Lunar polar exploration is a strategic point to for all space powers to compete with each other. Based on the brief summary of the development of lunar exploration in domestic and globe，the main scientific and technical issues that need to be solved are studied and analyzed in order to provide a reference for China’s future polar exploration.

Human-beings have achieved lunar soft-landing on the surface of mid or low latitude regions. However no one has realized the exploration mission for the polar regions，especially for the south polar region，which attracts most attention because of its high scientific and technological value. In this article，the environment of lunar south polar region is analyzed，including the temperature condition，topography，illumination condition and earth visibility. Different from the regions with mid or low latitude，the temperature for lunar south polar region is very low（from 100 K to 160 K）. The topography is more complicated （more craters，greater slope，scattered stones）. The sun elevation angle is very small（which is between?1.54° and 1.54° for the south pole） and there are more shadows because of the high mountains. And there are long durations of earth-invisibility. All these environment conditions will much affect the lunar south polar region soft landing mission. According to the analysis of lunar south polar environment， some engineering suggestions for the lunar south polar region soft landing mission are proposed，which will provide reference for the implement of engineering .

It is crucial to utilize water ice resources in the pole regions in order to support the construction and functions of the lunar base. Based on exploration and data analysis results of lunar missions，the distribution and existing form of water ice in the lunar poles are analyzed. Then，the technical scheme and implementation methods，as well as the developing trend of lunar polar resource utilization are introduced. The integrated development and utilization scheme of photothermal drilling is introduced in detail. The experimental model of surface water ice extraction principle is carried out, and the water extraction test of ground water bearing sand soil is carried out. The experimental results show that the device can achieve a water extraction rate of more than 30 g / h and a water extraction capacity of about 4 kg / h / m³ in the soil with 5 wt% water content，Finally some key problems and technical challenges of key technical aspects for water ice utilizing are discussed，including prospection，extraction，condensation and collection，and transferring of water ice. This paper aims to provide the reference for China’s lunar polar resource utilization.

The mission of lunar detailed survey，lunar polar relay and lunar polar region landing will be completed in the subsequent lunar exploration project. Because of the poor communicate condition between the earth and moon polar region，a relay satellite will be launched and put in the proper orbit to set up the communication ability. An inclined and elliptical lunar orbit with frozen eccentricity and orbit period of 12 hour is selected as relay orbit after comparative analysis of different relay orbits，trajectory design of relay satellite and lunar polar region exploration mission. The results show that the relay satellite can fly more than ten years in the orbit without orbit maintenance. During the two thirds of one orbit period the relay satellite can communicate with the rover landing on the lunar polar region，which will provide reference for engineering implementation.

The new version of American lunar lander carries a new circular membrane solar array with high deployment/closing ratio and high power/mass ratio. However，circular membrane solar array also has characteristics of rigid-flexible coupling，difficulty in dynamics modeling and analysis，complex movement of thin membrane under lunar circumstance and high deployment precision. In response，a numerical dynamics model of solar array structure is established in this paper to analyze deployment dynamics features. Absolute nodal coordinate formulation is used to model flexible components and thin membrane. Two-step detection method is employed to deal with the complex contact/collision between thin membranes. Solar array is driven by joint rotation trajectory based on Bézier curves. Trajectory of the pivot panel is planned and tracked by forward-feedback joint control to improve the deployment positioning accuracy and suppress the residual vibration. The proposed driving strategy is then applied to the solar array numerical model based on NASA prototype. Numerical simulations have demonstrated that circular membrane solar array can be well-ordered and accurately deployed，and the residual vibration can be effectively suppressed.

Lunar Antarctic is hot spot area of Lunar Exploration in the future and the communication is limited in south pole region. The Lunar relay communication needs to be designed to fulfill the science exploration mission. The requirements，characteristics and constraints of the relay communication mission of the lunar south are analyzed and the options for the communication orbit are put forward，including the elliptical orbit around the lunar and the translational point orbit. The advantages and disadvantages of the optional orbits are analyzed，The dual-satellite scheme is further proposed. This scheme can effectively improve the continuous coverage of the lunar south pole communication. The simulation results show that the two satellites can realize the visible complementarity of the lunar south pole，and reach real-time coverage of the lunar surface and the aircraft near the moon. It will provide reference for the implementation of the fourth phase lunar pole south exploration in the future.

