Water Ice Deposits Research Articles

Ice-mining lunar rover using Americium-241 radioisotope power systems

Permanently Shadowed Regions (PSRs) of the Moon contain rich deposits of water ice. They are very valuable to the space community as in-situ extracted water can be used for many purposes, such as propellant production and human habitat support. PSR craters never see sunlight, therefore solar power is not available there. They also present a cryogenic environment with regolith as cold as 40 K. These challenges can be overcome by employing a Radioisotope Power System (RPS) to provide both thermal and electrical power to resource extraction systems in the PSRs. The work presented here aims at characterizing an ice-mining lunar rover. The rover will be equipped with an Americium-241 (or 241Am) based RPS. 241Am has a 432-year long half-life and can provide decades of stable power output for the rover operations. The innovation lies in the fact that the RPS will not only provide electrical power to the rover, but that its waste heat will be employed to thermally mine ice from its deposits. The rover is equipped with a sublimation plate irradiating the underlying regolith to sublimate ice contained within, and with a cold trap where extracted volatiles will be deposited. This work studied the rover concept feasibility and developed a model of its Thermal Management System (TMS) to meet sublimation plate and cold trap temperature requirements. The results have been validated by a 3D finite element method thermal simulation for icy regolith conditions of 0–10 vol% water-ice content. The findings of this work suggest that it is possible to perform thermal ice-mining in the lunar PSR environment with an RPS-powered rover, with different degrees of efficiencies depending on the amount of ice in the deposits.

The Faustini Permanently Shadowed Region on the Moon

Faustini crater (41 km diameter) hosts a large (664 km2) permanently shadowed region (PSR) with a high potential to harbor water-ice deposits. One of the 13 candidate Artemis III landing areas contains a portion of the crater rim and proximal ejecta. The ShadowCam instrument aboard the Korea Pathfinder Lunar Orbiter provides detailed images of the PSR within Faustini. We characterize the terrain and thermal environment within the Faustini PSR from ShadowCam images, Lunar Reconnaissance Orbiter thermal measurements and laser ranging, and thermal modeling. Our mapping revealed three distinct areas of the floor of Faustini based on elevations, slopes, and surface roughness. These units broadly correlate with temperatures; thus, they may be influenced by variations in volatile sublimation. Crater retention and topographic diffusion rates appear to be asymmetric across the floor, likely due to differences in maximum and average temperatures. Several irregular depressions and a pronounced lobate-rim crater are consistent with subsurface ice. However, differences in the thicknesses of deposited materials on the floor may also explain the asymmetry. Additionally, zones of elevated surface roughness across Faustini appear to result from overprinted crater ray segments, possibly from Tycho and Jackson craters. Mass wasting deposits and pitting on opposite sides of the crater wall may have resulted from the low-angle delivery of material ejected by the Shackleton crater impact event, suggesting that the Artemis III candidate landing region named “Faustini Rim A” will contain material from Shackleton.

Geomorphology of craters located at Mercury’s north pole

Geomorphology of craters located at Mercury’s north pole

On the reachability and genesis of water ice on the Moon

Understanding the reachability of water ice by future in-situ experiments near the lunar poles is crucial for supporting growing exploration plans and constraining the uncertainties on its genesis and distribution. To achieve this objective, we perform a thorough three-dimensional mapping of the distribution of water ice in the lunar polar regions (70° onward), integrating radar, optical, and neutron detector observations from the Lunar Reconnaissance Orbiter mission (LRO). Our analysis reveals ∼5-to-8-fold larger expanse of subsurface water ice (∼1-3 m depth) compared to surface water ice (up to 1 m depth) for the north and south poles, respectively. Our investigation cannot rule out the possibility of deep-seated water ice deposits in the lunar poles that remains beyond the detection capabilities of existing instruments on LRO. Moreover, we find that the extent of water ice in the northern polar region (∼1100 ± 74 km2) is twice that in the southern polar region (∼562 ± 54 km2). Our mapping also suggests that the dichotomous latitudinal distribution and the antipodal longitudinal distribution of water ice are likely driven by Mare volcanism and preferential cratering. We provide additional evidence that outgassing during Imbrian volcanism was probably the primary source of subsurface water ice in the lunar poles, which favors larger expanse over meteoritic sources.

