Senior Flight Software 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 Flight Software Engineer to own flight software development and verification for a new constellation-ready spacecraft bus - a product line designed to scale to hundreds of spacecraft per year. This will be a full-time,exemptposition located in ourLong Beachlocation. About the role: You'll start with a proven heritage FSW baseline from prior Vast missions and a reusable ground segment - that's your foundation, not your ceiling. The heritage system was built for single-satellite missions. The real work is scaling it for a constellation product line: new GNC algorithms, updated C&DH, payload interfaces for multiple customer types, fault protection, and autonomy - all architected to work across a fleet, not just one spacecraft. As the product line scales to hundreds of spacecraft per year, you'll solve the constellation-specific FSW challenges - configuration management across payload variants, fleet software updates, and multi-satellite operations support. You're the primary stakeholder and customer of the HITL lab, driving its requirements and using it as your verification environment. You'll build and lead a small FSW team to execute all of this. Responsibilities: * Assess the heritage FSW baseline - catalog what's reusable, what needs modification, what's new for this mission * Implement GNC software - attitude determination, CMG steering law, mode management, momentum management (the GNC lead defines the algorithms, you implement and verify them in flight code) * Modify C&DH software - command and data handling, telemetry definitions, fault management updates for new bus architecture * Develop payload interface software for multiple payload types across the manifest * Build test and simulation infrastructure - unit test framework, software-in-the-loop (SIL) environment * Drive HITL lab requirements - define what the lab needs to verify, serve as its primary stakeholder and customer * Own flight software build, release, and configuration management processes * Develop on-board fault protection and autonomy for the satellite bus * Verify ground segment software interface compatibility (heritage ground segment, new bus) * Solve constellation-scale FSW challenges - configuration management across payload variants, fleet software updates, and multi-satellite operations support * Support on-orbit commissioning planning for FSW * Build and grow an FSW team as the program scales - define roles and hire as complexity demands Minimum Qualifications: * Bachelor's degree in Computer Science, Electrical Engineering, Aerospace Engineering, or a related technical discipline * 6+ years of embedded flight software development experience * Spacecraft flight software development experience - C/C++ on Linux-based or embedded real-time systems * Experience modifying and extending heritage flight software baselines (not just building from scratch) * GNC software implementation - translating control algorithms into flight code with real-time constraints * Experience defining HITL lab requirements and using HITL environments for FSW verification * C&DH subsystem experience - command processing, telemetry, data storage, fault management * Familiar with flight software V&V processes - unit test, SIL, HITL, integration test * Comfortable owning an entire FSW subsystem on a fast timeline with a small team Preferred Skills & Experience: * Able to obtain a security clearance * ADCS flight software experience on spacecraft or real-time robotics systems * Multi-satellite FSW configuration management - handling payload variants across a constellation * Experience with Linux-based flight software architectures * RTOS experience (RTEMS, FreeRTOS, Zephyr, or similar) for microcontroller nodes * Ground segment integration and compatibility testing 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: 100% 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.