End-of-life deorbiting services for small satellites making use of bare electrodynamic tethers

Guidelines for space debris mitigation call for a 25-year limit on the permanence in low Earth orbits for satellites of any mass size. The aim of this paper is to analyze bare electrodynamic tapes/tethers as deorbiting devices for small satellites. The analysis focuses on the deorbiting performances of electrodynamic tether systems from LEO high ranking hot spot regions (e.g., sun-synchronous orbits), and includes a realistic mass budget of a deorbiting system suitable for small satellites. A preliminary design was carried out by means of two synergetic software to the purpose of finding a light tether system configuration that can provide a relatively fast deorbit maneuver. The optimization process used in the present work consists in three main steps. In the first step an innovative semi-analytical algorithm was used to find the best conductive tether geometry. In the second step fundamental system variables (e.g., deorbit time, cut probability, electrical current) were found through numerical simulations utilizing simplified tether models. In the last step a simulator implementing a more complex tether model that takes into account flexibility and lateral dynamic of the tether was used to complete the optimization process.