New SPIS Capabilities to Simulate Dust Electrostatic Charging, Transport, and Contamination of Lunar Probes

Abstract

Abstract-The Spacecraft Plasma interaction Software (SPIS) has been improved to allow for the simulation of lunar and asteroid dust emission, transport, deposition and interaction with a spacecraft on or close to the lunar surface. The physics of dust charging and of the forces that they are subject to has been carefully implemented in the code. It is both a tool to address the risks faced by lunar probes on the surface, and a tool to study the dust transport physics. We hereby present the details of the physics that has been implemented in the code, as well as the interface improvements that allow for a user friendly insertion of the lunar topology and of the lander in the simulation domain. A realistic case is presented that highlights the capabilities of the code as well as some general results about the interaction between a probe and a dusty environment.

Lunar dust simulant charging and transport under UV irradiation in vacuum: Experiments and numerical modeling

“…In order to confirm our experimental hypothesis and help interpret the observations, the experiment was also simulated with the Spacecraft Plasma Interactions Software (SPIS) (http://www.spis.org). This open‐source software developed by ONERA under European Space Agency (ESA) and then Centre National d'Etudes Spatiales support since the 2000s has recently been upgraded to support dust charging and transport modeling, especially at the surface of airless bodies [ Hess et al , ]. In this work, the simulation reproduces as much as possible the experimental configuration (size and position of objects).…”

“…If the surface is perfectly smooth, it is equals to 1; otherwise, it is larger than the unity. A more detailed discussion of the dust charging model and of the determination of α can be found in Hess et al []. The use of such an amplification factor is needed since SPIS solvers were not designed to mesh dust grain details.…”

“…Numerical simulations show that dust mobilization by electrostatic forces is not sufficient to explain significant dust transport up to some kilometers of altitude but may be at play at lower altitudes [ Glenar et al , ; Poppe and Horányi , ]. This mechanism could be responsible for dust cloud observations some meters above the Moon surface [ Hartzell and Scheeres , ; Hess et al , ; Poppe et al , ]. According to Colwell et al [], those particles are very small dust grains of micron to submicron sizes and are mainly composed of silica.…”

“…At the region between the shadowed and the sunlit sides, named the terminator, it has been suggested that strong electric fields are present because of the fast potential transition from positive to negative potentials. Medium to small structures such as craters or rocks may amplify this aspect [ Criswell , ; Poppe et al , ; Hess et al , ]. This electric field could be the cause of electrostatic lofting of lunar dust grains.…”

Surface charging of a crater near lunar terminator

“…It is therefore important to understand the charging process of the surface, in particular near the area where increase dust particle flux has been observed. Recently, a new particle in cell code has been developed with the capability of simulating surface charging and dusty plasma in the lunar environment [5,6]. This paper presents simulation of the lunar surface charging over the lunar terminator region using the code.…”