LARES satellite: the best test particle for testing General Relativity

The LAser RElativity Satellite (LARES) is an Italian Space Agency laser ranged satellite. Soon after the successful launch with the VEGA maiden flight on the 13th of February 2012, the analysis of the ranging data from about 40 stations of the International Laser Ranging Service (ILRS) started. The satellite is passive and covered with optical Cube Corner Reflectors (CCRs) that allows the accurate positioning of the satellite, through the laser pulses sent towards the satellite. Aim of the LARES mission is to test frame-dragging and the Lense-Thirring effect of General Relativity. According to General Relativity a spinning body distorts spacetime, dragging the inertial frames around it and the orbital plane of a satellite. Analysing the data of LARES and LAGEOS satellites starting from the launch date of LARES, a comparison among the orbits shows that the LARES motion, after removal of the known non-gravitational perturbations, fits better the theoretical geodesic motion of an ideal test- particle than any other orbiting object in the solar system. In the paper, the scientific objectives of the mission and the preliminary results of the analysis will be reported. The paper will also address the outstanding behaviour of LARES as a test particle for fundamental physics and geodesy.