Surface Of The Moon Research Articles

Geological evidence for extensive basin ejecta as plains terrains in the Moon’s South Polar Region

Water ice and other volatiles that accumulated in the Moon’s polar regions are among the top priority targets for lunar exploration, due to their significances in both lunar geology and extraterrestrial resource utilization. Locating suitable landing sites and determining the provenance of sampled/measured surface materials are critical for future landed missions. Here, we map over 800 sites of plains terrains in the Moon’s south polar region, with a total surface area of ~46,000 km2. Orbital measurements and analog studies show that most of these plains have apparently higher albedo and lower iron content than volcanic mare plains, suggesting an origin of ejecta-induced debris flows from distant impact craters, especially from the Schrödinger basin. Our findings suggest that the entire lunar south polar region probably have experienced contributions from distant basin materials. We recommend these plains as priority landing sites for future exploration of lunar polar volatiles and early bombardment history.

Lunar distress communications: Interoperability, frequencies, and harmful interference, which normative model for the artemis accords?

A new space era begins with the Artemis Accords. These will allow the return of humans to the Moon. The starting point of this historic period was marked by the signing of this international agreement on October 13, 2020. Eight States are at the origin of these accords: the United States of America, Australia, Canada, Italy, Japan, Luxembourg, the United Arab Emirates, and the United Kingdom. Since then, thirteen other governments – including France – have joined this international space program led by NASA. Artemis will require the implementation of a new communication architecture called “LunaNet”, encompassing the search and rescue service known as “LunaSAR”. Therefore, like on Earth, on the Moon, search and rescue of people in distress will require the interoperability of international communications. From a legal point of view, the Artemis Accords are based on existing space law, particularly the 1967 Outer Space Treaty. According to this, Lunar missions shall be conducted for peaceful purposes. Transparency in the implementation of international partnerships is another key principle of this space program. From this, at the operational level, interoperability of the systems based on existing or future standards naturally follows. Beyond the technical or commercial aspects, what takes precedence over all other considerations is the safety of the astronauts working for the completion of the Artemis program. Thus, generally, the possible assistance brought to the astronauts in distress is foreseen in the United Nations treaties and principles on outer space. Regarding the implementation of the Artemis program, personnel will operate on board a spacecraft, a space station, or from the surface of the Moon. This is why NASA plans to implement the Astronaut's Lunar Lifeline, known as Lunar Search and Rescue or LunaSAR. Integrated with the LunaNet system, this system will assist workers in distress. In this study, therefore, we will focus on standards for communications interoperability, in the context of search and rescue of persons in distress. To do so, we will examine the Artemis program through the lens of satellite-assisted Earth search and rescue principles and techniques. In particular, we will focus on the COSPAS-SARSAT alerting service and the International Aeronautical and Maritime Search and Rescue (IAMSAR) Manual. In this context, issues such as, for example, the implementation of the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies of 1967, the Agreement on the Rescue of Astronauts, the Return of Astronauts and the Return of Objects Launched into Outer Space of 1968 and the Agreement Governing the Activities of States on the Moon and Other Celestial Bodies of 1979 as well as the protection of SAR frequencies and potential harmful interference will be addressed.

Exploratory habitation vehicles with trim intrinsic control

AbstractConsidering the space environment and its critical issues and consequent risks, the challenge is to define the way and tools with which future astronauts will be able to act, live and work in space and, in particular on the Moon and Mars, exploiting, at the state of art, knowledge of innovative science, engineering and technology. On the Moon and Mars, the most obvious environmental factors are extreme temperature fluctuations, low gravity and the virtual absence of atmosphere and magnetosphere. The health of a human body can be damaged by reduced values of gravity. Due to the reduced gravity on the Moon and Mars, human bones and muscles are unloaded and begin to weaken. It increases the risk of bone fractures and atrophied muscles for astronauts returning to Earth from prolonged missions. The magnetosphere and atmosphere on Earth shield from much of the dangerous solar and cosmic radiation. Radiation with extremely high energies can damage even living tissue. The surface of the Moon and Mars has been crushed by millions of impacts of celestial bodies such as asteroids, leaving a layer of regolith that could be very deep depending on the areas of the planets. The habitation module, described in this paper, is carried by a vehicle equipped with two pairs of compass shaped legs that act as supports for the habitation module capable of maintaining a certain controlled height with respect to the ground as well as a horizontal attitude, during the movement of the compass. A system of ropes wound on pulleys allows to control the height of the habitat with respect to the ground, control the structure in movement, descent and ascent. The habitat can also be lowered to the ground. The geometry of the shape of the pulleys, around which the ropes are wound, is determined in such a way that the habitation module remains at a certain height during the movement defined by the two compass-shaped advancement supports. The paper describes and analyzes the movement of the pulleys during the entire phase of the movement of the habitation module and their geometric shape is discussed.

