Characterization and Feasibility of Lunar Landing Sites: The Ingenii Basin Case

CHARACTERIZATION AND FEASIBILITY OF LUNAR LANDING SITES: THE INGENII BASIN CASE. G. Tognon1, R. Pozzobon1, G. Melchiori2, and M. Massironi1,2, 1Department of Geosciences, University of Padua, via Gradenigo 6, 35131 Padua ([email protected]), 2Center of Studies and Activities for Space “G. Colombo”, University of Padua, via Venezia 15, 35131 Padua. Introduction: In terms of lunar exploration, the South Polar Region and underground cave systems are considered prime locations for future exploration and development of human settlements. In the first case, the polar region represents an optimal location for permanently shadowed regions constituting volatile reservoirs containing also water ice [e.g. 1] as well as for their antithesis, namely permanently illuminated areas beneficial for a suitable thermal environment and access to solar energy. Lunar caves, on the other side, represent an alternative habitat solution being natural shelters against the space environment providing stable temperatures and, likely, dustfree environments [e.g. 2]. The renewed interest in the exploration of the Moon, both human and robotic, and the technological advancement made it more feasible to look at sites previously underrated for the paucity of highresolution data available (e.g. polar regions) and the challenges in communication (e.g. far side, accessibility and trafficability (e.g. caves). Here, we performed a geological characterization of a case scenario within the far side mare-flooded Ingenii basin (20.4°S, 129.1°E) considering a robotic mission with a rover-hopper [e.g. 3]. The Ingenii basin, indeed, represents a unique lunar case presenting both extensive and complex swirls, namely features related to crustal magnetic anomalies [4,5,6], and a pit with overhanging roof possibly giving access to a lava tube [e.g. 7]. Data: We used the highest quality remote sensed data available for our case scenario. In particular, we used the Lunar Reconnaissance Orbiter Wide Angle Camera (LRO-WAC) monochrome mosaic (~100 m/px) [8] and the Clementine UVVIS Warped Color Ratio mosaic (~200 m/px) [9] for a contextual geological and compositional interpretation of the area. We then used LRO Narrow Angle Camera (NAC) images (up to 0.5 m/px) [8] for a detailed characterization of the area surrounding the pit. The Lunar Orbiter Laser Altimeter (LOLA) and Kaguya TC merged Digital Elevation Model (DEM) provide the most up-to-date surface height and slope information (vertical accuracy of 3-4 m) [10] and a NAC-derived Digital Terrain Model (DTM) provides the best available elevation data for the area surrounding the pit. Methods: We characterized the area of interest and analyzed the feasibility of landing and roving using the open-source QGIS software. We then quantitatively assessed the topographical characteristics of the surface within a reasonable distance from the pit for the positioning of landing ellipses. Using a machine learning algorithm and LRO-NAC imagery [11], we also identified boulders within the landing ellipses. Starting from the landing ellipses, we then identified several traverse paths and evaluated slope and elevation variations along the paths taking into account engineering constraints considered during previous lunar rover missions. Finally, we performed simulations of the environmental conditions (i.e. illumination, Sun and Earth visibility, temperature) along each traverse path through an interactive tool provided by LROC Quickmap. Results: Firstly, we performed a geological characterization of the area surrounding the Mare Ingenii pit (35.9°S, 166.0°E) and identified several possible scientific targets of interest (e.g. boulders for rock sampling). Based on the statistical parameters of elevation and slope variations, we identified at least three optimal landing sites considering areas of 1500 and 500 m in diameter within 4 km from the pit. Within each landing ellipse, we then automatically detected boulders > 1 m and calculated their size-frequency distribution. Originating from the landing areas, we planned short (up to 5 km), intermediate-length (up to 10 km) and long (up to 15-20 km) traverses considering a typical slope tolerance of maximum 15°. All traverses take into account a hopping phase within the pit to explore its cave system and study its environmental conditions in terms of habitability and In-Situ Resource Utilization (ISRU). For each traverse, we considered a buffer zone of 10 m in order to account for possible unforeseen hazardous elements and avoidance, and produced elevation profiles and slope variation diagrams. Finally, we identified a mission operating window based on illumination and temperature conditions over a lunar day. Conclusions: The Ingenii basin case scenario sure entails a major effort in communicating with Earth given its location on the lunar far side, however, it is an issue that can be overcome as China’s Chang’e missions demonstrated. Being characterized by a smooth basaltic infilling, optimal for landing and roving, and primary scientific targets of interest, such as the enigmatic lunar swirls and a pit, the Ingenii basin represents a high-profile objective for the future exploration of the Moon. In this study, we characterized the area surrounding the Mare Ingenii pit and performed a feasibility study considering traverses of varying lengths, all providing for a hopping phase inside the pit, and simulated the environ- mental conditions along their paths. To conclude, we also identified the plausible payload needed onboard the lander and rover-hopper. 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