DSCS satellite dielectric charging correlation with magnetic activity

Summary form only given. Spacecraft charging is a result of spacecraft-plasma interaction in space. The onset of spacecraft charging depends not only on the surface material properties but also on the density and temperature of the ambient plasma. While the surface material properties are practically constant, the space plasma condition varies in time everyday. The variable space plasma condition is now commonly called space weather. In recent years, it has been established that the Sun controls significantly the Earth´s space weather, The Sun sends out plasma clouds propagating through and interacting with the interplanetary magnetic field. When a significant plasma cloud reaches the Earth´s geomagnetic environment, the Earth´s magnetic field and plasma conditions are disturbed. Compression and stretching of the magnetic field lines can result in plasma energization. Energetic plasma can cause the onset of negative charging of spacecraft surface materials. Extremely energetic (MeVs) electrons and ions can even cause deep (or bulk) charging in materials of low conductivity. We present the statistical results of three years of charging events of the dielectric surface samples on a DSCS satellite at geosynchronous altitudes and confirm a high correlation of the events with the level of geomagnetic.