Spaceflight Conditions Research Articles

ДОЛГОСРОЧНЫЕ ИЗМЕНЕНИЯ ВПОВЕДЕНИИ И НЕЙРОХИМИЧЕСКИХ ОСОБЕННОСТЯХ РАБОТЫ ГОЛОВНОГО МОЗГА КРЫС ПОСЛЕ КОМБИНИРОВАННОГО ВОЗДЕЙСТВИЯ ГИПОГРАВИТАЦИИ И ИОНИЗИРУЮЩИХ ИЗЛУЧЕНИЙ, МОДЕЛИРУЕМЫХ В НАЗЕМНОМ ЭКСПЕРИМЕНТЕ

We investigated the effects of combined exposure to hypogravity and ionizing radiations on neurochemical processes in key structures of the rat's brain leading to long dated changes in behavior. The authoring procedure consisted of a synchronous combination of chronic tail-suspension, gamma- irradiation and irradiation by 12С ions in an effort to extrapolate results of the ground-based experiment on real spaceflight conditions (Mars mission). The modeled factors brought about significant changes in animal behavior and metabolism of neuromediators that persisted for several months, that is roughly a quarter of this animal's life. The behavior analysis (Morris labyrinth) suggests sustained major disorders in spatial memory and orientation. Data of neurochemical analysis demonstrate also lasting shifts in dopamine metabolism.

Dried Urine Spot Analysis for assessing cardiovascular drugs exposure applicable in spaceflight conditions

Cardiovascular pharmacological countermeasures will be required as a preventive measure of cardiovascular deconditioning and early vascular ageing for long term space travelers. Physiological changes during spaceflight could have severe implications on drug pharmacokinetics and pharmacodynamics (PK/PD). However, limitations exist for the implementation of drug studies due to the requirements and constraints of this extreme environment. Therefore, we developed an easy sampling method on dried urine spot (DUS), for the simultaneous quantification of 5 antihypertensive drugs in human urine: irbesartan, valsartan, olmesartan, metoprolol and furosemide analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), considering spaceflight parameters. This assay was validated in terms of linearity, accuracy, and precision with satisfactory results. There were no relevant carry-over, matrix interferences. The targeted drugs were stable in urine collected by DUS until 6 months at +21 °C, +4°C, −20 °C (with or without desiccants) and at 30 °C during 48 h. Irbesartan, valsartan and olmesartan were not stable at 50 °C during 48 h. This method was found to be eligible for space pharmacology studies in terms of practicality, safety, robustness and energy costs. It has been successfully implemented in space tests programs led in 2022.

Drosophila melanogaster Oocytes after Space Flight: The Early Period of Adaptation to the Force of Gravity

The effect of space flight factors and the subsequent adaptation to the Earth's gravity on oocytes is still poorly understood. Studies of mammalian oocytes in space present significant technical difficulties; therefore, the fruit fly Drosophila melanogaster is a convenient test subject. In this study, we analyzed the structure of the oocytes of the fruit fly Drosophila melanogaster, the maturation of which took place under space flight conditions (the "Cytomehanarium" experiment on the Russian Segment of the ISS during the ISS-67 expedition). The collection of the oocytes began immediately after landing and continued for 12 h. The flies were then transferred onto fresh agar plates and oocyte collection continued for the subsequent 12 h. The stiffness of oocytes was determined by atomic force microscopy and the content of the cytoskeletal proteins by Western blotting. The results demonstrated a significant decrease in the stiffness of oocytes in the flight group compared to the control (26.5 ± 1.1 pN/nm vs. 31.0 ± 1.8 pN/nm) against the background of a decrease in the content of some cytoskeletal proteins involved in the formation of microtubules and microfilaments. This pattern of oocyte structure leads to the disruption of cytokinesis during the cleavage of early embryos.