Autonomous Robotic Capabilities in Space Exploration: From Mars to Beyond

The historical timeline of automated systems functioning in space settings spans around 75 years, whereas the existence of practical automated equipment to facilitate astronomical observation dates back over 200 years. Over time, physical servomechanisms have seen advancements in both hardware and software capabilities, enabling their successful operation on the Martian surface and even during journeys to the heliopause, which marks the outer boundary of interstellar space. Contemporary spaceflight operations exemplify a growing capacity to provide decentralized coordination across several automated systems, intricate communication networks, and diverse communities of scientists and engineers. This article examines the impact of autonomous robotic functionalities on space explorations, specifically emphasizing the investigation of Mars' surface. The article examines the use of robotic systems in past missions, specifically focusing on their application in activities like as the identification and analysis of water ice deposits, study of geological features, and the deployment of sensor devices. The article further emphasizes the achievements of autonomous operations in missions conducted in Earth's orbit, as well as the progress made in developing autonomy for operations in close vicinity to minor celestial bodies. This research explores the Chang'e 4 lunar mission and the OSIRIS-REx mission as instances of autonomous exploration and sample gathering on minor celestial bodies. The research also encompasses the exploration of prospective autonomy in forthcoming expeditions to oceanic realms and distant locales.

Low-Thrust Nonlinear Orbit Control for Very Low Lunar Orbits

In the next decades, both space agencies and private competitors are targeting the lunar environment as a scientific and technological resource for future space missions. In particular, the confirmed existence of water-ice deposits in the vicinity of the poles (predominantly the south pole) makes polar or near-polar low lunar orbits attractive for the purpose of designing space missions that could search for suitable Lunar base sites. However, traveling very-low-altitude orbits is very challenging, as they are strongly perturbed by the Moon’s gravity field as well as third- and fourth-body effects due to the Earth and the Sun. Several studies demonstrate that these orbits are expected to impact the lunar surface in a few months. Therefore, the definition and implementation of an effective station-keeping strategy represents a crucial issue in order to extend satellites’ lifetime. In this paper, a feedback nonlinear control law is employed in order to perform corrective maneuvers aimed at keeping the state of the satellite within acceptable margins. The satellite is assumed to be equipped with a steerable and throttleable low-thrust propulsion system. The control law is based on the Lyapunov stability theory and does not require any reference path to track, with a considerable decrease in the computational cost. The proposed real-time control law includes control saturation, related to the maximum available thrust magnitude, and is developed employing modified equinoctial elements, in order to avoid singularities and extend its range of application. Finally, the strategy at hand is tested in the presence of all the relevant perturbations (i.e., harmonics of the selenopotential, third- and fourth-body effects) in order to show its effectiveness and efficiency.

Radar Observations of Liquid Water in the South Polar Region of Mars: Indications from Astrobiology Perspectives

In recent decades, extensive research has led to the understanding that Mars once hosted substantial liquid-water reserves. While the current Martian landscape boasts significant water-ice deposits at its North and South poles, the elusive presence of liquid-water bodies has remained undetected. A breakthrough occurred with the identification of radar-echo reflections at the base of the Martian South Pole, using MARSIS (Mars Advanced Radar for Subsurface and Ionospheric Sounding) in 2018. These radar echoes strongly suggest the presence of a highly concentrated liquid-water body. However, a counter-narrative has emerged, contending that the subterranean conditions beneath the ice cap, encompassing factors like temperature and pressure, may be inhospitable to liquid water. Consequently, alternative hypotheses posit that the observed bright echoes could be attributed to conductive minerals or water-absorbing clay-like materials. The ongoing discourse regarding the presence of liquid water beneath the southern polar ice cap is a hot topic in the realm of Martian exploration. The primary focus of this paper is to provide a comprehensive overview of Martian radar detection, the recent controversies regarding liquid water’s existence in the Martian South Pole, and the implications regarding the potential existence of Martian life forms in the water on Mars. The revelation of liquid water on Mars fundamentally suggests an environment conducive to the viability of Martian life, consequently furnishing invaluable insights for future exploratory endeavors in the pursuit of Martian biospheres. In addition, this paper anticipates the forthcoming research dedicated to Martian liquid water and potential life forms, while also underscoring the profound significance of identifying liquid water on Mars in propelling the field of astrobiology forward.

