To support National Aeronautics and Space Administration's (NASA) lunar habitat plans utilizing hypobaric hypoxia (HH) environments, this study investigated the combined effects of acute hypoxia severity and physical fatigue on astronauts' autonomic nervous system and cardiac responses during manual tasks. Ten subjects conducted repeated 25-kg box manual material handling (MMH) tasks to fatigue across normobaric normoxia (NN, 0 m), moderate (MH, 3500 m), and severe hypobaric hypoxia (SH, 4500 m), while electrocardiogram-derived heart rate variability (HRV) indices were analyzed. Increasing severity of hypoxia evoked a significant decline in parasympathetic markers (root mean square of successive interbeat intervals differences (lnRMSSD, p = 0.032), Poincaré plot standard deviation perpendicular the line of identity (SD1, p = 0.032), natural logarithm of high frequency power (lnHF, p = 0.018)), coupled with a significant increase in heart rate and sympathovagal balance indices (SD2 (Poincaré plot standard deviation along the line of identity)/SD1, p = 0.008; lnLF (natural logarithm of low frequency power)/lnHF, p = 0.001). The number of MMH repetitions at the onset of moderate fatigue under SH was significantly lower than that under NN (p = 0.039). In the SH condition, both the time for each MMH set before (p = 0.036) and following (p = 0.018) the onset of moderate fatigue were significantly longer than those observed under the NN condition. At the moderate fatigue phase, the SD2/SD1 was significantly higher in SH than that in NN(p = 0.01) and SH(p = 0.01). The remaining HRV indices only demonstrated a main effect of time. The findings offer valuable insights into the design of hypoxic environments in extraterrestrial habitats and into the monitoring and safeguarding of astronaut fatigue and cardiovascular safety.

This study aimed to quantify the changes in myocardial glucose uptake in simulated microgravity hindlimb unloading (HU) mice via dynamic F-FDG PET/CT imaging and explore whether Shenqi Fuzheng injection (SFI) could improve myocardial abnormalities. FDG PET quantification suggested that the LV myocardial glucose uptake of HU mice decreased rapidly during the first week of HU, which rebounded temporarily in the second week but declined again during the third and fourth weeks. LV structure (LVAWd, LVAWs, LVPWd, and LV mass) and function (CO, FS and EF) decreased at the fourth week but not at the first week. The SFI improved myocardial glucose uptake during the first week of HU. A positive correlation between global_Ki and LV EF was found. The serum TG and NEFA levels of HU mice were reduced, whereas glucose, insulin and H&E staining revealed no obvious changes. SFI partially ameliorated glycogen accumulation and myocardial fibrosis. RNA sequencing suggested that the SFI might partially improve cardiac function through the TGF-β and apelin signaling pathways. Our results indicated that decreased myocardial glucose uptake might precede and trigger the onset of heart dysfunction induced by HU and that the SFI ameliorated myocardial glucose uptake at the early stage of HU.

Lunar and Martian dusts present emerging health hazards to astronauts, particularly during long-duration missions such as those planned under NASA's Artemis program. These extraterrestrial regoliths possess unique physicochemical properties-such as angular morphology, high surface area, and reactive mineral phases-that distinguish them from terrestrial dust and may influence their biological activity. This review synthesizes current findings from in vitro and in vivo toxicological studies involving lunar and Martian dust and their simulants. Lunar dust, which contains elevated levels of silica and nanophase metallic iron, has been associated with pulmonary inflammation, neutrophilic infiltration, and indications of fibrotic remodeling in animal models. Cell-based assays have also reported apoptosis, necrosis, and pro-inflammatory cytokine production in macrophages, epithelial cells, and fibroblasts following exposure. Martian dust simulants have shown cytotoxic effects and preliminary signs of neurotoxicity in vitro, although these findings are limited and based on analogs that may not fully represent actual Martian material. These findings show certain challenges of extrapolating human risk from simulants that may not fully replicate the properties of actual regolith. Future research must prioritize physiologically relevant inhalation models, and chronic low-dose exposure scenarios. These studies should also account for the combined impact of spaceflight-associated stressors-such as radiation, microgravity, and altered breathing mechanics-on toxicity outcomes. Mechanistic studies incorporating transcriptomic and proteomic tools, alongside standardized methodologies, will be essential for establishing evidence-based safety thresholds for human space exploration.

