Spacecrafts with high accuracy and stabilization are required to reduce the disturbing forces produced by flywheels during the operation as low as possible, so the microvibrations need to be reduced effectively in the transmission path from flywheels themselves to the installation surfaces on the spacecraft. In general, passive vibration isolation approaches are commonly applied in mechanical flywheels while active vibration control approaches are used in magnetically suspended flywheels. In this paper, the microvibration characteristics of mechanical flywheels and magnetically suspended flywheels are introduced separately, and microvibration sources are analyzed. Moreover, the principle of passive vibration isolation and active vibration control are presented. The effects of vibration control based on the recent tests are illustrated.

This paper investigates the method for evaluating the diagnosability of sensor faults and actuator faults in satellite attitude control systems without depending on the fault diagnosis algorithms. The purpose is to improve the fault diagnosability of the system in the design phase. Considering the existence of feedback control, the single fault may generate a number of abnormal symptoms due to the fault propagation in the closedloop systems. Thus, it is a challenge to the fault diagnosability in the closedloop control systems. The statespace model of a satellite attitude closedloop control system with model uncertainties is established via extending the fault to the state variables. For the extended system, according to the criterion of the observability, the diagnosability conditions of additive faults and multiplicative faults are presented and proved by rigorous mathematical proofs. The achieved conclusions can be used to guide the design of satellite attitude control systems to improve the fault diagnosability.

Global attitude acquisition (GAA) refers to an attitude control process of recovering the norminal attitude or a new orientation, when a spacecraft loses attitude reference. To overcome the deficiencies of traditional GAA using thruster system or magnetic torquer as main actuator, which costs fuel consumption or more recapture time, a method of GAA based on reaction wheel is proposed here. By using the conventional configuration of the spacecraft, this method can realize orientation to any space target, and is proved to be efficient, good at engineering operation by onorbit results.

The proximity process in a close distance is very important for onorbit servicing. In this paper, the kinematics and control for this process are studied. The relative position model and relative attitude model of the servicing spacecraft towards target spacecraft are established. The proximity guidance law in straight line is used with respect to the coordinate of the target spacecraft. The relative motion states are tracked and controlled under a usual PD control law. Finally, the Simulink dynamics model is established, and the corresponding simulation and analysis are carried out. The simulation results indicate the reliability of six dimensional relative motion models and the validity of the control method.

By applying Lambert algorithm to deal with the constraints of terminal orbit, an optimization model of multiimpulse transfer trajectory is introduced based on the iteration of feasible solutions. Particle swarm optimization is used to optimize the minimumfuel transfer orbit. The true anomaly and instants of impulses are employed as design variables respectively and the corresponding results are compared. The obtained results with respect to the same twoimpulse and threeimpulse orbit transfers  prove the validation and highefficiency of the proposed optimization model and algorithm. The simulation shows that the efficiency is better when the true anomaly of impulses are employed as design variables.

By applying Lambert algorithm to deal with the constraints of terminal orbit, an optimization model of multiimpulse transfer trajectory is introduced based on the iteration of feasible solutions. Particle swarm optimization is used to optimize the minimumfuel transfer orbit. The true anomaly and instants of impulses are employed as design variables respectively and the corresponding results are compared. The obtained results with respect to the same twoimpulse and threeimpulse orbit transfers  prove the validation and highefficiency of the proposed optimization model and algorithm. The simulation shows that the efficiency is better when the true anomaly of impulses are employed as design variables.

The problem of tracking the longitudinal skip reentry trajectory is considered for the lunar return vehicle with the rotation of the Earth. First, the influence of the Earth rotation on the guidance is given via the detailed analysis of guidance dynamics. Considering this problem, the guidance for lunar return vehicle is studied based on feedback linearization method with the consideration of the Earth rotation. The reentry dynamics equations are very complicated with the Earth rotation. If the guidance is designed using the exact feedback linearization method, too many states should be measured, and the guidance would be too complex to implement. A simplified guidance is designed in the paper, and the design principle is analyzed. It is concluded that with some uncertainties the proposed guidance has higher precision by comparison with shuttle entry guidance.

The model perturbation and system disturbance of a drill mechanism should be considered in the complex lunar environment. Robustness of a sampling controller plays a critical role during the sample process. The nominal control model is established for a class of rotation and pulling compound mechanism， and the model perturbation and system disturbance to control model are analyzed. The approach of linear matrix inequality is applied to design the robust state feedback controller. Simulation results show that the controller possesses robustness and disturbance rejection ability against the bounded model perturbation and random system disturbance.

For the fast connectedcomponent labeling problem of the optical imaging sensor for the last adjacent RVD, the twoscanning algorithm is improved via combining the procedures of labeling merge and second scanning. The fusion of target prerecognition and the labeling algorithm is presented when considering the mutual constraint conditions and some prior knowledge. The simulation results shows that both of them can improve the efficiency of valid connectedcomponent labeling (CCL). The improved CCL costs less than 98ms in average when repetitively dealing with an image with the size of 1 024×1 024, and has the ability of realtime implementation.

According to the need of control accuracy for eastwest station keeping of geostationary satellites, an optimization method of orbitcontrol parameters and propellant consumption are proposed. Considering the satellite orbital dragging force induced by attitudecontrol injection, the ignition time of orbitcontrol thrusters is compensated. The propellant consumption is estimated according to the ignition time of all thrusters. Some examples of the optimization process are given as illustration to show that the method is effective and correct, which can be used to correct the orbitcontrol strategy in practice.

Manifold algorithms on loopy Lambert problem have some limitation， such as low accuracy and hardly programming． By using the distribution characteristics of the solutions，the algorithm is improved． The achieved Matlab program can run at any moment， which offers the necessary condition for the development of loopy Lambert transfer． As an example, when two moving points rendezvous in space， a twolayer optimal model of transfer orbit is established and the corresponding solution is proposed combining with an intelligent algorithm． Finally， two application examples show that the program is correct and valid．

Based on the application of CRDS（camera type rendezvous and docking sensor）, the following contents are expounded respectively, including the difference between active and passive CRDS, the different schemes of lighting system, the composition and principle of LD lighting system, and the characteristics and choices of LD devices and optical fiber. The proposed LD lighting system solves the problem of uniform illumination under the condition of wide field and long distance, overcomes the difficulties in the performance of space adaptability, and strengthens CRDS’s capability of antijamming from undesired light source.