De LISA Pathfinder à LISA: Élaboration d’un simulateur dynamique pour la mission spatiale eLISA

摘要

The gravitational Universe and the rise of an entirely new astronomy using gravitational waves have been selected by ESA as the scientific theme for the future large space mission L3 planned for 2030 decade. In that context, eLISA (evolved Laser Interferometer Space Antenna) mission seems favored, and is besides preceded by the LISA Pathfinder mission, launched on December 2nd 2015, that aims to demonstrate the technology envisaged. The scientific outcome of this mission would be very wide, concerning at the same time fundamental physics, cosmology and astrophysics.The work described in this document allows to deliver a simulator reproducing the closed-loop dynamical behavior of a three-body system : the spacecraft and the two test-masses. The simulator is based on a Space State Model of the dynamical system, of the measurement and actuation systems and includes numerous modelled imperfections such as sensor noises and stray forces applied on the test masses (the inertial references of the system), hence allowing to study the impact of these imperfections on the detector performances. In particular, this simulation tool allows to perform preliminary estimates of a fundamental quantity, the residual acceleration, that will limit the sensitivity of eLISA to low frequency gravitational waves.