Long-term Manned Space Flight Research Articles

MICROBIAL BIOCONVERSION OF CELLULOSE-CONTAINING WASTE IN TERRESTRIAL AND SPACE CONDITIONS

One of the important ecological problems at present is the increasing pollution of the natural environment with cellulose waste. A similar process is also observed in long-term manned space flights: a huge amount of cellulose waste from clothing, hygiene materials, food residues and others accumulates, the processing and utilization of which is a definite scientific challenge. In recent years, many scientists have expanded and deepened their research on this important question, which still remains unresolved both in Earth’s conditions and during the long-term space flights. Many experiments are carried out on the biodegradation processes of cellulose-containing waste with the use of different populations of microorganisms – bacteria, fungi, etc., as well as with different parameters of the culture medium – composition, temperature, presence of oxygen, pH, etc. The synergistic action of these microbial populations, which have the capacity to degrade and assimilate complex carbohydrates (cellulose, hemicellulose and lignin) through the synthesis of a number of cellulolytic enzymes, thus restoring the carbon cycle in nature, has been proven. In parallel, research is being conducted in simulated microgravity conditions, focused on their future application for bioconversion and efficient utilization of waste in closed life support systems during long-duration manned space flights. An important condition is that the microorganisms used are not pathogenic, not resistant to antibiotics and do not form biofilms. There is already accumulated experimental data proving that microgravity conditions lead to changes in bacterial gene expression, growth rate, reduced motility, increased virulence, biofilm formation, etc. In this review, the most important results achieved by Bulgarian and foreign teams in this current and promising scientific field are briefly presented.

A surface-enhanced Raman scattering-based competitive lateral flow assay for on-orbit rapid detection of bone loss biomarker CTX I

The complexity of space environment will lead to a series of health problems, especially the bone loss caused by weightlessness is one of the key medical problems limiting long-term manned space flight. However, the size and energy constraints of the aircraft make conventional bone loss detection methods impractical. Hence, it is necessary to establish on-orbit bone loss detection methods to ensure the health of astronauts. As one of NASA's recommended methods, the lateral flow assay (LFA) would be an ideal tool to solve this problem. Herein, a surface-enhanced Raman based molecular probe was designed and integrated with LFA to detect carboxy-terminal cross-linked telopeptides of type I collagen (CTX I) with high sensitivity and specificity, and the limit of detection was 232 pg/mL. This method was not interference by the serum matrix or other targets, and the storage life of LFA was up to 6 months at 4 °C. Compared with the method previously reported, SERS-based LFA was an ideal detection method with simple operation, convenient and time saving. It is also expected to be chosen as a potential analytical tool to detect bone loss for long-term on-orbit, and guarantee the health of astronauts.

Dietary Needs, Approaches and Recommendations to Meet the Demands of Future Manned Space Flights

Space flight imposes a myriad of adverse effects upon the human body. Improved in-flight nutritional strategies help mitigate those adverse effects. This review examines how space flight changes human physiology, and how improved in-flight nutritional strategies may address the unique dietary needs created by microgravity exposure. Dietary approaches and recommendations to address those needs are discussed. This review also describes food sustainability methods for long-term manned space flight, how precision nutrition can aid in-flight dietary prescriptions, and how wearable technologies can help monitor dietary status and health during long-term manned space flight. This review describes the magnitude of adverse changes incurred from space flight, and the current knowledge base on how improved in-flight nutritional strategies may abate the adverse changes. Wearable technologies, used in conjunction with precision nutrition prescriptions, may best serve the demands of monitoring human health and dietary status on future manned space flights.

Relationship of collagen as the component of the extracellular matrix with the mechanisms of autonomic regulation of the cardiovascular system under simulated conditions of long-term isolation

The study of proteins - potential markers, associated signal transduction pathways, and their targets - provides a new understanding of the fundamental mechanisms occurring at the level of regulatory processes in the cardiovascular system (CVS), especially in space flight, as well as in model experiments that reproduce its individual effects on the human body. The article presents the results of studies in an experiment with 120-day isolation within the framework of the SIRIUS project in which 6 volunteers aged 28 to 44 years (three men and three women) participated. SIRIUS (Scientific International Research in Unique Terrestrial Station) is the international research project, which studies the issues of biomedical and psychological support of long-term manned space flights. The possible involvement of collagen different types, an extracellular matrix protein, in the mechanisms of autonomic regulation of the CVS was studied. Using chromatic mass spectrometry in urine samples and analysis of heart rate variability, we have established that the extracellular matrix collagen, which is present, in particular, in the structure of the blood vessel wall, are markers associated with the modulating effect of the autonomic nervous system on the regulatory mechanisms of blood circulation. We hypothesized that these proteins may be a biomarker of the autonomic balance in the regulatory mechanisms of the circulatory system. In addition, these proteins can also be markers of the aging process, which increases the risks of developing autonomic dysfunction of the cardiovascular system (dominance of sympathicotonia) and changes in the quality of the tissue of the heart muscle and blood vessels, provoking the development of prenosological conditions and diseases of the cardiovascular system.

