Search Results (191)

The aim of this work is to provide an extensive experimental study of the performance of a novel magnetically and gas-flow-stabilized arc discharge for carbon dioxide (CO₂) conversion and oxygen (O₂) production on Mars. The proposed discharge provides an additional degree of freedom for easy scalability by adjusting its length. The discharge is examined at a pressure range of 200–612 mbar in order to optimize it for oxygen production on Mars, where low-pressure operation is preferable due to energy costs. Additionally, two quenching configurations with an actively cooled region are evaluated. They are compared to a benchmark configuration without additional cooling. Two high-voltage power supplies (PSs) are used, and the results are compared—a constant direct current (DC) and a pulsed unipolar current. The pulsed power supply offers better CO₂ conversion performance at lower pressure due to stable operation in an arc regime. The energy cost for oxygen production on Mars is also presented, including a conservative estimation of the energy needed for compressing the Martian atmosphere at ambient pressure to the discharge operational pressure. It is discussed how this affects the energy cost of oxygen production. Full article

As humanity prepares for prolonged space missions and future extraterrestrial settlements, developing reliable and resilient food-production systems is becoming a critical priority. Space agriculture, the cultivation of plants beyond Earth (particularly on the Moon and Mars), faces a constellation of interdependent environmental, biological, and engineering challenges. These include limited solar radiation, elevated ionizing radiation, large thermal variability, non-Earth atmospheric pressures, reduced gravity, regolith substrates with low nutrient-holding capacity, high-CO₂/low-O₂ atmospheres, pervasive dust, constrained water and nutrient availability, altered plant physiology, and the overarching need for closed-loop, resource-efficient systems. These stressors create an exceptionally challenging environment for plant growth and require tightly engineered agricultural systems. This review examines these constraints by organizing them across environmental differences, resource limitations, biological adaptation, and operational demands, emphasizing their systemic interdependence and the cascading effects that arise when one subsystem changes. By integrating findings from planetary science, plant biology, space systems engineering, biotechnology, robotics, and controlled-environment agriculture (CEA), the review outlines current limitations and highlights emerging strategies such as regolith utilization, advanced hydroponics, crop selection and genetic engineering, and the use of robotics, sensors, and artificial intelligence (AI) for monitoring and automation. Finally, the article underscores the broader relevance of space–agriculture research for terrestrial food security in extreme or resource-limited environments, providing a structured foundation for designing resilient and sustainable agricultural systems for space exploration and beyond. Full article

This study explores the aerodynamic behavior of bioinspired airfoils under extremely low Reynolds number conditions, simulating those found in the Martian atmosphere. Modified NACA 0018 profiles with sinusoidal leading-edge tubercles were tested to assess their influence on flow separation and overall aerodynamic performance. Experiments were carried out in a hydrodynamic towing tank using ink-based flow visualization, enabling detailed observation of the evolution of the separation point with varying angles of attack. The study focuses on comparing different tubercle configurations, analyzing how wavelength and orientation affect the aerodynamics of the airfoil. The results showed variations in flow stability and delayed separation compared to the baseline profile, indicating potential aerodynamic benefits. These findings offer valuable insights for the application of bioinspired geometries in the design of aerial platforms intended for Mars exploration and low-speed flight regimes, with special attention paid to Micro Aerial Vehicles (MAVs). Full article

Understanding the thermal behaviour of radioisotope generators under Martian conditions is essential for the safe and efficient operation of planetary exploration rovers. This study investigates the heat transfer and flow mechanisms around a simplified full-scale model of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) by means of Computational Fluid Dynamics (CFD) simulations performed with ANSYS Fluent 2023 R1. The model consists of a central cylindrical core and eight radial fins, operating under pure CO₂ at a pressure of approximately 600 Pa, representative of the Martian atmosphere. Four cases were simulated, varying both the reactor surface temperature (373–453 K) and the ambient temperature (248 to 173 K) to reproduce typical diurnal and seasonal scenarios on Mars. The results show the formation of a buoyancy-driven plume rising above the generator, with peak velocities between 1 and 3.5 m/s depending on the thermal load. Temperature fields reveal that the fins generate multiple localized hot spots that merge into a single vertical plume at higher elevations. The calculated dimensionless numbers (Grashof ≈ 10⁵, Rayleigh ≈ 10⁵, Reynolds ≈ 10², Prandtl ≈ 0.7, Nusselt ≈ 4) satisfy the expected range for natural convection in low-density CO₂ atmospheres, confirming the laminar regime. These results contribute to a better understanding of heat dissipation processes in Martian environments and may guide future design improvements of thermoelectric generators and passive thermal management systems for space missions. Full article

