In view of the disturbance of the frequent Wheel Off-Loading(WOL) of Tianwen-1, firstly, this paper analysed the perturbation magnitude of WOL and the effect on the orbit in its relay and remote sensing orbits. Secondly, a uniform acceleration model in RTN coordinate system was established to describe the acceleration produced by WOL events, several strategies were proposed to analyze the orbit of the relay and remote sensing orbit respectively, and finally orbital accuracy was assessed by overlap comparison. The results show that WOL events are the main error, affecting orbital accuracy. The position accuracy of the relay orbit is about 150 m, and in the remote sensing orbit where the unloading events are more frequent, the position accuracy decreases to 700 m.

Based on the existing tracking and measuring conditions of China’s deep space exploration missions, the orbit determination accuracy of the DRO probe was simulated and analyzed. For the Cislunar space DRO exploration, the simulation adopted batch processing orbit determination method, selected celestial bodies centered on the Earth for orbit integration, and increased non-spherical gravitational perturbation of the moon. Under the current measurement conditions, the position and velocity accuracy of 2-day short-arc orbit determination using only range tracking data were the order of km and better than 3 cm/s respectively; for 7-day predictions, the maximum differences in the position and velocity are the order of ten kilometers and 6 cm/s respectively. When using ranging data combined with VLBI data, the position and velocity accuracy were the order of hundreds of meters and less than 0.4 cm/s respectively; for 7-day predictions, the maximum differences in the position and velocity were the order of kilometers and 2 cm/s respectively, which shows that VLBI data significantly improved the accuracy of short-arc orbit determination and prediction. Moreover, the position and velocity accuracy were better than 1 km and 1cm/s respectively when using 5-day long-arc range tracking data. For 7-day predictions, the maximum differences in the position and velocity were less than 2 km and 1cm/s respectively. This shows that an increase of ranging data significantly contributes to the accuracy of orbit determination and prediction for DRO.

This paper reviews the recent research on the Kuiper Belt dust dynamics. Specifically, we review the related space exploration missions, introduce the origin and destruction mechanism of the Kuiper Belt dust, summarize previous studies on the modeling of the Kuiper Belt dust dynamics, and discuss the population migration mechanism as well as the contribution of Kuiper Belt dust to interplanetary dust in the inner solar system. This study helps to understand the dust environment in the solar system boundary and the interstellar space, and provide valuable insights for the orbital design of solar system boundary missions from the perspective of space environmental safety.

Lava tunnels widely exist on planets and satellites, which can provide natural shelter for humans to land on in the future. Research on lava tunnels is of great significance. However, there are many challenges in extraterrestrial lava tunnel detection. Existing terrestrial lava tunnel detection schemes have devices that are not portable, with low levels of automation and work efficiency, and cannot be directly applied to the detection of extraterrestrial lava tunnels. To address the above problems, this paper proposes a 3D detection method for extraterrestrial lava tunnels based on the lightweight mobile measurement system, achieving efficient and detailed mapping as well as 3D morphology of lava tunnels, and carries out the verification in Earth lava tunnels. First, laser scanning is used to obtain the point cloud in the lava tunnel efficiently, and the 3D point cloud map of the tunnel is generated based on the iterative Kalman filtering algorithm. Subsequently, through point cloud processing methods such as ground filtering, tunnel wall extraction, and normal vector estimation, the 3D reconstruction of lava tunnels is achieved, followed by morphological analysis. This paper selects the Xianren Cave and Qishier Cave in Haikou, Hainan Province, as simulation scenarios for extraterrestrial lava tunnels to conduct experiments. Experiments indicate that the proposed method realizes real-time autonomous 3D mapping of lava tunnels. The generated point cloud maps and 3D models are more accurate and contain more detailed terrain information compared to existing research results. These indicate the proposed method better meets the morphological analysis needs of lava tunnels and provides a foundation for the in-depth study of extraterrestrial lava tunnels.

In this paper, a helical groove conical composite horn structure with multi-point drive rotation was proposed. A high-performance ultrasonic driller suitable for drilling in the inner wall of lava tubes was developed. An equivalent impedance network model was used to model and analyze the ultrasonic driller to predict the response characteristics of ultrasonic driller. The possibility of this drilling probe in applying complex ground conditions of lava tubes was verified through low gravity multi-angle simulated drilling tests and data analysis. The results show that the drilling rate increases with the increase of the hole’s opening angle for a drill rod diameter of 3 mm and a drilling pressure of 10 N. The maximum unloaded rotary speed of the driller is 506 rad/min，the drilling rate is 6.4 mm/min for vertical drilling，and the rotary speed while drilling is 259 rad/min.

