Investigation on Radiation-Induced Latch-Ups in COTS SRAM Memories Onboard PROBA-V

This work investigates the flight behavior of static random access memories (SRAMs) onboard the PROBA-V satellite. During the mission, unexpected error rates were observed for redundant modules that used commercial off-the-shelf (COTS) SRAMs. After undergoing an initial assessment, it was inferred that these errors were caused by single-event latch-ups (SELs). This result led to a broader study on single-event effects (SEEs) in these SRAM devices and their impact on the PROBA-V operation. Therefore, we proposed an experimental approach for evaluating and comparing the phenomena with the available PROBA-V flight data. Three experiments were performed: two irradiation campaigns, using heavy ions and protons, and laser testing. For that, a dedicated experimental setup was developed to enable the evaluation of specific test conditions and the discussion of hypotheses. The main results are reported, compared, and discussed. As an outcome of this study, we proposed an explanation for the observed behavior due to distinct environmental conditions of the redundant modules containing the SRAMs, notably, temperature and satellite shielding.