Thermal Environments and Volatile Stability Within Lunar Pits and Caves

AbstractLunar collapse pits and possible caves have been suggested as ideal locations for the storage and protection of lunar water ice deposits, due to their potential to create permanently shadowed regions (PSRs) at high latitudes and ability to protect ice from destructive surface processes. However, the thermal environments of these features have not been investigated at high latitudes, and it remains unclear what effects pit latitude and geometry would have on interior temperatures and ice stability. We create a 3D thermal and volatile transport model and use it to characterize the thermal environments and volatile‐trapping potential within lunar collapse pits and caves. We model the thermal behavior of lunar pits as it varies with latitude for several different pit geometries. We then apply the thermal model results to the volatile transport model and calculate water loss rates to space given an initial ice deposit. The model shows that in general, high‐latitude pits make poor cold traps for ice because their enclosed geometry increases the ability of multiple‐scattered infrared radiation to elevate pit interior temperatures. Although, the enclosed geometry of a cave might help trap volatiles in theory, in practice ice stability within pits and caves is primarily controlled by temperature and not geometric effects. We find that ice loss rates are higher within pits and caves than within PSRs of craters at similar latitudes. Nevertheless, some specific situations arise where pits can act as effective cold traps, such as when pits lie within PSRs created by exterior topography.

Synergistic use of remote sensing data and in-situ investigations to characterize the lunar surface

This review article provides an overview of various aspects of lunar exploration, including missions to the Moon, collection and analysis of lunar sample data in laboratories, and the processing and analysis of remote sensing data, particularly using radar techniques. Both remote sensing and in-situ methods are critical for advancing our understanding of the lunar surface and its properties. This review article focuses on the identification and quantification of water–ice deposits located in areas such as Permanently shadowed areas (PSRs) and the lunar poles (section “Lunar Poles and PSRs: A Special Environment”). These volatile resources have the potential to serve as valuable sources of fuel for future missions, making it crucial for the lunar community to determine their abundance and distribution. After thoroughly examining lunar samples using high-precision laboratory techniques, many preconceptions were dispelled which is highlighted in the section “Laboratory Investigation of Lunar samples”. But as in-situ observations are difficult to acquire, especially terrestrial bodies samples, remote sensing techniques allow the global understanding of the surface. The article specifically highlights the importance of understanding the electrical characteristics of the lunar surface and how radar inversion can provide valuable information in this regard. The “Conclusion” section of this review article serves as a key takeaway for readers, underscoring the critical role that both in-situ and remote sensing techniques play in advancing our understanding of the Moon.

Water extraction from icy lunar simulants using low power microwave heating

Identifying the best technique for extracting water ice deposits in permanently shadowed regions at the lunar poles will be crucial in determining how successful a long-term or permanent settlement at these locations will be for future scientific and technology missions. This study uses a low-power microwave heating method to extract water from icy lunar simulants. Samples of lunar highland and mare simulants at different water contents (3–15 wt %) were heated using 250 W, 2.45 GHz microwaves. A maximum of 67 ± 5% [2SD] of the water was extracted during heating runs of 25 min. Water was extracted more efficiently from the highland simulant than from the mare simulant. A significant reason for the different efficiency of water extraction in icy lunar simulants was the differing porosity of the samples made from different simulants. Pore space filled with ice leads to a reduced contact area between grains and an increased area of free ice, which causes poor heating performance. The results indicated that differences in chemical composition between the simulants had a negligible effect on water extraction, as the contact area between grains seems to dominate water extraction. This study found that low-power microwave heating is an effective technique for extracting water from cryogenic Icy simulants. It was also found that using a simple input energy principle (Input Energy = Absorbed Power x Heating Time) to estimate the additional heating time was sufficient to overcome inefficient heating due to differing absorbed powers. For undersaturated samples, microwave heating was an efficient heating mechanism, but is less efficient for saturated samples where alternative heating methods may be more efficient at melting free ice before employing microwave heating.

Ice-assisted electron-beam lithography for halide perovskite optoelectronic nanodevices

Metal halide perovskites (MHPs) have received substantial attention due to their impressive optoelectronic properties. In particular, nanoscale perovskite structures, such as nanowires (NWs) and nanoplates (NPs) are ideal building blocks for optoelectronic devices. However, metal electrodes can be hardly patterned on these materials with conventional lithographic methods due to the solvent sensitivity of perovskite crystals and alignment issues. Here, we report a solvent-free method to fabricate metal electrodes on perovskite NPs, which starts with the vapor deposition of water ice as an electron resist and ends in the sublimation of the ice followed by a “blow-off” process. The good compatibility between MHPs and ice as well as the in-situ imaging and patterning process guarantees the fabrication with high precision and resolution. Using this technique, we create metal electrodes on single-crystal MAPbBr3 NPs featuring a nanoscale gap of 296 nm and superior photodetection ability with responsivity of 653 A/W and detectivity of 3.08 × 1013 Jones. Our study helps the widely-used electron-beam lithography break down barriers in processing perovskite materials, and provides an excellent platform to fully exploit their potentials in optoelectronic devices.

