MICROSCOPE mission scenario, ground segment and data processing

Self Cite

The space mission MICROSCOPE dedicated to the test of the equivalence principle (EP) operated from April 25, 2016 until the deactivation of the satellite on October 16, 2018. In this analysis we compare the free-fall accelerations (a A and a B) of two test masses in terms of the Eötvös parameter η ( A,B ) = 2 a A − a B a A + a B . No EP violation has been detected for two test masses, made from platinum and titanium alloys, in a sequence of 19 segments lasting from 13 to 198 h down to the limit of the statistical error which is smaller than 10−14 for η(Ti, Pt). Accumulating data from all segments leads to η(Ti, Pt) = [−1.5 ± 2.3 (stat) ± 1.5 (syst)] × 10−15 showing no EP violation at the level of 2.7 × 10−15 if we combine stochastic and systematic errors quadratically. This represents an improvement of almost two orders of magnitude with respect to the previous best such test performed by the Eöt-Wash group. The reliability of this limit has been verified by comparing the free falls of two test masses of the same composition (platinum) leading to a null Eötvös parameter with a statistical uncertainty of 1.1 × 10−15.

Section: Scientific Sessions and Available Datamentioning

confidence: 99%

Section: Scientific Sessions and Available Datamentioning

confidence: 99%

“…Detection and elimination of the glitches. Glitches are detected in a double two steps procedure [45,47,48]: (i) we use a standard recursive σ-clipping technique (e.g. Ref.…”

Section: Glitchesmentioning

confidence: 99%

Section: Systematic Errorsmentioning

confidence: 99%

“…size of the satellite and global cost); for a more detailed presentation of MICROSCOPE the reader is referred to other papers of this volume (Ref. [34,37,38,[43][44][45][46][47][48]).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Result of the MICROSCOPE weak equivalence principle test

Touboul

Métris

Rodrigues

et al. 2022

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MICROSCOPE. mission analysis, requirements and expected performance

Touboul

Rodrigues²,

Métris³

et al. 2022

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The MICROSCOPE mission aimed to test the Weak Equivalence Principle (WEP) to a precision of 10-15. The WEP states that two bodies fall at the same rate on a gravitational field independently of their mass or composition. In MICROSCOPE, two masses of different compositions (titanium and platinum alloys) are placed on a quasi-circular trajectory around the Earth. They are the test-masses of a double accelerometer. The measurement of their accelerations is used to extract a potential WEP violation that would occur at a frequency defined by the motion and attitude of the satellite around the Earth. This paper details the major drivers of the mission leading to the specification of the major subsystems (satellite, ground segment, instrument, orbit...). Building upon the measurement equation, we derive the objective of the test in statistical and systematic error allocation and provide the mission's expected error budget.

MICROSCOPE mission: data analysis principle

Bergé

Baghi

Hardy

et al. 2022

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After performing highly sensitive acceleration measurements during two years of drag-free flight around the Earth, MICROSCOPE provided the best constraint on the weak equivalence principle (WEP) to date. Beside being a technological challenge, this experiment required a specialised data analysis pipeline to look for a potential small signal buried in the noise, possibly plagued by instrumental defects, missing data and glitches. This paper describes the frequency-domain iterative least-square technique that we developed for MICROSCOPE. In particular, using numerical simulations, we prove that our estimator is unbiased and provides correct error bars. This paper therefore justifies the robustness of the WEP measurements given by MICROSCOPE.