Exploring beyond Earth using space robotics.

Robotic spacecraft enable exploration of our Solar System beyond our human presence. Although spacecraft have explored every planet in the Solar System, the frontiers of space robotics are at the cutting edge of landers, rovers, and now atmospheric explorers, where robotic spacecraft must interact intimately with their environment to explore beyond the reach of flyby and orbital remote sensing. Here, we describe the tremendous growth in space robotics missions in the past 7 years, with many new entities participating in missions to the surface of the Moon, Mars, and beyond. We also describe the recent development of aerial missions to planets and moons, as exemplified by the Ingenuity helicopter on Mars and the Dragonfly mission to Titan. We focus on suborbital robotics-landers, rovers, and aerial vehicles-with associated challenges in sensing, manipulation, mobility, and system-level autonomy.

Lunar Lithium-7 Sensing (δ7Li): Spectral Patterns and Artificial Intelligence Techniques.

Lithium, a critical natural resource integral to modern technology, has influenced diverse industries since its discovery in the 1950s. Of particular interest is lithium-7, the most prevalent lithium isotope on Earth, playing a vital role in applications such as batteries, metal alloys, medicine, and nuclear research. However, its extraction presents significant environmental and logistical challenges. This article explores the potential for lithium exploration on the Moon, driven by its value as a resource and the prospect of cost reduction due to the Moon's lower gravity, which holds promise for future space exploration endeavors. Additionally, the presence of lithium in the solar wind and its implications for material transport across celestial bodies are subjects of intrigue. Drawing from a limited dataset collected during the Apollo missions (Apollo 12, 15, 16, and 17) and leveraging artificial intelligence techniques and sample expansion through bootstrapping, this study develops predictive models for lithium-7 concentration based on spectral patterns. The study areas encompass the Aitken crater, Hadley Rima, and the Taurus-Littrow Valley, where higher lithium concentrations are observed in basaltic lunar regions. This research bridges lunar geology and the formation of the solar system, providing valuable insights into celestial resources and enhancing our understanding of space. The data used in this study were obtained from the imaging sensors (infrared, visible, and ultraviolet) of the Clementine satellite, which significantly contributed to the success of our research. Furthermore, the study addresses various aspects related to statistical analysis, sample quality validation, resampling, and bootstrapping. Supervised machine learning model training and validation, as well as data import and export, were explored. The analysis of data generated by the Clementine probe in the near-infrared (NIR) and ultraviolet-visible (UVVIS) spectra revealed evidence of the presence of lithium-7 (Li-7) on the lunar surface. The distribution of Li-7 on the lunar surface is non-uniform, with varying concentrations in different regions of the Moon identified, supporting the initial hypothesis associating surface Li-7 concentration with exposure to solar wind. While a direct numerical relationship between lunar topography and Li-7 concentration has not been established due to morphological diversity and methodological limitations, preliminary results suggest significant economic and technological potential in lunar lithium exploration and extraction.

