In order to explore the influence of wheel surface structure on the trafficability of planetary rovers on soft ground, three kinds of wheels with different rigid wheel surface structures were selected for research. The basic performance parameters of the wheel on simulated planetary soil are measured and tested to explore the law of the wheel's sinkage, slip rate and traction coefficient. The results show that the wheel grouser increases the sinkage and slip rate of the wheel. The tread reduces the sinkage of the wheel, but it also reduces the traction performance of the wheel at a higher slip rate. Considering the complex working conditions of the planetary rover on the soft ground, the six-wheeled three-rocker-arm planetary rover is used to carry out passability tests in three terrains: obstacle crossing, out of sinkage and climbing. The results show that the grousers can cause disturbance and damage to the soft soil and have significant passing advantages. There may also be a slip phenomenon when crossing the obstacle, but it does not affect passing. The completely closed tread structure will cause soil accumulation between the tread and the grouser, affecting the wheel's ability to escape sinkage. This study provides a reference for the design of a rigid wheel surface structure for planetary rovers from the perspective of passing performance.

Appropriate environmental sensing methods and visualization representations are crucial foundations for the in situ exploration of planets. In this paper, we developed specialized visualization methods to facilitate the rover's interaction and decision-making processes, as well as to address the path-planning and obstacle-avoidance requirements for lunar polar region exploration and Mars exploration. To achieve this goal, we utilize simulated lunar polar regions and Martian environments. Among them, the lunar rover operating in the permanently shadowed region (PSR) of the simulated crater primarily utilizes light detection and ranging (LiDAR) for environmental sensing; then, we reconstruct a mesh using the Poisson surface reconstruction method. After that, the lunar rover's traveling environment is represented as a red-green-blue (RGB) image, a slope coloration image, and a theoretical water content coloration image, based on different interaction needs and scientific objectives. For the rocky environment where the Mars rover is traveling, this paper enhances the display of the rocks on the Martian surface. It does so by utilizing depth information of the rock instances to highlight their significance for the rover's path-planning and obstacle-avoidance decisions. Such an environmental sensing and enhanced visualization approach facilitates rover path-planning and remote-interactive operations, thereby enabling further exploration activities in the lunar PSR and Mars, in addition to facilitating the study and communication of specific planetary science objectives, and the production and display of basemaps and thematic maps.

Since leaving Vera Rubin ridge (VRr), the Mars Science Laboratory Curiosity rover has traversed though the phyllosilicate-bearing region, Glen Torridon, and the overlying Mg-sulfate-bearing strata, with excursions onto the Greenheugh Pediment and Amapari Marker Band. Each of these distinct geologic units were investigated using Curiosity's Mast Camera (Mastcam) multispectral instrument which is sensitive to iron-bearing phases and some hydrated minerals. We used Mastcam spectra, in combination with chemical data from Chemistry and Mineralogy, Alpha Particle X-ray Spectrometer, and Chemistry and Camera instruments, to assess the variability of rock spectra and interpret the mineralogy and diagenesis in the clay-sulfate transition and surrounding regions. We identify four new classes of rock spectra since leaving VRr; two are inherent to dusty and pyroxene-rich surfaces on the Amapari Marker Band; one is associated with the relatively young, basaltic, Greenheugh Pediment; and the last indicates areas subjected to intense aqueous alteration with an amorphous Fe-sulfate component, primarily in the clay-sulfate transition region. To constrain the Mg-sulfate detection capabilities of Mastcam and aid in the analyses of multispectral data, we also measured the spectral response of mixtures with phyllosilicates, hydrated Mg-sulfate, and basalt in the laboratory. We find that hydrated Mg-sulfates are easily masked by other materials, requiring >= 90 wt.% of hydrated Mg-sulfate to exhibit a hydration signature in Mastcam spectra, which places constraints on the abundance of hydrated Mg-sulfates along the traverse. Together, these results imply significant compositional changes along the traverse since leaving VRr, and they support the hypothesis of wet-dry cycles in the clay-sulfate transition. The clay-sulfate transition in Gale crater has long been hypothesized to record an environmental shift from warm and wet to cold and dry. The paleolake that once filled Gale crater allowed phyllosilicates to form. As Mars became cooler and drier, sulfates were able to precipitate above the phyllosilicates. This mineralogic transition has been observed in other places on Mars, implying a global environmental change. Different hydrated Mg-sulfates can reveal characteristics of the paleoenvironment at the time of deposition and thus clarify the geologic history. The goals of this study are to (a) characterize potential sulfate-bearing rocks with the Curiosity rover's multispectral imaging instrument, Mastcam; and (b) constrain Mastcam's Mg-sulfate detection threshold using laboratory techniques. We identify three new rock spectral classes inherent to the clay-sulfate transition and one new class associated with the Greeneheugh pediment. Our laboratory results indicate that it would be challenging to detect Mg-sulfate with Mastcam unless it is nearly pure. New rock spectral classes correspond to unique geologic units. One supports the hypothesis of wet-dry cycles in the clay-sulfate transition Cross instrument analyses imply that Mg- and Fe- sulfates are significant in the amorphous component of the clay-sulfate transition region The spectral signature of hydrated Mg-sulfates in visible to near infrared reflectance spectra are easily masked by phyllosilicates and/or basalt

The subject of the work is the analysis of satellite data in the database LROC: QuickMap. The article focuses on water ice deposits which could be converted into hydrogen or oxygen, among other things, and later used as a rocket fuel. The distribution of water ice deposits on the Moon is presented and a micro-trap on the Moon's south pole is proposed, which in the future could be an object for the exploration of water ice. An exit and descent route to the crater floor for the rover was also proposed, considering the degree of insolation and the degree of slope of the crater walls.