Spaceflight presents unique physiological challenges, with prolonged exposure to microgravity, cosmic radiation, and psychological stress impacting astronaut health. Hepatic dysfunction may contribute to the pathogenesis of astronaut diseases, including spaceflight-associated neuro-ocular syndrome (SANS), one of the largest physiologic barriers to future spaceflight. This paper explores the interconnected effects of spaceflight on the liver, particularly focusing on alterations in carbohydrate and lipid metabolism, liver injury, inflammation, and compromised biotransformation processes. The liver responds to the extreme conditions of spaceflight, including microgravity and chronic ionizing radiation. These responses include specific changes in gene expression and cytochrome activity, suggesting a complex interplay between the liver, brain, and eyes. This brain-eye-liver axis may be a crucial study area in understanding and mitigating SANS, for long-duration spaceflight (LDSF) missions, emphasizing the need for further research to unravel these complex interdisciplinary connections in the context of LDSF missions.

Biofilms are a community of microorganisms that can form on any surface, posing several challenges and significant medical issues. Their formation is not just limited to Earth but has also been observed in space stations and are termed as space biofilms. This is a major concern as certain biofilms can lead to high-risk compromising crew's health, while others have the capacity to corrode spacecraft and equipment, leading to instrument malfunction, which can jeopardize the mission. Additionally, the way biofilms form and behave in space is different from how they do on Earth due to microgravity. Microgravity and other space conditions intensify microbial biofilm formation, pathogenicity, and antibiotic resistance on spacecraft surfaces. This review examines spacecraft biofilms and their effects on equipment, crew health, and spacecraft. The review also discusses several key microbial species that are known to form biofilms on spacecraft. It highlights how antimicrobial coatings, biofilm disruptors, and multiple detection methods could protect space shuttle integrity and crew health during long missions. It also highlights the disruption and control strategies to mitigate and eradicate biofilms in spaceflight missions. However, significant research is still required to overcome existing challenges of studying space biofilms due to limited data, high cost and replicating space microgravity on earth. Innovative strategies are required for effective biofilm management in space, especially to address biofilm formation under microgravity, investigate antimicrobial efficacy, and to assess its health impacts on astronauts for sustainable long-term missions.

Extended space missions, such as upcoming crewed explorations to Mars, pose significant physiological challenges, including neuroinflammation due to microgravity, cosmic radiation, and prolonged confinement. This article explores therapeutic plasma exchange (TPE) as a potential countermeasure to mitigate post-spaceflight neuroinflammation by reducing circulating neurotoxic factors, stabilizing the blood-brain barrier, and replenishing protective plasma proteins. By examining parallels between spaceflight-induced neurological effects and terrestrial neurodegenerative conditions, we propose that TPE could serve as a viable intervention for astronaut health. The implementation of space-compatible apheresis technologies could play a crucial role in sustaining cognitive function and long-term brain health for deep-space travelers.

Spaceflight-Associated Neuro-ocular Syndrome (SANS) and Neuromyelitis Optica Spectrum Disorder (NMOSD) represent distinct neurological challenges with intriguing parallels in their disruption of central nervous system (CNS) fluid dynamics and the clinical neuro-ophthalmic manifestations. SANS, affecting astronauts during prolonged spaceflight, is characterized by optic disc edema, globe flattening, and vision changes resulting from microgravity-induced cephalad fluid shifts. NMOSD, an autoimmune astrocytopathy, is driven by aquaporin-4 (AQP4) autoantibodies that compromise astrocytic water regulation and blood-brain barrier integrity. This review explores the shared pathophysiological processes of SANS and NMOSD, focusing on AQP4 dysregulation, cerebrospinal fluid dynamics, and neuroinflammatory mechanisms. We examine advanced imaging techniques, biomarkers, and molecular pathways relevant to both conditions, highlighting how insights from NMOSD research might inform our understanding of SANS. The role of the glymphatic system and its potential impairment in both disorders is discussed as a novel perspective on CNS waste clearance. By identifying parallels between SANS and NMOSD, we aim to provide a framework for translating findings between space medicine and terrestrial neuroimmunology. This comparative analysis may drive innovative therapeutic approaches for conditions involving CNS fluid dysregulation, ultimately advancing both astronaut health and patient care for NMOSD and related disorders.

