MICROSCOPE mission analysis, requirements and expected performance

TL;DR

The MICROSCOPE mission aims to test the Weak Equivalence Principle with unprecedented precision by measuring differential accelerations of test masses in orbit, detailing system requirements, error analysis, and expected performance.

Contribution

This paper presents the detailed analysis, system specifications, and error budget for the MICROSCOPE mission's goal to test the WEP at a precision of 10^{-15}.

Findings

Mission design achieves the targeted measurement precision.

Error budget analysis identifies dominant systematic uncertainties.

Expected performance meets the mission's scientific objectives.

Abstract

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.