Abstract
The mission was designed to test the weak equivalence principle (WEP), stating the equality between the inertial and the gravitational masses, with a precision of in terms of the Eötvös ratio . Its experimental test consisted of comparing the accelerations undergone by two collocated test masses of different compositions as they orbited the Earth, by measuring the electrostatic forces required to keep them in equilibrium. This was done with ultrasensitive differential electrostatic accelerometers onboard a drag-free satellite. The mission lasted two and a half years, cumulating five months worth of science free-fall data, two-thirds with a pair of test masses of different compositions—titanium and platinum alloys—and the last third with a reference pair of test masses of the same composition—platinum. We summarize the data analysis, with an emphasis on the characterization of the systematic uncertainties due to thermal instabilities and on the correction of short-lived events which could mimic a WEP violation signal. We found no violation of the WEP, with the Eötvös parameter of the titanium and platinum pair constrained to at in statistical errors.
- Received 27 January 2022
- Revised 10 March 2022
- Accepted 30 March 2022
DOI:https://doi.org/10.1103/PhysRevLett.129.121102
© 2022 American Physical Society
Physics Subject Headings (PhySH)
Viewpoint
Satellite Confirms the Principle of Falling
Published 14 September 2022
The MICROSCOPE satellite experiment has tested the equivalence principle with an unprecedented level of precision.
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