LISA Dynamics & Control: Closed-loop Simulation and Numerical Demonstration of Time Delay Interferometry

International audienceLISA gravitational waves space-based detector involves a complex, multidimensional closed-loop dynamical system. Its instrument performance is expected to be less efficiently isolated from platform jitters than was its technological demonstrator, LISA Pathfinder. Therefore, it is of crucial importance to understand and model LISA dynamical behavior closely, to master the propagation of dynamical excitations through the response of the instrument down to the space interferometer data streams, and more generally, to prepare the processing and the interpretation of the in-flight metrology data. In this work, we present a comprehensive mathematical modeling of the closed-loop system dynamics and its numerical implementation within the LISA consortium simulation suite. We provide for the first time a full, time-domain numerical demonstration that post-processing Time Delay Interferometry techniques can efficiently suppress spacecraft noisy motion in the final interferometer data streams, in the idealized test case where physical coupling to spacecraft and telescope jitters (tilt-to-length, stiffnesses, actuation cross-talks) are turned off