The real-time critical embedded flight software serves as the intelligence behind the operation of the entire satellite. The Command and Data Handling (CDHS) software acts as the satellite's brain. It is a collection of rules, processes, and algorithms used by the spacecraft's onboard computer to execute its functions.

The Modular CDHS Software Development Project has created modular flight software based on RTOS architecture, capable of accommodating different types of spacecraft and various associated subsystems. This software can collect and store data from the spacecraft subsystems, payloads, and instruments, as well as encrypt/decrypt data and handle commands from the ground. The CDHS also manages watchdog timer(s), onboard real-time clock(s), a real-time task scheduler, and all onboard subsystems.

The Modular CDHS developed at NSSTC has the ability to adapt to a variety of subsystems, payloads, and mission requirements. Currently, the Modular CDHS is supporting two satellite missions at NSSTC: Al Ain Sat and GNSSaS Satellite.