Abstract: This paper presents a study of the short-term collision risk posed to the resident Earth-orbiting population by fragments generated in hypothetical explosions in the geosynchronous ring. Debris clouds resulting from such explosions contain constrictions, which are regions of high fragment density caused by the Earth's central gravitational attraction. The highest density constriction, the pinch point, is almost fixed inertially and occurs at the breakup point. Hence most of the resident geosynchronous population flies near it. In this study, the computer programs IMPACT and DEBRIS were used to assess collision risk. Program IMPACT was used to model the explosions, and program DEBRIS was used to perform short-term debris cloud propagation and compute collision risk. The four cases considered are all based on the explosion of a generic liquid apogee kick stage which has never happened in the geosynchronous ring. The satellites for which collision risk was assessed were taken from an August 1995 update of the USSPACECOM Satellite Catalog. It was found that short-term collision risk was low, even though the entire geosynchronous population flies near the pinch point. This occurs because the fragments are spread over very large volumes in geosynchronous orbit. However, approximate extrapolation of these results indicates an increased collision risk in the intermediate time frame of several months to a year. Due to the lack of a cleansing perturbation in the geostationary region, collisions are statistically likely to occur. !15
展开▼
