Structure

Like its predecessor, LARES 2 is a passive satellite based on a monolithic metal structure. Its spherical shape and high mass-to-surface-area ratio minimise the effects of radiation pressure (both solar and from the Earth’s albedo), atmospheric drag (which is minimal, given the altitude of approximately 6,000 km) and disturbances caused by thermal anisotropy effects on the satellite, such as the Yarkovsky effect.

Satellite Laser Ranging

The position of LARES 2 is measured using the Satellite Laser Ranging (SLR) technique by the network of stations belonging to the International Laser Ranging Service.

LARES 2 is the first long-duration mission (excluding a few technological demonstation tests on smaller satellites) to use cube-corner reflectors (CCRs) with a diameter of 24.5 mm (1″); furthermore, unlike LARES, the reflectors are COTS (Commercial Off-the-Shelf) units.

The arrangement of the 303 reflectors across the spherical surface is innovative. The positions of the CCRs are not distributed evenly but according to an optimisation study inspired by "Thomson problem".

The combination of optimised dimensions and distribution of the CCRs makes it possible to significantly reduce errors in satellite position measurement.

Orbit

The mission relies on the specific combination of the orbits of the LAGEOS and LARES 2 satellites. The orbit of LARES 2 is circular; it has the same semi-major axis as the LAGEOS orbit but an additional inclination. In other words, the sum of the inclinations of the two orbital planes is 180°.

This allows the effects of classical gravitational disturbances caused by the even zonal harmonics of the Earth’s gravitational field to be removed from the measurement.

For further reading:

The science of LARES and LARES 2