Establishment of Debris Index Evaluation Criteria and Comparison of Index Effects

This paper discusses the processes which should be taken to establish debris indices that assess the orbital environmental impact of spacecraft or missions in orbit. The first process is establishing a methodology and criteria for evaluating an impact on the orbital environment. This study proposed an assessment method to evaluate the cumulative environmental changes during an evaluation period. It evaluated the impact of an uncontrolled LC mission abandoned in orbit This study used NEODEEM, an orbital environmental evolutionary model that Kyushu University and JAXA developed. The second process is the index formulation. This study considered four steps to establish the debris index, and proposed an index that could be evaluated by NEODEEM. The difference between the calculated index values and the environmental impact was also discussed. Further, this study conducted numerical simulations of un-controlled large-constellation satellites abandoned in low earth orbit in different scenarios, and of active debris removals of large intact objects by NEODEEM. This paper discusses the applicability of proposed environmental assessment methods and the debris index.