Electrostatic accelerometers for the equivalence principle test in space

Abstract

The concept of the three-axis electrostatic accelerometers based on the full electrostatic suspension of one unique proof mass is very suitable for space applications requiring very high resolution of acceleration measurement or drag-free control of satellite. This concept has been tested in orbit with the accelerometer CACTUS from ONERA in the late seventies and recently with the accelerometer ASTRE on board Columbia shuttle in June 1996. The accelerometer outputs are derived from the measurement of the electrostatic forces, necessary to maintain the mass motionless at the centre of the accelerometer cage. The relative test-mass position and attitude are servo-controlled from measurements of capacitive sensors exhibiting resolutions of better than depending on the geometrical configuration.