Basked factor is one of the most important information sources in launch window determination system of recovery satellite and an important parameter to affect stability of the satellite. Environment temperature of the satellite is related to its exposed time in sunlight. In order to meet the requirements of the environment temperature, it is necessary to analyze the relative positions among the satellite, the Sun and the Earth, and the relation between launch window and exposed time in sunlight of the satellite. In this paper, according to the concept of basked factor, the calculating model of basked factor is established; the calculation results of basked factor relative to different injection time and date of the satellite are given. Based on analysis of relation between basked factor and launch window, information fusion method of launch window determination to meet the requirements of environment temperature of the satellite is proposed.