Vestibular tests in the selection of cosmonauts.

Vestibulo-vegetative disorders in cosmonauts and astronauts occurring during space flight compel otolaryngologists to search for vestibular tests enabling a precise evaluation of the activity of the vestibular apparatus and showing disposition to motion sickness. Otoneurological investigation of Polish candidates for cosmonaut status consisted of the following vestibular tests: caloric, rotatory, optokinetic, swinging torsion, statokinesimetric and vestibulo-vegetative. The value of various vestibular tests for aviation and space medicine is presented in this paper, taking into account the results of investigations of the equilibrium system with the group of pilots selected for space flight as well as extensive experience with candidates for the air service and also trained pilots and patients. The relatively frequent lack of correlation between the results of the applied tests, which renders difficult the proper evaluation of the equilibrium system, is emphasized in the paper. Finally, the results of investigations of acute habituation of the vestibular apparatus are discussed.     

Effects of long-duration space flight on target acquisition

The purpose of the study was to explore the effects of long-duration space flight on the acquisition of specific visual targets in the horizontal plane. Seven cosmonauts (4 high performance pilots and 3 non-pilots) who had flown between 186–198 days on Mir served as subjects. Baseline testing was performed 4 times prior to launch and 4 times following landing at different intervals totrack recovery. During testing the subjects were required to acquire targets that were randomly presented with both a head and eye movement using a time optimal strategy. Prior to flight two unique head movement strategies, related primarily to piloting experience, were used for target acquisition. Non-pilots employed a Type-I strategy consisting of high velocity head movements with large peak amplitudes, while high performance pilots used primarily low velocity, small amplitude head movements (Type-II) to acquire the targets (p<0.02). For both strategies peak head velocities increased as the angular distance to the target increased (p<0.01) resulting in greater discrimination between strategies for the 60° targets. While preflight eye velocity between strategies did not reach statistical significance, postflight testing revealed a decrease in eye velocity for Type-I compared with their preflight performance (p<0.02) for the 60° targets. Postflight, the Type-I group showed a decrease in head velocity (p<0.20) while the Type-II group compensated by increasing head velocity (p<0.02). Variability for both of the head and eye parameters tended to increase postflight for both types of strategies.     

Psychological considerations of man in space: problems & solutions

With concrete plans for long duration flight taking form a new impetus is lent to preparing man for this hostile and unnatural environment. Cramped conditions, isolation from family and loved ones, work stress, fear, and incompatibility with fellow crew, are but a few of the problems suffered by astronauts and cosmonauts during their long missions in orbit about the earth.

Although criteria for selection of crew is one aspect of attacking the problem, it has not solved it Notwithstanding good selection, team combination, and counselling before flight, problems have still occurred with unwanted consequences. Incompatibility of team members, far from being the exception, has been frequent. This has been detrímental both physiologically and psychologically for the individual as well as for the operational success and safety of the missions.

Because problems will inevitably occur in future long duration missions, especially when they are of international and multi-cultural nature, the importance of dealing with them is underlined. This paper takes a different approach towards ameliorating these problems, namely that of psychological group training before a mission.     

Plasma and urine catecholamine levels in cosmonauts during long-term stay on Space Station Salyut-7.

The activity of the sympathetic adrenal system in cosmonauts exposed to a stay in space lasting for about half a year has so far been studied only by measuring catecholamine levels in plasma and urine samples taken before space flight and after landing. The device "Plasma 01", specially designed for collecting and processing venous blood from subjects during space flight on board the station Salyut-7 rendered it possible for the first time to collect and freeze samples of blood from cosmonauts in the course of a long-term 237-day space flight. A physician-cosmonaut collected samples of blood and urine from two cosmonauts over the period of days 217-219 of their stay in space. The samples were transported to Earth frozen. As indicators of the sympathetic adrenal system activity, plasma and urine concentrations of epinephrine and norepinephrine as well as urine levels of the catecholamine metabolites metanephrine, normetanephrine, and vanillylmandelic acid were determined before, during and after space flight. On days 217-219 of space flight plasma epinephrine and norepinephrine levels were slightly increased, yet not substantially different from normal. During stress situations plasma norepinephrine and epinephrine levels usually exhibit a manifold increase. On days 217-219 of space flight norepinephrine and epinephrine levels in urine were comparable with pre-flight values and the levels of their metabolites were even significantly decreased. All the parameters studied, particularly plasma norepinephrine as well as urine norepinephrine, normetanephrine, and vanillylmandelic acid, reached the highest values 8 days after landing. The results obtained suggest that, in the period of days 217-219 of the cosmonauts stay in space in the state of weightlessness, the sympathetic adrenal system is either not activated at all or there is but a slight activation induced by specific activities of the cosmonauts, whereas in the process of re-adaptation after space flight on Earth this system is considerably more markedly activated.     

