This system will simulate the guidance control system (gcs) of a mars lander. the definition of the software requirements for the gcs project focuses on two primary needs for the software: (a) to provide guidance and engine control of the lander vehicle during its terminal phase of descent onto the planet's surface and (b) to communicate sensory information to an orbiting platform about the vehicle and its descent. the lander vehicle is to be controlled includes a guidance package containing sensors that obtain information about the vehicle state, a guidance and control computer, and actuators providing the thrust necessary for maintaining a safe descent.