npj Microgravity最新文献

Space missions require sustainable life support systems capable of producing oxygen and biomass under microgravity. We report the use of acoustic levitation to trap and manipulate the filamentous cyanobacterium Limnospira indica PCC 8005 during parabolic flights. Within a millimeter-scale fluidic chamber, this helical microorganism rapidly assembles into thin layers under a standing ultrasonic wave. Stable trapping in microgravity requires substantially less acoustic power (0.42 mW) than on Earth (1.4 mW), highlighting the potential for energy-efficient bioprocessing in space. Monte Carlo simulations and light attenuation modeling show that layered structuring enhances light penetration, potentially overcoming the "compensation point" limitation in bulk cultures. These findings open new perspectives for photobioreactors using acoustic manipulation to boost photosynthetic efficiency and reduce energy demands for oxygen and biomass production in space.

Spaceflight stressors such as microgravity and radiation disrupt mitochondria in ocular tissues, leading to impaired energy production, oxidative stress, and reduced repair capacity. The anatomical distribution of mitochondria and disease localization presents an interesting relationship: cortical lens mitochondria align with the type of cataracts seen in spaceflight, while retinal mitochondria correspond to the pathology of SANS. These observations suggest mitochondrial damage may be more central to spaceflight-associated pathologies than previously recognized.

Human expansion into deep space necessitates sustainable life support. Current prepackaged food systems face nutritional, logistical, and psychological limits on long missions. Cell agriculture, particularly yeast-based biomanufacturing, emerges as a pivotal solution. Yeast's genetic flexibility, metabolic resilience, and tolerance to extreme conditions make it an ideal chassis for in-situ food and nutrient production. This review systematically explores yeast's application in creating closed-loop space food systems, analyzing its progress, challenges, and future potential for enabling sustained extraterrestrial presence.

Microgravity provides a unique model for accelerated skeletal muscle loss and potentially muscle ageing. During spaceflight, astronauts experience pronounced muscle atrophy, similar to age-related decline on Earth but over a much shorter timescale. Despite daily aerobic and resistance exercise on the International Space Station (ISS), countermeasures remain suboptimal, reflecting similar challenges seen in ageing populations. The MicroAge Mission used microgravity on the ISS to assess whether the molecular mechanisms behind reduced adaptive responses to contractile activity during ageing resemble those triggered by spaceflight. It also tested proof-of-concept genetic interventions, including Heat Shock Protein 10 (HSP10) overexpression, to mitigate muscle atrophy and functional loss. A tissue-engineering approach was used to fabricate human skeletal muscle constructs secured to 3D-printed scaffolds. These scaffolds incorporated microfluidic channels to interface with the flight hardware's fluid-handling system. The hardware, developed by Kayser Space Ltd, was designed to operate with the European Space Agency's (ESA) Kubik incubator on the ISS. This research addresses key methodological constraints in low Earth orbit (LEO) experimentation, outlining pre-flight protocol development, muscle construct biofabrication methods, and operational considerations. The findings provide a translational framework for future studies on musculoskeletal degeneration, with implications for therapies targeting both terrestrial ageing and astronaut musculoskeletal health.

The adverse effects of spaceflight on skeletal health are well documented; however, the onset and underlying mechanism of these changes remain poorly understood. This study investigated alterations in bone microarchitecture, density, strength, and remodeling in eight crew members (four males, four females) aboard the SpaceX Crew Dragon spacecraft as part of the Fram2 and Polaris Dawn missions. The primary aim of this study was to investigate the impact of short-duration spaceflight (3-5 days) on bone strength and microarchitecture to determine the onset of bone deterioration. Secondary objectives included examining how these changes compared to typical age-related bone loss and potential sex-specific differences in the skeletal response to microgravity. High-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the distal radius and tibia were performed pre- and post-spaceflight. Postflight, the tibia demonstrated significant reductions in total bone density (p < 0.05), and adverse alterations in trabecular bone microarchitecture, including decreased trabecular bone density (p < 0.05), trabecular thickness (p < 0.01) and separation (p < 0.05). In contrast, the radius exhibited no significant changes in bone density, microarchitecture or strength. These findings suggest there is early onset of bone loss and microstructural changes following 3-5 days in microgravity, highlighting the value of short-duration missions for studying skeletal deterioration that may be used for the future development and assessment of targeted skeletal countermeasures.

