4 juin - 7 juin 2013


S06 Astrométrie de haute précision et applications

Software tools for the validation of the in-flight calibration performance of the MICROSCOPE space mission

E. Hardy, A. Levy, M. Rodrigues, P. Touboul (ONERA), G. Métris (OCA)

The MICROSCOPE space mission aims at testing the Equivalence Principle (EP) with an accuracy of 1e-15. The instrument will be embarked on board a drag-free microsatellite orbiting the Earth, and consists in a differential electrostatic accelerometer composed of two cylindrical test masses submitted to the same gravitational field but made of different material. The electrostatic accelerations applied to the masses to maintain them relatively motionless are measured and will demonstrate a violation of the universality of free fall if found unequal.

The accuracy of the measurement exploited for the EP test is limited by our a priori knowledge of the instrument physical parameters. An in-orbit calibration is needed to finely characterize them in order to correct the measurement. The calibration procedures have been determined and their analytical performances evaluated. The two stages of the measurement processing are numerically simulated: first the calibration sessions, and then the measurement correction using the estimated parameters in order to validate the mission performance on the EP parameter determination.