<h2>AAS 99-174</h2>
<h2>Computation of Orbital Conjunctions and Collision Prediction Methods                                                                             </h2>
<h4>D.M. Henderson                                                                                                                                                                      </h4>
Boeing-Houston                                                                                                                                                            
<h2> Abstract </h2>
This paper discusses a method of predicting orbital conjunctions of a space vehicle with the known orbiting space objects. It emphasizes the importance of an accurate database of orbiting space objects in order to compute conjunction parameters accurately enough to be useful in determining threatening collision situations. The analysis shows how the difference in the conjunction arrival time of the space vehicle and that of the conjuncting space object can be used in a collision prediction system. Application of these collision prediction methods can be extended to compute conjunctions for space vehicles of orbiting constellations with considerable reduction of computing resources.