ARTEMIS Mission Research Articles

A Study of Ionospheric Heavy Ions in the Terrestrial Magnetotail Using ARTEMIS

AbstractIonospheric heavy ions in the distant tail of the Earth's magnetosphere at lunar distances are observed using the ARTEMIS mission. These heavy ions are originally produced in the terrestrial ionosphere. Using the ElectroStatic Analyzers (ESA) onboard the two probes orbiting the Moon, these heavy ions are observed as cold populations with distinct energies higher than the baseline energy of protons, with the energy‐per‐charge values for the heavy populations highly correlated with the proton energies. We conducted a full solar cycle survey of these heavy ion observations, including the flux, location, and drift energy, as well as the correlations with the solar wind and geomagnetic indices. The likelihood of finding these heavy ions in the preferred regions of observation called “loaded” quadrants of the terrestrial magnetotail is ∼90%, regardless of the z orientation of the IMF. We characterize the ratio of the heavy ion energy to the proton energy, as well as the velocity ratio of these two populations, for events from 2010 to mid‐2023. This study shows that the “common velocity” assumption for the proton and heavy ion particles, as suggested in previous work through the velocity filter effect, is not necessarily valid in this case. Challenges in the identification of the mass of the heavy ions due to the ESA's lack of ion composition discrimination are addressed. It is proposed that at the lunar distances the heavy ion population mainly consists of atomic oxygen ions (O+) with velocities ∼25% more than the velocity of the co‐located proton population.

Application of Artificial Intelligence in Solar System Exploration and Beyond

Carl Sagan’s reflections emphasize the boundless potential awaiting humanity in space, regardless of our past achievements or failures. This optimistic view resonates with current space agencies, private space startups, and enthusiasts, all driven by the ambition to make humans a multiplanetary species. Key examples include Elon Musk’s goal to terraform Mars, despite skepticism from some scientists. Space exploration faces numerous challenges, such as dealing with space debris, unpredictable climates on other planets, and the complexities of missions like NASA’s attempts to land on Mars. Space missions confront obstacles in navigation, life detection, and sample testing. Astronauts also encounter physical and mental limitations due to the harsh conditions of space. Artificial Intelligence (AI) has emerged as a crucial tool in addressing these challenges. AI is categorized into supervised learning, unsupervised learning, and semi-supervised learning, with reinforcement learning being a distinct method used for autonomous applications. Neural networks, including convolutional and recurrent neural networks, mimic human behavior for tasks like image inspection and sequential data handling. Deep learning aids in complex pattern recognition, and natural language processing facilitates speech recognition and development. Expert systems enhance decision-making processes. This review explores various AI applications in space missions. AI technologies have been integral to recent missions such as the James Webb Space Telescope, which uses AI for object and galaxy inspection, and the ARTEMIS mission, which employs AI in designing new spacesuits. SpaceX leverages AI for reusable launch vehicles, while the European Space Agency (ESA) uses AI for autonomous spacecraft to cut mission costs. India plans to launch the AI-based Vyommitra robot in space and has utilized AI in the Chandrayaan mission for landing and navigation. Mars exploration benefits significantly from AI, given the planet’s unpredictable weather and cratered surface. AI technologies, like the OASIS system, aid in mission planning and rover navigation. AI also supports space agriculture research, as demonstrated by the UAE’s habitat design efforts. Beyond Mars, AI influences the exploration of asteroids and deep space. AI techniques, such as convolutional neural networks, assist in space dynamics calculations to predict asteroid trajectories and potential Earth impacts. AI has been employed in Voyager missions to seek extraterrestrial life and in the Hubble telescope for imaging exoplanets. AI enhances satellite communication and automates tasks on space stations, saving time and costs. Weather satellites, powered by AI, provide crucial alerts for natural disasters. Despite the challenges, AI offers promising solutions for advancing space exploration. The historical tendency to deem certain challenges insurmountable is gradually shifting, as past impossibilities, like human flight and space travel, have become historical milestones. This reinforces the importance of maintaining hope and persistence in the quest to explore space, as today's dreams may become tomorrow's history.

