LAUSR

Abstract The impact of small pieces of space debris (less than 2 mm in size) that ground-based observations are unable to detect can cause fatal damage to a spacecraft. Accordingly, to monitor the environment of these small pieces, in-situ measurements that utilize on-orbit impact sensors capable of detecting small objects are being advanced. One of the advantages of in-situ measurements is its capability to derive data with high time resolution, thus allowing the investigation of changes in the aforementioned environment. In this paper, two statistical methods—one based on the chi-squared test and the other on the Akaike Information Criterion—are proposed to detect environmental changes, and an equation that clarifies the correlation between the impact detector area, measurement duration, and limit of the detectable extent of change is derived. One of the proposed methods can also estimate the extent of environmental changes. To evaluate these methods and the derived equation, numerical simulations are conducted. The outcome of this study affords a quantitative assessment of changes in the environment of small pieces of space debris and is anticipated to contribute to the improvement of systems designed for investigating the such changes using in-situ measurements.