Trajectory Design And Orbital Dynamics Of Deep Space Exploration

The term deep space exploration is used for the exploration in which a probe, unlike an earth satellite, escapes from the Earth's gravity field and conducts the exploration of celestial bodies within or away from the solar system. In China, It includes exploration of all celestial bodies except the Earth, while it excludes that of the Moon according to some other countries and institutes. The content of this concept would be constantly updated with the development of aerospace technology.As the aerospace science and technology progress, exploration of the Moon and other planets of the solar system have attracted more and more attention throughout the world since late1990s. China also accelerated its lunar exploration progress in recent years. Its first lunar-orbiting spacecraft, CE-1, was successfully launched on24October2007. It then achieved the goals of "accurate maneuver and lunar orbiting", acquired a large amount of scientific data and a full lunar image, and finally impacted the Moon under control. The success of the CE-1mission, following that of its artificial Earth satellite and human space flight, is seen as the third landmark in Chinese space program, indicating that China has joined the countries with deep space exploration capability. On1October2010, China launched CE-2with success, which obtained a full map lunar image of higher resolution and a high-definition image of the Sinus Iridum, and completed multiple extended missions such as orbiting the Lagrangian point L2, laying the groundwork for future deep space exploration.As the first phase of the three main operational phases ("Orbit, Land, Return") of the Chinese Lunar Exploration Program, the successful launches and flights of CE-1and CE-2are excellent applications of the orbit design of both the Earth-Moon transfer orbit and the lunar orbit, yet not involving the design of the entire trajectory consisting of the Earth-Moon transfer orbit, the lunar orbit, and the return orbit, which is produced particularly for sample return spacecraft. This paper studies the entire orbit design of the lunar sample return spacecraft which would be employed in both the third phase of the lunar exploration program and the human lunar landing program, analyzes the dynamic characteristics of the orbit/track, and works out the launch window based on specific conditions. The results are universally applicable and could serve as the basis of the orbit design of the lunar sample return spacecraft.Meanwhile, China's independent Mars exploration is in progress. In this context, this paper also carries out comprehensive related researches, such as the orbit design and computation of the Earth-Mars transfer orbit, the selection of its launch window, and mid-course trajectory correction maneuver, etc.. It conducted calculations and dynamic analysis for Hohmann Transfer orbit in accurate dynamic model, providing basis for the selection and design of the transfer orbit in China's Mars exploration.On the basis of Orbit dynamics theory of the small bodies including detectors in the solar system, all the works concerned about trajectory design in this paper are worked out in an complete and reasonable dynamic model, that is why the results have sometiong referential value for trajectory design in deep space exploration.The major innovations in this paper are as follows:1. This paper studies different types of Earth to Moon transfer orbit on the basis of orbit dynamics theory of small bodies in the solar system and provides the theoretical basis of the orbit type selection in practice missions.2. This paper works on the orbit dynamics of the free return orbit, which intends to guarantee the safety of the astronauts in the human moon exploration, and carries out the free return orbit calculated in the real dynamic model.3. This paper shows the characteristics of the re-entry angle of the Moon to Earth transfer orbit. With the coditions of the landing range of our country taken into account, our works carried out the constraints of the re-entry angle and the latitude of the explorer at re-enty time and provide the basis of orbit type choice for practical applications.4. Based on the error transition matrix of the small bodies' motion, this paper analyzes the attributes of he error propagation of the Earth-Moon transfer orbit, on the basis of which it proposes the timing methods as well as the equation for the determination of the velocity increment for TCMs.5. Based on the IAU2000Mars orientation model, this paper studies the precession part of the change of Mars gravitation. And this lays the foundation for further study of its influence to the Mars orbiter's orbit of precession and the solution of the corresponding coordinate additional perturbations.6. This paper studies the characteristics of Earth to Mars transfer orbit in the real dynamic model and put forward the according theoretical analysis.7. The theoretical analysis of error propagation is performed on the basis of error transition matrix, thereafter the determination of time and the calculation of velocity increment for TCMs is given. By comparing results of different methods, it proves that the linear method of TCM calculation is the most timesaving one among all applicable methods for a certain accuracy requirement.8. All the numerical simulations in the production of this paper are done/carried out by programs written on my own, which could apply to other relevant missions.