How to use the Sun–Earth Lagrange points for fundamental physics and navigation

• Published in: General relativity and gravitation Vol. 50; no. 1; pp. 1 - 21
• Main Authors: Tartaglia, A., Lorenzini, E. C., Lucchesi, D., Pucacco, G., Ruggiero, M. L., Valko, P.
• Format: Journal Article
• Language: English
• Published: New York Springer US 2018; Springer Nature B.V
• Subjects: Astronomy; Astrophysics and Cosmology; Classical and Quantum Gravitation; Dark matter; Differential Geometry; Feasibility studies; Gravitation; Gravity; Inner solar system; Lagrangian equilibrium points; Mathematical and Computational Physics; Navigation; Navigation systems; Physics; Physics and Astronomy; Project feasibility; Quantum Physics; Relativity Theory; Research Article; Solar system; Spacecraft; Sun; Theoretical; Time lag; Sun rotation; Gravitation; Reference systems; Galactic halo
• ISSN: 0001-7701; 1572-9532
• DOI: 10.1007/s10714-017-2332-6

We illustrate the proposal, nicknamed LAGRANGE, to use spacecraft, located at the Sun–Earth Lagrange points, as a physical reference frame. Performing time of flight measurements of electromagnetic signals traveling on closed paths between the points, we show that it would be possible: (a) to refine gravitational time delay knowledge due both to the Sun and the Earth; (b) to detect the gravito-magnetic frame dragging of the Sun, so deducing information about the interior of the star; (c) to check the possible existence of a galactic gravitomagnetic field, which would imply a revision of the properties of a dark matter halo; (d) to set up a relativistic positioning and navigation system at the scale of the inner solar system. The paper presents estimated values for the relevant quantities and discusses the feasibility of the project analyzing the behavior of the space devices close to the Lagrange points.