MICROSCOPE Mission: First Results of a Space Test of the Equivalence Principle
Chhun, Ratana; Métris, Gilles; Rodrigues, Manuel; Touboul, Pierre; Baghi, Quentin; Robert, Alain; Foulon, Bernard; Hardy, Emilie; Boulanger, Damien; Christophe, Bruno; Danto, Pascale; Guidotti, Pierre-Yves; Huynh, Phuong-Anh; Lebat, Vincent; Liorzou, Françoise; Reynaud, Serge; Serron, Laura; Fayet, Pierre; André, Yves; Bergé, Joël; Bremer, Stefanie; Carle, Patrice; Cipolla, Valerio; Damour, Thibault; Dittus, Hansjoerg; Gageant, Claude; Hagedorn, Daniel; Inchauspe, Henri; Kayser, Patrick; Lala, Stéphanie; Lämmerzahl, Claus; Leseur, Pierre; List, Meike; Löffler, Frank; Panet, Isabelle; Pouilloux, Benjamin; Prieur, Pascal; Rebray, Alexandre; Rievers, Benny; Selig, Hanns; Sumner, Timothy; Tanguy, Nicolas; Visser, Pieter
France, Germany, United Kingdom, Netherlands
Abstract
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, aims to test its validity at the 10-15 precision level, by measuring the force required to maintain two test masses (of titanium and platinum alloys) exactly in the same orbit. A nonvanishing result would correspond to a violation of the equivalence principle, or to the discovery of a new long-range force. Analysis of the first data gives δ (Ti ,Pt )=[-1 ±9 (stat)±9 (syst)]×10-15 (1 σ statistical uncertainty) for the titanium-platinum Eötvös parameter characterizing the relative difference in their free-fall accelerations.