Dielectric characterization and polarimetric analysis of lunar north polar crater Hermite-A using Chandrayaan-1 Mini-SAR, Lunar Reconnaissance Orbiter (LRO) Mini-RF, and Chandrayaan-2 DFSAR data

Studies of the lunar surface from Synthetic Aperture Radar (SAR) data have played a prominent role in the exploration of the lunar surface in recent times. This study uses data from SAR sensors from three Moon missions: Chandrayaan-1 Mini-SAR, Lunar Reconnaissance Orbiter (LRO) Mini-RF and Chandrayaan-2 Dual Frequency Synthetic Aperture Radar (DFSAR). DFSAR sensor is the first of its kind to operate at L-band and S-band in fully and hybrid polarimetric modes. Due to the availability of only L-band data out of the two bands (L-and S-band) for the study site, this study only used DFSAR's L-band data. The dielectric characterization and polarimetric analysis of the lunar north polar crater Hermite-A was performed in this study using Chandrayaan-1 Mini-SAR, LRO Mini-RF and Chandrayaan-2 DFSAR data. Hermite-A lies in the Permanently Shadowed Region (PSR) of the lunar north pole and whose PSR ID is NP_879520_3076780. Because of its location within the PSR of the lunar north pole, the Hermite-A makes an ideal candidate for a probable location of water-ice deposits. This work utilizes S-band hybrid polarimetric data of Mini-SAR and Mini-RF and L-band fully polarimetric data of DFSAR for the lunar north polar crater Hermite-A. This study characterizes the scattering mechanisms from three decomposition techniques of Hybrid Polarimetry namely m-delta, m-chi, and m-alpha decompositions, and for fully polarimetric data Barnes decomposition technique was applied which is based on wave dichotomy. Eigenvector and Eigenvalue-based decomposition model (H-A-Alpha decomposition) was also applied to characterize the scattering behavior of the crater. This study utilizes the hybrid-pol and fully polarimetric data-based Integral Equation Model (IEM) to retrieve the values of dielectric constant for Hermite-A crater. The dielectric constant values for the Hermite-A crater from Chandrayaan-1 Mini-SAR and LRO Mini-RF are similar, which goes further in establishing the presence of water-ice in the region. The values of the dielectric constant for Chandrayaan-2 in some regions of the crater especially on the left side of the crater is also around 3 but overall the range is relatively higher than the compact/hybrid polarimetric data. The dielectric characterization and polarimetric analysis of the Hermite-A indicatively illustrate that the crater may have surface ice clusters in its walls and on some areas of the crater floor, which can be explored in the future from the synergistic use of remote sensing data and in-situ experiments to confirm the presence of the surface ice clusters.

Arecibo S-band Radar Characterization of Local-scale Heterogeneities within Mercury’s North Polar Deposits

Abstract Ground-based planetary radar observations first revealed deposits of potentially nearly pure water ice in some permanently shadowed regions (PSRs) on Mercury’s poles. Later, the MESSENGER spacecraft confirmed the icy nature of the deposits, as well as their location within PSRs. Considering the geologic context provided by MESSENGER, we further characterized the north polar deposits by pairing spacecraft data with new Arecibo S-band radar observations. Here we show that some ice deposits within PSRs have a gradational pattern in their radar properties that is likely associated with differences in ice purity. Radar-bright features with a circular polarization ratio μ c > 1 can be characterized by water ice with ≳3% impurities by volume while those with μ c < 1 by ≳20% impurities. Furthermore, areas in PSRs with μ c < 1 typically surround locations of stronger radar backscatter with μ c > 1. Therefore, deposits of nearly pure water ice are likely surrounded by lower-purity material, such as water-ice-rich regolith, which could be the result of impact gardening or the crater’s thermal environment. However, such deposits are not always colocated within large polar craters where ice should be the most stable, even at the surface. In fact, we found that there is no significant difference between the radar backscattering properties of deposits thought to have surficial ice and those with buried ice. Our results also help improve the identification of icy reservoirs elsewhere, such as the Moon. Indeed, we found that μ c is not an adequate diagnostic, but rather the radar backscatter in each circular polarization independently provides information to identify water-ice deposits.