A novel onboard trajectory planning methodology is proposed for lunar crater exploration. For the first time the flight trajectory is divided in to 5 phases：the vertical rise，the single axis rotation，the unpowered gliding，the approach and the vertical descent. According to different characters in these phases，transfer conditions and control modes are designed. Then a new method for state updating is developed in analytical and numerical ways. After that，3 optimization parameters and 2 optimization objects are chosen. Considering the constraints，the reference trajectory is finally generated by the particle swarm optimization. Different from other planning，the guidance law is introduced during the unpowered gliding and the approach phase to improve optimization efficiency. Numerical simulations show that the methodology proposed is good real-time and the planned trajectory can meet all the requirements，which can improve the autonomous survivability of the explorer and is suitable for the lunar crater exploration.

According to China’s lunar exploration program，after completing lunar soil sample return mission of Chang’E-5，in-situ exploration and sample return exploration will be carried out for the lunar polar region，and the exploration of material composition，resource distribution and existing form in the lunar polar region will be important scientific objectives for the follow-up lunar exploration missions. Because of the special environmental characteristics of the lunar polar region，there is a great possibility of the existence of water-bearing lunar soils in the form of icy soil. The study of sampling technology for such objects will strongly support the demonstration and implementation of future lunar exploration missions，which has great engineering significance. Based on the investigation and analysis of the characteristics of the lunar polar region and the sampling techniques of lunar icy soil，the key drilling and sampling techniques of the lunar icy soil in the polar region are proposed，and the key technical approaches are clarified. The design idea of samplers for both in-situ detection mission and sample return mission is proposed，and the research progress is introduced.

Since the idea of water-ice on the moon was put forward by American scientist Kenneth Watson in 1961，whether there is water in the permanent shadow area has been debated. Lunar water-ice is a major scientific problem related to the "dry" and "wet" theory of the moon. Since the 1990s，the existence of water-ice in the permanent shadow area of the lunar polar region and the problem of water in the early lunar period have become the hot spot of international lunar exploration. Based on the research status of lunar water， the key scientific problems related to lunar water are analyzed from different space dimensions and different exploration methods，and the science objectives，the payload configuration and technical indicators of China's follow-up lunar water-ice exploration projects are put forward

Solar radiation pressure（SRP）area is one of the key parameters of orbit determination and prediction in deep space detection，and directly affecting the prediction precision. The calculating method of SRP area based on target characteristics is used，and the sphere，cube，cylinder and cone are chosen to be analytical targets，assuming the materials are purely diffuse，purely specular and mixed surface separately. While the attitude angle changing from 0° to 360°，the influences of the surface materials，size and the shape of the target on the total SRP area of the target are analyzed，the general laws governing influential factors are described by comparing simulated results. These conclusions can provide reference for further research on SRP modeling solution and spacecraft design.

The Moon is an important destination for humans to carry out deep space exploration activities. The lunar surface exploration project has increasingly become a global concern. The lunar mobile robot is the foundation of the exploration project and an indispensable part of achieving the goal of lunar exploration. The complex terrain and a large number of craters and massive lunar rocks which put forward higher requirements for the lunar robot’s mobile ability. The lunar surface mobile robot with jumping ability can flexibly adapt to the change of lunar terrain. The robot combines conventional walking，post-deformation walking and pneumatic jumping to achieve the function of moving on the lunar surface and crossing obstacles. When the robot is moving on the regular terrain，the movement mode is consistent with the wheeled robot and the movement efficiency is high; when moving on irregular terrain，it works in the form of irregular wheels which can overcome relatively low obstacles; when encountering large obstacles，the jumping system is used to get over the obstacles with strong ability. The research of the mobile robot can provide a technical reference for the implementation of the lunar patrol and exploration missions.

Aiming at the failure against structural damage in the exposed section of adiabatic diffuser during ground hot-firing test of a heavy-lift carrier rocket，the failure mode analysis was carried out，based on the modal results and the measured data of power spectral density also，the dynamics simulation was calculated. The simulation results show that the adiabatic diffuser at the junction with the tail of the nozzle shell generates a higher alternating stress under the action of high vibration load，with the continuous high-temperature，high-pressure and high-speed gas flow and particle scouring of the rocket motor，the material performance of the adiabatic expansion section is reduced，the inner surface of the high-stress site begins to exhibit abnormal phenomena such as carbon cloth shedding，and the wall thickness continues to decrease，which eventually leads to cracking at this site and triggers the disintegration of the adiabatic diffuser. According to the above fault location，a reinforcement scheme for extending the nozzle shell is proposed，which increases the structural integrity maintenance ability of the adiabatic diffuser under high vibration load environment，and successfully passes the verification test of the ground hot-firing test，indicating that the improvement scheme is reasonable，the measures are effective.