A new laser-ranged satellite for General Relativity and space geodesy: III. De Sitter effect and the LARES 2 space experiment

Ignazio Ciufolini,Richard Matzner,Vahe Gurzadyan,Roger Penrose

doi:10.1140/epjc/s10052-017-5339-y

Abstract

In two previous papers we presented the LARES 2 space experiment aimed at a very accurate test of frame-dragging and at other tests of fundamental physics and measurements of space geodesy and geodynamics. We presented the error sources of the LARES 2 experiment, its error budget and Monte Carlo simulations and covariance analyses confirming an accuracy of a few parts in one thousand in the test of frame-dragging. Here we discuss the impact of the orbital perturbation known as the de Sitter effect, or geodetic precession, in the error budget of the LARES 2 frame-dragging experiment. We show that the uncertainty in the de Sitter effect has a negligible impact in the final error budget because of the very accurate results now available for the test of the de Sitter precession and because of its very nature. The total error budget in the LARES 2 test of frame-dragging remains at a level of the order of 0.2%, as determined in the first two papers of this series.

Highlights

The tracking data collected by the Satellite Laser Ranging (SLR) network are analysed, organized and distributed by the International Laser Ranging Service (ILRS) [7]
By measuring the total round-trip travel time we are today able to determine the instantaneous distance of a retro-reflector on the LAGEOS and LARES satellites with a precision of a few millimetres [8]
The LARES 2 satellite is planned for launch in 2019 with the new VEGA C launch vehicle of ASI, ESA, AVIO and ELV

Summary

LARES 2 and an introduction to the de Sitter effect

The LARES 2-LAGEOS space experiment is designed to achieve a new, accurate measurement of the General Relativistic frame-dragging due to the rotation of the Earth. In addition to the frame-dragging, gravitomagnetic effect, whose test is the main objective of the LARES 2-LAGEOS space experiment, there is another general relativistic perturbation of an orbiting gyroscope, relative to an asymptotic inertial frame: the de Sitter or geodetic (or geodesic) precession [9] (see [10]). This precession is due to the coupling between the velocity of a gyroscope orbiting a central body and the static part of the field (Schwarzschild metric) generated by the central mass.

Direct tests of the de sitter effect

Findings

Summary and conclusions