Precise Autonomous Orbit Maintenance of a Low Earth Orbit Satellite

In this paper, the problem of precise autonomous orbit maintenance of a satellite using output feedback and quadratic optimal regulators in a low Earth orbit is investigated. Autonomous on-board orbit maintenance refers to automatic control of different operational parameters within their control windows. In this paper, the problem of autonomous absolute orbit control is converted to a relative orbit control problem in which reference orbit includes the orbital elements of a virtual satellite, which is influenced only by the Earth's gravity field. The paper focuses on increasing the accuracy of orbit control during the satellite mission lifetime. This is accomplished by considering satellite mass reduction due to fuel consumption in the dynamic model. Also, a precise passive control of the eccentricity vector is presented by choosing an appropriate in-orbit location of the along-track maneuvers. Analysis of both the in-plane and out-of-plane relative motion of satellite with respect to reference orbit is presented. Numerical simulations are performed to show validation of the proposed control methods and techniques.