Precise modeling and simulation (M&S) of the degradation of spacecraft solar array power is crucial for mission planning, assessing remaining useful life, and extending operational lifespan. A relevant case is the Cluster spacecraft fleet, launched in and managed at the European Space Operation Centre (ESOC). The fleet’s solar arrays have undergone significant degradation due to space radiation, posing challenges to regular operations and mission planning. However, the current models have shown limitations in effectively representing the substantial decrease in power generation over the spacecraft’s extended operational life.