FLEX

Flight Software Framework
One codebase. Simulation to flight.

Most programs spend months building flight software infrastructure before writing a single line of guidance, navigation and control (GNC) code. The FLEX flight software framework provides a validated GNC foundation, using the same codebase from simulation through hardware-in-the-loop to first flight.

FLEX flight software simulation of autonomous aircraft and loitering munitions

From Simulation to First Flight

The FLEX framework is a flight software platform for defense and aerospace programs. It comprises three modules: FLEX Simulation Software, FLEX Embedded Software, and REVEAL Performance Analytics. FLEX Simulation is built on the same FLEX Embedded runtime, so the code running in simulation is the same code that flies.

From Simulation to First Flight

The FLEX framework is a flight software platform for defense and aerospace programs. It comprises three modules: FLEX Simulation Software, FLEX Embedded Software, and REVEAL Performance Analytics. FLEX Simulation is built on the same FLEX Embedded runtime, so the code running in simulation is the same code that flies.

FLEX flight software framework from concept definition through flight-proven hardware integration

FLEX Modules

01

FLEX Simulation Software
  • 6 degrees of freedom (DOF) model library spanning satellites, launch vehicles, missiles, hypersonics, and UAS
  • Software-in-the-loop (SIL) and hardware-in-the-loop (HWIL) support, early and often
  • High-fidelity simulation data early, for better design decisions

02

FLEX Embedded Software
  • Same codebase from simulation to HWIL to flight, eliminating integration risk
  • Hard real-time, Motor Industry Software Reliability Association (MISRA)-compliant, processor-agnostic across customer-specified hardware
  • Ships preinstalled on BRAIN flight computers

03

REVEAL Performance Analytics
  • Harvests data from large-scale Monte Carlo runs
  • 30,000 simulation hours per night
  • Key performance parameter (KPP) tracking, 3D visualization, and continuous integration/continuous deployment (CI/CD) regression testing
  • Identifies performance gaps before SIL and HWIL, when they are the cheapest to fix

04

GPS-Denied Navigation
FLEX Embedded software enables navigation without GPS or external signals by fusing data from the vehicle’s native sensors using a multi-sensor Extended Kalman Filter (EKF). ScavengerNav GPS-denied navigation software works with the FLEX framework to deliver positioning in Anti-Access/Anti-Denial (A2/AD) environments, day and night, without GPS or datalink.

What the FLEX Framework Was Built For

  • GNC performance beyond what microcontroller-based architectures can deliver
  • Autonomous operation requiring deterministic, verifiable flight control
  • Aggressive development schedules with limited tolerance for integration risk
  • GPS-denied or communications-degraded navigation
  • Collaborative swarming with autonomous teaming algorithms alongside deterministic flight control

Proven Across Defense and Space Programs

The FLEX software framework has been applied to UAVs, CUAS interceptors, missiles, hypersonics, loitering munitions, spacecraft, reentry vehicles, and launch systems.
Autonomous quadcopter UAV using FLEX flight software in a desert environment