Accurate Mapping and Evaluation of Small Impact Craters within the Lunar Landing Area

Impact craters, as the most distinct lunar structural unit and geological structure, are marked on the Moon’s surface. For over a decade, researchers have focused on identifying and exploring large- to medium-sized impact craters on the surface of the Moon (craters with a diameter greater than 1 km). Small impact craters have obvious statistical significance owing to their magnitude in numbers. The identification and analysis of small craters provide indispensable clues for the study of lunar geological evolution. However, such craters only remain in specific images and regions. At present, there is no comprehensive record of small impact craters in the existing lunar impact crater databases. The small impact craters on the surface of the Moon are enormous and vary in size by orders of magnitude, exhibiting small target characteristics in space. The present study focuses on the identification and spatial analysis of small impact craters on the surface of the Moon. A feature amplification strategy-based identification model was established for small impact crater detection, achieving accurate recognition of the small impact craters on the surface of the Moon (with a recall rate of 86.97% and a false-positive rate as low as 0.54% ± 0.16%). In total, 228,897, 142,872, and 42,008 new small lunar impact craters (with diameters as low as 4.5 m) were identified in the ten lunar landing areas of returned samples from the Apollo, Luna, and Chang’e-5 missions. In addition, the spatial distribution characteristics of small impact craters during different geological periods in the landing area are provided. Data on the newly identified small impact craters will provide an important basis for revealing the lunar impact fluxes and young lunar surface dating in lunar geological evolution research.

The First Ground-based White Light Lunar Polarization Imaging: A New Kind of FeO Observation on the Near Side of the Moon

Lunar optical polarization is a fascinating phenomenon that occurs when sunlight reflects off the surface of the Moon and becomes polarized. This study employs a novel split-focus plane polarimetric camera to conduct the initial white light polarimetric observations on the near side of the Moon. We obtained the linear degree of polarization (DOP) parameters of white light by observation from the eastern and western hemispheres of the Moon. The findings indicate that the white light polarization is lower in the lunar highland than in the lunar maria overall. Combining the analysis of lunar soil samples, we noticed and determined that the DOP parameters of white light demonstrate high consistency with iron oxide on the Moon. This study may serve as a new diagnostic tool for the Moon.

Realizing the gravity of the simulation: adaptation to simulated hypogravity leads to altered predictive control

Accurate predictive abilities are important for a wide variety of animal behaviors. Inherent to many of these predictions is an understanding of the physics that underlie the behavior. Humans are specifically attuned to the physics on Earth but can learn to move in other environments (e.g., the surface of the Moon). However, the adjustments made to their physics-based predictions in the face of altered gravity are not fully understood. The current study aimed to characterize the locomotor adaptation to a novel paradigm for simulated reduced gravity. We hypothesized that exposure to simulated hypogravity would result in updated predictions of gravity-based movement. Twenty participants took part in a protocol that had them perform vertically targeted countermovement jumps before (PRE), during, and after (POST) a physical simulation of hypogravity. Jumping in simulated hypogravity had different neuromechanics from the PRE condition, with reduced ground impulses (p ≤ .009) and muscle activity prior to the time of landing (i.e., preactivation; p ≤ .016). In the 1 g POST condition, muscle preactivation remained reduced (p ≤ .033) and was delayed (p ≤ .008) by up to 33% for most muscles of the triceps surae, reflecting an expectation of hypogravity. The aftereffects in muscle preactivation, along with little-to-no change in muscle dynamics during ground contact, point to a neuromechanical adaptation that affects predictive, feed-forward systems over feedback systems. As such, we conclude that the neural representation, or internal model, of gravity is updated after exposure to simulated hypogravity.

Lunar highlands simulant — Geotechnical characterization, 3D discrete element modeling, and cone penetration simulations

Lunar regolith on the surface of the Moon has gained great attention as a resource for many proposed lunar exploration projects. Not only is it serving as the ground support for construction projects on the Moon, but it is also the most accessible construction material for building the human habitat and a key component in in-situ resource utilization efforts. Therefore, gaining a fundamental understanding of the characteristics of lunar regolith is a critical step in the success of lunar exploration projects. However, it is challenging and expensive to obtain samples of lunar regolith directly, or conduct physical experiments on lunar regolith samples in situ. Hence, investigative alternatives, such as laboratory experiments and numerical simulation tools are very important means of investigating the properties of lunar regolith. This paper presents a comprehensive study on lunar highlands simulant (LHS-1), using both laboratory experimentation and discrete element method (DEM) simulations. In the laboratory experiment, triaxial tests were conducted on samples of LHS-1 to explore the stress–strain behaviors of the lunar regolith simulant. Correspondingly, 3D DEM simulations of the triaxial tests were conducted to generate the initial model parameters and the Taguchi method was performed to obtain the optimal calibrated input parameters of the DEM model. With the calibrated parameters, 3D DEM model of the cone penetration into LHS-1 was then built to study the responses of the regolith simulant during the penetration process. The effects of porosity and vertical stress on the tip resistance and sleeve friction profiles were investigated for both terrestrial and lunar environments to study the correlation between the in-situ state of the regolith simulants with the force reactions during the penetration.