Martian manned mission: what cosmonauts think about this

The experience of cosmonauts who have participated in long-duration space flights has great value for solving problems connected with realization of the Martian manned mission. To study the cosmonauts’ opinion in relation to the Martian crew size, professional specialization of crewmembers, duration of their joint training, the possible sources of psychological tension in the flight, etc., a special questionnaire has been developed. The results of the 11 Russian cosmonauts’ survey are presented in this article.     

On the correlation between individual biochemical parameters of human blood serum following space flight and their basal values

The article presents data concerning the osmolality and concentration of electrolytes and hormones regulating their balance for blood serum of 223 cosmonauts and astronauts. The obtained results allow us to judge the constancy of physicochemical parameters for the blood serum of healthy individuals and how they react to extreme conditions of space flight. The parameters used for evaluation included not just absolute values for the examined indices, but also how they responded to space flight, the dependence on baseline values and the interrelationship between ions. These data are important to predict the effect of exposure to extreme conditions and point to what extent the effect depends on the characteristics of the individual.     

Methodological approach to study of cosmonauts errors and its instrumental support

The methodological approach to the study of cosmonauts errors is discussed in the paper. Within its framework an error is considered in psychophysiological aspect as consequence of cosmonaut "psychophysiological troubles" caused by combined effect of flight extreme conditions on his/her organism. This approach was used for the investigation of interrelation between cosmonauts errors, their psychophysiological state and work-rest schedule peculiarities. It includes procedures of expert analysis of data received in the course of radio and TV sessions with crew, analysis of timelines as well deviations in "crew-spacecraft" system functioning. These data are accumulated, systematized and processed in data base. Realization of the suggested approach does not require specialized onboard equipment and crew members time expenditure. Some results of inflight data analysis are presented to illustrate its potentials.     

Study of values and interpersonal perception in cosmonauts on board of international space station

The increased heterogeneity of International Space Station (ISS) crews′ composition (in terms of nationality, profession and gender) together with stressful situations, due to space flight, can have a significant impact on group interaction and cohesion, as well as on communications with Mission Control Center (MCC) and the success of the mission as a whole. Culturally related differences in values, goals, and behavioral norms could influence mutual perception and, thus, cohesive group formation. The purpose of onboard “Interaction-Attitudes” experiment is to study the patterns of small group (space crew) behavior in extended space flight. Onboard studies were performed in the course of ISS Missions 19–30 with participation of twelve Russian crewmembers. Experimental schedule included 3 phases: preflight training and Baseline Data Collection; inflight activities once in two weeks; post-flight measurement. We used Personal Self-Perception and Attitudes (PSPA) software for analyzing subjects′ attitudes toward social environment (crewmembers and MCC). It is based on the semantic differential and the repertory grid technique. To study the content of interpersonal perception we used content-analysis with participation of the experts, independently attributing each construct to the 17 semantic categories, which were described in our previous study. The data obtained demonstrated that the system of values and personal attitudes in the majority of participated cosmonauts remained mostly stable under stress-factors of extended space flight. Content-analysis of the important criteria elaborated by the subjects for evaluation of their social environment, showed that the most valuable personal traits for cosmonauts were those that provided the successful fulfillment of professional activity (motivation, intellectual level, knowledge, and self-discipline) and good social relationships (sociability, friendship, and tolerance), as well. Post-flight study of changes in perceptions, related to Real Self-image, did not reveal significant differences between the images of Russian crew-members and representatives from foreign space agencies. A certain difference in perceptions was found in cosmonauts with more integrated system of evaluations: after space flight they perceived foreign participants as “closer” to their Ideal, while Russian crew-members were perceived mostly as “distant” from Ideal Self of these subjects. Perceptions of people from Earth were also more critical. These differences are likely to be manifestations of interpersonal perception stereotypes. Described patterns of changes in perceptions of cosmonauts, who have performed space flight as a part of ISS multinational crew, allow us to suggest the recommendations for development of ISS crew training, in particular, it seems useful to increase the time of joint training for deepening of intercultural interaction.     