Plants are regarded as a core component of the life support system for crewed space missions, particularly in deep-space endeavors such as lunar and Martian missions. Therefore, understanding the responses of plants to deep-space flight is considered essential. Japonica rice dry seeds (Oryza sativa L.) were carried aboard the Chang'e 5 spacecraft on a flight to the lunar orbit for 23 days. Following their return to Earth, these seeds were planted and cultivated until the tillering and heading stages. Through comparative transcriptomic analysis with the ground control, it was found that rice plants exhibited a significantly higher number of differentially expressed genes (DEGs) during the tillering stage after lunar orbital flight compared to the heading stage, with distinct transcriptional regulatory patterns observed between the two developmental stages. During the tillering stage, dysregulated biological pathways included starch and sucrose metabolism, glycolysis/gluconeogenesis, amino sugar and nucleotide sugar metabolism, plant hormone signal transduction, and cellular wall organization and biogenesis. These pathways also interacted with each other in a complex pattern. During the heading stage, pathways were enriched in glutathione metabolism and photosynthesis. Additionally, certain biological pathways related to defense, development, and secondary metabolism were represented in both developmental stages. In summary, our research reveals stage-specific differences in transcriptional response patterns in rice following lunar orbital flight.

Previous studies have shown that plants can complete their life cycle under microgravity. However, the effects of long-term exposure to altered gravity conditions, including microgravity, on most of the biological processes of a plant's life cycle remain largely unexplored. Given the limited opportunities for space experiments, ground-based experiments using altered gravity conditions have been conducted. To investigate the longer-term effects of centrifugal acceleration, we have developed and utilized a custom-built centrifugal cultivation system using a centrifuge equipped with lighting, enabling the continuous growth of seed plants under centrifugal acceleration. In this study, we examined the effects of 10 g centrifugal acceleration on the biomass of the shoot system (stems and rosette leaves) and the root system of Arabidopsis thaliana for the first time, covering the entire cultivation period from germination to 40 days. Our results showed that the dry mass of the stem per unit length was significantly larger under 10 g compared to the 1 g control, indicating a typical gravity resistance response of the stem. Moreover, the total dry mass of the stems, rosette leaves, and roots was larger under 10 g centrifugal acceleration compared to the 1 g control, suggesting an increase in biomass at the individual plant level. We also observed that the leaf mass per area of the rosette leaf was larger under centrifugal acceleration compared to the 1 g control, indicating enhanced photosynthesis rates in Arabidopsis and resulting in increased biomass of individual plants. In terms of biomass allocation, both root-shoot ratio and root mass fraction were significantly higher under centrifugal acceleration compared to the 1 g control. Furthermore, we measured the concentration of mineral elements in the main stem and rosette leaves using inductively coupled plasma optical emission spectrometry. Despite the increase in dry mass of the root system, we found no significant differences in the concentration of any of the ions between 10 g and 1 g conditions, indicating that mineral nutrient uptake homeostasis is maintained even under centrifugal acceleration.

Long-term exposure to microgravity influences musculoskeletal health and enhances the likelihood of sustaining orthopedic injuries while on a microgravity mission and upon return to Earth. Although countermeasures are being investigated to alleviate some risks of injury, such as resistive (or weight) exercise and Lower Body Negative Pressure (LBNP), evidence is accumulating that current paradigms do not ensure the safety or health of astronauts because of a lack of in-flight diagnostic methods, in which load/diagnostic metrics can be assessed over time. Here, we suggest the integration of a new vision-language large language model (DeepSeek-VL) as a potential autonomous diagnostic agent for monitoring musculoskeletal health in a microgravity environment. DeepSeek-VL will autonomously analyze radiographic data and biomechanical data streamed from a LBNP device. Determinations will be made based on lost or compromised density in bone, lost joint-centered stability, or ineffective loading patterns - providing personalized and specific feedback regarding musculoskeletal health with the astronaut as the primary user. Unlike conventional reporting approaches that rely on cross-institutional analysis by household experts, DeepSeek-VL allows for real-time, and autonomous interpretation of musculoskeletal imaging metrics (and physiological metrics) for on-time personalized countermeasure development. Here, we review architectural adaptations including microgravity specific samplings of data, training protocols and implications of deployment in the ISS. We anticipate DeepSeek's timely development of flight-ready diagnostic reporting will facilitate in-flight/systematic monitoring of musculoskeletal health and safety, especially for astronauts undergoing load management training (e.g., LBNP) and ensure effectiveness of countermeasures, their outputs. We will address methods to circumvent limitations and barriers to risk, and establish the importance of a federated, adaptive, and resilient AI-based platform to mitigate risk for astronaut musculoskeletal health during extended missions. Finally, we address some considerations for terrestrial model and a healthcare authority within a current context of growing importance for effective orthopedic healthcare.

