Spacecraft and Satellite charging effects Numerical Simulation
Spacecraft charging includes both surface charging and internal dielectric charging. The absolute charging of spacecraft surfaces is not generally detrimental; rather it is the possible discharge effects which can disrupt satellite operations. Most of the undesired effects of both charging types are due to the discharge arcing, and include physical materials damage and electromagnetic interference generation. The buildup of large potentials on spacecraft and satellite relative to the ambient plasma is not, of itself, a serious electrostatic discharge design concern. However, such charging enhances surface contamination, which degrades thermal properties. It also compromises scientific missions seeking to measure properties of the space environment. Spacecraft systems referenced to structure ground are not affected by a uniformly charged spacecraft. However, spacecraft surfaces are not uniform in their material properties, surfaces will be either shaded or sunlit, and the ambient fluxes may be anisotropic.
These and other charging effects can produce potential differences between spacecraft surfaces or between spacecraft surfaces and spacecraft ground. When a breakdown threshold is exceeded, an electrostatic discharge can occur. The transient generated by this discharge can couple into the spacecraft electronics and cause upsets ranging from logic switching to complete system failure. Discharges can also cause long term degradation of exterior surface coatings and enhance contamination of surfaces.
Vehicle torquing or wobble can also be produced when multiple discharges occur. The ultimate results are disruptions in spacecraft operation.Surface charging could disrupt environmental measurements on scientific spacecraft. For this application and others where control of electrostatic fields is required, material selection to minimize differential charging is mandatory. For operational spacecraft, surface charging can also cause problems. The hallmark of the spacecraft charging phenomena is the occurrence of electronic switching anomalies.
These anomalies are believed to result from transients caused differential charging induced discharges. These anomalous events even seem to occur in systems that are supposedly immune to noise. The discharge induced transients, under very severe environmental conditions, can cause system failures.
The presence of spacecraft in ionospheric plasma can change plasma properties, vice versa plasma can lead to charge buildup on spacecraft. The level of charging, through electric potential of spacecraft, initially depends on plasma density.
Energetic particles from the solar wind
- mostly electrons and protons (fully ionized plasma)
- Earth magnetic field: Deviation of the solar wind , Trapping
- solar activity: storms
Low Earth orbit
- ionospheric plasma
- trapped particles (everywhere on the orbit)
With combination of finite element method, boundary element method and finite difference method we simulate real world condition of systems including probabilistic damage scenario during service load in complex space environments.
Research and Development in Plasma Technologies
Simulation of Complex Systems to Gain Most Optimized Configuration with Advanced Technology
Magnetized plasma simulations of realistic devices using the kinetic or the multi-fluid plasma models are examples that benefit from high-order accuracy. The multi-fluid plasma model only assumes local thermodynamic equilibrium within each fluid, e.g. ion and electron fluids for the two-fluid plasma model.
Plasma Dynamics use advanced electromagnetic FEA, CFD and particle-in-cell (PIC) codes, designed for executing multi-scale, plasma physics simulations. Based on the problem and its detail, we use special commercial code or even develop new codes and subroutines to capture the interaction between charged particles (electrons and ions) and external and self-generated electric and magnetic fields.