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To improve the autonomous navigation ability of navigation constellation, a kind of autonomous orbit determination technology based on a solar sail at an artificial Lagrange point is proposed for navigation satellite. Based on crosslink range observation, real-time position information provided by the solar sail is used to eliminate the error of autonomous orbit determination caused by the overall rotation and drift of the navigation constellation. Nonsingular orbit elements are chosen as state vector when the extended Kalman filter (EKF) is designed to fuse satellite dynamics model and two kinds of observation information to determine the orbit. International GNSS service (IGS) precise ephemeris of GPS constellation is adopted to validate the method. The results of simulation show that the proposed algorithm can not only ensure the long-term stability, but also provide higher precision of orbit determination compared with the approach of combining crosslink range observation with inter-satellite orientation observation. [ABSTRACT FROM AUTHOR]

For solar sail spacecraft with control vanes, solar sail attitude dynamics equations considering elastic vibration and vibration equations were deduced. The solutions of solar sail spacecraft dynamics equations were achieved by utilizing the concepts of unconstraint modes. The PD controller with Bang-Bang control strategies was designed considering the problems of yaw axis earth-pointing of solar sail on super-synchronous transfer orbit. Numerical simulation shows that the designed controller based on control vanes is capable of controlling the yaw axis earth-pointing fast and accurately. [ABSTRACT FROM AUTHOR]

In this paper, solar-sail attitude control system which employed moving masses for pitch/yaw trim control and roll stabilizer bars for roll control was studied. Physical model of solar-sail attitude control system had been analyzed, and the dynamical model was established using Euler's attitude dynamical equations. According to the model, a nonlinear PID controller was found to control the three-axis attitudes. Finally, a series of simulations, including the Solar Polar Orbit Radio Telescope misson's trajectory transfer, were run to determine the effectiveness of the attitude controller and characterize the behavior of attitude control method using moving masses and RSB. [ABSTRACT FROM AUTHOR]