By analyzing the defects of traditional scheduling in space missions, sequential mission scheduling architecture, SMSA, is proposed in this paper to cope with progressively increasing number of state modes of spacecrafts and space missions. The improvements of SMSA lie in both methodologies and ideologies, which make it closer to the core of resource and activity scheduling. The key technologies that the scheduling architecture concerns are indicated and the typical process of scheduling is given. With this methodology as well as corresponding software and systems, human work spent in mission scheduling can be remarkably reduced. And also, efficiency in mission scheduling and flexibility of emergency control is increased. SMSA reveals brand new trends of research and development for the upcoming 10 years of China's space explorations.