The approach to numerical simulation of the spatial movement of fluid with forming free gas inclusions in propellant tank at space flight conditions

The space propulsion systems ensure se veral start-ups and shutdowns of main liquid-propellant rocket engines under microgravity conditions for the spacecraft program movements and reorientation control. During the passive flight of the space stage (after its main engine shutdown), the liquid propellant in the tanks continues to move by inertia in microgravity away from the propellant management device as much as possible. In this case, the pressurization gas is displaced to the propellant management device, which creates the potential danger of gas entering the engine inlet in quantities unacceptable for the reliable engine restart. In this regard, determining the parameters of fluid movement in propellant tanks in microgravity conditions is an urgent problem that needs to be solved in the design period of liquid propulsion systems. We have developed an approach to the theoretical computation of the parameters of the motion of the ‘gas — fluid’ system in the propellant tanks of modern space stages in microgravity conditions. The approach is based on the use of the finite element method, the Volume of Fluid method and modern computer tools for finite-element analysis (Computer Aided Engineering — CAE systems). For the passive leg of the launch vehicle space flight, we performed mathematical modeling of the spatial movement of liquid propellant and forming free gas inclusions and determined the parameters of movement and shape of the free surface of the liquid in the tank as well as the location of gas inclusions. The numerical simulation of the fluid movement in an experimental sample of a spherical shape tank was performed with regard to the movement conditions in the SE Yuzhnoye Design Bureau ‘Drop tower’ for studying space object s in microgravity. The motion parameters of the ‘gas — fluid’ interface obtained as a result of mathematical modeling are in satisfactory agreement with the experimental data obtained. The use of the developed approach will significantly reduce the amount of experimental testing of the designed space stages.

Applications of methods of psychological support developed for astronauts for use in medical settings.

Over the past 40 years, psychological support (PS) for cosmonauts and astronauts has remained an important part of the regular biomedical provision of space crews during extended orbital flights. It includes well-developed principles and a set of methods that have proven its effectiveness for the maintenance of behavioral health under extreme conditions of space flight. The main principle of PS in flight is to restore the usual sensory input to compensate for the monotony and lack of external stimuli as a result of a long stay under isolation and confinement. Risk factors for the psychological health and well-being defined for the astronauts, such as sensory and social deprivation, monotony, confinement, and lack of privacy, also remain part and parcel of several civil professions. These include polar wintering, submarines, working on oil platforms, and ocean fishing. Most of these factors also adversely affect the recovery rate of a large contingent of medical institutions, especially bedridden patients with chronic diseases. Finally, due to the negative epidemiological situation associated with the spread of COVID-19, an increasingly wide range of citizens forced to be in self-isolation faces negative manifestations of the deprivation phenomena described previously. Several cases of successful use of PS under isolation, monotony, crowding, and confinement are presented. Thus, we assume that the use of psychological support methods developed for space flights could be extremely relevant in civil medicine and everyday life.

Real and Simulated Microgravity: Focus on Mammalian Extracellular Matrix.

The lack of gravitational loading is a pivotal risk factor during space flights. Biomedical studies indicate that because of the prolonged effect of microgravity, humans experience bone mass loss, muscle atrophy, cardiovascular insufficiency, and sensory motor coordination disorders. These findings demonstrate the essential role of gravity in human health quality. The physiological and pathophysiological mechanisms of an acute response to microgravity at various levels (molecular, cellular, tissue, and physiological) and subsequent adaptation are intensively studied. Under the permanent gravity of the Earth, multicellular organisms have developed a multi-component tissue mechanosensitive system which includes cellular (nucleo- and cytoskeleton) and extracellular (extracellular matrix, ECM) “mechanosensory” elements. These compartments are coordinated due to specialized integrin-based protein complexes, forming a distinctive mechanosensitive unit. Under the lack of continuous gravitational loading, this unit becomes a substrate for adaptation processes, acting as a gravisensitive unit. Since the space flight conditions limit large-scale research in space, simulation models on Earth are of particular importance for elucidating the mechanisms that provide a response to microgravity. This review describes current state of art concerning mammalian ECM as a gravisensitive unit component under real and simulated microgravity and discusses the directions of further research in this field.

