Research On High Level Spacecraft Surface Charging Characteristics Induced By Jovian Plasma Environment

Spacecraft surface charging,which result from space plasma interaction,is one of the major hazards to spacecrafts in space environment.It is accepted that spacecraft surface charging is not only a concern in Earth orbits,but also in Jupiter's orbits for its' electron-heavy plasma environment.Moreover,Jupiter has the strongest magnetic field in solar system which will effect the process of surface charging.Exploration of Jupiter is an important candidate in deep space exploration plans.However,it is lack of surface charging analysis in Jupiter plasma and magnetic field environments.In this paper,research on high-level surface charging in Jupiter's orbit is carried out in order to mitigate hazards to the spacecrafts in Jupiter's orbit.Firstly,high-level charging environment are described by a double maxellian distribution plasma environment model and a magnetic field model based on Gauss Schmidt theory.A user-friendly fast charging evaluation code,based on Qt framework,was developed to pre-evaluate the charging level.Secondly,the 3D PIC simulation was carried out for surface charging analysis in high-level charging environment at Jupiter's orbits.The results showed that charging potentials exceed 1000 V at 2Rj,15 Rj polar orbits and exceed 10000 V at 25 Rj polar orbits in the dark side.It is accordance with fast charging evaluation code result.The absolute charging level in the dark side is most severe and the differential potential in the process of sunlit and eclipse exit is largest.According to our simulated satellite model,the solar panel edge faces serious discharging risk because of its' severe reversal potential gradient.Finally,Jupiter's strong magnetic field is also considered as an important parameter in the process of surface charging in this thesis.It is calculated that secondary electron gyration is smaller when the magnetic field intensity is larger at low orbit.In our simulation,charging potential for ITOC,CFRP and CERS increase 300 V,150V and 250 V correspondingly.Furthermore,motional electric field is induced by a conductor moving in the magnetic field.Charging potentials for ITOC and CFRP in the simulation increase 410 V and 550 V in “Juno” orbit.Differential potentials between adjacent solar cells also increase discharging risk.