LARES (satellite)


LARES is a passive satellite of the Italian Space Agency.

Mission

Launch

LARES was launched into orbit on 13 February 2012. It was launched on a Vega rocket from the ESA Guiana Space Centre in Kourou, French Guiana.

Composition

The satellite is made of THA-18N, a tungsten alloy, and houses 92 cube-corner retroreflectors, which are used to track the satellite via laser from stations on Earth. LARES's body has a diameter of about and a mass of about. LARES was inserted in an orbit with of perigee, an inclination of 69.5°, and reduced eccentricity. The satellite is tracked by the International Laser Ranging Service stations.
The LARES satellite is the densest object known orbiting the sun. The high density helps reduce disturbances from environmental factors such as solar radiation pressure.

Scientific goals

The main scientific target of the LARES mission is the measurement of the Lense–Thirring effect with an accuracy of about 1%, according to principal investigator Ignazio Ciufolini and the LARES scientific team, but the reliability of that estimate is contested.
In contrast, a recent analysis of 3.5 years of laser-ranging data reported a claimed accuracy of about 4%. Critical remarks appeared later in the literature.
Beyond the project's key mission, the LARES satellite may be used for other tests of general relativity as well as measurements in the fields of geodynamics and satellite geodesy.

LARES 2

A second satellite, LARES 2, is due to launch on a Vega-C in December 2020.
LARES 2 may improve the accuracy of the frame-dragging effect measurement to 0.2%. LARES 2's material is unknown, but it may use a copper alloy instead of a tungsten alloy.