The paper describes the space operations, gives brief remarks about the design of the current system, and states the future vision. We propose four fundamental abilities of the control system via analysis of typical tasks, including autonomousflying management, noncooperative target reconstruction and recognition, quick orbital transfer and agile pointing, and space complex programming control.

Thrusters and reaction wheels are combined to stabilize the attitude of the platform as a large disturbance may exist during launch process. A thrusterbased minimum time control law and a reactionwheelbased sliding mode control law are investigated, and the switching condition of the hybrid control is presented. The rapidity, accuracy, and the flexible vibration suppression capacity of the control strategy are validated by the numerical simulation.

In order to keep perturbed relative motion stable, an energy matching principle under J2 perturbation is presented and two iteration methods for the along track relative velocity and radial relative position are developed. A new leaderfollower formation and its initial relative states are designed according to the two proposed methods. Then an analytical expression of formation keeping impulse is derived based on Lagrangian multiplier method in order to mitigate the effect of formation initialization error. Simulation results show that the condition of energy matching under J2 perturbation can lead to a stable leaderfollower formation. Furthermore, the new formation and its design method can reduce the designing error of separation distance.

Abstract： A variety of errors and disturbances exist in control moment gyro (CMG) system, affecting the accuracy of spacecraft attitude control. This paper analyzes the characteristics of the main components of the largescale single gimbal control moment gyro (SGCMG) as well as errors and disturbances, including the static and dynamic imbalances of rotor, installation error of rotor axis, friction of bearing, characteristics of rotor motor and gimbal motor, harmonic gear drive. Numerical simulation results of the dynamics fine model of largescale SGCMG indicate that adding harmonic gear into gimbal servo system of largescale SGCMG significantly improves output torque accuracy, simultaneously brings highfrequency resonance to gimbal. The disturbing torque caused by dynamic imbalance of rotor is the main factor that results in output torque deviation in the direction of gimbal rotation axis and the output torque direction of SGCMG.

In order to test and verify storage performance of vane type surface tension tank (STT), a model testing system is established and the microgravity drop tower tests are conducted based on experimental study of fluid storage and transportation behavior of propellant refillable reservoir (PRR). The rules of fluid storage and transportation of PRR in microgravity environment are obtained. The test results show that doublecone PRR have good liquid storage capacity more than cuniform PRR, and the doublecone PRR exhibits good liquid storage capacity with lateral acceleration. A rational design of PRR can effectively store liquid and control the velocity of liquid transportation. The test results offer a guideline for the optimization of newstyle vanetype PMD, and also provide a new method for fluid control in space environment.  

This paper investigates the problem of attitude compound control for spacecraft with multiple moving appendages. The representative dynamical model of twocoupled rigid bodies is established and the coupling relationship is analyzed. And a finitetime disturbance observer (FTDO) is designed to estimate the disturbances introduced by appendages and the external environment. The total disturbance is actively compensated via the terminal sliding mode controller (TSMC). By using the extended Lyapunov stability theory, the finitetime convergence of the main body’s control system is proved. To reduce the influence of spacecraft attitude maneuver to the appendages, a controller with angular acceleration compensation is considered. The simulation results show that the developed method can accurately estimate and compensate the total disturbance with a high control precision and faster system response.

Based on the Hill equation，the safety strategy of doubleimpulsive flyaround process is researched. Firstly, the model of doubleimpulsive flyaround is given and all the flyaround trajectories outside the global safety area are obtained by ergodic simulation. Then a curved surface can be plotted, which expresses the relations among flyaround time, the consumption of the fuel and the starting point. Furthermore, the curve which is critically safe can be obtained and fitted. Finally, the fitting error is analyzed and it is showed that the trajectory deviates slightly.

A design of new biaxial solar array drive electronics is proposed according to the requirements for twomotor biaxial solar array. Based on the existing solar array drive electronics, via designing a current direction switching delay circuit, the problem that power transistor is easily short at the moment of current direction switching is solved and the safety of the circuit is ensured. The small power transistor can be used to simplify the design and realize the miniaturization. By crossing recombination between the array driving circuit and motor coil, the real isolation between the main and secondary electronics is ensured and the reliability is greatly improved.

A design of a mobile simulator for lunar rover based on embedded system is introduced. The corresponding function and performance requirements are analyzed. The hardware and software design is provided in this paper. Finally, the validity of the proposed method is illuminated via system testing with the real drive and control unit. The mobile simulator is designed on the level of power for motors and load. It satisfies the testing requirement for assembly of moving controller and driver system. It has good universality and expandability.

The performances of the extended Kalman filter (EKF), unscented Kalman filter and squareroot Kalman filters (SREKF, SRUKF) for relative navigation based on lineofsightonly measurement in spacecraft rendezvous operation are compared. The characteristics of the proposed relative navigation and the algorithms for the above four Kalman filters are introduced. The relative dynamic models of the chaser and the target spacecraft as well as the measurement model of the lineofsightonly relative navigation are established. Numerical simulations are undertaken for three typical relative motions. The simulation results show that the accuracies of the relative navigation based on lineofsightonly measurement via the four filtering algorithms (EKF, UKF, SREKF, and SRUKF) are at the same level. The UKF performs a little better than the EKF, and the SREKF and SRUKF perform a little better than the EKF and UKF on the accuracy of the relative distance.

A new design for twoposition threeway pilot solenoid valve is presented, which proposes that two groups of permanent magnets and three groups of control coils construct three permanent magnetic lock circuits and two electromagnetic bias circuits. This proposal not only results in the miniature structure of valve and no power consumption for holding position, but also improves the sealing reliability of valve. Such solenoid valve can be used as the pilot control valve of the main valve of largethrust engine propellant which can meet the  needs of the longterm application in orbit. The feasibility of this design scheme is verified by finite element analysis and productprototype experiment. The verification results show that all performance indices of the new type of pilot solenoid valves achieve the design target.