LARES mission: engineering aspects

LARES is a satellite of the Italian Space Agency, successfully launched with the new VEGA launcher in the occasion of its inaugural flight, VV01. It was put in a circular orbit at 1450 km altitude. This altitude was required to reduce atmospheric drag, whereas the satellite was designed to minimize the non-gravitational perturbations acting on the surface of the satellite. This was of paramount importance because the mission objective is to test Einstein general relativity, and any unmodeled effect could spoil the accuracy of the relativistic measurement. With the optimal design achieved, this non-gravitational unmodeled effects are maintained below 1% of frame-dragging or Lense-Thirring effect. This effect is the orbital node shift induced by the Earth rotation as predicted by general relativity. To achieve the accuracy required for the test, it was conceived a constellation of three laser ranged satellites (LAGEOS 1, LAGEOS 2 and LARES) along with the latest determination of the Earth gravitational field by GRACE satellite. The satellite is a passive system and embedded with 92 Cube Corner Reflectors that have the properties of reflecting back to the emitting ground station the laser pulses, thus allowing its precise orbital determination. In this paper engineering aspects of the mission will be addressed.