ELEMENTS OF TECHNOLOGY OF ELECTRON BEAM WELDING OF ALUMINUM ALLOYS FOR INSTALLATION AND REPAIR AND RESTORATION WORK ON THE SURFACE OF THE MOON

The exploration of the Moon cannot be carried out without the creationof long-term lunar bases (LB), as well as other objects that ensure the livelihoods and work of expeditions. These can be assembly and assembly operations during the creation of space complexes or repair and maintenance work related to ensuring the duration of operation of existing systems. Experiments on automatic welding in space, which were carried out on the “Vulkan” equipment, as well as welding with the manual electron beam tool «URI» in outer space, showed that electron beam welding (EBW) is the optimal technological process for performing welding work in space conditions. In this process, the effective efficiency is 85—90 %, which is the maximum compared to other welding methods. EBW in the conditions of terrestrial gravity allows us to ensure the mechanical and chemical properties of welded joints, as well as their density almost at the level of the base metal of the structure, which is impossible with other welding methods. Thus, the strength coefficient of the weld metal of welded joints from aluminum alloys obtained by EBW is 0.85...0.93, and with arc and plasma-arc methods, it is 0.7…0.8. At the same time, obtaining such properties of welded joints in space conditions is difficult. Of course, reduced gravity, low temperatures, and ultra-high vacuum, which are the natural environment on the lunar surface, contribute to the formation of internal leaks in the form of pores in welds (PW). This is primarily manifested in the welding of aluminum alloys, which are used as the main material in spacecraft structures.To obtain high-quality welded joints and exclude such defects as pores, cracks, and non-fusion of edges in the weld roots to be welded, a system of equipment for periodic deflection of the electron beam with a programmable heating intensity along a given trajectory was developed and manufactured. As a result of technological work carried out using a complex of equipment with a discrete deviation of the electron b eam, welded joints (WJ) were obtained from alloys AMg6, A1570, and 1201 with a thickness of 2 to 8 mm. The obtained PW was subject to visual inspection and X-ray control to determine external and internal defects in the WJ. Also, mechanical tests for the strength of resistance by tearing were carried out, the chemical composition was determined, and metallographic studies of PW obtained by the proposed method were performed. The results of the tests and studies showed the high quality of PP from aluminum alloys obtained by EBW using a discrete deflection of an electron beam with a programmable heating intensity along a given trajectory. The purpose of this work was to analyze the methods of degassing the molten metal of the weld pool, as well as the development and testing of the elements of the technological process of the EBW of aluminum alloys using the created equipment, which, when performing installation and repair and restoration work on the surface of the moon, will allow us to obtain high-quality WJ that meets the requirements for space designs.

Presence of non-solar derived krypton and xenon unveiled by Chang'e-5 lunar soils

The extent of volatile elements on the surface and interior of the Moon remains a highly debated topic. Previous studies conducted on bulk lunar soil samples and solar wind samples collected by the Genesis mission indicate a discernible isotope mass- or non-mass-dependent fractionation of krypton and xenon. However, a detailed investigation of these processes is missing, particularly in determining the possible incorporation of cometary volatiles in the lunar regolith. New lunar soil samples returned by the Chang'e-5 mission provide a chance to answer these key questions. In this study, noble gas isotopes of nine subsamples from a Chang'e-5 scooped sample were analysed through stepwise-heating and total fusion laser extraction. The results reveal that a simple binary mixture of solar wind and cosmogenic components did not explain alone the isotopic composition of these samples. The Xe data shows insignificant amounts of atmospheric Xe and presents clear evidence of cometary contributions to the lunar regolith, with a significant depletion of 134,136Xe compared to that in the solar wind. Additionally, a meteoritic component is identified. Compared to the Apollo results, our findings further validate the theory of Earth's atmospheric escape, substantiate the plausibility of these exogenous admixtures to elucidate the isotopic fractionation mechanisms of Kr and Xe within the lunar regolith, and provide novel insights into long-term constancy in the solar wind composition.

