Senior Flight Software Engineer Long , California,

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
, exempt position located in our Long Beach location.

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.

• 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

• 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…