An Automated Wayfinding Algorithm to Find Rovers' Path on the Lunar South Pole

As a part of the upcoming Artemis mission, NASA released a large satellite dataset (latitude, longitude, height, and slope) of the lunar south pole, around the area of the lunar module landing site and rover exploration site near the Shackleton Crater. While designing the rover, it’s important to understand the minimum power the rover needs (the amount of slope it can overcome) to navigate the terrain. Our goal was to process the data, visualize the data in 2-D and 3-D, and develop an algorithm that would automatically map the shortest possible path (or no possible path) between two coordinates according to the lunar terrain and rover parameters. To accomplish that, we processed a large unorganized dataset into an equally spaced and sequential matrix of latitude, longitude, height, and slope. The matrix was then converted into a go/no-go maze of the terrain and the Breadth First Search (BSF) and A* algorithms were applied to the maze to find the optimal path. The terrain and the optimal path were plotted in 2-D using Matplotlib and interactively displayed in 3D using Plotly. We developed a Jupyter Notebook web-based app that will allow a user to interactively use the algorithm and visualize the lunar terrain. The results identify the minimum rover slope and various paths depending on higher rover slopes. The algorithm and the rover paths were validated by the NASA SCaN (Satellite Communication and Navigation) team of engineers and the application can be used for design, validation, and training purposes.

Limits on the Density of the Lunar Ionosphere: ARTEMIS Observations

The Moon of our Earth has a tenuous atmosphere, known as an exosphere. The ionization of this exosphere is speculated to possibly form a weak ionosphere. Some radio occultation (RO) experiments have suggested the presence of a dense ionosphere with an electron density on the order of hundreds of cm−3 near the surface. Using in situ measurements from the ARTEMIS mission during 2012–2021, we conduct statistical analyses and case studies to investigate the plasma density at near-surface altitudes. ARTEMIS measurements reveal no plasma densities at altitudes between 10 and 50 km that exceed 35 cm−3, and therefore they provide no evidence for a steady-state or global lunar ionosphere at the level suggested by some RO observations. Density profiles with local time and altitude show higher density in the sunlit sector than in the shadowed sector. These observations suggest that the natural variation of solar wind plasma flux with solar zenith angle plays a critical role in controlling the plasma population near the surface. This research provides a reference for a comparison with RO observations and a statistical view of the low-altitude plasma environment near the lunar surface.

Automated astronaut traverses with minimum metabolic workload: Accessing permanently shadowed regions near the lunar south pole

The Artemis exploration zone is a topographically complex impact-cratered terrain. Steep undulating slopes pose a challenge for walking extravehicular activities (EVAs) anticipated for the Artemis III and subsequent missions. Using 5 m/pixel Lunar Orbiter Laser Altimeter (LOLA) measurements of the surface, an automated Python pipeline was developed to calculate traverse paths that minimize metabolic workload. The tool combines a Monte Carlo method with a minimum-cost path algorithm that assesses cumulative slope over distances between a lander and stations, as well as between stations. To illustrate the functionality of the tool, optimized paths to permanently shadowed regions (PSRs) are calculated around potential landing sites 001, nearby location 001(6), and 004, all within the Artemis III ‘Connecting Ridge’ candidate landing region. We identified 521 PSRs and computed (1) traverse paths to accessible PSRs within 2 km of the landing sites, and (2) optimized descents from host crater rims into each PSR. Slopes are limited to 15° and previously identified boulders are avoided. Surface temperature, astronaut body illumination, regolith bearing capacity, and astronaut-to-lander direct view are simultaneously evaluated. Travel times are estimated using Apollo 12 and 14 walking EVA data. A total of 20 and 19 PSRs are accessible from sites 001 and 001(6), respectively, four of which maintain slopes <10°. Site 004 provides access to 11 PSRs, albeit with higher EVA workloads. From the crater rims, 94 % of PSRs can be accessed. All round-trip traverses from potential landing sites can be performed in under 2 h with a constant walk. Traverses and descents to PSRs are compiled in an atlas to support Artemis mission planning.