Cells of Serratia liquefaciens were grown on trypticase soy agar (TSA) for 28 d under Martian conditions of 7 mbar, 0 °C, and CO₂-enriched anoxic atmospheres (called Mars low-PTA conditions). Earth controls were maintained for 24 h at 1013 mbar, 30 °C, and a standard pN₂/pO₂ gas composition. Cells were harvested at either 24 h or 28 d from TSA surfaces and processed for SEM and TEM imaging. Cells of S. liquefaciens grown under Earth conditions were uniform in shape and size, averaging approximately 1.25 µm in length and 0.5 µm in width. Fimbriae were observed on 10–20% of cells grown under Earth conditions. Key features of low-PTA grown cultures were (1) cells exhibited swollen blunt ends at sites of cell division tapering to unusually constricted points on the distal ends of progeny cells, (2) cell division appeared disrupted with division planes occurring at odd angles often forming right-angle oriented daughter cells, (3) some cells failed to form divisional planes resulting in long spiral and oddly shaped cells measuring up to 6–8 µm in length, and (4) fimbriae were lacking. Cell walls were found to be approx. 17% thinner when cells were grown in low-PTA environments compared to lab-standard conditions. Full article

Dust storms have a significant impact on the Martian atmosphere and climate. Previous studies have found that regional and global dust storms mainly occur in the Mars perihelion season. However, an anomalous spring regional dust storm occurred in the aphelion season of Martian year 35 (MY 35). The occurrence and evolution of this new type of large dust storm and its impact on the Martian atmosphere are not yet fully understood. Using Mars Climate Sounder (MCS) dust observations, this study investigates the evolutionary characteristics of the MY 35 anomalous spring storm during its pre-storm, onset, expansion, and decay phases, by comparing it with other types of regional dust storms. The evolution of the MY 35 anomalous spring dust storm is more similar to that of the MY 35 C storm, showing north–south mirror symmetry relative to the equator, suggesting that the two storms may have similar evolutionary mechanisms. Additionally, we analyze the effects of the anomalous MY 35 storm on the atmospheric thermal and dynamical structures using a combination of MCS temperature observations and LMD-GCM wind simulation results. Eastward winds in the high latitudes of both hemispheres and westward winds in the low-to-mid latitudes are significantly enhanced during the storm, corresponding to the change in the atmospheric thermal structure and the global circulation. Finally, we performed a preliminary analysis of changes in the wind field during the spring dust storm in the Chryse and Utopia plains, which are two potential landing areas for China’s Tianwen-3 Mars sample-return mission. The vertical profiles of the simulated horizonal wind in the two plains show that, during the E storm peak time, the change in daily mean wind speed is significant above 20 km, but relatively small in the atmospheric boundary layer below ~5 km. Within the boundary layer, the horizontal wind speed shows remarkable diurnal variation, remaining relatively low during the midday hours (10:00 a.m. to 4:00 p.m.). These results can provide necessary environmental parameters related to spring dust storms for China’s Tianwen-3 mission. Full article

We investigated the ammoxidation of methanol for the production of hydrogen cyanide. Silica-supported FeMo oxide catalysts achieved above 98% conversion of methanol, with more than 90% selectivity for the ammoxidation reaction product, HCN. The oxidation products, CO and CO₂, were formed with a molar selectivity less than 10%, depending on the operating conditions. The kinetics of the ammoxidation of methanol were investigated in a fixed-bed tubular reactor at 320–445 °C and atmospheric pressure. A Mars–van Krevelen model accounted for the ammoxidation of methanol as well as the formation of CO and CO₂. The Levenberg–Marquardt algorithm was used to estimate the model parameters, which were statistically significant and fit the experimental data well. The model can be used to simulate and guide the operation of the industrial reactor. Full article

The presence of solid particles (or droplets) in a flow leads to a significant increase in heat fluxes, the occurrence of chemical reactions, and erosive surface wear of various aircraft moving in the dusty (or rainy) atmosphere of Earth or Mars. A review of computational, theoretical, and experimental work devoted to the study of the characteristics of the boundary layers (BL) of gas with solid particles was performed. The features of particle motion in laminar and turbulent boundary layers, as well as their inverse effect on gas flow, are considered. Available studies on the stability of the laminar boundary layer and the effect of particles on the laminar–turbulent transition are analyzed. At the end of the review, conclusions are drawn, and priorities for future research are discussed. Full article

