In this study, transient analyzes were conducted to predict the thermal distortion of the Korea Multi-Purpose Satellite (KOMPSAT) solar array during its orbital motion. The solar array consists of five honeycomb sandwich panels with aluminum facesheets. To enable future improvements, the solar arrays were also analyzed with composite facesheets for the temperature distribution and thermal distortion. in order to evaluate the degradation effects of the material properties of the composite facesheets in low earth orbit environment, the composite materials were: exposed to simulate low earth orbit environmental conditions including ultraviolet (UV) radiation, high vacuum and thermal cycling. The values of the degraded properties were used in the thermal distortion analysis. The results show that the solar arrays with composite facesheets are beneficial with regard to weight savings, temperature distribution and thermal distortion during the mission when compared to those with aluminum facesheets, even though the composite materials are degraded due to low earth orbit environmental factors.