3D Printed TiO2 Negative Electrodes for Sodium-Ion and Lithium-Ion Batteries Using Vat Photopolymerization

Additive manufacturing represents a unique approach to develop three-dimensional shape-conformable batteries with enhanced surface area, ion diffusion, and power. For the first time, a composite photocurable resin loaded with solid particles of active materials and conductive additives was prepared and used as feedstock to print negative electrodes for sodium-ion and lithium-ion batteries by means of a vat photopolymerization (VPP) 3D printer. In alignment with NASA’s Artemis mission goals to develop sustainable lunar energy storage infrastructure to support long-term human operations, TiO2 was selected as an active material for the negative electrode due to its abundance on the lunar surface. The TiO2 loading in the composite photocurable resin was increased as high as possible to maximize the electrochemical performance of the printed electrodes, while simultaneously ensuring printability and good mechanical strength for sample handling. The effect of thermal post-processing on the electrical, electrochemical, and mechanical performance is reported. A configurational study is implemented to identify the impact of electrode designs (cubic and gyroid) on the electrochemical performance. This work addresses the difficulties related to the introduction of solid particles within a photocurable resin and the need for a compromise between the electrochemical performances and printability to obtain fully functional VPP-printed electrodes.

Pre-launch lessons learned from NASA’S deep space network support for the artemis I mission to the moon

NASA's Deep Space Network (DSN) serves as a critical element in the exploration of deep space, providing telecommunication services such as tracking, telemetry, command, and delivery of science data to its customers around the globe. In addition to supporting robotic spacecraft for scientific missions, the DSN also supports human spaceflight (HSF) endeavors, including NASA's flagship Artemis missions to the Moon. This paper describes DSN lessons learned during preparations for the first Artemis mission, Artemis I. Topics covered include DSN performance and reliability, network loading, interface management, international collaboration and the role of international partners. Lessons learned will be applied to future missions, including Artemis II and beyond.

Ion Kinetics of Plasma Flows: Earth's Magnetosheath versus Solar Wind

Revealing the formation, dynamics, and contribution to plasma heating of magnetic field fluctuations in the solar wind is an important task for heliospheric physics and for a general plasma turbulence theory. Spacecraft observations in the solar wind are limited to spatially localized measurements, so that the evolution of fluctuation properties with solar wind propagation is mostly studied via statistical analyses of data sets collected by different spacecraft at various radial distances from the Sun. In this study we investigate the evolution of turbulence in the Earth’s magnetosheath, a plasma system sharing many properties with the solar wind. The near-Earth space environment is being explored by multiple spacecraft missions, which may allow us to trace the evolution of magnetosheath fluctuations with simultaneous measurements at different distances from their origin, the Earth’s bow shock. We compare ARTEMIS and Magnetospheric Multiscale (MMS) Mission measurements in the Earth magnetosheath and Parker Solar Probe measurements of the solar wind at different radial distances. The comparison is supported by three numerical simulations of the magnetosheath magnetic and plasma fluctuations: global hybrid simulation resolving ion kinetic and including effects of Earth’s dipole field and realistic bow shock, hybrid and Hall-MHD simulations in expanding boxes that mimic the magnetosheath volume expansion with the radial distance from the dayside bow shock. The comparison shows that the magnetosheath can be considered as a miniaturized version of the solar wind system with much stronger plasma thermal anisotropy and an almost equal amount of forward and backward propagating Alfvén waves. Thus, many processes, such as turbulence development and kinetic instability contributions to plasma heating, occurring on slow timescales and over large distances in the solar wind, occur more rapidly in the magnetosheath and can be investigated in detail by multiple near-Earth spacecraft.

Phasing with near rectilinear Halo orbits: Design and comparison

In the next future, space agencies are planning to return to the Moon. The objective is to assemble an orbiting space station, called Gateway, on a Near Rectilinear Halo Orbit around the Moon as a base for future Moon and deep space missions. Within this framework, multiple side missions will be planned to sustain the Gateway (Artemis mission). The proposed work is thought in framework of the preliminary design of future cargo missions, in particular on the design of an efficient phasing trajectory, under the Circular Restricted Three body problem hypotheses, to bring a cargo vehicle from the end of the Earth-Moon transfer to the beginning of the proximity operations such as rendezvous and docking with the space station. The work aims covering the lack of literature in phasing trajectories with the NRHO by proposing three different strategies to connect the Earth-Moon transfer trajectory with the proximity operations. The three strategies are classified based on the choice of the parking orbits or the choice of the manifolds. Two strategies use butterfly and Halo orbits to park the vehicle before transferring to the target orbit. The third strategy, instead, uses manifolds to allow a direct phasing. In the paper, the three innovative strategies are designed and compare in a specific scenario.

