Istituto di Scienza e Tecnologie dell'Informazione     
Pardini C., Anselmo L. Revisiting the cataloged debris collision risk for the Iridium and Cosmo-skymed satellite constellations. In: IAC 2016 - 67th International Astronautical Congress (Guadalajara, Mexico, 26-30 September 2016). Proceedings, vol. DVD article n. IAC-16-A6.2.2. International Astronautical Federation (IAF), 2016.
After two decades of slightly declining growth rate, the population of cataloged debris around the Earth increased by more than 56% in just a couple of years, from January 2007 to February 2009, due to two collisions in space involving the catastrophic destruction of three intact satellites (Fengyun 1C, Cosmos 2251 and Iridium 33) in high inclination orbits. Both events had occurred in the altitude range already most affected by previous launch activity and breakups. In 2011 a detailed analysis had been carried out to analyze the consequences of these fragmentations, in particular concerning the evolution of the collision risk for the Iridium and COSMO-SkyMed satellite constellations. Five years after such first assessment, the cataloged debris environment affecting the two constellations was revisited to evaluate how the situation had evolved due to the varying contribution of the above mentioned breakup fragments and the space activities carried out in the meantime. Being distributed, at 778 km, over six nearly polar orbit planes separated by just 30 at the equator, the Iridium satellites represent a very good gauge for checking the evolution of the debris environment in the most critical low Earth region. In approximately five years, from May 2011 to June 2016, the average debris flux on the Iridium satellites increased by about 14%, to 1.59 x 10-5 m-2 per year. The cataloged fragments of Fengyun 1C, Cosmos 2251 and Iridium 33 still accounted for, on average, 54% of the total flux. More than 39% of the latter was associated with the Fengyun 1C fragments, about 11% with the Cosmos 2251 fragments and less than 4% with the Iridium 33 fragments. Specifically concerning the mutual interaction among the Iridium 33 debris and the parent constellation, the progressive dispersion and rather fast decay of the fragments below the Iridium operational altitude, coupled with a slow differential plane precession and low average relative velocities with respect to four of the six constellation planes, determined in five years, on average, a decline of the flux by about 31%, i.e. to about 5.75 x 10-7 m-2 per year. The decrease occurred in each constellation plane, even though with different rates and percentages, due to the varying relative orbit geometry. From May 2011 to June 2016, the mean debris flux on the COSMO-SkyMed satellites, at 623 km, increased by about 26%, to 7.24 x 10-6 m-2 per year. The Fengyun 1C, Cosmos 2251 and Iridium 33 cataloged fragments accounted for, on average, about 1/4 of the total, with 12% due to Fengyun 1C, 8% to Cosmos 2251 and 4% to Iridium 33.
Subject Space debris
Fengyun 1C
Cosmos 2251
Iridium 33
Debris flux evolution
Low Earth orbit
70F15 Celestial mechanics

Icona documento 1) Download Document PDF

Icona documento Open access Icona documento Restricted Icona documento Private


Per ulteriori informazioni, contattare: Librarian http://puma.isti.cnr.it

Valid HTML 4.0 Transitional