Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases, more companies launching payloads to space continue to emerge. For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles. Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more. We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.  ABOUT THE ROLE We are seeking a seasoned Senior Spacecraft GNC Engineer to work on a closely integrated team who will drive the design of the GNC system, including hardware and software, to meet the position, attitude, knowledge and stability requirements of our bus. You will have an opportunity to approach this from a clean sheet design and inform coupled trades across the vehicle architecture. You will be innovative in your approach to push the limits of design and performance, while disrupting and making an impact on the industry. This role reports directly into the Director of GNC, HITL & Mission Ops. Responsibilities: * Develop and implement GNC algorithms for satellite systems, including attitude determination and control, orbit determination and control, and precision pointing. * Conduct analysis of spacecraft dynamics and perform simulations to evaluate system performance, stability, and accuracy. * Design, develop, and test spacecraft control systems, including reaction wheels, thrusters, and magnetic torquers, to achieve desired mission objectives. * Collaborate with spacecraft and payload engineers to define system requirements and ensure GNC system compatibility and integration. * Perform trade studies and make recommendations for optimal GNC configurations, considering factors such as power consumption, mass, and cost. * Develop and execute test plans and procedures for GNC systems, including system-level testing, performance evaluation, and anomaly resolution. * Analyze and interpret spacecraft telemetry data to diagnose and troubleshoot GNC-related anomalies and performance issues. * Collaborate with software engineers to develop GNC software modules and interfaces, ensuring seamless integration with overall satellite systems. * Stay up-to-date with industry advancements and emerging technologies in GNC systems, and contribute to continuous improvement initiatives. * Provide technical expertise and support to cross-functional teams, including project managers, system engineers, and operations personnel. * Develop GNC algorithm and subsystem tests and validation criteria for functional and performance verification. Requirements: * U.S. Person status is required as this position needs to access export controlled data. * Bachelor's or Master's degree in Aerospace Engineering, Electrical Engineering, or a related field. * 8+ years of professional experience as a GNC Engineer, preferably in the satellite or aerospace industry. * Strong knowledge of spacecraft dynamics, orbital mechanics, and control theory. * Proficiency in programming languages such as C/C++, MATLAB, Python with experience in numerical simulation and analysis. * Familiarity with GNC hardware and software components, such as sensors (gyroscopes, accelerometers, star trackers), actuators, and control algorithms. * Experience with simulation tools and software packages commonly used in spacecraft GNC engineering (e.g., MATLAB/Simulink, STK). * Strong analytical and problem-solving skills, with the ability to evaluate complex system dynamics and propose effective solutions. * Excellent teamwork and communication skills, with the ability to collaborate effectively with cross-functional teams and stakeholders. * Self-motivated and able to work independently with minimal supervision, as well as in a team-oriented environment. * Attention to detail, organizational skills, and the ability to manage multiple priorities and meet project deadlines. * Ability to lead solutions to engineering problems from beginning to end. #LI-HC1 WHY JOIN APEX? Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup that has raised more than $500M in funding, and we invest heavily in our people from day one. WHAT WE OFFER FOR FULL-TIME EMPLOYEES: * Shared upside: Receive equity in Apex, letting you benefit from the work you create * Best-in-class healthcare: 100% company-paid medical, dental, and vision for you and your dependents, plus $100k life insurance at no cost * Comprehensive PTO package to reset and recharge - starting at 15 days vacation, growing to 20+ days annually, plus 10 paid holidays * Competitive 401(k) plan with generous matching - 100% match on first 3%, 50% on next 2% * 8 weeks paid parental leave plus childcare reimbursement up to $350/day for work-related travel * Daily catered lunch and unlimited snacks to keep you fueled throughout the day * Vibrant community: Monthly office socials, pickleball tournaments, run club, and gatherings for you and your family * Your dream desk setup and all the tools you need to be your most productive self * World-class Playa Vista office with the benefit of in-person collaboration with amazing coworkers and flexibility to integrate work and life * Real impact opportunity: Work alongside experts from aerospace, new space, and other cutting-edge industries to make a lasting difference Ready to join a team where your contributions matter and your future is bright? Let's build something extraordinary together. EQUAL OPPORTUNITY EMPLOYER Apex Technology, Inc. is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Candidates and employees are always evaluated based on merit, qualifications, and performance. We will never discriminate on the basis of race, color, 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.