Passive-mode treadmill test effectively reveals neuromuscular modification of a lower limb muscle: sEMG-based study from experiments on ISS

The study was aimed at exploring informative value of nonlinear parameters of surface electromyogram (sEMG) to characterization of neuromuscular activity in respect with duration of space flight (SF) and stepping mode. The working hypothesis held that sEMG entropy, correlation dimension (CD), and Lyapunov's exponent, which characterize signals in terms of regularity and predictability, may inform on motor units (MUs) synchronization or content of MUs of different types in muscle activity. In addition, median frequency (MDF), mean amplitude, and kurtosis of the probability distribution of sEMG were computed. sEMG samples were collected from the soleus of 6 cosmonauts on board of the International Space Station during 5 modes of stepping on the passive-mode treadmill in the MO-3 test, and 5 study points - before and after SF on ground (preSF, postSF) and for 3 periods of time in SF (1–80, 81–120, 120–170 days of SF). Altogether, 15 individual sEMG sample sets were successfully obtained. It was found that 1) the sEMG parameters pooled for all subjects by the stepping mode, except for MDF and kurtosis, did modify in the direction of higher regularity of the signal with growing speed of stepping, 2) the conditions of SF exerted effect on MDF, Lyapunov's exponent, entropy, and kurtosis of the probability distribution of sEMG, which probably indicated on greater involvement of the faster type motor units in muscle activity. In conclusion, nonlinear sEMG parameters look promising for characterizing the neuromuscular activity of skeletal muscles under SF conditions. Nonetheless, a small number of sample sets combined with different study points in different cosmonauts allow considering these facts as promising, but not yet definitely established.

Melanin protects Cryptococcus neoformans from spaceflight effects.

SummaryAs human activity in space continues to increase, understanding how biological assets respond to spaceflight conditions is becoming more important. Spaceflight conditions include exposure to ionizing radiation, microgravity, spacecraft vibrations and hypervelocity; all of which can affect the viability of biological organisms. Previous studies have shown that melanin‐producing fungi are capable of surviving the vacuum of space and Mars‐simulated conditions in Low Earth Orbit. This survival has been associated in part with the protective effects of melanin, but a comparison of fungal viability in the presence or absence of melanin following spaceflight has never been tested. In this study, we evaluated the protective effects of melanin by comparing the viability of melanized and non‐melanized clones of Cryptococcus neoformans yeasts following a roundtrip to the International Space Station. Yeast colonies were placed inside two MixStix silicone tubes; one stayed on Earth and the other was transported inside for 29 days before returning to Earth. Post‐flight analysis based on colony‐forming unit numbers shows that melanized yeast viability was 50% higher than non‐melanized yeasts, while no difference was observed between the Earth‐bound control samples. The results suggest that fungal melanin could increase the lifespan of biological assets in space.

Sperm of Fruit Fly Drosophila melanogaster under Space Flight.

Studies of reproductive function under long-term space flight conditions are of interest in planning the exploration of deep space. Motility, including the use of various inhibitors, cellular respiration, and the content of cytoskeletal proteins were studied, assessing the level of expression of the corresponding genes in spermatozoa of Drosophila melanogaster, which were in space flight conditions for 12 days. The experiment was carried out twice on board the Russian Segment of the International Space Station. Sperm motility speed after space flight, and subsequently 16 h after landing, is reduced relative to the control by 20% (p < 0.05). In comparison with the simulation experiment, we showed that this occurs as a result of the action of overloads and readaptation to the Earth’s gravity. At the same time, cellular respiration, the content of proteins of the respiratory chain, and the expression of their genes do not change. We used kinase inhibitor 6-(dimethylamino)purine (6-DMAP) and phosphatase inhibitors; 6-DMAP restored the reduced the speed of spermatozoa in the flight group to that of the control. These results can be useful in developing a strategy for protecting reproductive health during the development of other bodies in the solar system.

