Incorporating Orbital Debris Risk Analysis Into Cislunar Orbital Procedures and Post-Mission Disposal

With the onset of the Artemis program, we expect to see a paradigm shift towards a coordinated, sustained presence of space traffic in key cislunar orbits. As a result, we are likely to see multiple spacecraft operating in orbits close to each other or performing proximity operations. In order to ensure the sustainable growth of key orbit families in the cislunar regime we thus need to take a preventative approach to orbital debris mitigation, since debris generated in these orbits has no means to decay and could remain present indefinitely in the nominal orbits of key program elements such as the Lunar Gateway. Further, most advantageous families of orbits in the cislunar regime are at a mechanical energy level such that debris generated in one location is likely to proliferate across the domain, thus debris from collisions of defunct spacecraft could flow back into orbits occupied by Artemis program elements. In addition to the incorporation of preventative strategies in the spacecraft design process, it is important to encourage the mitigation of orbital debris generation by developing standard operational procedures for spacecraft in close proximity to each other, identifying safe flightpath corridors, and assessing post-mission disposal methods, mirroring equivalent measures currently in place for near-Earth orbits. Our work proposes to leverage probabilistic risk analyses for debris generation and proliferating in the cislunar regime to assess the nominal operational scenarios of proposed cislunar missions. We explore missions in key cislunar orbits, specifically those operating close to the Lunar Gateway, and assess the probability of debris generation during their nominal operations and their post-mission disposal. Collectively, our work would help provide a means of risk assessment for orbital debris generation to cislunar mission designers for both the mission’s nominal operations and post-mission disposal. Our work could also be useful for the development of safety protocols for Gateway, such as keep-out spheres and approach zones that minimize the risk of debris generation.