Simultaneous investigation of magnetospheric plasma and spacecraft charging

The results of magnetospheric plasma fluxes measurement in geosynchronous orbit are presented. The measurements were done onboard the geosynchronous Russian “Electro” spacecraft (SC) in 1995–1997 years. The diurnal variations of the plasma density and temperature were observed at various levels of geomagnetic activity. Distortions of the measured electron and proton spectra caused by negative potential of the charged SC were registered. Typical electron spectra and plasma parameters were determined for various SC charging levels. Similar measurements in low polar orbits at the “Meteor” SC (launched in 2003 year) and the “Universitetskiy–Tatyana” SC (launched in 2005 year) were done.