Phenotypic, genomic, and transcriptomic changes in an Acinetobacter baumannii strain after spaceflight in China's Tiangong-2 space laboratory.

Acinetobacter baumannii is an opportunistic pathogen often found in patients with low immunity. It causes nosocomial infections, which are difficult to treat. This bacterium can rapidly mutate, developing resistance to antimicrobials and adapting to environmental stress, thereby increasing its survival. Understanding such adaptive mechanisms will be beneficial for controlling the spread of A. baumannii. Astrobiology studies have demonstrated that microbiomes from astronauts and manned spaceflight environments show resistance to stress and antibiotics. Astronauts also encounter low immunity during spaceflight missions. The extreme conditions of spaceflight provide a unique research platform for studying how opportunistic pathogens such as A. baumannii adapt to conditions such as microgravity and mutate during spaceflight. In this study, we compared phenotypic variations and analyzed genomic and transcriptomic variations in A. baumannii strains exposed to three different conditions: ST1 (64days on Tiangong-2 space laboratory), GT1 (ground control), and Aba (original strain). Biofilm formation ability of the ST1 strain increased after 64days of spaceflight. In addition, high-throughput sequencing revealed that some differentially expressed genes were upregulated in the ST1 strain compared to the GT1 strain. These results provide insights into the environmental adaptation of this widespread pathogen.

Spaceflight-Associated Vascular Remodeling and Gene Expression in Mouse Calvaria.

Astronauts suffer from a loss of bone mass at a rate of 1.5% per month from lower regions of the body during the course of long-duration (>30 days) spaceflight, a phenomenon that poses important risks for returning crew. Conversely, a gain in bone mass may occur in non-load bearing regions of the body as related to microgravity-induced cephalad fluid shift. Representing non-load bearing regions with mouse calvaria and leveraging the STS-131 (15-day) and BION-M1 (30-day) flights, we examined spatial and temporal calvarial vascular remodeling and gene expression related to microgravity exposure compared between spaceflight (SF) and ground control (GC) cohorts. We examined parasagittal capillary numbers and structures in calvaria from 16 to 23 week-old C57BL/6 female mice (GC, n = 4; SF, n = 5) from STS-131 and 19–20 week-old C57BL/6 male mice (GC, n = 6; SF, n = 6) from BION-M1 using a robust isolectin-IB4 vessel marker. We found that the vessel diameter reduces significantly in mice exposed to 15 days of spaceflight relative to control. Capillarization increases by 30% (SF vs. GC, p = 0.054) in SF mice compared to GC mice. The vessel numbers and diameter remain unchanged in BION-M1 mice calvarial section. We next analyzed the parietal pro-angiogenic (VEGFA) and pro-osteogenic gene (BMP-2, DMP1, RUNX2 and OCN) expression in BION-M1 mice using quantitative RT-PCR. VEGFA gene expression increased 15-fold while BMP-2 gene expression increased 11-fold in flight mice compared to GC. The linkage between vascular morphology and gene expression in the SF conditions suggests that angiogenesis may be important in the regulation of pathological bone growth in non-weight bearing regions of the body. Short-duration microgravity-mediated bone restructuring has implications in planning effective countermeasures for long-duration flights and extraterrestrial human habitation.

Exploring planet geology through force-feedback telemanipulation from orbit.

