• BepiColombo mission
• Brans-Dicke theory
• MORE
• orbit determination
• PPN formalism
• radio science experiment

The Mercury Orbiter Radio science Experiment (MORE) is one of the experiments on-board the ESA/JAXA BepiColombo mission to Mercury, launched in October 2018, whose arrival is scheduled for December 2025. Thanks to full on-board and on-ground instrumentation capable to perform very precise tracking from the Earth, MORE will allow to accurately determine the mercurycentric orbit of the spacecraft and the heliocentric orbit of Mercury and the Earth. One of the main scientific goals of MORE consists in providing an accurate test of relativistic theories of gravitation (relativity experiment).

In the first part of this Thesis, I present the derivation of the equations of motion for massive bodies in the parameterized post-Newtonian (PPN) framework, which constitute the basis of the relativistic model for the motion of Mercury and of the Earth-Moon barycenter in the context of the MORE experiment.

In the second part, I tackle the problem of testing Brans-Dicke theory by means of a set of simulations of the MORE relativity experiment, performed with a dedicated orbit determination software, ORBIT14, developed by the Celestial Mechanics Group of the University of Pisa. The aim of the simulations is to determine the expected accuracy in constraining the coupling constant which characterizes Brans-Dicke theory. In particular, I show that Brans-Dicke theory should be suitably constrained thanks to the MORE relativity experiment.