An approach for estimating perpetual endurance of the stratospheric solar-powered platform

The high altitude solar-powered airships have been proposed for use as long endurance platforms, for a variety of military and civilian applications. The challenges of perpetual endurance flight require the airship to generate sufficient power over a wide range of operational latitudes so that the aerial vehicle can keep station through high wind events and maintain persistence. This paper provides a theoretical approach to analyzing the perpetual endurance performance of a high altitude solar-powered airship. According to the features of stratospheric airship and the theoretical model, a custom tool is developed using MATLAB computer program when the airship operates in the cruise condition. The effects of the operational latitudes, wind velocities and solar array areas on the energy ratio are numerically investigated in detail, and the required areas of solar array under the conditions of different minimum energy ratio were discussed. The results showed that the solar-powered airships faced severe operational limitations at high latitudes in the winter, especially in the high wind. In addition, a case study was analyzed to demonstrate the effectiveness of this approach to predicting the perpetual endurance region. The results demonstrated that the theoretical approach suggested a pathway towards planning the flight date and location for an airship.