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 , exempt position located in our Long Beach location.

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 …