This paper proposes a closed-loop nonlinear model predictive control for the first time for the trajectory tracking of a spaceplane descending and gliding on Mars. Previous studies presented the optimization of descending trajectory solving optimal control problems to reach a specific region (longitude, latitude, and altitude) by the end of the atmospheric flight. Following those approaches, in this work, an optimal trajectory was selected for a semi-optimal controller, specifically the nonlinear model predictive control. This controller and its robustness were validated through Monte Carlo simulations, demonstrating that it is robust enough to direct the spaceplane along the reference path, even when the atmospheric density changes by 15% of the standard deviation. Full article

In response to problems such as large target scale variations, strong background noise, and blurred features leading by low contrast in infrared target detection in near space environments, this paper proposes an efficient detection model, YOLO-MARS, which is based on YOLOv8. The model introduces a Space-to-Depth (SPD) convolution module into the backbone section, which retains the detailed features of smaller targets by downsampling operations without information loss, alleviating the loss of the target feature caused by traditional downsampling. The Grouped Multi-Head Self-Attention (GMHSA) module is added after the backbone’s SPPF module to improve cross-scale global modeling capabilities for target area feature responses while suppressing complex thermal noise background interference. In addition, a Light Adaptive Spatial Feature Fusion (LASFF) detector head is designed to mitigate the scale sensitivity issue of infrared targets (especially smaller targets) in the feature pyramid. It uses a shared weighting mechanism to achieve adaptive fusion of multi-scale features, reducing computational complexity while improving target localization and classification accuracy. To address the extreme scarcity of near space data, we integrated 284 near space images with the HIT-UAV dataset through physical equivalence analysis (atmospheric transmittance, contrast, and signal-to-noise ratio) to construct the NS-HIT dataset. The experimental results show that ${mAP}_{@0.5}$ increases by 5.4% and the number of parameters only increase 10% using YOLO-MARS compared to YOLOv8. YOLO-MARS improves the accuracy of detection significantly while considering the requirements of model complexity, which provides an efficient and reliable solution for applications in near space infrared target detection. Full article

Accurate trajectory control during atmospheric entry is critical for the success of Mars landing missions, where strong non-linearities and uncertain dynamics pose significant challenges to conventional control strategies. This study develops a computational framework that integrates fuzzy parameter-varying models with Lyapunov-based analysis to achieve robust trajectory stabilization of Mars entry vehicles. The non-linear longitudinal dynamics are reformulated via sector-bounded approximation into a Takagi–Sugeno fuzzy parameter-varying model, enabling systematic gain-scheduled controller synthesis. To reduce the conservatism typically associated with quadratic Lyapunov functions, a fuzzy Lyapunov function approach is adopted, in conjunction with the Full-Block S-procedure, to derive less restrictive stability conditions expressed as linear matrix inequalities. Based on this formulation, several controllers are designed to accommodate the variations in atmospheric density and flight conditions. The proposed methodology is validated through numerical simulations, including Monte Carlo dispersion and parametric sensitivity analyses. The results demonstrate improved stability, faster convergence, and enhanced robustness compared to existing fuzzy control schemes. Overall, this work contributes a systematic and less conservative control design methodology for aerospace applications operating under severe non-linearities and uncertainties. Full article

Development of sustainable agriculture on Mars is a critical step towards its colonisation. However, Martian regolith is coarse-grained, and its mineral profile differs significantly from that of terrestrial arable soil, resulting in poor seed germination success and stunted plant development. This study investigates whether germination success and plant growth can be improved by exposing seeds and plants to water enriched with either i) biochemically active reactive oxygen and nitrogen species generated by atmospheric pressure plasma (PAW) or (ii) nano-/micro-bubbles and minerals such as potassium and calcium extracted from Aquapulse^® feldspar (APW), a type of rock that is readily available on Mars, at different stages of the crop lifecycle. As a crop model, microgreen crops of B. oleracea and M. sativa are chosen for their short growth cycle, low resource requirements, and high nutritional value. For B. oleracea crops, soaking of seeds in PAW followed by irrigation with APW led to an increase in germination by ~566.7%, in biomass by 412.4%, and in chlorophyll content by 17.7% compared to crops grown using normal water for seed soaking and irrigation. For M. sativa crops, the use of APW for soaking and irrigation yielded an increase of 41.7% in seed germination and 45.2% in crop biomass, whereas the use of PAW for both soaking and irrigation resulted in the greatest improvement in seed germination, 41.7%, when compared to control. These results suggest that, with further optimisation, a regiment of treatment with PAW and APW in place of normal water can be used to address stage-specific challenges of the crop lifecycle in Martian regolith. As amending Martian regolith with a minimum of 1% organic matter is required to promote healthy plant development, further studies should investigate the use of plasma-mediated reforming of biowaste for in situ production of e.g., biochar. Full article

