qualifications: * Bachelor's degree in Aerospace Engineering, Mechanical Engineering, Physics, Mathematics, or a related technical discipline

• 6+ years of spacecraft GNC or ADCS development experience
• GNC algorithm development experience for spacecraft — attitude determination,

control law design, actuator management * Experience with reaction wheels or CMGs — actuator sizing, control allocation, momentum management

• Built and validated 6DOF spacecraft simulations
• Pointing budget development and allocation across sensor/actuator chains
• HITL test environment design and execution
• Comfortable working from architecture trades through flight software

implementation * Strong dynamics and controls fundamentals Preferred Qualifications:

• Able to obtain a security clearance
• CMG experience — steering laws, singularity avoidance, pyramid configuration

optimization * Momentum management for LEO spacecraft (magnetic desaturation, gravity gradient)

• Star tracker and IMU selection / characterization experience
• Agile / small-sat GNC development — you've done this with a small team on a

fast timeline * GNC flight software implementation experience Pay Range: California

$159,900—$226,980 USD

COMPENSATION AND BENEFITS

Base salary will vary depending on job-related knowledge, education, skills, experience, business needs, and market demand. Salary is just one component of our comprehensive compensation package. Full-time employees also receive company equity, as well as access to a full suite of compelling benefits and perks, including: medical, dental, and vision coverage for employees and dependents, generous paid time off; up to 20+ days of vacation for exempt staff and up to 10+ days of vacation for non-exempt staff with the ability to cash-out unused vacation annually, paid parental leave, short and long-term disability insurance, life insurance, access to a 401(k) retirement plan, ClassPass credits, personalized mental healthcare through Spring Health, and other discounts and perks. We also take pride in offering exceptional food perks, with snacks, drip coffee & onsite barista, cold drinks, and dinner meals remaining free of charge, and lunch subsidized as part of Vast’s ongoing commitment to providing high-quality meals for employees.

U.S. EXPORT CONTROL COMPLIANCE STATUS

The person hired will have access to information and items subject to U.S. export controls, and therefore, must either be a “U.S. person” as defined by 22 C.F.R. § 120.62 [ or otherwise eligible for deemed export licensing. This status includes U.S. citizens, U.S. nationals, lawful permanent residents (green card holders), and asylees and refugees with such status granted, not pending.

EQUAL OPPORTUNITY

Vast is an Equal Opportunity Employer; employment with Vast is governed on the basis of merit, competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.