GNC Engineer

Job Title:

GNC Engineer - Hypersonics

Job Category:

Engineering

Leander, TX, 78641

Summary

As a GNC Engineer at Firefly, you will design, analyze, and operate the GNC systems for operational launch vehicles including the Alpha Launch Vehicle and emerging hypersonic programs. In this role, you will develop GNC and simulation software tailored to high-speed flight regimes, perform dynamic analyses across diverse trajectory profiles, and support mission operations while building breadth across multiple vehicle programs. This position offers hands-on experience with launch vehicle ascent guidance, hypersonic guidance algorithms, attitude control in high dynamic pressure environments, and real-time flight operations in a fast-paced environment. You will deepen your technical capabilities in flight mechanics and controls, with particular emphasis on hypersonic applications, taking ownership of system elements and software tools supporting Fireflys expanding vehicle portfolio.

Responsibilities

• Develop and validate GNC software to ensure successful mission execution across multiple vehicle programs
• Design and tune attitude determination and control algorithms for all phases of flight including boost, ascent, and terminal phases
• Perform 6DOF dynamic analysis of nominal and dispersed trajectories including aerodynamic heating effects, trajectory shaping, and range optimization
• Develop and maintain simulation models for aerodynamics, hypersonic thermal constraints, propulsion systems, sensors, and actuators
• Create tools to automate workflows, process flight data, and generate technical reports for vehicle performance
• Conduct stability analysis, sensitivity studies, and hardware-in-the-loop testing of GNC systems under flight conditions including off-nominal scenarios
• Interface with cross-discipline teams (aerodynamics, propulsion, structures, thermal) to integrate GNC software with vehicle hardware
• Support trajectory optimization and targeting for mission profiles including launch vehicles and high-speed flight regimes
• Serve as a GNC console operator for vehicle launch operations and perform post-flight analysis to improve vehicle models and performance predictions
• Author technical documentation and analysis reports that communicate GNC concepts and results to diverse audiences
• Build proficiency across GNC competencies while contributing to continuous improvement of GNC processes and tools

Skills/Experience:

Qualifications

Required

Bachelors degree in aerospace engineering, mechanical engineering, electrical engineering, physics, mathematics, computer science, or related field

2-5 years of professional experience in aerospace guidance, navigation, and control, or related technical discipline

Understanding of flight mechanics, aerodynamics, and attitude dynamics

Familiarity with numerical simulation techniques, integration methods, and modeling of dynamic systems

Experience with Python for scripting, data analysis, and visualization

Familiarity with C++ for real-time or flight-critical applications

Understanding of software development best practices including version control (Git), code documentation, and testing

Strong written and verbal communication skills

Desired

Advanced degree (masters or PhD) in aerospace engineering or related field with focus on GNC, flight mechanics, hypersonics, or controls

Experience supporting launch vehicle or hypersonic vehicle GNC across development, integration, and flight

Experience with high-speed or hypersonic flight test, wind tunnel testing, or flight dynamics analysis

Knowledge of aerodynamic and aerothermal effects on vehicle performance and control, particularly in high-speed flight regimes

Understanding of trajectory optimization techniques for hypersonic mission profiles including skip trajectories, boost-glide profiles, and multi-phase mission design

Proficiency in C++ for embedded systems or real-time applications

Knowledge of state estimation techniques including Kalman filtering, sensor fusion, and covariance analysis

Experience with control allocation and adaptive control techniques for vehicles with varying control authority

Familiarity with modern flight software frameworks and real-time operating systems

Familiarity with CI/CD workflows and automated testing practices

Experience with Linux development environments and command-line tools

Exposure to flight test campaigns, launch operations, or mission operations

Understanding of multi-phase trajectory design for vehicles transitioning between propulsion modes or flight regimes