Promising manned spacecraft for a long-duration flight with a flexible inflatable shell

The development of astronautics is approaching the stage of colonization of space objects of the Solar System, which will lead to regular and long-term manned space flights. Perspective projects of colonization and long-term stay of a man in space flight conditions were considered. The project proposed in this article is based on a conceptual approach. This paper considers the new type of promising spacecraft that solve the problem of the influence of the absence of gravity on a person in space during a long flight. The principle of a new generation manned spacecraft (MS) is presented. Using a flexible inflatable shell is a solution to reduce the mass of the MS. The analysis of existing solutions of flexible inflatable shells of American and Russian analogues and for the developed design of a new generation spacecraft is carried out. The comparison of the characteristics of three types of shells is made, with the definition of general and distinctive features of the structure and the system that provides the deployment of shells. Advantages and disadvantages of projects are described.

Osmolyte Depletion and Thirst Suppression Allow Hibernators to Survive for Months without Water.

Thirteen-lined ground squirrels (Ictidomys tridecemlineatus) are obligatory hibernators who can survive over 6months of the year in underground burrows or laboratory hibernaculum without access to food or water [1]. Hibernation consists of prolonged periods of torpor, lasting up to 18days, which are characterized by low body temperature and suppressed metabolism. This torpidity is interspersed with short periods of interbout arousal, lasting up to 48 h, during which squirrels temporarily return to an active-like state and lose small amounts of water to urination and evaporation [2]. Water is also lost during torpor due to a positive vapor pressure difference created by the slightly higher temperature of the body compared to its surroundings [2, 3]. Here, we investigate the physiological mechanism of survival during prolonged water loss and deprivation throughout hibernation. By measuring hydration status during hibernation, we show that squirrels remain hydrated during torpor by depleting osmolytes from the extracellular fluid. During brief periods of arousal, serum osmolality and antidiuretic hormone levels are restored, but thirst remains suppressed. This decoupling of thirst and diuresis enables water retention by the kidney while suppressing the drive to leave the safety of the underground burrow in search of water. An acute increase in serum osmolality reinstates water-seeking behavior, demonstrating preservation of the physiological thirst circuit during hibernation. Better mechanistic understanding of internal osmolyte regulation and thirst suppression could translate to advancements in human medicine and long-term manned spaceflight. VIDEO ABSTRACT.

Modeling the influence of heavy ion beams on neurogenesis and functioning of hippocampal neural networks

Radiation-induced impairment of hippocampal neurogenesis is one of serious factors associated with cognitive detriments after radiation therapy of brain cancers and realization of long-term manned space flights. The goal of this study is to develop a mathematical model describing radiation-induced changes in cellular populations participating in neurogenesis and how these alterations worsen the processing of information by hippocampus. Modeling results have demonstrated that heavy ions may cause non-reversible suppression of neurogenesis, which is followed by failure of pattern encoding and retrieval by hippocampal neural networks.

Research on the variations in the volatile compound and vitamin content in space foods after storage on the TG-1 spacecraft

ABSTRACTMaintaining the nutrients and flavor acceptability of space food is critical for long-term manned space flights. Five different space food items from one batch, including braised beef with potatoes, stewed duck with sauce, black tomato powder, tea seed oil and fish oil were launched on the TG-1 spacecraft, and then brought back to Earth by the SZ-9 and SZ-10 manned spaceships respectively. The same food items and materials as those sent into space were stored in an environmentally controlled chamber on Earth as controls. Variations in certain volatile compounds in both braised beef with potatoes and stewed duck with sauce were observed after space flight, but no notable differences were observed in the vitamin contents in black tomato powder, tea seed oil, or fish oil. More attention should be focused on volatile compounds variations, and measures should be taken to maintain food acceptability during storage in space.