Experimental study on the radiation-induced destruction of organic compounds on the surface of the Moon

Volatile organic molecules and a complex organic refractory material were detected on the Moon and on lunar samples. The Moon’s surface is exposed to a continuous flux of solar UV photons and fast ions, e.g. galactic cosmic rays (GCRs), solar wind (SW), and solar energetic particles (SEPs), that modify the physical and chemical properties of surface materials, thus challenging the survival of organic compounds. With this in mind, the aim of this work is to estimate the lifetime of organic compounds on the Moon’s surface under processing by energetic particles. We performed laboratory experiments to measure the destruction cross section of selected organic compounds, namely methane (CH4), formamide (NH2CHO), and an organic refractory residue, under simulated Moon conditions. Volatile species were deposited at low temperature (17 - 18 K) and irradiated with energetic ions (200 keV) in an ultra-high vacuum chamber. The organic refractory residue was produced after warming up of a CO:CH4 ice mixture irradiated with 200 keV H+ at 18 K. All the samples were analyzed in situ by infrared transmission spectroscopy. We found that destruction cross sections are strongly affected (up to one order of magnitude) by the dilution of a given organic in an inert matrix. Among the selected samples, organic refractory residues are the most resistant to radiation. We estimated the lifetime of organic compounds on the surface of the Moon by calculating the dose rate due to GCRs and SEPs at the Moon’s orbit and by using the experimental cross section values. Taking into account impact gardening, we also estimated the fraction of surviving organic material as a function of depth. Our results are compatible with the detection of CH4 in the LCROSS eject plume originating from layers deeper than about 0.7 m at the Moon’s South Pole and with the identification of complex organic material in lunar samples collected by Apollo 17 mission.

Stratasys to test 3D-printed material performance on moon

On March 12, 2024, Stratasys Ltd. announced that it will provide 3D-printed materials for an upcoming lunar mission to test their performance on the surface of the moon. The experiments are part of Aegis Aerospace, Inc.’s first Space Science & Technology Evaluation Facility mission (SSTEF-1).

The lunar dust environment: concerns for Moon-based astronomy.

The Moon has no atmosphere, hence, it offers a unique opportunity to place telescopes on its surface for astronomical observations. It is phase-locked with Earth, and its far side remains free from ground-based interference, enabling the optimal use of radio telescopes. However, the surface of the Moon, as any other airless planetary object in the solar system, is continually bombarded by interplanetary dust particles that cause impact damage and generate secondary ejecta particles that continually overturn the top layer of the lunar regolith. In addition, there is evidence, that small particles comprising the lunar regolith can be electrically charged, mobilized and transported, also representing a hazard for covering sensitive surfaces and interfering with exposed mechanical structures. In addition to the naturally occurring dust transport, rocket firings during landings and take-offs, pedestrian and motorized vehicle traffic will also liberate copious amounts of dust, representing a potential hazard for the safe and optimal use of optical platforms. This article is part of a discussion meeting issue 'Astronomy from the Moon: the next decades (part 2)'.

Additive manufacturing of hydrogel-based lunar regolith pastes: A pathway toward in-situ resource utilization and in-space manufacturing