Challenges of operating a drilling instrument on a small rover at the lunar poles - LVS-PIE phase A study results

The “LVS-PIE Phase A″ project successfully investigated the feasibility of using the Lunar Volatiles Scout instrument on the ispace Polar Ice Explorer rover to search for possible cold-trapped water ice deposits at the lunar poles. The suitability of the two systems for a joint mission was studied based on identified conflicts between both initial systems, such as the envelope for integration or the power budget. The interfaces were made compatible, mechanical structure and mechanisms were updated to enable system integration and thermal simulations were performed to refine the thermal design for safe operation within the thermal limits under lunar conditions. Thermal extraction simulations for the instrument constrained the power requirement during the instrument's heating phase. Real drilling down forces and reaction torques were determined with representative experiments for both rover and instrument revealing stable conditions during the envisioned drilling process. In the developed mission scenario, operational feasibility of the LVS-PIE mission concept was demonstrated using a notional traverse, remote sensing data and investigation of technical budgets. The mission can reach sites of high scientific interest at the lunar poles and perform relevant measurements with the instrument. A joined mission consisting of an instrument package for drilling and gas analysis on a rover below 20 ​kg total mass is found to be technically feasible and scientifically valuable.

Resource potential of lunar permanently shadowed regions

The lunar polar regions contain permanently shadowed regions (PSRs) or local topographic depressions that never receive direct sunlight. These environments (<110 K) have the potential to cold-trap volatile materials in the form of ice, which are essential resources for exploration and industrialization of cislunar space and the Solar System. Orbital observations and those from the LCROSS impactor experiment provide evidence of the existence of water ice and other cold-trapped volatiles in PSRs; however, constraints on volatile abundance and distribution remain ambiguous as individual observations are not always in concord. Here we compile observations indicating the presence of volatiles from ten remotely sensed datasets in 65 PSRs to estimate the locations and mass of water ice deposits. Faustini, Cabeus, de Gerlache, Shoemaker, Haworth, Sverdrup, Slater, and Amundsen are likely the most resource-rich PSRs. Based on co-locations of observations indicative of surface frost and subsurface hydrogen abundance, we find that the craters with the highest potential mass in metric tons (t) of water ice include Cabeus (~11 × 106 t), Shoemaker (~5 × 106 t), Faustini (~4 × 106 t), de Gerlache (~3 × 106 t), and Haworth (~3 × 106 t). Future prospecting of lunar volatiles and water ice is contingent on filling knowledge gaps in resource potential, notably accurate measurements of grade and depth of volatiles. Our proposed ranking and estimates for resource tonnage are a tool to guide future orbital and landed missions that could accurately determine the resource potential of PSR deposits.

Water Group Exospheres and Surface Interactions on the Moon, Mercury, and Ceres

Water ice, abundant in the outer solar system, is volatile in the inner solar system. On the largest airless bodies of the inner solar system (Mercury, the Moon, Ceres), water can be an exospheric species but also occurs in its condensed form. Mercury hosts water ice deposits in permanently shadowed regions near its poles that act as cold traps. Water ice is also present on the Moon, where these polar deposits are of great interest in the context of future lunar exploration. The lunar surface releases either OH or H2O during meteoroid showers, and both of these species are generated by reaction of implanted solar wind protons with metal oxides in the regolith. A consequence of the ongoing interaction between the solar wind and the surface is a surficial hydroxyl population that has been observed on the Moon. Dwarf planet Ceres has enough gravity to have a gravitationally-bound water exosphere, and also has permanently shadowed regions near its poles, with bright ice deposits found in the most long-lived of its cold traps. Tantalizing evidence for cold trapped water ice and exospheres of molecular water has emerged, but even basic questions remain open. The relative and absolute magnitudes of sources of water on Mercury and the Moon remain largely unknown. Exospheres can transport water to cold traps, but the efficiency of this process remains uncertain. Here, the status of observations, theory, and laboratory measurements is reviewed.

Morphometry and Temperature of Simple Craters in Mercury’s Northern Hemisphere: Implications for Stability of Water Ice

