Benoit Thiébault

Modeling of Plasma Probe Interactions With a PIC Code Using an Unstructured Mesh

A new Spacecraft Plasma Interaction Software has been developed in the frame of the Spacecraft Plasma Interaction Network (SPINE). This software is designed to simulate the kinetic processes of ions and electrons, taking into account their space charge and their interaction with spacecraft surfaces. It is freely available worldwide in open source. While the development and the qualification of the software functionalities were under the responsibility of a consortium led by ONERA under contract with the European Space Agency, the test and validation of the applicability of the code for solving problems in plasma physics remained under SPINE responsibility. The validation program includes step-by-step applications of the software to sheath modeling in simple geometry, artificial plasma injection, and spacecraft charging. We report here on the progress along this program, including Langmuir probe tests with spherical and cylindrical geometry and comparison with other numerical methods.

Simulation of the Cluster-Spacecraft Floating Probe Potential

In this paper, a numerical model of the Cluster-spacecraft electric potential has been developed and validated. This model provides a good fit to the plasma density as a function of spacecraft chassis potential relative to a Langmuir probe as recorded along the Cluster-spacecraft orbit when the plasma density was between 1 and 80 cm -3 during a plasmaspheric crossing. The model is used to assess the uncertainty in density-determination methods based on potential measurements. Furthermore, this model provides constraints on the parameters suitable for describing the photoelectron emission and might be used in the future to estimate plasma temperature in space

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

The spacecraft-plasma interaction simulator 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.

Simulation and Analysis of Spacecraft Charging Using SPIS and NASCAP/GEO

Spacecraft charging in GEO particularly concerns dielectric surfaces that may charge to significant voltages relative to spacecraft ground because of the space environment. Testing materials helps to define the level of risk and to maintain confidence in a spacecrafts immunity to damaging effects. Another factor defining the risk involves numerical simulation of spacecraft charging. Several tools aim to calculate surface charging, which is particularly hazardous in harsh environments produced by geomagnetic sub storms, where particles in the energy range of a few to hundreds of kiloelectronvolts are present. The main codes include Nascap-2k, Spacecraft plasma Interaction Software (SPIS), MUSCAT, and Coulomb-2. They use different numerical and sometimes physical models and cross checking their results is a necessary process to achieve better confidence in simulations performed by spacecraft prime manufacturers. The objective of this paper is to simulate different GEO spacecraft configurations with NASA Charging Analyzer Program at geosynchronous orbits (a 1980s to 1990s predecessor to Nascap-2k) and SPIS and to compare the results, both in terms of absolute and differential potentials. The first section concerns the SCATHA spacecraft. The second part of this paper compares efforts to model a modern telecom spacecraft. Finally, we conclude on the reliability of the simulations performed and possible areas for modeling improvement.

SPIS 5: New Modeling Capabilities and Methods for Scientific Missions

Since the last version, the numerical core and the user interface of Spacecraft Plasma Interaction Software (SPIS) have been significantly improved to achieve two objectives: 1) to make SPIS more user friendly and robust for industrial use and 2) to extend the multiscale capabilities and the precision of the solvers in order to model a large range of scientific missions. The new numerical algorithm and modeling capabilities are presented in detail. This new version permits modeling of time variations of the plasma environment, spinning spacecraft, semitransparent grids, secondary emission from 1-D thin elements (e.g., wires or booms), 2-D thin elements (for example, solar arrays), the effect of v × B electric field, particle detectors, and Langmuir probes onboard spacecraft.

SPIS-DUST: Modeling the Interactions between Spacecraft, Plasma and Dusts

The Spacecraft Plasma Interaction Software, a.k.a. SPIS, is an open source software initially developed to model the charging of spacecraft in the GEO environments. It underwent several improvements to simulate the behavior of instruments onboard spacecraft and more recently to model the interaction of dusts with plasma and satellite. We present hereafter the models of dust and dusty soils charging and of dust interaction with the spacecraft that have been implemented as well as a realistic simulation of the dust interaction with a lunar lander and with ESA’s Philae lander that demonstrates the new SPIS capabilities.