Lava tubes are one of the prime candidates for establishing extraterrestrial bases. To verify the feasibility of using ground-penetrating radar to detect lava tubes on extraterrestrial bodies, this paper first conducted a technical study to validate the detection of lava tubes using a 400 MHz ground-penetrating radar system on the Seventy-Two Caves and Wolong Cave in the Shishan Volcanic Group in Haikou, Hainan. It is found that the upper interface of the lava tube is clearly displayed when the depth of the tube is 2 m, and the radar image shows the upper and lower boundaries when the height is less than 3 meters. Additionally, the genetic algorithm is employed to inverse the dielectric constant of the lava tube’s wall. The reliability of the genetic algorithm in calculating the dielectric constant is validated through comparison with results obtained from the depth method and sample measurement. Furthermore, the analysis of samples establishes a simple relationship between porosity and dielectric constant. These findings are of significant importance for assessing the underground spatial distribution and wall stability of the lava tubes, providing a reference for future lunar base establishment.

This article proposed a 3D real scene modeling method for lava tubes that integrates airborne LiDAR, close-range photogrammetry, and point cloud data from GeoSLAM handheld laser scanner, with a focus on future lunar surface scientific explorations. Firstly, the entities were divided, and then entity feature extraction was performed based on semantic information. A new mesh model construction method was proposed, which uses multi-level model construction method and skeleton-plus-detail modeling method to construct the mesh model of the inner surface of the lava tube. Finally, entities were constructed separately between different layers inside the model to simulate the original state of different layers, and to measure layer thickness and volume of spallation. The 3D modeling of the lava tube located in Jingpo Lake, Heilongjiang province, shows that the 3D modeling method for lava tubes based on multi-source data fusion has high precision and high realism, providing an important reference for subsequent lunar lava tube skylight detection, Earth-Moon simulation comparison and internal exploration.

For the detection of lava tubes on extraterrestrial bodies, this paper utilizes LiDAR technology to conduct field surveys on lava tubes in the Shishan Volcanic Cluster area of Haikou City, which has a high degree of similarity with the Moon and Mars. It also proposes a skylight detection method based on grid division and applies a crack detection method based on data enhancement and multi-scale feature learning network to detect the internal structure of the lava tube and study its morphology. The interior of the lave tubes is scanned in all directions using a portable handheld laser scanner in the first. Based on the high-precision point cloud data obtained by measurement, this paper completes a three-dimensional model using the ContextCapture software, and some special miniature geomorphic like skylight in the tube and the tubes’ inner fissure is detected and extracted automatically. The experimental results show that the laser scanner combined with point cloud processing software and program can efficiently, intuitively and truly restore the morphology and structure of the lava tube, conduct quantitative analysis, and detect the special miniature geomorphology in the tube.

Aiming at the localization of lunar lava tubes, the volcanic lava cave in Haikou City, Hainan Province, was selected as the experimental area for simulated lunar lava. Localization methods including stereo vision-based method, laser scanning point cloud based method, vision fused IMU based method, laser point cloud fused IMU based method, and vision, laser point cloud and IMU fused method are applied to localization in the field areas of simulated lava tubes. The experimental results show that the accuracy of stereo vision could reach 3.59% in long-distance travelling mode, but the accuracy and robustness decreased significantly in harsh lighting conditions. Lidar could achieve a similar-level accuracy as vision-based method, reaching 1.89% in local area, but its robustness was affected by data acquisition rate and field of view. The integrated localization method using stereo vision, LiDAR, and IMU achieved robust localization results in lava tube areas with extremely harsh lighting and terrain undulations, making it the preferred choice for long-distance continuous localization. The research conclusions provide valuable reference for subsequent research on sensor configuration and localization methods for lunar lava exploration missions.