Abstract Multiple lines of evidence support the hypothesis that Mercury’s polar regions host deposits of water ice in permanently shadowed regions, often within the interiors of craters. Pre-MErcury, Surface, Space, ENvironment, GEochemisty, and Ranging (MESSENGER) thermal modeling of the temperature of idealized simple craters found that the interiors of these craters were too hot to host near-surface ice on geologic timescales unless within 2° of the poles. However, results from the Arecibo Observatory and the MESSENGER mission identified many small, &lt;10 km diameter, simple craters that host radar-bright deposits located considerably farther than 2° from the pole. Here we investigate the location and morphometry of north polar craters with diameters of 5–10 km and find that the craters were, on average, 30% shallower than the idealized simple crater morphometry assumed in previous thermal studies. The craters that host radar-bright deposits have an asymmetric longitudinal distribution that cannot be fully explained by the thermal environment and may be related to the original water ice deposition. We also investigate the maximum and average temperatures of the shadowed regions in these craters and find that many of them possess temperatures that allow water ice to be stable under a thermally insulating layer on geologic timescales outside of 2° from the pole. Thus, while the presence of radar-bright deposits in 5–10 km craters is not necessarily a constraint on the stability of the deposits, it provides additional information on the distribution and deposition of the water ice.

Taxonomic Characterization and Microbial Activity Determination of Cold-Adapted Microbial Communities in Lava Tube Ice Caves from Lava Beds National Monument, a High-Fidelity Mars Analogue Environment.

Martian lava tube caves resulting from a time when the planet was still volcanically active are proposed to contain deposits of water ice, a feature that may increase microbial habitability. In this study, we taxonomically characterized and directly measured metabolic activity of the microbial communities that inhabit lava tube ice from Lava Beds National Monument, an analogue environment to martian lava tubes. We investigated whether this environment was habitable to microorganisms by determining their taxonomic diversity, metabolic activity, and viability using both culture-dependent and culture-independent techniques. With 16S rRNA gene sequencing, we recovered 27 distinct phyla from both ice and ice-rock interface samples, primarily consisting of Actinobacteria, Proteobacteria, Bacteroidetes, Firmicutes, and Chloroflexi. Radiorespiration and Biolog EcoPlate assays found these microbial communities to be metabolically active at both 5°C and -5°C and able to metabolize diverse sets of heterotrophic carbon substrates at each temperature. Viable cells were predominantly cold adapted and capable of growth at 5°C (1.3 × 104 to 2.9 × 107 cells/mL), and 24 of 38 cultured isolates were capable of growth at -5°C. Furthermore, 14 of these cultured isolates, and 16 of the 20 most numerous amplicon sequences we recovered were most closely related to isolates and sequences obtained from other cryophilic environments. Given these results, lava tube ice appears to be a habitable environment, and considering the protections martian lava tubes offer to microbial communities from harsh surface conditions, similar martian caves containing ice may be capable of supporting extant, active microbial communities.

Lunar thermal mining: Phase change interface movement, production decline and implications for systems engineering

Thermal mining is a promising architecture, which may provide reliable and ‘dirt-simple’ means of production of space-sourced water, oxygen and rocket propellant in the future. It is especially tailored to water ice deposits that exist within lunar Permanently Shadowed Regions, where our quest for riches of the Outer Space might begin.Here, the thermal mining extraction system is simulated and analysed with combined heat and mass transfer FEM modelling. The results exhibited that water extraction on the Moon might follow specific production phases, which closely relate to changes in the sublimation interface movement over large timeframes. The production behaviour on the Moon might have many characteristics of relevant production systems on Earth. This may open door for many well-established terrestrial models and production projections to be refitted to extraterrestrial case.It was found that the required water yields of the thermal mining architecture, which make its case economically and commercially viable, are hard to reach without production optimization and new systems development. The production is projected to be significantly hindered by sublimation lag build-up, which would create thermal insulation for the icy deposits. Sublimation lag removal and other strategies might be the answer to that problem.

Availability of subsurface water-ice resources in the northern mid-latitudes of Mars

Multiple nations and private entities are pushing to make landing humans on Mars a reality. The majority of proposed mission architectures envision ‘living off the land’ by leveraging Martian water-ice deposits for fuel production and other purposes. Fortunately for mission designers, water ice exists on Mars in plentiful volumes. The challenge is isolating accessible ice deposits within regions that optimize other preferred landing-site conditions. Here we present the first results of the Mars Subsurface Water Ice Mapping (SWIM) project, which has the aim of searching for buried ice resources across the mid-latitudes. Through the integration of orbital datasets in concert with new data-processing techniques, the SWIM project assesses the likelihood of ice by quantifying the consistency of multiple, independent data sources with the presence of ice. Concentrating our efforts across the majority of the northern hemisphere, our composite ice-consistency maps indicate that the broad plains of Arcadia and the extensive glacial networks across Deuteronilus Mensae match the greatest number of remote-sensing criteria for accessible ice-rich, subsurface material situated equatorwards of the contemporary ice-stability zone.