The Micro-Satellite à traînée Compensée pour l'Observation du Principe d'Equivalence (Micro-Satellite with Compensated Drag for Observing the Principle of Equivalence, MICROSCOPE) is a 300-kilogram (660 lb) class minisatellite operated by CNES to test the universality of free fall (the equivalence principle) with a precision to the order of 10−15,[6] 100 times more precise than can be achieved on Earth.

[7] To test the equivalence principle (i.e. the similarity of free fall for two bodies of different composition in an identical gravity field), two differential accelerometers are used successively.

The masses are maintained within their test areas by electrostatic repulsion, designed to render them motionless with respect to the satellite.

[1] The satellite employs a Drag-Free Attitude Control System (DFACS), also called the Acceleration and Attitude Control System (AACS), that uses a double-redundant primary and backup set of four microthrusters (sixteen total) to "fly" the satellite around the test masses.

[12] After completing its mission goals and exhausting its supply of nitrogen fuel, the decommissioning of MICROSCOPE was announced on 18 October 2018.