Once in a Blue Moon

NASA’s Artemis mission will see a journey further beyond the Moon than ever before. Melissa Bradshaw takes a look at its bumpy progress to date.

A Review of Lunar Space Environment Study

After more than fifty years lunar exploration, our understanding of the lunar space environment is still superficial. The lunar dusty exosphere research was based on ARTEMIS mission and the lunar atmosphere and dust environment detector which were developed by NASA. Based on the radio experiments of several lunar missions, the existence of lunar ionosphere is determined. The current status and observation of lunar exosphere and ionosphere are introduced in this paper. With the help of the low frequency radio astronomical payloads carried by Chang'E-4 relay satellite and the lander, more of lunar space environment will be uncovered.

Characterization in Dynamic Load Environment of COTS Synthetic Sapphire Bearings for Application in Magnetic Suspension in Space

The present research investigates the application of a cardan suspension making use of permanent magnet (PM) bearings employed to obtain high reliable/low-cost solutions for the permanent alignment of directional payloads such as laser reflectors for the Next Generation Lunar Retroreflector (NGLR) experiment or antennas to be deployed on the moon’s surface. According to Earnshaw’s Theorem, it is not possible to fully stabilize an object using only a stationary magnetic field. It is also necessary to provide axial control of the shaft since the PM bearings support the radial load but, they produce an unstable axial force when losing alignment between the stator and rotor magnets stack. In this work, the use of commercial off-the-shelf (COTS) sapphire as axial bearings in the cardan suspension has been investigated by testing their behavior in response to some of the dynamic loads experienced during the qualification tests for space missions. The work is innovative in the sense that COTS sapphire assembly has never been investigated for space mission qualification. As Artemis mission loads have not been yet provided for NGLR, test loads for this study are those used for the proto-qualification of the INFN INRRI payload for the ESA ExoMars EDM mission. Tests showed that, along the x and y directions, no damages were produced on the sapphire, while, unfortunately, on the z direction both sapphires were badly damaged at nominal loads.

Bombardment of Lunar Polar Crater Interiors by Out-of-ecliptic Ions: ARTEMIS Observations

Abstract Permanently shadowed regions (PSRs) inside lunar polar craters likely harbor volatiles which are of great interest for both science and resource utilization. The origin and evolution of this resource is in part driven by external space weathering, including the bombardment by space plasma ions. Previous work has investigated the flux of horizontal solar wind ions that are deflected into lunar polar craters by plasma wake electrostatic fields. Here, we constrain the flux of ions that travel northward or southward in the natural environment encountered by the Moon along its orbit. Using 9 years of in situ ion measurements gathered by the ARTEMIS mission, we find that all locations inside lunar craters are altered by a flux of out-of-ecliptic ions of 10−3 times the solar wind flux. In particular, the central floor of Shackleton’s crater is weathered by a non-null ion flux. The origin of northward and southward ions impacting the Moon is identified as (i) shocked thermalized solar wind ions in the terrestrial magnetosheath and (ii) the isotropic component of ion distributions in the terrestrial magnetotail. The energy spectrum of out-of-ecliptic ions is found to be flatter than the solar wind spectrum. Thus, sputtering of pure water ice irradiated by out-of-ecliptic ions would be created for more than 30% by &gt;3 keV protons, unlike equatorial locations that are mostly sputtered by 1 keV protons. Future work may investigate the influence of the low, but nonzero flux of out-of-ecliptic ions reported here on the budget of volatiles in lunar PSRs.

Investigating the Moon's Interaction With the Terrestrial Magnetotail Lobe Plasma

AbstractWe present observations of the Moon's plasma interaction in Earth's magnetotail lobes by the ARTEMIS mission, and compare these to hybrid model results to constrain the global properties of the lunar electromagnetic environment. We identify, for the first time in the magnetotail lobes, a low‐energy wake extending multiple lunar radii downstream of the Moon along the ambient flow direction. This wake is tilted out of the lunar optical shadow, allowing for detection of the otherwise unobservable cold ambient magnetospheric plasma. Similar eclipse encounters may provide additional opportunities to measure this low‐energy plasma potentially originating from the terrestrial ionosphere. We find lunar ionospheric outflow extending multiple Moon radii downstream that generates asymmetries in the Moon's plasma environment and shares characteristics with the plasma interactions of Rhea, Tethys, and Dione. The extensive ARTEMIS data set may therefore provide additional insights into the plasma environments near moons of the outer solar system.

