optimal maneuver strategy and orbit design for servicing spacecraft

Paper number

IAC-08.C1.2.7

Author

Dr. Xiaohong Yu, Beijing University of Aeronautics and Astronautics, China

Coauthor

Dr. Daniel J. Scheeres, University of Michigan, United States

Coauthor

Prof. Yuanwen Cai, Beijing University of Aeronautics and Astronautics, China

Year

2008

Abstract

On-orbit services can extend the lifetime of spacecraft, quickly upgrade their functionality, save system development and operation costs, and make the entire system more efficient. Applications of servicing spacecraft are constrained by many aspects, but especially by three basic elements, i.e. time, energy and the possibility of completing a task. These are involved with orbital maneuver strategy, orbit deployment, orbital maneuver window, and optimal orbit design. This paper focuses on these problems. It utilizes principles of system engineering to solve the problem of integral optimization for orbit design and orbit maneuver in terms of effectiveness of complicated space missions. 
I. Aimed at routine and emergency services, the maneuver strategies with relatively lower energy and time cost has been studied. Three co-orbital maneuver models are established, i.e. drift model, combination model and direct ballistic trajectory model. The relationships between the time, the energy required in the maneuvers and the relative phase angle are formulated and some numerical results are presented. Some options for maneuver strategies are put forward according to different response time periods.
II. The concept of maneuver window is put forward and defined. The calculation of the maneuver window between circular orbits under the energy limit is discussed with emphasis. The energy-saving drift maneuver window and the time-saving quick maneuver window are studied separately according to the emergency degree of the service mission. The impact from ground and space-based TT&C supports on maneuver window is discussed.
III. The orbital deployment problem of SSC for servicing Spacecraft with the same orbit features and/or the same function features has been discussed. Two cases of uniformly and non-uniformly distributed satellite rings, Walker-type constellations are taken into consideration. The advantages and disadvantages between the co-orbital and separate-orbital deployments are compared. A servicing pattern and flew are given. An orbital deployment pattern for constellations with several orbit planes is put forward. 
IV. Making use of Analytic Hierarchy Process, this report brings forward a methodology for orbital optimization based on effectiveness in the case of the orbital deployment for SSC. Firstly, the possible tasks of SSC are decomposed and their degrees of importance are given by time, probabilities, and values of their applications. Then, the capabilities supporting the tasks are discussed from the viewpoint of orbit design, and the means of their weights determination is put forward. Finally, the relationships between the orbital parameters and the effectiveness are established by using Utility Function.

Abstract document

IAC-08.C1.2.7.pdf

Manuscript document

IAC-08.C1.2.7.pdf (🔒 authorized access only).

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