Explore the development of a real-time Linux-based flight control system for the HTTP-3A rocket by the Advanced Rocket Research Center in Taiwan. Delve into the intricacies of building rocket steering and attitude control for high-dynamics environments, aiming to launch a sounding rocket vertically with a 10 KG payload to an apogee exceeding 100 KM. Learn about the PREEMPT_RT Linux foundation, hardware-assisted hard real-time sensing and actuation, and the use of EtherCAT for guaranteed real-time capability. Discover the avionics system architecture, PRU-ICSS for sensing I/O, computing models, flight software framework, and inter-process communication. Gain insights into the flight control evaluation process, including Hardware-in-Loop (HIL) testing and the Mazu Rocket Simulation. Understand the ongoing open-source projects and progress of ARRC's rocket development in this comprehensive exploration of cutting-edge rocket flight control systems.