Additive Manufacturing (AM), combined with efficient in-situ resource utilization, has the potential to enable sustained presence on the Moon through in-situ production and replacement of construction blocks, engineered parts, and devices in the lunar terrain. As an initial step toward realizing this vision, this work proposes a new material formulation utilizing lunar regolith simulants (LHS-1), water, and a hydrophilic hydrogel-forming polymer (Pluronic F127) to produce a hydrogel-based lunar regolith paste suitable for material extrusion AM. This formulation enables the use of water as another potential lunar in-situ resource for the first time in the literature, considering the recent confirmation of large quantities of water-ice in the shadowed craters around the lunar poles and the presence of water on the sunlit surface of the Moon. To systematically investigate the viability of the proposed hydrogel-based lunar regolith material feedstock and the application of material extrusion AM, this work introduces a three-stage design of experiment (DOE) framework to achieve two fundamental objectives. First, the viable range of lunar regolith simulant in the hydrogel-based material formulation is identified using a categorical quality evaluation of single and multi-layer material depositions. Second, the material printability window is established in terms of printing speed and extrusion rate for different viable material compositions through hierarchically designed experiments. The observed porosity of the sintered parts decreased with increasing regolith content in the material composition, while the density and compressive strength increased with higher regolith content. For material compositions consisting of 25–40 vol% regolith simulants, the observed porosity of the sintered parts decreased from 6.4 to 2.18 %, their density increased from 0.78 to 0.89 g/cm3, and their average compressive strength ranged between 0.68 and 1.32 MPa. Finally, the printability of the material was demonstrated by producing various prototype hand tools and lab-scale construction blocks with varying geometrical complexities. This work represents a crucial step toward in situ resource utilization and sustainable in-space manufacturing, sets the stage for future investigations, and the introduced DOE driven framework offers a pathway toward systematically identifying the optimal material compositions and the corresponding process parameters to enable high-quality prints.

Numerical investigation on cooling performance and control effect of a novel evaporation-driven cooling unit for Mars extravehicular space suit application

The special environment of Mars brings new challenges to the thermal control of spacecraft on Mars missions. The outstanding advantages of water evaporation cooling technology make it promising for use in the thermal control system of the Mars spacecraft. This paper proposes a novel concept of evaporation cooling hardware that integrates heat collection, heat transfer and heat rejection, namely evaporation-driven cooling unit. The evaporation-driven cooling unit has a simple structure, high evaporation efficiency and the potential to simplify the system topology. Furthermore, an expert hierarchical coordination control strategy applied to the Mars extravehicular space suit cooling loop with an evaporation-driven cooling unit as its heat sink is proposed. The dynamics model of this cooling loop is also constructed using the lumped parameter method. The numerical results have shown that the expert hierarchical coordination control strategy can achieve precise temperature control and reduce the water consumption of the system. The average water consumption rate during extravehicular activity is 0.6975 kg/h when the mean heat load is 572 W (including member metabolic heat and electronic waste heat). Compared to the open-loop case with the same input heat load, a typical extravehicular activity lasting 8 h will save about 11.5 g water if the expert hierarchical coordination control is applied. The proposed evaporation-driven cooling unit will provide more choices for heat rejection of extravehicular space suits. It is expected that the evaporation-driven cooling unit and expert hierarchical coordination control have potential applications in thermal control systems for other space vehicles in near-Earth orbit, on the surface of the Moon and Mars.

The Amateur Astronomer as Image Producer

Abstract This article approaches the history of amateur astronomers in the late nineteenth century via visual and material sources. It adopts three separate viewpoints: Jules Pierrot Deseilligny’s home-based workshop, two self-portraits of amateurs at work, and a corpus of selenographic images published in the Bulletin de la Société Astronomique de France. These sources throw light on amateur savant practices, which are largely based on producing images, sometimes taking the form of a structured scholarly project, and giving rise to exchanges, debates, and sociabilities. It identifies a proliferation during the years 1880 to 1914, characterised by a particular sensitivity to the extraterrestrial life feeding a powerful desire to observe the surface of the moon.