Ocular surface tumors, originating from either the conjunctiva or the cornea, primarily fall into three categories of malignant or premalignant neoplasms: ocular surface squamous neoplasia (OSSN), ocular surface melanocytic tumors, and conjunctival lymphoid tumors. These neoplasms can originate from either the conjunctiva or the cornea. Exposure to space radiation, particularly galactic cosmic rays, and solar particle events, poses a significant threat to astronaut health, including the development of ocular malignancies. As such, the objective of this study was to describe the exposure risk for ocular surface malignancies, current mitigation strategies, and management considerations for a mission to Mars. The current mitigation strategies for space radiation include physical and structural shielding along with dietary interventions. Additionally, management of ocular health during a Mars mission can include holoportation, AI-powered diagnostics, newest in-space surgical technology, optical coherence tomography (OCT), and more. Conclusively, further research and collaboration amongst space and healthcare professionals is necessary to ensure the safety and well-being of astronauts during future space exploration endeavors.

While galactic cosmic rays (GCRs) are inherently isotropic, in several important cases they are constrained to certain solid angle region. This directional irradiation leads to non-trivial deviations in radiation exposure from simple solid angle proportionality, since human organs/tissue sensitive to radiation also exhibit distinct spatial orientations within body. In this paper we investigate GCR incidence patterns through two characteristic geometries: the upper and anterior (front) hemispherical incidence relative to the ICRP110 human voxel phantom, and make comparison with the isotropic incidence. The fluence-to-dose-equivalent conversion coefficients are calculated by the particle physics Monte Carlo toolkit GEANT4, for all the Z=1-28 ions and 27-36 energy points for each ions. Our analysis encompasses both the unshielded configuration and a shielded configuration with a uniform 5 g/cm aluminum shell, approximating spacecraft habitat shielding. We found that upper hemispherical incidence demonstrates ≲10% dose coefficient variation compared to the isotropic baselines, while anterior incidence exhibits pronounced ∼80% higher dose coefficients within the 10 MeV/n to 1000 MeV/n energy range for the unshielded configuration. Dose equivalent rates with hemispherically filtered GCR fluxes show corresponding differences. Interestingly the deviation from solid angle proportionality can be utilized, that strategic astronaut orientation (Earth-facing with eastern alignment) may reduce cumulative radiation exposure by ∼15%.

In the past six decades, the progress of spaceflight projects has won the admiration of the whole world. However, how to evaluate the values of research projects remains an esoteric and cost effective question. To improve the selections in space science projects, we utilized AI tools to provide an overall framework for broader audience. Our work conducted a three-phased study. We explored space life science research as it is one of the most intensively researched areas in space science. We learned the domain science data and constructed a space science knowledge graph. Subsequently, to better extract semantic features, we introduced SpaceBERT, a pre-trained language model fine-tuned with contrastive learning. We then developed SpaceGL, a deep learning framework tailored for predicting frontier research. Lastly, we prioritized candidate space experimental projects based on AI model and compared with the real results from the science panel judges and the "Lottery model."

The space environment presents extreme conditions for the human body. Exposure to such challenging conditions may lead to both short- and long-term health problems. Microgravity and ionizing radiation levels are two major stressors influencing humans in space. Non-terrestrial gravity imposes deleterious effects on human physiology, thereby creating obstacles for long-term space missions. This review explores how microgravity and space radiation influence the physiological well-being of space travelers. Molecular and systemic effects of these stressors on gastrointestinal, cardiovascular, neuro-ocular, and musculoskeletal systems have been discussed. Moreover, the countermeasures in vogue such as exercise, nutrition, and pharmacological interventions, which are critical for maintaining astronaut health have been documented. Additionally, this review highlights the role of cutting-edge health technologies in space sciences research, offering a visionary approach for monitoring, prevention, and treatment of spaceflight-induced disorders. Finally, the review presents a vision, emphasizing the relevance of the current state-of-art from a futuristic perspective, where extreme conditions necessitate enhanced physiological resilience and human performance optimization. Tapping such strategies can help in improving the health, adaptability, and endurance of humans during long-term space missions.

