Vol 43, No 7 (2017)

During 520-day isolation in a confined space as an imitation of a long-term interplanetary flight, the neurofunctional condition of six crew members was examined using synchronous recording of electrical ( electroencephalogram) and energy (constant potential level) activities of the brain. Two background studies made it possible to predict high adaptability level of all crewmembers and low probability of adaptation reserve depletion in the course of the experiment. During isolation, the dynamics of neurofunctional correlates of cerebral activity generally corresponded to factors to which the crew was subjected during its activity. During the events significant for the crew, we observed physiological reactions in both metabolic and electrical activities of the brain. During the 54th week, the state of physiological adaptation of the crew to the experimental environment was observed, which was expressed in decreases in constant potential level (CPL), without interhemispheric asymmetry, and absolute α-power value. Throughout the experiment, none of crewmembers exhibited distinct stress reaction signs (α-activity asymmetry accompanied by a significant CPL decrease), which confirmed our prediction of a low probability of adaptation reserve depletion in the participants of the 520-day isolation study.

This paper discusses the influence of the social status and psychological stability of individuals on their communicative behavior in space flight on the basis of retrospective analysis of the findings of the Mars-500 experiment, in which six participants were isolated for a period of simulating a long-term exploration mission. Data were obtained using both classic social-psychological methods and observation of video recorded behavior. Communicative behavior of the crew members was dependent on the level of individual anxiety and social status in the isolated small group.

A ten-year follow-up study was focused on comparison of risk factors of atherosclerosis and damage to target organs in a group of 40- to 65-year-old cosmonauts and volunteers in the same age range. It was shown that the incidence of supraventricular extrasystoles in the groups increased with aging by 85 and 80%, respectively, inferring the risk of supraventricular tachyarrhythmias. The primary predictors of atherosclerosis and coronary artery disease (CAD) in cosmonauts are decreased endothelium-dependent vasodilation in the right brachial artery, C-reactive protein (hsCRP) level > 2 mg/L, and high atherogenic index. These CAD predictors should be of particular concern during medical screening of candidates for cosmonauts.

The objective of this study was to evaluate the functions of the sympathoadrenomedullary system and the related psychophysiological reactions of pilots, depending on flying hours on a highly maneuverable aircraft. The study involved 78 volunteer pilots (41 high-maneuverability pilots and 37 bomber and transport aviation pilots). A set of methods was chosen with the possibility of their use according to the principle of comprehensive evaluation of the body functional state under flight loads taken into account. Our results indicate that highly maneuverable aircraft piloting induces a significant activation of the sympathoadrenomedullary system in pilots, compared to bombing and transport aircrafts. This is particularly common to young pilots with the total flying time of less than 1000 h. It has been recorded that changes in adaptation to the effect of flight factors on the body develop with age and flight experience.

In a 105-day experiment simulating crew life in a interplanetary spaceship, shifts in the nutritional status were assessed in six volunteersthat differed in the body weight index, basal metabolic rate, attitude to the proposed diet, physical exercise, and workload. The results of the investigation showed that hard physical work under the conditions of the experiment led to the formation of the nutritional status against the background of more intensive basal metabolism, elevated metabolism of carbohydrates and lipids, and their increased mobilization from fat depot. Food ration, though it was sufficient to sustain health and fairly high calorie, did not fully meet individual taste preferences of some crewmembers and energy needs for physical activities. Under these conditions, heavy workloads required mobilization of lipids from fat depot and reducedthe hepatic detoxification and metabolic capacities. Self-limitation of eating protein-rich desserts led to a relative deficiency of protein intake. These changes in the diet were the reason why four out of six test subjects reduced their basal metabolism and lost body mass. The recovery of metabolism and slowdown of the body weight loss were achieved under these conditions by supplementing meals with digestible proteincontaining products.

The system of signaling pattern recognition receptors was studied in eight cosmonauts at the ages from 35 to 56 years before and after long-term space flights (SFs) on board the International Space Station (ISS). The peripheral blood samples were analyzed for the content of monocytes and granulocytes that express the signaling pattern recognition Toll-like receptors (TLRs) with surface (TLR1, TLR2, TLR4, TLR5, and TLR6) and intracellular (TLR3, TLR8, and TLR9) localization. The serum concentration of basic ligands of TLR2 (HSP60) and TLR4 (HSP70 and HMGB1) were also measured. The results of the studies showed a growth of the HSP60, HSP70, and HMGB1 concentrations on the first day after long-term flight. The increase in the concentration of endogenous ligands was followed by a growth of the number of both monocytes and granulocytes that express the respective pattern recognition receptors, TLR2 and TLR4, in the overwhelming majority of the examined cosmonauts. Thesse relationships suggest that changes in the system of signaling pattern recognition receptors may be due to the prevailing influence of endogenous ligands in response to the effect of long-term spaceflight factors on the human body.

Investigations made by the World Health Organization have shown that lack of physical activity and sedentary lifestyle are among ten major causes for death and disability. Typically, studies of the negative effects of reduced physical activity and their prevention face difficulties of providing standard conditions. These issues were obviated successfully in the Mars-500 experiment on simulation of a space exploration mission. The sample of subjects consisted of six volunteers from Russia, France, Italy, and China, who were isolated in a limited space for 520 days. To prevent the negative effects of low physical activity, the volunteers performed resistive and cyclic exercises in different periods of isolation. The study was designed with two pauses in the training program. Physical performance was evaluated with an incremental loading test, maximal voluntary effort test (Russian–Austrian MDS resistive exercise system), and PWC-170 (bicycle ergometer). The level of physical performance of the subjects in this experiment never degraded to below baseline values. The proposed training system comprising different kinds of exercise ensured stability or improvement physical performance as compared with the baseline level.

The investigation was aimed at evaluation of level and rate of cutaneous and tympanic temperature drop due to a single short-timed (3 min) cooling in a cryosauna (–70°С), and adaptation-indicative physiological parameters, including blood catecholamines, ACTH, lipoproteins and free fatty acids. The subjects were seven healthy men. Exposure to cold invariably reduced the internal (tympanic) and cutaneous temperature by 1°С and 7°С on average, respectively. Tympanic temperature remained 0.4°С low on the average for more than 20 min after exposure. Cutaneous temperature was 1°С below the norm for an hour after cooling. For one hour after the short-term cold exposure, blood norepinephrine remained increased, and so did the blood concentrations of high-density lipoprotein cholesterol and free fatty acids. These results demonstrate brief adaptive changes following a single exposure at–70°C.

This article considers the theoretical basics of the flight safety risk management concept that are related to arranging and conducting aeromedical support activities for civil aviation. The characteristic of procedures of discovering flight safety risk factors and hazards is presented. The concept of medical risk is defined. The process of managing risk factors related to changes in the health state of aviation staff is considered. The practical significance of the flight safety risk management concept for the health assessment of aviation and airline traffic control staff is shown.