Analysis of accidental spacecraft break-up events in cislunar space

Abstract

Fragmentation events are the most common source of artificial debris in space. Such events can happen for multiple reasons, ranging from collisions with active or inactive objects to propellant tanks or battery explosions. They are an inherent part of human activities in space, regardless of the location. At the same time, the interest in the Moon and the space around it increases. Multiple planned missions want to leverage the peculiar dynamics of the Earth-Moon system to build an infrastructure likely to support human exploration of space for centuries to come. The present research puts a step forward in the direction of Space Debris Mitigation techniques for future cislunar missions. After being tuned with novel implementation techniques, the NASA Standard Break-up Model has been employed to simulate explosion events in multiple locations in cislunar space. Notably, the Circular Restricted Three-Body Problem model has been employed to generate orbits, corrected in a higher-fidelity model to generate initial conditions for long-term propagations. Moreover, multiple starting positions along each orbit have been crossed with several possible event dates, providing a broader understanding of the aftermath of explosion events. Three case studies have been considered: an EML2 southern Near Rectilinear Halo Orbit (NRHO), candidate for the Gateway station, a larger Halo orbit of the same family, and a Distant Retrograde Orbit (DRO). These locations have been chosen to characterize dynamically different trajectories used in current applications. Results provided include the number, locations, and characteristics of collision with the Moon and the Earth, together with considerations on the interactions with Earth’s protected orbital regions of Low Earth Orbit (LEO) and Geostationary Orbit (GEO). A novel analysis is also introduced to determine the immediate danger for the Gateway station in the case of such an event. This research lays the foundation to develop a cislunar Space Debris Mitigation (SDM) framework in the hopes that awareness is raised when there is still time for proper implementation of guidelines.