This paper, founded on the synthesis of recent exploration achievements and prior research, supplemented by on-site investigations of diverse terrestrial lava tubes, delves into the value and challenges associated with lunar lava tube exploration and development. Employing lunar remote sensing data and focusing on lunar lava tubes in areas such as Mare Fecunditatis and Mare Tranquillitatis, the paper formulates a collaborative exploration blueprint comprising lunar landing platforms, rovers, and autonomous robots. Furthermore, in line with the objective of utilizing natural cavities within lava tubes for potential lunar base construction, the paper scrutinizes the prerequisites and complications linked to lava tube modification and construction. It presents conceptual solutions, encompassing cave interior floor construction, communication and power infrastructure deployment, as well as residential facility establishment, providing a fundamental reference for the construction of future lunar bases.

Lava tubes, formed by the flow and cooling processes of volcanic lava, have been discovered on the surface of several heavenly bodies in the solar system and have become a window into the volcanic activity and thermal history of Earth-like planets. At the same time, lava tubes have extremely important scientific and engineering applications because of their thermostatic and radiation-proof interiors, which are also natural shelters for future human exploration activities or extraterrestrial survival. In this paper, the formation mechanism, detection and identification methods of lava tubes, and the distribution of lava tubes on the surface of different heavenly bodies in the solar system were summarized, the scientific significance and application prospects of lava tube detection were discussed. It was proposed that the Earth’s lava tubes are the most important objects for planetary lava tube analogical studies and detection, and the theory and methodology of the analogical studies of lava tubes were introduced, to provide theoretical basis and simulation experimental support for future exploration of extraterrestrial lava tubes.

In this paper，scientific objectives and payloads configuration of international asteroid exploration missions in the past three decades were reviewed. On the basis of summarizing the main scientific questions of asteroid exploration， the selection of detection objects，scientific objectives and payloads configuration of China’s asteroid exploration project，which named Tianwen-2 mission were discussed. Focusing on the realization of scientific objectives，corresponding scientific research contents and payload technical specifications were proposed.

In the process of small body attachment detection，due to the limitation of computational resources，it is difficult for the sequence image autonomous relative navigation system to process a large amount of optical image information. In this paper，a relative navigation observation sequence planning method is proposed，and an observable measurement index describing the observation accuracy of the landmark is established based on the Fisher information matrix，which is used as an index to design the observation strategy for the preferred selection of the key observation moments. In order to verify the validity of the relative navigation method，a small body attachment experiment platform is constructed，and the 6-degree-of-freedom attachment motion simulation of the lander is realized by pulling the load platform with 8 ropes in parallel. Finally，a visible light camera is mounted on the experimental platform to realize the semi-physical simulation of the relative navigation of small body attachment，which greatly reduces the computational burden of the navigation system while providing high-precision relative navigation. It will provide reference for the asteorid project in the future.

Given the complex and numerous morphological features during asteroid landing，which lead to challenges such as huge number of feature combinations，high computational load in online feature selection and low computational efficiency，in this paper an online multi-type feature rapid selection method was proposed. Using rapid selection criteria for multi-type features combined with search region，a method for selecting single-frame image features was established. Additionally，considering the short sampling interval，high inter-frame image overlap，and high feature inheritance probability during asteroid landing，a method for inter-frame image feature inheritance selection was proposed. Simulation experiments show that the design of single-frame image search regions and inter-frame image feature inheritance methods substantially reduces the number of feature combinations，thereby greatly enhancing the efficiency of computational and online feature selection.

Aiming at the possible inaccuracy of the prior pose during the visual navigation of an asteroid landing，a feature tracking aided pose estimation method is proposed. First，the generation of navigation features relies on pre-existing pose information and a database of navigation features. Subsequently，a multi-feature discriminative correlation filter (DCF) is employed to track the position of the navigation features in the navigation camera images by combining handcrafted and depth features. The average peak correlation energy (APCE) is subsequently employed to effectively screen dependable tracking outcomes for the initial estimation of the pose. Finally，the navigation features are recalculated using the initial estimation of the pose and adjusted to match with the navigation camera image by using normalized correlation coefficients (NCC). The proposed methodology involves the integration of the process within a differentiable Levenberg-Marquardt (LM) framework， specifically designed for pose optimization. This framework incorporates constraints based on the NCC. Experimental results， utilizing images，terrain, and ephemeris data obtained from the Osiris mission，demonstrate that the proposed method's pose estimation exhibits reprojection errors within the sub-pixel range. At 1 km from the asteroid surface，the position estimation error is within 2 m and the attitude estimation error is within 1°.