Collision risk effects on Low Earth targets due to satellite breakups
- Paper number
IAC-06-B6.P.2.01
- Author
Dr. Anil Kumar A. K., Indian Space Research Organisation (ISRO), India
- Year
2006
- Abstract
When a satellite breaks up the resulting fragments forms a cloud loosely around the parent body till the orbital perturbations disperse the fragments to the background environment. Assessing the effects of breakups on the low earth targets is important as the manned space activities usually takes place in altitude ranges of 200 km to 400 km. Based on historical reports nearly 50 fragmentation events took place from 1991 onwards until 2003 in the Low Earth Orbits. The fragments small or large generated out of these events can cause collision risk for targets between 200 km to 400 km together with other tracked objects. This paper tries to analyze these breakup events by simulating the fragments using ASSEMBLE model and propagating all the fragments till date. For average values of the solar activity and objects below 800 km altitude, only the drag effect is considered for the orbital propagation effecting the changes in semi major axis and eccentricity together with effects of Earths oblateness (J2 alone). Since each of the break ups can generate numerous fragments large and small, the long-term propagation of fragments is carried out through the approach based on the equivalent fragment concept and constant gain Kalman filter approach. The evolution of the space debris scenario was dealt earlier from an estimation theoretic approach involving the Kalman filtering technique. In contrast to other approaches in the literature such a space debris modeling approach helped to handle parameter or state uncertainties, unmodellable features, and also enabled to systematically assimilate information from the newer breakups as well as expansion of the scenario. The system states of the equivalent fragments (than all the fragments) in various semi major axis, eccentricity, and ballistic coefficient bins could be rapidly propagated in time and updated using measurements based on constant Kalman gains. This study provides a methodology that is useful in assessing the collision probability due to these evolved fragments at low earth target altitudes, in particular for manned space activities in the altitude range of 200 - 400 km. References 1. Anz-Meador, P. D., History of On-Orbit Satellite Fragmentations, 13th Edition, JSC 62530, NASA, May 2004. 2. Anilkumar, A. K., Ananthasayanam, M. R., and Subba Rao, P. V., A posterior semi stochastic low earth debris on-orbit breakup simulation model, Acta Astronautica, Vol. 13, November 2005. 3. King-Hele, D., Satellite Orbits in an Atmosphere: Theory and Applications, Blackie, Glasgow and London, 1987. 4. Ananthasayanam, M. R., Anilkumar, A. K., and Subba Rao, P. V., Evolution and Expansion of the Orbital Debris Scenario based on Constant Gain Kalman Filter Approach, IAC-04-IAA-5.12.1.10, IAF Conference, Vancouver, October 2004, Proceedings of IAC 2004, Science and Technology Series, 2005.
- Abstract document