LAser RElativity Satellite

LARES is a satellite of the Italian Space Agency, launched on 13 February 2012 on the maiden flight of the Vega launch vehicle, following an agreement with the ESA.

The scientific objective of the mission is to measure the general relativity effect known as frame-dragging or the Lense–Thirring effect. LARES is also used to study other fundamental physics phenomena from space and to carry out high-precision space geodesy measurements.

To achieve the scientific objective with the required accuracy, LARES has been designed to minimise the effects of non-gravitational perturbations on its orbit. The satellite is entirely passive; its spherical body is a single piece of tungsten alloy and carries 92 retroreflectors for laser ranging. The retroreflectors enable the stations of the International Laser Ranging Service (ILRS) to measure the satellite’s position with extreme precision.

The analysis of orbital data is carried out at the School of Aerospace Engineering - Sapienza University of Rome in collaboration with the Italian Space Agency (ASI), the University of Maryland – Baltimore County, NASA Goddard, the University of Texas at Austin, and the German Research Centre for Geosciences (GFZ) in Potsdam.

In 2019, the results of the mission’s data analysis were published, confirming the measurement of the frame-dragging effect with a systematic error of less than 2% [1].

[1] Ciufolini, I., Paolozzi, A., Pavlis, E.C., Sindoni, G., Ries, J., Matzner, R., Koenig, R., Paris, C., Gurzadyan, V., Penrose R., An improved test of the general relativistic effect of frame-dragging using the LARES and LAGEOS satellites. Eur. Phys. J. C 79, 872 (2019). https://doi.org/10.1140/epjc/s10052-019-7386-z