PNT Flight Software Test & Verification Engineer

Moonshot Aerospace is seeking a PNT Flight Software Test & Verification Engineer to develop, integrate, and verify real-time flight and ground support software for spacecraft positioning, navigation, and timing (PNT) subsystems. The position is on-site at a customer facility in Houston, TX, supporting commercial and government lunar and cislunar spacecraft programs. 

This is a software-first role. The engineer will write and integrate real-time software in C and C++, build the software-in-the-loop and hardware-in-the-loop environments that exercise it, and verify subsystem behavior against requirements. The primary qualification is demonstrated depth in flight or embedded software development; navigation and estimation domain knowledge strengthens an application but is not a substitute for software capability. GPS/GNSS receiver experience and formal test and verification experience are the strongest differentiators among otherwise comparable candidates. 

The requisition is open at two levels. Responsibilities, technical ownership, and compensation scale with demonstrated capability. 

Responsibilities  

• Develop, integrate, and test real-time flight software for spacecraft PNT subsystems in C and C++ 

• Build and maintain software-in-the-loop (SWIL) and hardware-in-the-loop (HWIL) test environments for navigation and GN&C software 

• Develop automated test infrastructure, regression suites, and analysis tooling in Python 

• Execute software verification against subsystem requirements and document results with traceability to those requirements 

• Integrate and test navigation sensor and timing interfaces, including GNSS receivers, IMUs, star trackers, optical navigation cameras, and frequency references 

• Support bench and testbed integration of flight software with flight-like avionics 

• Troubleshoot software, interface, and timing anomalies during integrated test and drive them to closure 

• Support Test Readiness Reviews and produce test plans, procedures, and post-test reports 

• Perform post-test data reduction and navigation performance analysis 

• Work within Agile development processes using Git version control and JIRA issue tracking 

• Collaborate across GN&C, avionics, systems engineering, and customer teams 

Required Qualifications  

• U.S. Citizenship and ability to obtain and maintain a security clearance 

• B.S. in Computer Science, Computer Engineering, Electrical Engineering, Aerospace Engineering, or related field 

• Level III: 5+ years of professional flight, embedded, or real-time software development experience. Level IV: 10+ years, or M.S. with 8+ years 

• Demonstrated depth in C and C++ on real-time, embedded, or resource-constrained targets 

• Proficiency in Python for test automation, scripting, and data analysis 

• Experience integrating and testing software against hardware interfaces (serial, Ethernet, SpaceWire, CAN, MIL-STD-1553, or equivalent) 

• Experience with software test and verification practice, including test procedure development and defect tracking to closure 

• Experience with Git version control and software configuration management 

• Working knowledge of spacecraft dynamics, orbital mechanics, coordinate frames, and time systems 

• Effective written and verbal communication, including clear documentation of test results 

• Ability to work on-site in Houston, TX 

Preferred Qualifications  

• GPS/GNSS experience: receiver integration, receiver software, signal processing, or GNSS simulator operation 

• Formal verification experience in an aerospace, safety-critical, or flight-certified software environment 

• Development of SWIL and HWIL test environments, including real-time interface emulation 

• Real-time operating system experience (VxWorks, RTEMS, embedded Linux, or equivalent) 

• Implementation of Kalman filters or other state estimators in flight software 

• M.S. in Computer Science, Computer Engineering, Electrical Engineering, Aerospace Engineering, or related field 

• Experience with the NASA Trick simulation framework, CSPICE, GMAT, GEONS, or equivalent 

• Optical navigation, image processing, or feature detection software 

• Monte Carlo analysis and navigation performance characterization 

• Linux and Bash development environment fluency 

• Requirements management and verification traceability tools 

• Spacecraft integration and test (I&T) or flight operations experience 

• Lunar, cislunar, or deep-space mission experience