NASA Prepares To Drill for the “Oil of Space”

“We’re going to the Moon, and we’re going there to stay this time,” has become a NASA mantra as the US competes with other countries, including China and Russia (https://jpt. spe.org/esa-roscosmos-to-mine-oxygen-water-from-moon-rocks-as-nasa-eyes-first-artemis-lunar-mission), to be the first to put humans on the Moon and Mars. The race will rely heavily on using resources available on the planetary bodies - or in-situ resource utilization (ISRU). Chief among these is water, which has been called “the oil of space.” As NASA prepares for Artemis mission astronauts to land on the Moon in 2024, it will fly at least two preliminary missions to look for water and gather information about the lunar south pole. The Polar Resources Ice-Mining Experiment (PRIME-1) and Volatiles Investigating Polar Exploration Rover (VIPER) missions, which will be launched in late 2022 and 2023, respectively, will be the first missions to study ISRU on another celestial body. They will also mark the first time NASA will robotically sample and analyze for ice from below the surface. And they will use technologies transferred and adapted from oil and gas exploration. Reconnaissance Missions Data from nearly 3 decades of lunar orbiter and impactor missions suggest that the Moon’s “soils,” particularly at its south pole and other regions, could contain hundreds of millions of gallons of water that could eventually be harvested and converted to oxygen, fuel, or drinkable water for human use on the Moon, Mars, and beyond. But, at what concentrations? In what kinds of soils? And is the water in a form that’s accessible? Most of the information we have about the presence of water-ice on the Moon comes from orbital measurements. The only direct evidence acquired to date came in 2009 from a sensing satellite aboard a spacecraft that was purposely crashed in the Cabeus crater. The material ejected as a result of the impact was analyzed with a spectrometer to reveal the presence of 5.6%±2.9% water-ice by mass. The form, distribution, composition, and quantity of the water-ice remain largely uncertain. The only way to reduce this uncertainty is to obtain ground-truth data by drilling exploratory boreholes in the crater. This will be the purpose of the PRIME-1 and VIPER missions. PRIME-1 will last a week to 10 days, during which a robot will deploy a drill and mass spectrometer to harvest and preliminarily evaluate moon-ice for quality and regional heights and to determine how much of the ice is lost to a process known as sublimation, wherein the water transforms directly from solid ice into vapor, rather than first going through a liquid phase. In addition to ice, PRIME-1 will gather samples including rock samples to help date the sequence of impact events on the Moon, core tube samples to capture ancient solar wind trapped in regolith layers (unconsolidated, inorganic rocky material), and paired samples of material to characterize the presence of volatiles and to assess geotechnical differences between materials inside and outside permanent shadows. The samples will be returned to Earth and studied to characterize and document the regional geology, including the small, permanently shadowed regions. The data from the mission will help scientists understand how a mobile robot to be used on the subsequent VIPER mission can search for water at the Moon’s pole, and how much water may be available to use as NASA plans to establish a sustainable human presence on the Moon by the end of the decade (Fig. 1).

Ultrahigh accuracy time synchronization technique operation on the Moon

Ultrahigh accuracy time synchronization technique based on the optical frequency comb and the GHZ radio frequency spiral scanning deflector is suggested to install on the Moon during the ARTEMIS mission. The comparison with the parameters of an analogous device operated in the Earth gravity will enable the testing to high accuracy fundamental physical principles.

ARRT Development for the Upcoming Human Exploration Missions

AbstractThe health risks of space radiation present big challenges to space exploration, with the possibility of large Energetic Solar Particle Events (ESPEs) inducing Acute Radiation Sickness (ARS) during upcoming Artemis missions. An operational software Acute Radiation Risks Tool (ARRT) was developed to directly use measurements from onboard dosimeters to project organ doses during times of increased radiation exposure, so that any possible ARS risks of the astronauts can be modeled and monitored in real time using a data stream at the astronaut location. To enable ARRT to handle variant scenarios of any possible ESPEs in an automatic manner for mission operation, two data sets were employed in developing its modules, one involving historical solar protons recorded over the past four decades and the other using the real‐time telemetry readings of dosimeters onboard International Space Station (ISS). Though vastly different in terms of data cadence, smoothness, and data gaps, all events in these data sets can be correctly processed to output organ doses and ARS risks and generate flight notes for communication within the Flight Control Team (FCT). All these tasks are completed with close interactions between multiple modules developed with many state‐of‐the‐art facilities of full stack web applications. This work demonstrates that ARRT meets the requirement to project radiation exposure and to provide clinical guidelines in very short time steps as the ESPE unfolds, even for the longest event in data sets, making this tool eligible to be tested during the upcoming unmanned Artemis mission and utilized in future space exploration.

