Space operations and Non-Keplerian orbit motion

Based on the analyzing and summarizing of the technical characteristics of aerospace vehicles during its development in past fifty years, it is pointed out that space operations will be the mainstream and necessity of future space activities. During space operation, it is required that spacecrafts can maneuver to a wide area quickly and accurately. So the spacecraft orbits are not belongs to Keplerian orbit and the description of celestial bodies motion by Keplerian theory is not valid yet. This paper describes the connotation of Non-Keplerian motion, discusses the methods for studying this problem, and puts forward the special and general method. Then the main research areas of Non-Keplerian motion are suggested. The concept of Non-Keplerian motion given in this paper can help to understand and investigate the essence of space maneuvering, can promote the development of correlated theory and technology of space maneuvering and help to establish the basement of future space technology.