The MICROSCOPE mission: A space test of the weak equivalence principle

Kurzfassung

According to the Weak Equivalence Principle, all bodies should fall at the same rate in a gravitational field. The MICROSCOPE satellite, launched in April 2016, aimed to test the principle’s validity at the 10-15 precision level, by measuring the electrostatic forces required to maintain two collocated test masses (of titanium and platinum alloys) exactly in the same orbit. A non-vanishing relative acceleration would correspond to a violation of the Weak Equivalence Principle. The scientific measurement was done by using ultra-sensitive differential electrostatic accelerometers (T-SAGE) on board of a drag-free controlled satellite, the mission lifetime was two and a half years. In this talk I will summarize the mission planning, final design, and the obtained result for this so far best space test of the Weak Equivalence Principle. Additionally, I will give a short overview on possible constraints MICROSCOPE sets on fifth forces.