Current space exploration roadmaps envision exploring the surface geology of celestial bodies with robots for both scientific research and in situ resource utilization. In such unstructured, poorly lit, complex, and remote environments, automation is not always possible, and some tasks, such as geological sampling, require direct teleoperation aided by force-feedback (FF). The operator would be on an orbiting spacecraft, and poor bandwidth, high latency, and packet loss from orbit to ground mean that safe, stable, and transparent interaction is a substantial technical challenge. For this scenario, a control method was developed that ensures stability at high delay without reduction in speed or loss of positioning accuracy. At the same time, a new level of safety is achieved not only through FF itself but also through an intrinsic property of the approach preventing hard impacts. On the basis of this method, a tele-exploration scenario was simulated in the Analog-1 experiment with an astronaut on the International Space Station (ISS) using a 6-degree-of-freedom (DoF) FF capable haptic input device to control a mobile robot with manipulator on Earth to collect rock samples. The 6-DoF FF telemanipulation from space was performed at a round-trip communication delay constantly between 770 and 850 milliseconds and an average packet loss of 1.27%. This experiment showcases the feasibility of a complete space exploration scenario via haptic telemanipulation under spaceflight conditions. The results underline the benefits of this control method for safe and accurate interactions and of haptic feedback in general.

What food will we be eating on our journey to Mars?

The aim of this review is to show the possibilities of food production during space travel and to demonstrate the potential of technological solutions that can play a significant role in achieving the goal of colonizing other planets. The paper briefly outlines the conditions of space flight and the associated possible threats that may occur. It is assumed that the basic problem is cosmic radiation, which not only can significantly affect the health of astronauts, but also prevent potential cultivation of plants or animal breeding on board a spacecraft. The solution to this problem proposed here is a shield which provides protection against collisions with high kinetic energy particles, while reducing the speed of corpuscular radiation. Particular attention is given to various biotechnological and bioengineering methods that could be used for food production on board a spacecraft. Technological development in the field of bioprinting or genetic modification of organisms may play a key role in the success of long-distance technological missions. Moreover, organisms such as algae, fungi and insects are indicated as a potential source of energy for future colonizers. In sum, the review covers both the field of engineering and biotechnology, as well as the possibility of checking these technological methods in the test flights.

Understanding the Complexities and Changes of the Astronaut Microbiome for Successful Long-Duration Space Missions.

During space missions, astronauts are faced with a variety of challenges that are unique to spaceflight and that have been known to cause physiological changes in humans over a period of time. Several of these changes occur at the microbiome level, a complex ensemble of microbial communities residing in various anatomic sites of the human body, with a pivotal role in regulating the health and behavior of the host. The microbiome is essential for day-to-day physiological activities, and alterations in microbiome composition and function have been linked to various human diseases. For these reasons, understanding the impact of spaceflight and space conditions on the microbiome of astronauts is important to assess significant health risks that can emerge during long-term missions and to develop countermeasures. Here, we review various conditions that are caused by long-term space exploration and discuss the role of the microbiome in promoting or ameliorating these conditions, as well as space-related factors that impact microbiome composition. The topics explored pertain to microgravity, radiation, immunity, bone health, cognitive function, gender differences and pharmacomicrobiomics. Connections are made between the trifecta of spaceflight, the host and the microbiome, and the significance of these interactions for successful long-term space missions.

In Vitro Models of Bone Marrow Remodelling and Immune Dysfunction in Space: Present State and Future Directions.

Spaceflight affects the body on every level. Reports on astronaut health identify bone marrow remodelling and dysfunction of the innate immune system as significant health risks of long-term habitation in space. Microgravity-induced alterations of the bone marrow induce physical changes to the bone marrow stem cell niche. Downstream effects on innate immunity are expected due to impaired hematopoiesis and myelopoiesis. To date, few studies have investigated these effects in real microgravity and the sparsely available literature often reports contrasting results. This emphasizes a need for the development of physiologically relevant in vitro models of the bone marrow stem cell niche, capable of delivering appropriate sample sizes for robust statistics. Here, we review recent findings on the impact of spaceflight conditions on innate immunity in in vitro and animal models and discusses the latest in vitro models of the bone marrow stem cell niche and their potential translatability to gravitational biology research.

Evaluation of the stability of furosemide in tablet form during six-month storage in spaceflight and peculiarities of its pharmacokinetics and pharmacodynamics under conditions of anti-orthostatic hypokinesia.

