Variations in Satellite Charge Drag Coefficient With Solar Cycle

Abstract Ionospheric plasma interaction with charged satellite surfaces can lead to a substantial increase in orbital drag. In this context, natural events related to solar activity can have a detrimental effect on a satellite's lifespan and introduce uncertainty in orbital trajectory predictions. This work investigates the variations in charge drag coefficient during solar minimum and solar maximum conditions for Low Earth Orbits with altitudes in the range 300–1,000 [km]. Two months, August 2008 and January 2014, near the solar minimum and solar maximum activities are selected to represent variations of ion and electron densities and temperatures during the solar cycle. The simulations are performed using pdFOAM, an electrostatic particle‐in‐cell code. The results show that the charge drag coefficient increases with altitude. Variations are more pronounced during solar minimum than maximum. The variation of the charge drag coefficient depends significantly on the total ion density as well as the percent fraction of lighter ions . In the lower part of the ionosphere (300 [km]), dominated by , the charge drag coefficient , varies in the range . At higher altitudes 1,000 [km], dominated by , especially during the night, it varies in the range , with the extreme values being related to the solar minimum. For both solar minimum and solar maximum conditions, the charge drag force can become significant compared to the neutral drag force and it is 2 times higher at altitude 1,000 [km].