Fengyun-1C Orbital Debris Cloud Short-Term Risk Analysis

Abstract

The breakup of the Fengyun-1C satellite resulted in the generation of an orbital debris cloud containing a large number of fragments that pose a collision risk to operating satellites. This paper presents an analysis of the risk posed by the Fengyun-1C debris cloud during its short-term evolution period to several sample groups of satellites. Scatter plots of risk and time profiles of flux and cumulative risk for selected satellites are shown. Results indicate that debris cloud short-term risk varied significantly across the satellites considered. I. Introduction T he breakup of the Fengyun-1C (FY-1C) satellite resulted in the generation of an orbital debris cloud containing a large number of fragments that pose a collision risk to operating satellites. The highest potential risk per unit time was posed during the short-term evolution of the debris cloud. During this period of time, the fragments had not yet uniformly spread around the debris cloud parent orbit, and the local spatial density of fragments was highest. The debris cloud was highly dynamic, and the risk posed to individual satellites was determined by the timing and geometry of penetration of the debris cloud by those satellites. This paper presents results of an analysis of the risk posed by the FY-1C debris cloud during its short-term evolution period. For the purpose of this analysis, the short-term period covers the first seven days after breakup. The risk to several sample groups of satellites is presented. Time profiles of flux and cumulative risk for selected satellites are shown. Both absolute risk (raw collision probability) and relative risk are shown. The relative risk is defined as the ratio of the absolute risk posed by the debris cloud fragments to the absolute risk posed by pre-event background objects in the same size range and over the same time interval.