Radiation Effects in the Inner Heliosphere With BepiColombo

Radiation poses significant challenges for space missions due to galactic cosmic rays (GCRs) and solar energetic particles (SEPs). While there are methods employed on the ground to characterize and mitigate the effects of the space radiation environment on electrical components, these are seldom verified using flight data. In this work, we evaluated the rates of single event effects (SEEs) on the memories embedded in four instruments aboard the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) BepiColombo mission, cruising in interplanetary space, on its way to Mercury since October 2018. We found that, in the period between 2019 and 2024, the contribution of SEPs was negligible. We leveraged this fact, performing time-series parametric analysis of static random access memories (SRAMs), considering GCRs only, to determine the shielding and sensitive volume thicknesses of several memories. With this analysis, we showed that standard modeling parameters overestimate the rates and that little variation between the same memory types occurred. Additionally, we studied different radiation effects on synchronous dynamic random access memories (SDRAMs). In this case, we showed that periodic mode register resets are successful at mitigating single event functional interrupts (SEFIs) but not large errors.