Legged rovers are gaining interest for planetary exploration due to their high mobility. However, loose regolith on celestial surfaces like the Moon and Mars often leads to slippage as legs disturb the soil. To address this, a walking technique has been proposed that enhances soil support by transmitting vibrations from the robot’s legs. This approach aims to improve mobility by increasing the ground’s bearing capacity. To evaluate its effectiveness in space-like environments, this study experimentally investigates the effect of vibration on bearing capacity under low atmospheric pressure, which can influence soil behavior due to reduced air resistance. Using Silica No. 5 and Toyoura sand as test materials, experiments were conducted to compare bearing capacities under standard and low pressure. The results demonstrate that applying vibration significantly improves bearing capacity and that the influence of atmospheric pressure is minimal. These findings support the viability of vibration-assisted locomotion for planetary rovers operating in low-pressure extraterrestrial environments. Full article

Mars has been a primary focus of planetary science, with significant advancements over the past two decades across disciplines including geological evolution, surface environment, and atmospheric and space science. However, the rapid growth of the related literature has rendered traditional manual review methods increasingly inadequate. This inadequacy is particularly evident in interdisciplinary research, which is often characterized by dispersed topics and complex semantics. To address this challenge, this study proposes an automated analysis framework based on natural language processing (NLP) to systematically review the Martian research in Earth and space science over the past two decades. The research database contains 151,196 Mars-related sentences extracted from 10,655 publications spanning 2001 to 2024. Using machine learning techniques, the framework clusters Mars-related sentences into semantically coherent groups and applies topic modeling to extract core research themes. It then analyzes their temporal evolution across the Martian solid, surface, atmosphere, and space environments. Finally, through sentiment analysis and semantic matching, it highlights unresolved scientific questions and potential directions for future research. This approach offers a novel perspective on the knowledge structure underlying Mars exploration and demonstrates the potential of NLP for large-scale literature analysis in planetary science. The findings potentially provide a structured foundation for building an interdisciplinary, peer-reviewed Mars knowledge base, which may inform future scientific research and mission planning. Full article

Transient increments of X-ray radiation and extreme ultraviolet (EUV) during solar flares are strong drivers of thermospheric dynamics on Mars, yet their class-dependent impacts remain poorly measured. This work provides the first direct, side-by-side study of Martian thermospheric reactions to flares X8.2 on 10 September 2017 and M6.0 on 17 September 2017. This study shows nonlinear, class-dependent effects, compositional changes, and recovery processes not recorded in previous investigations. Species-specific responses deviated significantly from irradiance proportionality, even though the soft X-ray flux in the X8.2 flare was 13 times greater. Argon (Ar) concentrations rose 3.28× (compared to 1.13× for M6.0), and radiative cooling led CO₂ heating to approach a halt at ΔT = +40 K (X8.2) against +19 K (M6.0) at exobase altitudes (196–259 km). N₂ showed the largest class difference, where temperatures rose by +126 K (X8.2) instead of +19 K (M6.0), therefore displaying flare-magnitude dependent thermal sensitivity. The 1.95× increase in O concentrations during X8.2 and the subsequent decrease following M6.0 (−39 K cooling) illustrate the contradiction between photochemical production and radiative loss. The O/CO₂ ratio at 225 km dropped 46% during X8.2, revealing compositional gradients boosted by flares. Recovery timeframes varied by class; CO₂ quickly re-equilibrated because of effective cooling, whereas inert species (Ar, N₂) stabilized within 1–2 orbits after M6.0 but needed >10 orbits of the MAVEN satellite after the X8.2 flare. The observations of the X8.2 flare came from the western limb of the Sun, but the M6.0 flare happened on the far side. The CME shock was the primary driver of Mars’ EUV reaction. These findings provide additional information on atmospheric loss and planetary habitability by indicating that Mars’ thermosphere has a saturation threshold where strong flares induce nonlinear energy partitioning that encourages the departure of lighter species. Full article