The objective of the study is to model a system which can effectively prevent the collision between space debris and spacecraft by robust design and algorithms of the system. The location and trajectory of the debris field at each and every instant are tracked with the help of image processing. The Voronoi diagram and Dijkstra’s algorithm are utilized to determine the alternate orbits for the spacecraft in order to avert the collision. The discrete subsystem, namely, orbit determination system, orbit maneuvering system, and reaction control system, is modeled and simulated using the Simulink platform. The collision avoidance system employs the most energy-efficient Hohmann maneuver to find the alternate orbits for spacecraft between circular orbits. The simulation results shown from the present work clearly evidences the effectiveness of collision avoidance. The present collision avoidance system always determines the safe and fuel economic trajectory for spacecraft independent of human interference.