The experience in operation and improving the Orlan-type space suits

Nowadays significant experience has been gained in Russia concerning extravehicular activity (EVA) with cosmonauts wearing a semi-rigid space suit of the "Orlan" type. The conditions for the cosmonauts' vital activities, the operational and ergonomic features of the space suit and its reliability are the most critical factors defining the efficiency of the scheduled operation to be performed by the astronaut and his safety. As the missions performed by the cosmonauts during EVA become more and more elaborate, the requirements for EVA space suits and their systems become more and more demanding, resulting in their consistent advancement. This paper provides certain results of the space suit's operation and analysis of its major problems as applied to the Salyut and MIR orbiting stations. The modification steps of the space suit in the course of operation (Orlan-D, Orlan-DM, Orlan-DMA) and its specific features are presented. The concept of the suited cosmonauts' safety is described as well as trends for future space suit improvements.     

Effect of geomagnetic field disturbances on the adaptive stress reaction of cosmonauts

Investigations of the effect of geomagnetic activity factors on the cardiac rhythm regulation and arterial pressure of cosmonauts during the expeditions onboard the Soyuz spacecraft, and the MIR and ISS orbital space stations was carried out for various durations of flight in weightlessness and, under control. Groups of cosmonauts were inspected under flight conditions outside the geomagnetic disturbances and in ground preflight conditions, during disturbances without them. The presence of specific effect of geomagnetic disturbances on the system of vegetative regulation of blood circulation of cosmonauts during the flight was demonstrated for the first time. The response of cosmonauts’ cardiac rhythm on the magnetic storm is definitely revealed; however, it depends on the initial functional background and, in particular, on the state of mechanisms of vegetative regulation (the duration of flight and adaptation to it).     

The dynamics of blood biochemical parameters in cosmonauts during long-term space flights

Most of the previously obtained data on cosmonauts' metabolic state concerned certain stages of the postflight period. In this connection, all conclusions, as to metabolism peculiarities during the space flight, were to a large extent probabilistic. The purpose of this work was study of metabolism characteristics in cosmonauts directly during long-term space flights. In the capillary blood samples taken from a finger, by "Reflotron IV" biochemical analyzer, "Boehringer Mannheim" GmbH, Germany, adapted to weightlessness environments, the activity of GOT, GPT, CK, gamma-GT, total and pancreatic amylase, as well as concentration of hemoglobin, glucose, total bilirubin, uric acid, urea, creatinine, total, HDL- and LDL cholesterol, triglycerides had been determined. HDL/LDL-cholesterol ratio also was computed. The crewmembers of 6 main missions to the "Mir" orbital station, a total of 17 cosmonauts, were examined. Biochemical tests were carried out 30-60 days before launch, and in the flights different stages between the 25-th and the 423-rd days of flights. In cosmonauts during space flight had been found tendency to increase, in compare with basal level, GOT, GPT, total amylase activity, glucose and total cholesterol concentration, and tendency to decrease of CK activity, hemoglobin, HDL-cholesterol concentration, and HDL/LDL - cholesterol ratio. Some definite trends in variations of other determined biochemical parameters had not been found. The same trends of mentioned biochemical parameters alterations observed in majority of tested cosmonauts, allows to suppose existence of connection between noted metabolic alterations with influence of space flight conditions upon cosmonaut's body. Variations of other studied blood biochemical parameters depends on, probably, pure individual causes.     

Natural killer cells after ALTAIR mission

Reduced in vitro NK cytotoxic activity have routinely been observed after both prolonged and short-term space flights. This study investigated the effects of space flight on NK cell functions, NK cell counts and the production of IL-2 and TNF by lymphocytes of French-Russian crew members. In the French cosmonaut, after 21 days space flight, the cytotoxic activity of NK cells, the capacity the NK cells to bind and lyse the individual target cells and the percentage of NK cells were decreased. In this cosmonaut a twofold reduction TNF production in cultures of lymphocytes stimulated with PMA and with the mixture of PHA and PMA was observed on the first day after landing. However, the activity of the production of TNF in 48-hour PHA-cultures of lymphocytes was unchanged and the biological activity of IL-2 was not reduced. The immunological examination did not detecte any substantial deviations from the norm in both russian cosmonauts after 197 days space flight. Various explanations for decreased cytotoxicity in cosmonauts after space flight can be proposed, and these include the defective function of NK cells and reduced numbers of circulating effector cells.     

