The Elliptical Uranian Relativity Orbiter (EURO) Mission

Recent years have seen an increasing interest in sending a mission to Uranus, visited so far only by Voyager 2 in 1986.

EURO (Elliptical Uranian Relativity Orbiter) is a preliminary mission concept investigating the possibility of dynamically measuring the planet’s angular momentum S by means of the Lense-Thirring effect affecting a putative Uranian orbiter.

It is possible, at least in principle, to separate the relativistic precessions of the orbital inclination I to the Celestial Equator and of the longitude of the ascending node Ω of the spacecraft from its classical rates of the pericentre ω induced by the multipoles Jℓ,ℓ=2,3,4,… of the planet’s gravity field by adopting an orbital plane containing the planet’s spin axis k̂ , perpendicular to the Celestial Equator, and whose position in the latter is the same as of the projection of k̂ on to it.

For a wide and elliptical 2000×100000km orbit, the gravitomagnetic signatures amount to tens of milliarcseconds per year, while, for a suitable choice of the initial conditions, the peak-to-peak amplitude of the range-rate shift can reach the level of ≃1.5×10−3 millimetre per second in a single pericentre passage of a few hours. By lowering the apocentre height to 10000km, the Lense-Thirring precessions are enhanced to the level of hundreds of milliarcseconds per year. The uncertainties in the orientation of k̂ and in I are major sources of systematic bias; it turns out that they should be determined with accuracies as good as ≃0.1−1 and ≃1−10 milliarcseconds, respectively.

Lorenzo Iorio, Athul P. Girija, Daniele Durante

Comments: LaTex2e, 38 pages, 7 figures, no tables
Subjects: General Relativity and Quantum Cosmology (gr-qc); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Space Physics (physics.space-ph)
Cite as: arXiv:2303.00812 [gr-qc] (or arXiv:2303.00812v1 [gr-qc] for this version)
https://doi.org/10.48550/arXiv.2303.00812
Focus to learn more
Submission history
From: Lorenzo Iorio
[v1] Wed, 1 Mar 2023 20:28:17 UTC (603 KB)
https://arxiv.org/abs/2303.00812