Astronauts on lunar and Martian surfaces face increased health risks due to lack of Earth's protective atmosphere and magnetosphere, including higher cancer and DNA damage risks from cosmic radiation and solar wind. Antioxidant intake, sourced mainly from fresh produce, is crucial for countering these threats. Our research addressed the challenge of producing high-antioxidant vegetables in situ for Bioregenerative Life Support Systems (BLSS), focusing on optimizing growth conditions for lettuce varieties to enhance ascorbic acid synthesis.It aimed to boost ascorbic acid metabolism in lettuce by manipulating green light intensity and nitrogen levels. We tested 'youmaicai' and 'rapid' lettuce under varying green light (10 %, 20 %, 30 %) and nitrogen (2.5, 10.5, 18.5 mmol/L) conditions, assessing ascorbic acid content, total production of ascorbic acid, AsA-GSH cycle enzyme activities, and gene expression. We found optimal conditions for each variety: 10 % light and 2.5-10.5 mmol/L nitrogen for 'youmaicai', and 30 % light and 10.5-18.5 mmol/L nitrogen for 'rapid'. This research not only contributes to the understanding of how green light and nitrogen supply can be optimized to boost the nutritional quality of lettuce but also offers practical strategies for improving crop yield and quality in controlled environments.By tailoring light and nutrient conditions, it is possible to significantly enhance the vitamin C content and overall growth efficiency of plants, which has important implications for sustainable food production both on Earth and in extraterrestrial settings.

An internal jugular venous thrombus in an astronaut was first identified in 2020 following a two-month microgravity exposure. This raised concerns about thromboembolic events (TE) during spaceflights. Studies have suggested that microgravity can induce changes in blood composition, venous flow and endothelial dysfunction, which might all contribute to a hypercoagulable state. However, whether these proposed mechanisms translate into a clinically significant increase in TE risk remains unclear since, even though humans have spent >200 person-years in space, no studies of blood coagulation in microgravity have been carried out. Additionally, the specific risks and implications of microgravity-induced coagulation changes in diverse populations, including future spacefarers with varying health conditions and ages, remain unclear. The precise risks and effects of microgravity-induced coagulation, especially as they relate to diverse groups such as future space travellers with different health conditions and age ranges, remain ambiguous and require further exploration. Thrombelastography (TEG), often used in trauma, surgery and anesthesiology, offers a comprehensive assessment of whole blood coagulation dynamics, providing a more holistic view compared to traditional coagulation assays. In particular, TEG has the ability to predict the hypercoagulable state associated with TE. A previous study of coagulation disorders in a 60-day bedrest setting has provided valuable insights into blood coagulation dynamics, although TEG did not differ in this specific study. However, the transferability of these findings to true microgravity environments remains to be elucidated. Understanding the effects of microgravity on the coagulation process is crucial for ensuring the health and safety of astronauts during space missions. By leveraging thrombelastography to study the end-result of the coagulation cascade, we can obtain valuable insights into the impact of microgravity on the coagulation system and comprehensively evaluate the risk of TE. Furthermore, this knowledge could inform preventive strategies and enhance the safety of future long-duration missions and diverse populations participating in future low-cost spaceflight ventures.

The growing interest in space exploration and human spaceflight has highlighted the critical challenges posed by microgravity on human physiology. Among these, a significant issue is space anemia, which adversely affects Red Blood Cells (RBC) and alters its behavior. RBC depends on biofluids, for their systemic transport, a process that experiences disruption in the microgravity environment. This study aims to quantitatively address the puzzle of how red blood cells are influenced by gravity when they are suspended in bio-fluid. Dissipative Particle Dynamics (DPD) approach was used to model blood and the cell by applying gravity as an external force along the vertical axis and varied from 0g to 2g during parameter sweeps. Key metrics, including Elongation and Deformation indices, pitch angle, and normalized center of mass, were utilized to assess cellular behavior. Results revealed that gravity induces shape changes and spatial alignment in red blood cells. The Elongation Index and the normalized center of mass declined linearly with the applied gravity. Correlation analysis showed a strong correlation between applied gravity and the aforementioned variables. Additionally, forces acting on the cell, such as drag, shear stress, and solid forces, diminished as gravitational force increased. Further analysis indicates that increasing gravity affected the cell's velocity, resulting in prolonged proximity to vessel walls and intensified viscous interactions with surrounding fluid particles, thereby triggering morphological changes. This study provides crucial insights into the biophysical effects of gravity on the red blood cell and presents a significant step toward understanding cellular dynamics under altered gravitational conditions.

