Surface charging of JUICE in the solar wind

JUICE is ESA’s first large class mission to the outer Solar System. The main objectives of JUICE are to study Jupiter and its space environment with a special focus on Jupiter’s moons Europa, Ganymede, and Callisto, and their potential habitability. In order to fulfil these objectives, the JUICE measurements need to be accurately corrected for any possible perturbations. Here, we present Spacecraft Plasma Interaction Software (SPIS) simulations of the surface charging of JUICE in the solar wind. The results will be used to correct the future JUICE measurements for the impact of the charging. 

We have used a solar wind environment model (i.e. a description of the environment covering typical values for parameters such as electron and ion densities, temperatures, and velocities, magnetic field strengths, and EUV flux) for the location where JUICE will perform its first measurements, between 1500 and 3000 R_E from Earth. The typical values for the solar wind parameters and the minimum and maximum values from the expected parameter ranges have been used to simulate the interaction in both average and “extreme” solar wind conditions. Here we present the main results from the SPIS simulations: the surface potential of the spacecraft; the potentials at the locations of the particle and field instrumentation such as the RPWI Langmuir probes and the PEP plasma analysers; the electron and ion density at the locations of the RPWI instruments and the PEP plasma analysers; the characteristics of perturbing particle populations such as photoelectron and secondary electron populations produced by the spacecraft itself; and the properties of the ion wake of the spacecraft. The detailed knowledge of the listed parameters will be used to provide accurate analyses of the first in-situ particle and field measurements performed by JUICE.