Anabaena, a nitrogen-fixing cyanobacterium from the Nostocaceae family, is a promising chassis for sustained space exploration. Using NEKO, this study surveys 2000 publications on Anabaena and summarizes the research, including systems biology, modeling, and potential space applications. Future research should examine its metabolism in space environments, such as microgravity and radiation, and develop bioreactor designs and genetic tools for reliable, self-regulating biomanufacturing systems in these environments.

Our study investigates the effects of long-duration spaceflight on brain aging in spacefarers using structural MRI and machine learning models. Pre-, post-, and follow-up scans of ROS cosmonauts ESA astronauts, and matched Earth-bounding controls were analyzed. We found a considerable difference between the spacefareres and the control group, especially in the ESA cohorts (ß = 0.63). In the ROS cohorts, we observed a difference between the pre- and post-flight scans. A post-hoc analysis revealed that the pre-flight brain age delta was 0.842 years less than the immediate post-flight brain age delta after long-duration spaceflight. All three machine learning models showed good to excellent intraclass correlation coefficients (ICC) between the two consecutive MRI sessions. Our findings suggest that long-duration spaceflight may have an effect on human brain aging as observed from MRI.

Understanding thermophysical properties such as surface tension (σ), total hemispherical emissivity (ε), specific heat capacity (c_p) and viscosity (η) as a function of temperature is essential for optimizing the vitrification of bulk metallic glasses (BMGs). In this study, the thermophysical properties of liquid Vit106a were measured aboard the International Space Station (ISS) using the electromagnetic levitator (EML). The surface tension σ exhibited a similar value with other Zr-based BMG, with a weak temperature dependence described by σ(T) = 1.557-4.36 ×10^-5 × (T - 1106) N.m^-1. The viscosity temperature-dependence η(T) was analyzed using the Vogel-Fulcher-Tammann (VFT) equation, yielding a kinetic fragility parameter of D* = 9.8 at high temperature, compared to D* = 21.6 at low temperature, that indicates a fragile-to-strong transition characteristic of Zr-based metallic glass formers. XRD analysis confirms full crystallization of the sample, despite being cooled at a rate of 16 K.s⁻¹, over nine times faster than the critical cooling rate of 1.75 K.s⁻¹ reported in the literature. The crystallized sample reveals a heterogeneous distribution of binary intermetallic phases, including ZrAl₃, Zr₂Cu, Zr₂Ni, ZrAl and Nb₂Ni. These findings provide insights into the thermophysical behavior of liquid Vit106a for large-scale manufacturing but also raise important questions regarding its good glass-forming ability for larger casting thickness.

Microgravity strongly affects human physiology during spaceflight. Biological sex has not yet been sufficiently considered as a variable for spaceflight deconditioning. The VivalDI studies investigated physiological systems affected by 5-days dry immersion (DI) in females and males, with a focus on immune changes in this report. In both sexes proportions of peripheral granulocytes and NK cells were elevated during DI and T-cell numbers were reduced. Leukocyte activation and cytokine levels were moderately affected. Females showed a higher Torque-Teno-virus shedding at the end of DI. Noradrenaline concentrations increased during the study with sex-specific patterns. Hemodynamics suggest that immunological changes were caused by DI-induced fluid shifts. Moreover, male study participants' patterns were compared to a historical data set from a 5-days head-down-tilt bed rest (HDT-BR) study. Changes in leukocyte proportions and body fluid indicators were stronger in DI versus HDT-BR. These analyses indicate that fluid shifts primarily drive intervention-related immune-physiological differences, independent of biological sex. ClinicalTrials.gov, TRN: NCT05043974 and NCT05493176.

Experiments conducted onboard the International Space Station help investigate the physiological changes that living organisms undergo in microgravity. On Earth, the two-axis clinostat serves as an alternative that can continuously change the direction of gravity and simulate microgravity conditions by time-averaging the gravity vector. However, its structural characteristics inevitably produce poles where gravity is unevenly concentrated. This study conducted a quantitative analysis and comparison of pole formation across four representative clinostat control strategies. To evaluate the poles, two quantitative indicators were defined. The commonly used control strategies, maintaining a constant angular velocity or following a random distribution, were found to induce severe poles. In contrast, when the angular velocity of the external motor followed a specifically designed reciprocal sinusoidal profile, pole formation could be significantly reduced by adjusting the ratio between the minimum and maximum angular velocities. These trends, identified through simulations, were further validated through experiments using an inertial measurement unit.