The present study investigated the stability of furosemide under space-flight conditions on board the International Space Station, as well as its pharmacokinetics and pharmacodynamics under conditions simulating exposure to some space-flight factors. Quantitative analysis of furosemide tablets by HPLC was performed before spaceflight (background), then after six months storage under normal ground conditions (control) and under spaceflight conditions (SF). The pharmacokinetics and pharmacodynamics of furosemide were studied in six healthy volunteers after a single oral dose of 40mg under normal conditions (background) and under anti-orthostatic hypokinesia (ANOH). Quantitative content of furosemide in tablets before SF was 40.19±0.28mg (100.47±0.71%), after 6months storage: under normal conditions (control)- 39.9±0.39mg (99.73±0.98%), under SF- 39.24±0.72mg (98.11±1.80%), which was within the prescribed limits. Studying basic hemodynamic parameters showed that in ANOH conditions 6h after furosemide administration there was a statistically significant increase of the stroke volume (SV) (+36.5 Δ%), a tendency for increasing of the stroke index (SI) (+36.5 Δ%) and decreasing of the total peripheral resistance (TPR) (-21.9 Δ%) compared to baseline study. It has been established that various factors of space flight (overloading, excessive vibration, microgravity, etc.) do not negatively influence the stability of furosemide in tablet form during storage for 6months on board the International Space Station.

Crash Prediction Using Deep Learning in a Disorienting Spaceflight Analog Balancing Task.

Were astronauts forced to land on the surface of Mars using manual control of their vehicle, they would not have familiar gravitational cues because Mars’ gravity is only 0.38 g. They could become susceptible to spatial disorientation, potentially causing mission ending crashes. In our earlier studies, we secured blindfolded participants into a Multi-Axis Rotation System (MARS) device that was programmed to behave like an inverted pendulum. Participants used a joystick to stabilize around the balance point. We created a spaceflight analog condition by having participants dynamically balance in the horizontal roll plane, where they did not tilt relative to the gravitational vertical and therefore could not use gravitational cues to determine their position. We found 90% of participants in our spaceflight analog condition reported spatial disorientation and all of them showed it in their data. There was a high rate of crashing into boundaries that were set at ± 60° from the balance point. Our goal was to see whether we could use deep learning to predict the occurrence of crashes before they happened. We used stacked gated recurrent units (GRU) to predict crash events 800 ms in advance with an AUC (area under the curve) value of 99%. When we prioritized reducing false negatives we found it resulted in more false positives. We found that false negatives occurred when participants made destabilizing joystick deflections that rapidly moved the MARS away from the balance point. These unpredictable destabilizing joystick deflections, which occurred in the duration of time after the input data, are likely a result of spatial disorientation. If our model could work in real time, we calculated that immediate human action would result in the prevention of 80.7% of crashes, however, if we accounted for human reaction times (∼400 ms), only 30.3% of crashes could be prevented, suggesting that one solution could be an AI taking temporary control of the spacecraft during these moments.

Testing Laser-Structured Antimicrobial Surfaces Under Space Conditions: The Design of the ISS Experiment BIOFILMS

