Mapping Long-Term Natural Orbits about Titania, a Satellite of Uranus

TL;DR

This study investigates long-duration polar and circular orbits around Titania, considering gravitational asymmetries and perturbations, to identify stable orbit configurations for future exploration missions.

Contribution

It provides the first detailed numerical analysis of long-term orbits around Titania, incorporating gravitational field asymmetries and perturbations from Uranus.

Findings

Low-altitude, near-circular orbits have longer lifetimes.

Non-zero periapsis and node angles significantly increase orbit lifetime.

Eccentricity of 10^-3 is most sensitive to gravitational coefficient errors.

Abstract

Close polar and circular orbits are of great interest for the exploration of natural satellites. There are still no studies in the literature investigating orbits around Titania, the largest satellite of Uranus. In this work, we present results of a set of numerical simulations carried out to obtain long-duration orbits for a probe around Titania. Through an expansion of the gravitational potential up to second order, the asymmetry of the gravitational field due to Titania's coefficient $C_{22}$, the zonal coefficient $J_2$, and the gravitational perturbation of Uranus is considered. The analysis of lifetime sensitivity due to possible errors in the values of $J_2$ and $C_{22}$ is investigated using multiple regression models. Simulations were performed for different eccentricity values, and lifetime maps were constructed. The results show that low-altitude and near-circular orbits have longer lifetimes due to the balance between the disturbance of Uranus and the gravitational coefficients of Titania. The results also show that non-zero values of the longitude of periapsis ($\omega$) and longitude of the ascending node ($\Omega$) are essential to increase the lifetime up to eight times compared to cases where $\omega= \Omega=0^\circ$. We also show that an orbit with eccentricity $10^{-3}$ is the most affected by errors in the values of $J_2$ and $C_{22}$.