ОЦЕНКА РАДИАЦИОННОЙ ОБСТАНОВКИ ПРИ КРАТКОВРЕМЕННЫХ ПОЛЕТАХ НА ЛУНУ

Background: The issue of assessing the features of factors affecting the formation of radiation doses of astronauts while in orbit of the Moon and on its surface remains insufficiently studied, which is important for ensuring the anti-radiation safety of astronauts on lunar missions. Purpose: To analyze the factors influencing the formation of the radiation dose of astronauts at the stage of finding the spacecraft in orbit of the Moon and the lander on its surface. Material and methods: The features of the dose load levels on astronauts at the stages of the Moon’s orbit and on the Moon’s surface are analyzed and generalized, calculation methods are used taking into account the orbit of the spacecraft around the Moon, the anti-radiation properties of the materials of the lander and spacesuit and the time spent in them during a short-term lunar mission. Results: The total radiation doses of astronauts for 14 days, calculated according to dosimetric measurements during the years of low solar activity (2009 and 2018‒2019), are 19.5‒23.2 mSv for astronauts staying in a spacecraft in lunar orbit, and from 22,7 to 24,0 mSv for astronauts on the Lunar surface, depending on the mass thickness of the protection at the maximum permissible 250 mSv for 1 month. An increase in the mass thickness of the anti-radiation protection of the lander in the equivalent of aluminum from 1.5 to 3-5 g/cm2 and the lunar spacesuit in the equivalent of aluminum from 0.2 to 0.5‒1 g/cm2 will reduce the total radiation dose of astronauts no more than 1.3 times during a 14-day stay on the surface of the moon. The results indicate that in order to minimize the radiation doses that astronauts receive during a lunar mission, it is important to take into account the forecast of solar activity in order to optimize the launch time of the spacecraft in the «windows» with minimal levels of radiation exposure. Conclusion: When predicting radiation hazard levels for astronauts during a short-term lunar mission, it is necessary to assess the levels of exposure to cosmic ionizing radiation both in the orbit of the Moon, depending on the lunar trajectory of the spacecraft, and on the surface of the Moon, taking into account the time spent in the lunar module and in a spacesuit, as well as levels of solar activity. It is important to take into account the analyzed features of the formation of cosmonauts’ radiation doses while orbiting the Moon and on its surface when predicting the time limits of the lunar mission, anti-radiation protection of astronauts and their compliance with the regulatory limits of exposure.

Titanium-rich basaltic melts on the Moon modulated by reactive flow processes

The origin of titanium-rich basaltic magmatism on the Moon remains enigmatic. Ilmenite-bearing cumulates in the lunar mantle are often credited as the source, but their partial melts are not a compositional match and are too dense to enable eruption. Here we use petrological reaction experiments to show that partial melts of ilmenite-bearing cumulates react with olivine and orthopyroxene in the lunar mantle, shifting the melt composition to that of the high-Ti suite. New high-precision Mg isotope data confirm that high-Ti basalts have variable and isotopically light Mg isotope compositions that are inconsistent with equilibrium partial melting. We employ a diffusion model to demonstrate that kinetic isotope fractionation during reactive flow of partial melts derived from ilmenite-bearing cumulates can explain these anomalously light Mg isotope compositions, as well as the isotope composition of other elements such as Fe, Ca and Ti. Although this model does not fully replicate lunar melt–solid interaction, we suggest that titanium-rich magmas erupted on the surface of the Moon can be derived through partial melting of ilmenite-bearing cumulates, but melts undergo extensive modification of their elemental and isotopic composition through reactive flow in the lunar mantle. Reactive flow may therefore be the critical process that decreases melt density and allows high-Ti melts to erupt on the lunar surface.

The Iris CubeSat mission: Science payload description for a pathfinder geological space weathering investigation

The Iris mission is a student-led 3-U CubeSat comprised of a science payload of 20 geological samples placed in low-Earth orbit (LEO) to study the effects of space weathering (i.e., those aspects that can be investigated in LEO). This experiment is the first of its kind to take place in the vacuum of space. The science objective of the mission is to investigate how space weathering processes affect the surfaces of airless planetary bodies by monitoring the spectral reflectance properties of geological samples over time. Two three-color cameras acquire spectral reflectance data within the visible spectrum to measure any spectral and/or textural changes exhibited throughout the ∼1-year orbital mission. This mission will provide valuable data to help understand how the space environment may affect the surfaces of the Moon, Mercury, and main-belt and near-Earth asteroids. The acquired data will help constrain meteorite-asteroid links and provide insight into the spectroscopic analysis of samples returned from the Moon, and near-Earth asteroids Itokawa, Bennu, and Ryugu. The results of this mission will also complement the results of laboratory simulations of space weathering. All samples selected for flight on the CubeSat have undergone several tests to ensure suitability for launch and operations. This paper describes the payload subsystem, sample selection and preparation.