The dusty plasma environments of airless bodies present challenges for both exploration and science missions to their surfaces. Objects moving on the surface, such as rover wheels, transfer charges onto regolith dust due to the triboelectric effect. The charged dust particles can readily stick to spacesuits as well as the optical, electronic, and mechanical components of equipment and instruments, causing their degradation. This effect is more pronounced in permanently shadowed regions (PSRs) of the Moon, where the charge dissipation rate is low due to a lack of ambient plasma. Here we report the first results of an experimental investigation of the tribocharging effect between dust and rover wheels. Various wheel surface materials along the triboelectric series are selected. The effects of varying wheel speeds and dust types are explored. Results indicate that charge distributions conform to the triboelectric properties of the dust and material it comes into contact with. High charges of up to -2 pC are measured on dust grains -100 lm in diameter, which is equivalent to a surface potential of few hundred volts. Results also suggest that higher wheel speeds may result in more dust-dust interactions, changing the charging behavior of the dust grains. These findings indicate a need for future studies to better understand tribocharging in various exploration scenarios in order to design effective dust mitigation strategies and methods.& COPY; 2023 COSPAR. Published by Elsevier B.V. All rights reserved.

Power and communications are required for successful operations in the permanently shaded regions (PSRs) located at the lunar poles. However, due to the location of PSRs, direct solar power from the Sun and line of sight communications to Earth are limited. NASA solicited solutions from universities within the United States with the Breakthrough, Innovative, and Game-changing (BIG) Idea Challenge. The Planetary Surface Technology Development Lab (PSTDL) at Michigan Technological University (MTU) developed the Tethered-permanently shadowed Region EXplorer (T-REX) to address this problem. A conventional round tether in series with a superconducting tape tether connects to a lander at a crater rim to provide power and communications to T-REX during its descent into a PSR. This mission is enabled by the passive cooling of hardware within the naturally occurring cold environment of a PSR. T-REX was developed by using an iterative approach with testing conducted from component to system-level. System validation included testing within a sloped lunar regolith simulant chamber and component-wise testing under cryogenic temperatures. T-REX has been shown to be capable of traversing down 45 degrees slopes and obstacles in a lunar highland terrain simulant during system mobility testing. The on-board tether deployment system was able to unspool a superconducting tether (SCT) while maintaining controlled rates of under 5 N of tension. A data transfer rate of 94 Mbps via very-high-speed Digital Subscriber Line-2 and 132.2 W of DC power transfer over the SCT when cooled to 77 K was validated through testing. Thermal analyses on the system analytically validated the performance of T-REX during the transition between shaded and illuminated regions. The T-REX rover technology was raised to Technology Readiness Level 5 over 1.5 years of research. The SCTs are high-efficiency, low mass means of providing power and data in extreme lunar environments.

Future sustained human presence on the Moon will require us to make use of lunar resources. This in-situ resource utilisation (ISRU) process will require suitable feedstock (i.e., lunar regolith) that has been both acquired and prepared (or beneficiated) to set standards. Acquisition of pre-processed regolith, is an often overlooked engineering challenge in the demanding and low-gravity environment of the lunar surface. Currently, regolith excavation and size separation are often developed independently of each other. Here, we present the Lunar Excavation and Size Separation System (LES3), which is an engineered one-system solution to combine the acquisition of lunar regolith as well as separate it into two distinct size fractions, and therefore, can assist to define the quality of the feedstock material for ISRU processes. Intended for use with a lightweight (40-60 kg) lunar rover (LUnar Volatiles Mobile Instrumentation-X; LUVMI-X) currently under development, the mechanism utilises vibrations to reduce excavation forces and facilitate size separation. Low excavation forces are crucial for lunar excavators to be deployable on lightweight robotic platforms as limited traction forces are available. The rationale behind the mechanism is explained, its capabilities in the support of science and ISRU are showcased, and results from several laboratory test campaigns, including tests of gravitational dry sieving of different regolith simulants, are presented. The LES3 can excavate up to 100 g in a single charge while maintaining excavation forces of less than 8 N and having a mass of less than 2 kg. Finally, areas of improvement for a second iteration of the design are presented and explained. The LES3 proof of concept shows that combining of regolith excavation and size-separation in a single mechanism is feasible.

