Monte Carlo simulation of spacecraft breakup events in Low Lunar Orbit

Abstract

Monte Carlo simulations of spacecraft breakup events in Low Lunar Orbit are conducted to study the behavior of artificial debris across all orbit types in this environment. 2000 breakup events at random initial states in lunar orbit are simulated, and the resulting nearly 500,000 particles are propagated for five years using a high-fidelity lunar trajectory model. Debris from a smaller sample of 200 breakup events is also propagated for ten years. Trends in the rate of decay of debris from lunar orbit are analyzed to investigate the longevity of debris in lunar orbit, and the locations of lunar surface impacts are plotted to determine if some regions of the Moon would be at greater risk than others from an orbital breakup event. Across all orbits, about 38% of the debris remained in lunar orbit after five years, and the longevity of debris was found to depend significantly on the pre-breakup perilune and inclination. Debris generally remained in lunar orbit for less time as the pre-breakup perilune decreased, although an average of 19% the debris remained in lunar orbit after five years even for pre-breakup perilune altitudes below 50 km. Debris was also found to be highly unstable in certain inclinations. The rates of decay across all orbit types tended to slow greatly after two years, suggesting that a portion of the debris can often remain in lunar orbit for at least a decade. Finally, clusters of lunar surface debris impacts were identified, which could have applications for lunar satellite disposal after mission completion. The results of this study provide novel insights into the consequences of lunar breakup events, helping support the development of debris mitigation recommendations for lunar orbit as international interest in exploration of the Moon grows.