A collision simulator based on Two-Line-Elements

Space objects are generally defined as any orbiting object around the Earth, both from natural and artificial origin. In the last years, space activities are increasing the number of space objects, raising concern about the likelihood of collisions between operational spacecrafts. To mitigate this dangerous phenomenon, studies about probability of collision and avoidance maneuvers have played an important role in the last decades. Through the Two-Line-Element sets, position and velocity information of space objects can be computed at a known instant of time and then propagated to future time period with the Simplified General Perturbation model. Accurately knowing the motion of each object helps in the detection of collisions. This thesis deals with spacecraft collision probability by drafting a layout of a collision simulator and developing part of it in MATLAB environment. To compute the probability of collision in a validation example, the procedure that has been followed consisted in propagating the trajectory of a European satellite to the time of closest approach. At this instant of time, an encounter region has been defined, finding the likelihood of collision between another object with Foster’s analytical method and with non-linear Monte Carlo simulations. This dissertation ends with a general flowchart of the simulator, which illustrates its functioning and includes the future works to be developed.