Impact Risk Analysis for a Spacecraft in Cosmo-Skymed Orbit

This paper presents a case study of Micrometeoroids and Orbital Debris risk assessment for a spacecraft flying in an orbit close to that of the Italian Cosmo-Skymed constellation. The aim of the analysis was to calculate the failure flux impinging on the satellite external shell, taking into account both geometry and materials of satellite surfaces. Furthermore the analysis included the evaluation of the contribution to debris population at the selected orbit of the fragments produced by a Chinese Anti-SATellite experiment, which caused the catastrophic break-up of the satellite Fengyun 1C in January 2007. A first computation was carried out using ESABASE2/Debris v.1.4.2. This software made it possible to perform geometrical analysis of a satellite subjected to a given debris environment, but the most up to date available models, ORDEM2000 and MASTER2001, gave significantly different results. An independent procedure for risk assessment analysis was implemented to further analyse such issue and to provide damage equation adequate to represent the behaviour of the selected structural aluminium honeycomb sandwich panels covered by Multi-Layer Insulation. Debris fluxes were calculated applying MASTER2005 and ORDEM2000 environment models, then results were compared to those of ESABASE2. Failure fluxes were calculated implementing special damage equations for honeycomb structures available from the open technical literature. The expected flux contribution of catalogued debris from the Chinese Anti-SATellite (ASAT) experiment was estimated independently using the code SDIRAT (Space Debris Impact Risk Analysis Tool) developed at the Institute of Information Science and Technologies (ISTI).