Maintaining crew health and safety are essential goals for long-term human missions to space. Attaining these goals requires the development of methods and materials for sustaining the crew’s health and safety. Paramount is microbiological monitoring and contamination reduction. Microbial biofilms are of special concern, because they can cause damage to spaceflight equipment and are difficult to eliminate due to their increased resistance to antibiotics and disinfectants. The introduction of antimicrobial surfaces for medical, pharmaceutical and industrial purposes has shown a unique potential for reducing and preventing biofilm formation. This article describes the development process of ESA’s BIOFILMS experiment, that will evaluate biofilm formation on various antimicrobial surfaces under spaceflight conditions. These surfaces will be composed of different metals with and without specified surface texture modifications. Staphylococcus capitis subsp. capitis, Cupriavidus metallidurans and Acinetobacter radioresistens are biofilm forming organisms that have been chosen as model organisms. The BIOFILMS experiment will study the biofilm formation potential of these organisms in microgravity on the International Space Station on inert surfaces (stainless steel AISI 304) as well as antimicrobial active copper (Cu) based metals that have undergone specific surface modification by Ultrashort Pulsed Direct Laser Interference Patterning (USP-DLIP). Data collected in 1 x g has shown that these surface modifications enhance the antimicrobial activity of Cu based metals. In the scope of this, the interaction between the surfaces and bacteria, which is highly determined by topography and surface chemistry, will be investigated. The data generated will be indispensable for the future selection of antimicrobial materials in support of human- and robotic-associated activities in space exploration.

Effect of Space Flight Factor on Dormant Stages in Aquatic Organisms: A Review of International Space Station and Terrestrial Experiments.

This work is a review of the experiments carried out in the Russian segment of the ISS (inside and outside) from 2005 to 2016 on the effect of the space flight factor on the resting stages of organisms. In outer space, ultraviolet, a wide range of high and low temperatures, cosmic radiation, altered gravity, modified electromagnetic field, vacuum, factors of technical origin, ultrasound, microwave radiation, etc. and their combination determine the damaging effect on living organisms. At the same time, biological dormancy, known in a wide range of bacteria, fungi, animals and plants, allows them to maintain the viability of their dormant stages in extreme conditions for a long time, which possibly allows them to survive during space flight. From 2005 to 2016, the resting stages (propagules) of micro- and multicellular organisms were tested on the ISS to assess their ability to survive after prolonged exposure to the conditions of open space and space flight. Among the more than 40 species studied, about a third were dormant stages of aquatic organisms (eggs of cyprinodont fish, daphnia embryos, resting eggs of fairy shrimps, tadpole shrimps, copepods and ostracods, diapausing larvae of dipterans, as well as resting cysts of algae). The experiments were carried out within the framework of four research programs: (1) inside the ISS with a limited set of investigated species (Akvarium program); (2) outside the station in outer space without exposure to ultraviolet radiation (Biorisk program); (3) under modified space conditions simulating the surface of Mars (Expose program); and (4) in an Earth-based laboratory where single-factor experiments were carried out with neutron radiation, modified magnetic field, microwave radiation and ultrasound. Fundamentally new data were obtained on the stability of the resting stages of aquatic organisms exposed to the factors of the space environment, which modified the idea of the possibility of bringing Earth life forms to other planets with spacecraft and astronauts. It also can be used for creating an extraterrestrial artificial ecosystem and searching for extraterrestrial life.

Molecular Basis to Integrate Microgravity Signals into the Photoperiodic Flowering Pathway in Arabidopsis thaliana under Spaceflight Condition.

Understanding the effects of spaceflight on plant flowering regulation is important to setup a life support system for long-term human space exploration. However, the way in which plant flowering is affected by spaceflight remains unclear. Here, we present results from our latest space experiments on the Chinese spacelab Tiangong-2, in which Arabidopsis wild-type and transgenic plants pFT::GFP germinated and grew as normally as their controls on the ground, but the floral initiation under the long-day condition in space was about 20 days later than their controls on the ground. Time-course series of digital images of pFT::GFP plants showed that the expression rhythm of FT in space did not change, but the peak appeared later in comparison with those of their controls on the ground. Whole-genome microarray analysis revealed that approximately 16% of Arabidopsis genes at the flowering stage changed their transcript levels under spaceflight conditions in comparison with their controls on the ground. The GO terms were enriched in DEGs with up-regulation of the response to temperature, wounding, and protein stabilization and down-regulation of the function in circadian rhythm, gibberellins, and mRNA processes. FT and SOC1 could act as hubs to integrate spaceflight stress signals into the photoperiodic flowering pathway in Arabidopsis in space.