With the continuous progress of aerospace technology, the role of the space Telemetry, Operation, Command and Control (TOCC) system is increasingly critical, and therefore, improving its performance is of great significance for addressing the high-density and diverse demands of future space missions. Comparative analyses of TOCC system architectures and operational models between domestic and international frameworks are provided. This paper analyzes the research progress and development opportunities of these key technologies, presenting a detailed analysis across four domains of TOCC system. The development trajectory of these systems is further clarified in terms of autonomy, efficiency, and coverage, proposing an integrated construction approach with standardization, intensification, and intelligence. This paper introduces the concept of an integrated TOCC system, systematically identifying fulllink technical challenges and developments tailored to the future space development.

Exoatmospheric intercept plays a crucial role in strategic defense. However, existing approaches for exoatmospheric intercept guidance primarily rely on either proportional navigation or Lambert’s problem solution, which needs continuous relative measurements or requires constant orbit corrections due to its sensitivity to perturbation forces. To address these limitations, this paper proposes a novel guidance scheme based on relative-motion control. First, by introducing the zero-effort orbit as a reference orbit, the intercept problem is transformed into an equivalent relative-motion control problem with respect to the zero-effort orbit. The relative-motion dynamics model is adopted to analytically solve the velocity-to-be-gained vector, which avoids the iterative computation in the Lambert routine. Then, the guidance scheme is established, which generates a command thrust vector aligned with the velocity-to-be-gained vector in each guidance period. Through feedback control, the desired velocity is incrementally achieved until the velocity-to-be-gained vector becomes zero, ensuring accurate interception. Compared with the existing exoatmospheric intercept guidance methods, the presented method improves 1 or 2 orders of guidance accuracy in the low-Earth orbit intercept mission and 3 orders of guidance accuracy in the high-Earth orbit intercept mission, which are practical options for engineering applications.

Fuzzy logical control is a robust and effective control method in industrial fields, which renders it applicable to the attitude control of a solar sail. However, it is hard to apply in black-box and time-varying problem as real solar sail attitude control. Considering the lack of a priori knowledge and the unacceptable manual workload in the design of the fuzzy logical controller (FLC), an intelligent FLC designer (IFLCD) is developed by introducing neural network modelling and automatic design method. Besides, IFLCD also supports self-adaption for better control accuracy. By applying the proposed IFLCD in the attitude stabilization of a solar sail with individually controllable elements (SSICE), an effective solution of unmanned, time-varying, and complex system control method is offered without any mathematical model, which also overcomes the difficulties in FLC design Considering the performance degradation, accident, and distance problems faced by spacecraft, IFLCD can help with more practical problems that are hard be solved by traditional control theory.

A frozen orbit is beneficial for observation owing to its stationary apsidal line. The traditional gravitational field model of frozen orbits only considers the main zonal harmonic terms $J_2$ and limited high-order terms, which cannot meet the stringent demands of all missions. In this study, the gravitational field is expanded to $J_{15}$ terms and the Hamiltonian canonical form described by the Delaunay variables is used. The zonal harmonic coefficients of the Earth are chosen as the sample. Short-periodic terms are eliminated based on the Hori–Lie transformation. An algorithm is developed to solve all equilibrium points of the Hamiltonian function. A stable frozen orbit with an argument of perigee that equals neither 90 ${}^{\circ }$ nor 270 ${}^{\circ }$ is first reported in this paper. The local stability and topology of the equilibrium points are obtained from their eigenvalues. The bifurcations of the equilibrium points are presented by drawing their global long-term evolution of frozen orbits and their orbital periods. The relationship between the terms of the gravitational field and number of frozen points is addressed to explain why only limited frozen orbits are found in the low-order term case. The analytical results can be applied to other Earth-like planets and asteroids.

In this paper, the orbit acquisition and maintenance strategies for the repeat-groundtrack orbit are investigated to maintain the ground track of the satellite within a certain range. Two kinds of orbital dynamics models are introduced to calculate the on-orbit state of satellite. One is the orbital propagation model which is of high fidelity and can approximately express the forces acting on the satellite. The other is the design model which is of low fidelity and utilized by the semi-analytical acquisition algorithm to yield the reference repeat-groundtrack orbit. Combining the differential correction and analytical expressions, the results computed by the semi-analytical acquisition algorithm are of relatively high precision compared with the genetic algorithm. At the same time, the computational burden of the semi-analytical acquisition algorithm is far less than the genetic algorithm. Based on the reference orbit, two orbit maintenance strategies which are designed for chemical and electric engines are put forward to correct the orbit in order to make the ground track of satellite shift in a certain range. The application to the Chinese-French Oceanic Satellite mission has well validated the feasibility of these two strategies. Simulation results have shown that the strategy designed for chemical engine can keep the ground track displacement within 200 m, while all the orbit points can possess sub-meter repeat distance through adopting the strategy designed for the electric engine, which satisfies the requirements of the Chinese-French Oceanic Satellite mission.