Regenerative Life Support Systems (LSS) fulfill the essential functions for human survival in space, such as atmosphere revitalization, water recovery, food production, and waste management, and are crucial for long-term space missions where the resupply of resources from Earth is not feasible or reliable. Operating a regenerative LSS poses several challenges, mainly related to its complexity, efficiency, and reliability. A set of heterogeneous subsystems involving mechanical, chemical, biological, and energetic processes has to be optimally coordinated in order to meet the requirements on mass, power, crew time, safety, reliability, sustainability and efficiency. In this paper, we address these challenges by proposing a supervisory control layer based on a nonlinear and time-varying Model Predictive Control (MPC) approach. The mathematical framework for deriving the prediction model addresses generic regenerative LSS. The MELiSSA (Micro-Ecological Life Support System Alternative) project developed by the European Space Agency is used here as the test case. For the first time, a complete dynamical model including all the MELiSSA compartments connected on all the phases (solid, liquid, gas) is derived, simulated, and controlled by a supervisory MPC. The design of such a controller follows a large set of requirements pre-defined by the MELiSSA project. Results on a mission lasting 14 weeks, which also includes a system failure scenario, are reported and evaluated for a specific MELiSSA network architecture.

Health monitoring for astronauts is critical to ensure the safety and well-being of crew members during long-duration space missions. This paper presents an overview of the technologies developed to monitor various physiological parameters in space, focusing on the challenges posed by the space environment, including microgravity, radiation, and isolation. The paper reviews the evolution of wearable health monitoring systems and analyzes key advancements in sensor technology, AI-driven diagnostics, and data transmission. It evaluates past and present systems, highlighting trends such as improved sensor accuracy, miniaturization for enhanced wearability, and the shift from Earth-dependent monitoring to autonomous, AI-supported health assessments. Despite these advancements, challenges remain, including sensor complexity, data processing limitations, and system longevity. Based on this evaluation, the paper proposes a framework for a next-generation health monitoring system to optimize astronaut health monitoring in deep space. This system integrates minimal yet strategic physiological sensors, machine learning-driven predictive diagnostics, efficient data compression, and adaptive sensing. This review aims to provide insights into the strengths and gaps of existing technologies while suggesting potential advancements for future space missions.

Long-duration spaceflight poses significant risks to ocular health due to prolonged microgravity exposure and space environmental stressors, contributing to conditions such as Spaceflight-Associated Neuro-ocular Syndrome (SANS) and Spaceflight-Associated Dry Eye Syndrome (SADES). These conditions, along with radiation exposure and risk of ocular trauma in resource-limited environments, necessitate development of innovative countermeasures to safeguard astronauts' vision, particularly for future planetary missions such as Mars. Traditional ophthalmic care depends on specialized equipment and materials impractical for cargo limitations and transport in space, highlighting the need for adaptive solutions. Advances in 3D printing and bioprinting offer an innovative approach to space ophthalmology by enabling on-demand fabrication of customized eyewear, contact lenses, moisture chambers, radiation-shielding lenses, and surgical tools. Furthermore, emerging bioprinting capabilities may facilitate production of biocompatible tissues for ocular repair. The precision, adaptability, and mission-specific applicability of 3D printing provide a strategic advantage to address preventive and therapeutic ocular health needs. However, challenges include optimizing biocompatible materials, refining high-resolution printing techniques, and ensuring structural and functional viability of printed tissues in space conditions. Further research is required to improve material durability, integrate protective elements such as boron nitride nanotubes, and adapt 3D printing processes to the constraints of microgravity. Beyond space medicine, 3D printing applications in space can drive innovations for ophthalmic care on Earth, from customized intraocular lenses to regenerative therapies. This review highlights the critical role of 3D printing in space ophthalmology and need for continued development and deployment to ensure success of future deep-space missions.

Cardiovascular disease remains an important challenge for human space travel, it is particularly important for astronaut health to accurately simulate cardiac conditions in weightless environments. In this study, a coupled flow-solid model of the left ventricular (LV) and mitral valve (MV) is developed by the immersed boundary/finite element (IB/FE) method, and the boundary conditions of the model were determined from the relationship between gravitational level, LV sphericity and LV end-diastolic pressure. Based on this model, the dynamic deformation and haemodynamic parameters of the LV and the MV are investigated in different gravitational environments, such as Zero Gravity, the Moon (0.167 g), the Mars (0.38 g) and the Earth. The validity and accuracy of the model is verified by comparing the Zero Gravity simulation results with the real data obtained from the space flight experiment. The prediction results of the model can provide some references on how to combat the adverse effects of weightlessness during spaceflight.