Electrostatic waves driven by electron beam in lunar wake plasma

A linear analysis of electrostatic waves propagating parallel to the ambient field in a four component homogeneous, collisionless, magnetised plasma comprising fluid protons, fluid He++, electron beam, and suprathermal electrons following kappa distribution is presented. In the absence of electron beam streaming, numerical analysis of the dispersion relation shows six modes: two electron acoustic modes (modes 1 and 6), two fast ion acoustic modes (modes 2 and 5), and two slow ion acoustic modes (modes 3 and 4). The modes 1, 2 and 3 and modes 4, 5, and 6 have positive and negative phase speeds, respectively. With an increase in electron beam speed, the mode 6 gets affected the most and the phase speed turns positive from negative. The mode 6 thus starts to merge with modes 2 and 3 and generates the electron beam driven fast and slow ion acoustic waves unstable with a finite growth. The electron beam driven slow ion-acoustic waves occur at lower wavenumbers, whereas fast ion-acoustic waves occur at a large value of wavenumbers. The effect of various other parameters has also been studied. We have applied this analysis to the electrostatic waves observed in lunar wake during the first flyby of the ARTEMIS mission. The analysis shows that the low (high) frequency waves observed in the lunar wake could be the electron beam driven slow (fast) ion-acoustic modes.

Scheme design of the CHANG’E-5T1 extended mission

Flight schemes for the CHANG’E-5T1 extended mission are investigated in this paper. In the flight scheme and trajectory design, the remaining propellant of the CHANG’E-5T1 mission is utilized. The CHANG’E-5T1 mission is firstly introduced with feasible flight goals derived based on the terminal trajectory and satellite status. The flight schemes are designed to include a lunar return and the libration points in the Sun-Earth/Moon and Earth-Moon systems, with an emphasis on the Earth-Moon triangle libration point thus far unexplored. Secondly, three schemes are proposed for the CHANG’E-5T1 extended mission with different flight goals. The direct libration point orbit transfer and injection method is adopted to solve the issue in the transfer trajectory design. Furthermore, an innovative concept is proposed to transfer from the Earth-Moon collinear libration point to the triangle point using the Sun-Earth/Moon libration point. Finally, the merits and drawbacks of the three schemes are discussed in terms of flight time, control energy and frequency, flight distance, and goal value. As a result, the scheme including a lunar return and the Earth-Moon L2 libration point is selected for the CHANG’E-5T1 extended mission. A flight to the Earth-Moon libration point is achieved, replicating the achievement of the ARTEMIS mission.

Ion dynamics in magnetotail reconnection in the presence of density asymmetry

AbstractWe present the first dual‐spacecraft observations of antiparallel, asymmetric magnetic reconnection in the Earth's magnetotail. The measurements were made with the comprehensive instrumentation of the ARTEMIS mission at the lunar distance near the dusk flank. The north lobe had high‐density mantle and boundary layer plasma, while the south lobe had a much lower density, consistent with the prevailing solar wind conditions. The two spacecraft observed a finite width reconnection flow channel emanating from a tailward moving X line. Within the jet, the Hall magnetic field polarity corresponding to the high‐density north lobe was enhanced, and the peak flow velocity was shifted toward the low‐density south side, consistent with expectations from simulations. Two counterstreaming populations are seen in the distribution functions in most parts of the exhaust, in contrast to single‐population convective flows reported in a previous asymmetric magnetotail reconnection event. Furthermore, the density difference of the two distinct mixing populations of different density is visible in the exhaust distributions up to ∼150di downstream of the X line. We observe no signatures of Speiser‐like ion motion near the neutral plane, in agreement with theoretical expectations for asymmetric boundary conditions.