NASAs Volatiles Investigating Polar Exploration Rover (VIPER) will be the first robotic mission to prospect for water ice near the south pole of the Moon in late 2023 on a 100 Earth-day mission. The information that the VIPER rover provides will help improve understanding of the composition, distribution, and accessibility of Lunar polar volatiles and will help determine howthe Moons resources can support future human space exploration. VIPER, however, represents a radical departure from the way that NASA has traditionally developed planetary robotic missions. A key consequence of these differences is that estimating the cst of VIPERs rover software is challenging and complex. For example, VIPER is being developed using management procedures typically applied to NASA research and technology projects, rather than space flight programs. In addition, key portions of the rovers software are being designed as ground software to run on mission control computers (rather than on board the rover as flight software as with prior planetary missions) taking advantage of continuous, interactive data communications between the Moon and Earth and higher performance computing available on the ground. Moreover, the rovers software is being engineered using Agile software development practices and incorporates a significant amount of open-source code rather than following traditional (spir al, waterfall, etc.) development methods and mouse code. In this paper, we present an innovative process to estimate the life cycle cost of VIPERs rover software. We first describe how we modeled the architecture and code counts for three software elements: Rover Flight Software (RFSW), Rover Ground Software (RGSW), and Rover Simulation Software (RSIM). We then discuss key challenges and unique aspects of our approach, such as the lack of Lunar rover analogies, the need to integrate and test large opersource software, and the strategie developed to account for use of nonspace flight management practices and the impact of the COVID-19 pandemic We conclude with a summary of our results, including cumulative distribution, nearest neighbors and clusteanalysis, as well as heuristics used to confirm the reasonableness of the cost estimate.

Many large cold traps exist at both lunar poles where temperatures never exceed 110 K annually, allowing the preservation of water ice. Much has been learned about these regions from orbital measurements, but in situ access is needed to truly understand the abundance, distribution, texture, and chemistry of volatiles that might be present in the regolith. We systematically studied the accessibility of the larger cold traps to wheeled vehicles from nearby staging areas. We calculated minimum energy routes for 20 north pole cold traps and 39 south pole cold traps >50 km(2) in area. At each, accessibility metrics were determined for paths into and out of the cold trap and for round trip paths that return to the same location. We found that 55 of the 59 cold traps are readily accessible without exceeding 25 degrees slopes. Smaller cold traps are generally more accessible than larger ones, with certain exceptions. The accessibility data set is presented graphically, in tabular form, and as ArcGIS shapefiles, all of which can be used to inform site selection and mission planning for future scientific and resource-focused activities. Plain Language Summary There are certain areas at the poles of the Moon which are cold enough to host ice deposits, but they have never been studied directly by robots or astronauts. In this study we determined how easy or difficult it would be for wheeled vehicles to get into and back out of coldest areas at the poles, which are found in topographic lows that sometimes have high slopes all around. We found that most of the cold areas can be driven into and back out of safely to nearby staging areas that have enough sunlight to recharge batteries. The smaller cold areas are generally easier to access, but some of the larger ones have safe, fast routes, especially for entry.

In a new era of lunar exploration, pyroclastic deposits have been identified as valuable targets for resource utilization and scientific inquiry. Little is understood about the geomechanical properties and the trafficability of the surface material in these areas, which is essential for successful mission planning and execution. Past incidents with rovers highlight the importance of reliable information about surface properties for future, particularly robotic, lunar mission concepts. Characteristics of 149 boulder tracks are measured in Lunar Reconnaissance Orbiter Narrow Angle Camera images and used to derive the bearing capacity of pyroclastic deposits and, for comparison, mare and highland regions from the surface down to similar to 5-m depth, as a measure of trafficability. Results are compared and complemented with bearing capacity values calculated from physical property data collected in situ during Apollo, Surveyor, and Lunokhod missions. Qualitative observations of tracks show no region-dependent differences, further suggesting similar geomechanical properties in the regions. Generally, bearing capacity increases with depth and decreases with higher slope gradients, independent of the type of region. At depths of 0.19 to 5m, pyroclastic materials have bearing capacities equal or higher than those of mare and highland material and, thus, may be equally trafficable at surface level. Calculated bearing capacities based on orbital observations are consistent with values derived using in situ data. Bearing capacity values are used to estimate wheel sinkage of rover concepts in pyroclastic deposits. This study's findings can be used in the context of traverse planning, rover design, and in situ extraction of lunar resources. Plain Language Summary Future explorers will be visiting pyroclastic deposits for research and resource extraction. However, the properties of the surface are not well known and it is unclear how well vehicles and humans are able to travel across these areas. Properties of 149 boulder tracks are measured in spacecraft imagery and are used to derive estimations for the strength of pyroclastic, mare, and highland area material from the surface down to similar to 5-m depth. Results are compared and complemented with soil strength estimates that have been derived based on in situ measurements taken during previous lunar surface missions. In all regions of interest, tracks have similar appearances, implying that the surface material has comparable properties. Generally, soil strength increases with increasing depth and decreases with higher local slope angles. At depth, pyroclastic deposits show equal or significantly higher strength in comparison to mare and highland areas and, therefore, might be equally trafficable at surface level. Calculations based on globally distributed spacecraft images agree with values derived from Apollo-era in situ data. Based on the soil strength, the sinkage of rovers in the areas of interest is estimated. Potential applications of this work include rover design and mission planning, infrastructure construction, and resource extraction.