A test of gravitational theories including torsion with the BepiColombo radio science experiment

TL;DR

This paper discusses how the BepiColombo mission's radio science experiment can test gravitational theories including torsion by precisely measuring Mercury's orbit and analyzing relativistic effects.

Contribution

It introduces a strategy for accurate orbit determination and examines the impact of the solar Lense-Thirring effect on relativistic parameter estimation.

Findings

Enhanced orbit determination accuracy for Mercury and Earth-Moon barycenter.

Assessment of the solar Lense-Thirring effect's influence on relativistic tests.

Strategies to address rank deficiencies in orbit determination.

Abstract

The Mercury Orbiter radio Science Experiment (MORE) is one of the experiments on-board the ESA/JAXA BepiColombo mission to Mercury, to be launched in October 2018. Thanks to full on-board and on-ground instrumentation performing very precise tracking from the Earth, MORE will have the chance to determine with very high accuracy the Mercury-centric orbit of the spacecraft and the heliocentric orbit of Mercury. This will allow to undertake an accurate test of relativistic theories of gravitation (relativity experiment), which consists in improving the knowledge of some post-Newtonian and related parameters, whose value is predicted by General Relativity. This paper focuses on two critical aspects of the BepiColombo relativity experiment. First of all, we address the delicate issue of determining the orbits of Mercury and the Earth-Moon barycenter at the level of accuracy required by the purposes of the experiment and we discuss a strategy to cure the rank deficiencies that appear in the problem. Secondly, we introduce and discuss the role of the solar Lense-Thirring effect in the Mercury orbit determination problem and in the relativistic parameters estimation.