Microgravity, Stem Cells, and Embryonic Development: Challenges and Opportunities for 3D Tissue Generation

Space is a challenging environment for the human body, due to the combined effects of reduced gravity (microgravity) and cosmic radiation. Known effects of microgravity range from the blood redistribution that affects the cardiovascular system and the eye to muscle wasting, bone loss, anemia and immune depression. About cosmic radiation, the shielding provided by the spaceship hull is far less efficient than that afforded at ground level by the combined effects of the Earth atmosphere and magnetic field. The eye and its nervous layer (the retina) are affected by both microgravity and heavy ions exposure. Considering the importance of sight for long-term manned flights, visual research aimed at devising measures to protect the eye from environmental conditions of the outer space represents a special challenge to meet. In this review we focus on the impact of microgravity on embryonic development, discussing the roles of mechanical forces in the context of the neutral buoyancy the embryo experiences in the womb. At variance with its adverse effects on the adult human body, simulated microgravity may provide a unique tool for understanding the biomechanical events involved in the development and assembly in vitro of three-dimensional (3D) ocular tissues. Prospective benefits are the development of novel safety measures to protect the human eye from cosmic radiation in microgravity during long-term manned spaceflights in the outer space, as well as the generation of human 3D-retinas with its supporting structures to develop innovative and effective therapeutic options for degenerative eye diseases.

Spaceflight Effects on Cytochrome P450 Content in Mouse Liver.

Hard conditions of long-term manned spaceflight can affect functions of many biological systems including a system of drug metabolism. The cytochrome P450 (CYP) superfamily plays a key role in the drug metabolism. In this study we examined the hepatic content of some P450 isoforms in mice exposed to 30 days of space flight and microgravity. The CYP content was established by the mass-spectrometric method of selected reaction monitoring (SRM). Significant changes in the CYP2C29, CYP2E1 and CYP1A2 contents were detected in mice of the flight group compared to the ground control group. Within seven days after landing and corresponding recovery period changes in the content of CYP2C29 and CYP1A2 returned to the control level, while the CYP2E1 level remained elevated. The induction of enzyme observed in the mice in the conditions of the spaceflight could lead to an accelerated biotransformation and change in efficiency of pharmacological agents, metabolizing by corresponding CYP isoforms. Such possibility of an individual pharmacological response to medication during long-term spaceflights and early period of postflight adaptation should be taken into account in space medicine.

The role of a space patrol of solar X-ray radiation in the provisioning of the safety of orbital and interplanetary manned space flights

In interplanetary flight, after large solar flares, cosmonauts are subjected to the action of energetic solar protons and electrons. These energetic particles have an especially strong effect during extravehicular activity or (in the future) during residence on the surface of Mars, when they spend an extended time there. Such particles reach the orbits of the Earth and of Mars with a delay of several hours relative to solar X-rays and UV radiation. Therefore, there is always time to predict their appearance, in particular, by means of an X-ray-UV radiometer from the apparatus complex of the Space Solar Patrol (SSP) that is being developed by the co-authors of this paper.The paper discusses the far unexplored biophysical problem of manned flight to Mars, scheduled for the next decade. In long-term manned space flights on the orbital stations “Salyut” Soviet cosmonaut crews from three of the co-authors (cosmonauts V.V. Kovalenok, A.S. Ivanchenkov, and V.P. Savinykh) had repeatedly observed the effect of certain geophysical conditions on the psychological state of each crew. These effects coincide with the increased intensity of global illumination in the upper ionosphere space on flight altitudes (300–360km). It is important that during all of these periods, most of the geomagnetic pulsations were completely absent. Possible ways to study the synergistic effects of the simultaneous absence of the geomagnetic field, the magnetic pulsations and the microwave radiation of the terrestrial ionosphere are considered for a flight to Mars.

Space dosimetry for long-term manned space flight: Difference between radiation environments on earth and in space

Space dosimetry for long-term manned space flight: Difference between radiation environments on earth and in space

Analytical basis for the determination of the lacunar–canalicular permeability of bone using cyclic loading

An analytical model for the determination of the permeability in the lacunar-canalicular porosity of bone using cyclic loading is described in this contribution. The objective of the analysis presented is to relate the lacunar-canalicular permeability to a particular phase angle that is measurable when the bone is subjected to infinitesimal cyclic strain. The phase angle of interest is the lag angle between the applied strain and the resultant stress. Cyclic strain causes the interstitial fluid to move. This movement is essential for the viability of osteocytes and is believed to play a major role in the bone mechanotransduction mechanism. However, certain bone fluid flow properties, notably the permeability of the lacunar-canalicular porosity, are still not accurately determined. In this paper, formulas for the phase angle as a function of permeability for infinitesimal cyclic strain are presented and mathematical expressions for the storage modulus, loss modulus, and loss tangent are obtained. An accurate determination of the PLC permeability will improve our ability to understand mechanotransduction and mechanosensory mechanisms, which are fundamental to the understanding of how to treat osteoporosis, how to cope with microgravity in long-term manned space flights, and how to increase the longevity of prostheses that are implanted in bone tissue.

