Fly-by-wire control systems in aircraft and spacecraft primarily fall under Mechanical Engineering, specifically its subfields of Aerospace or Aeronautical Engineering. While Computer Science and Mathematics contribute to developing algorithms that integrate these systems with GPS and other controls, the mechanical aspects remain the domain of Mechanical Engineers. The discussion also touches on the role of Electrical Engineering in building computers and satellite systems, highlighting that GPS integration involves both hardware and software components. Electrical Engineering is responsible for hardware aspects like satellite communication systems, while Computer Engineering and Computer Science focus on software and peripheral devices. The conversation emphasizes the interdisciplinary nature of these technologies, with various engineering fields collaborating to address challenges such as environmental stresses and electromagnetic interference.