Projets par an
Solar radiation pressure affects the evolution of high area-to-mass geostationary space debris. In this work, we extend the stability study of Valk et al. (2009) by considering the influence of Earth's shadows on the short- and long-term time evolutions of space debris. To assess the orbits stability, we use the Mean Exponential Growth factor of Nearby Orbits (MEGNO), which is an efficient numerical tool to distinguish between regular and chaotic behaviors. To reliably compute long-term space debris motion, we resort to the Global Symplectic Integrator (GSI) of Libert et al. (2011) which consists in the symplectic integration of both Hamiltonian equations of motion and variational equations. We show how to efficiently compute the MEGNO indicator in a complete symplectic framework, and we also discuss the choice of a symplectic integrator, since propagators adapted to the structure of the Hamiltonian equations of motion are not necessarily suited for the associated variational equations. The performances of our method are illustrated and validated through the study of the Arnold diffusion problem. We then analyze the effects of Earth's shadows, using the adapted conical and cylindrical Earth's shadowing models introduced by Hubaux et al. (2012) as the smooth shadow function deriving from these models can be easily included into the variational equations. Our stability study shows that Earth's shadows greatly affect the global behaviour of space debris orbits by increasing the size of chaotic regions around the geostationary altitude. We also emphasize the differences in the results given by conical or cylindrical Earth's shadowing models. Finally, such results are compared with a non-symplectic integration scheme. © 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.
14/11/08 → …
Outstanding Paper Award for Young Scientists: Charles Hubaux, "aspirant FNRS" from 2009 to 2013 (supervisor: Anne Lemaitre) and PhD in mathematics since June 2013, obtained the « Outstanding Paper Award for Young Scientists » which recognizes the best paper published in Advances in Space Research written by a young researcher (less than 31 years old) in the period 2012-2014, in the category PEDAS (Panel on Potentially Environmentally Detrimental Activities in Space)
Charles Hubaux (Bénéficiaire), 2012
Prix: Prix (y compris les médailles et récompenses)