Optimizing edible fungal growth and biodegradation of inedible crop residues using various cropping methods

Long-term manned space flights to Mars require the development of an advanced life support (ALS) ecosystem including efficient food crop production, processing and recycling waste products thereof. Using edible white rot fungi (EWRF) to achieve effective biomass transformation in ALS requires optimal and rapid biodegradative activity on lignocellulosic wastes. We investigated the mycelial growth of Lentinula edodes and Pleurotus ostreatus on processed residues of various crops under various cropping patterns. In single cropping, mycelial growth and fruiting in all strains were significantly repressed on sweet potato and basil. However, growth of the strains was improved when sweet potato and basil residues were paired with rice or wheat straw. Oyster mushroom ( Pleurotus) strains were better than shiitake ( L. edodes) strains under single, paired, and mixed cropping patterns. Mixed cropping further eliminated the inherent inhibitory effect of sweet potato, basil, or lettuce on fungal growth. Co-cropping fungal species had a synergistic effect on rate of fungal growth, substrate colonization, and fruiting. Use of efficient cropping methods may enhance fungal growth, fruiting, biodegradation of crop residues, and efficiency of biomass recycling.

(162) Edible Fungal Growth and Fruiting on Composted Containerized Inedible Crop Biomass

Current goals for space exploration are predicated upon long-term manned space flights and colonization of planetary habitats. Long periods in space without payloads of necessary items from Earth require the development of a self-sustaining ecosystem that will allow astronauts to grow their own food and efficiently recycle the waste products. Crops suggested for growth in space include wheat, rice, carrots, soybean, mushrooms, etc. Optimal and rapid biodegradation of lignin and other cellulosic material of crop residues by candidate edible white rot fungal strains is paramount in the use of these organisms to achieve effective biomass recycling in an advanced life support system (ALS). The incorporation of organic N into the substrate and pairing crop residues may enhance growth and fruiting of the edible fungi, thus increasing the rate of biodegradation of the substrates and biomass recycling. We investigated the mycelial growth of two strains of Pleurotusostreatus (`Grey Dover' and `Blue Dolphin') on processed single vegetative residues of soybean, cowpea, tomato, sweetpotato, or their 1:1 combination with wheat or rice straw. Growth and fruiting of the two strains including another strain (`Pohu') on rice straw mixed with solid thermophilic aerobic reactor (STAR) effluent for degradation and recycling were also studied. Mycelial growth and fruiting in `Grey Dover' and `Blue Dolphin' were significantly repressed on sweetpotato and basil; however, growth of the two strains was improved when sweetpotato and basil substrates were paired with rice or wheat straw. Fruiting was prolific in paired combinations of soybean with wheat or rice straw. High concentration of STAR residue enhanced mycelial growth; however, a relatively lower concentration was required for abundant fruiting.

Skeletal muscle unweighting: spaceflight and ground-based models.

Long-term manned spaceflight requires that flight crews be exposed to extended periods of unweighting of antigravity skeletal muscles. This exposure will result in adaptations in these muscles that have the potential to debilitate crew members on return to increased gravity environments. Therefore, the development of countermeasures to prevent these unwanted adaptations is an important requirement. The limited access to microgravity environments for the purpose of studying muscle adaptation and evaluating countermeasure programs has necessitated the use of ground-based models to conduct both basic and applied muscle physiology research. In this review, the published results from ground-based models of muscle unweighting are presented and compared with the results from related spaceflight research. The models of skeletal muscle unweighting with a sufficient body of literature included bed rest, cast immobilization, and unilateral lower limb suspension. Comparisons of changes in muscle strength and size between these models in the context of the limited results available from spaceflight suggest that each model may be useful for the investigation of certain aspects of the skeletal muscle unweighting that occur in microgravity.

On Some Optimization Problems of Long-Term Manned Space Flights

On Some Optimization Problems of Long-Term Manned Space Flights

Emphasis of biological research for space radiation

The paper summarized issues, current status and the recent topics in biological research of space radiation. Researches to estimate a risk associated with space radiation exposure during a long-term manned space flight, such as in the International Space Station, is emphasized because of the large uncertainty of biological effects and a complexity of the radiation environment in space. The Issues addressed are; 1) biological effects and end points in low dose radiation, 2) biological effects under low dose rate and long-term radiation exposure, 3) modification of biological responses to radiation under space environments, 4) various aspects of biological end points vs. cellular and molecular mechanisms, 5) estimation of human risk associated with radiation exposure in space flight, 6) regulations for radiation exposure limits for space workers. The paper also summarized and introduced recent progress in space related radiation researches with various biological systems.

Dosimetric complex for long-term manned space flights

Abstract A dosimetric complex is proposed for use in long-term manned space flight on the orbital station and for the planned Mars expedition. This complex includes thermoluminescence dosimeters with on-board readout, a channel for continuous monitoring of dose rate and a channel for continuous measurement of absorbed and equivalent doses, as well as measurement of the LET spectra. The last four parameters are measured by a tissue-equivalent proportional counter.