Effects of space flights on human allergic status (IgE-mediated sensitivity)

Suppression of the immune system after space flights of different duration has been reported earlier by Konstantinova [Immune system in extreme conditions, Space immunology. B. 59. M. Science 1988. 289p. (in Russian) [4]; Immunoresistance of man in space flight, Acta Astronautica 23 (1991) 123–127 [5]]. Changes in T- and B-mediated activities of the immune system were demonstrated during and after space flight. However, the influence of the space flight conditions on the allergic status of cosmonauts and astronauts is still unclear. The goal of this investigation was to analyze total blood IgE levels, specific IgE-antibodies and interleukin-4 in blood of Russian crew members before and after space flights to the International Space Station (ISS) and during a long-term isolation study. For this purpose, we used the ELISA assays as well as other special kits. It was noticed that four out of nine cosmonauts had high total serum IgE (more than normal clinical values of 120 IU/ml). At the same time, there were no statistically significant changes in serum IgE levels before and after long-term space flights (128–195 days). A similar situation was observed regarding preflight IgE levels of cosmonauts who performed short-term flights (7–11 days). However, seven out of 11 cosmonauts had increased IgE level in blood post short flights as compared with pre-flight values. We also measured specific IgE-antibodies, because their high concentration may cause the increased production of total IgE indicating sensitization of cosmonauts. This becomes more important when humans spend a longer time in the closed environment of a space vehicle. Also our ground-based investigations showed that a stay in such conditions does not enhance sensitization to allergens (total number of tested allergens 27) including food, inhalants and cross-reactive proteins. Serum interleukin-4 level measured after short- and long-term space flights was identical. A linear correlation between levels of immunoglobulin E and interleukin-4 also was not significant. Despite the fact that our investigations did not establish any influence of space flight on sensitization and development of immediate-type allergic reactions, they demonstrated the necessity to control the allergic status of cosmonauts very carefully both before and after space flights. At the same time, it is necessary to pay special attention to outcomes of atopic individuals with high pre-flight level of total blood IgE.     

Study of water-salt metabolism and renal function in cosmonauts

In manned space flights the renal function and water-salt metabolism undergo substantial changes. With the reserve capabilities of kidneys in mind, their function and regulation of the water-salt balance were investigated in cosmonauts postflight and in Earth-bound simulation experiments with the aid of water loading, hormonal injections (pituitrin, engiotensin, DOCA, ACTH); water- and ion-release were also studied during LBNP and physical exercises. The cosmonauts who performed space flights of 2 to 5 days showed water retention and increased urine excretion of salts during the first postflight days in response to a water load. After the 18-day flight water excretion remained unchanged whereas salt excretion increased. The capacity for osmotic concentration and urine dilution did not alter. The study of the hormonal effect in simulation experiments of different duration demonstrated a normal renal response to the hormonal excretion. After the LBNP tests and physical exercises the water- and salt-excretion declined; a correlation between the level of water- and salt-excretion and the level of these loads was established. The data on the blood- and urine-ionic composition, excretion of nitrogen metabolites, and hormones postflight as well as the results of load and functional tests suggest that changes in the renal function of cosmonauts in weightlessness are associated with regulatory effects on the kidney rather than disturbances in the function of nephron cells.     

Diuretic as a means for rapid adaptation to weightlessness

In a number of flights, cosmonauts and astronauts have experienced aggravation of their health status and general condition in the initial hours and days in a weightless environment. One of the trigger mechanisms for the onset of these unfavourable conditions at the start of space flight is a redistribution of body fluids and a blood shift towards the head. To ensure controlled hypohydration as a countermeasure to the deleterious effects of 0-g and to investigate the feasibility to control adaptation, six cosmonauts were administered lasix once a day during the first 3 days of a mission. All data of the experiment (correction test, questionnaire, hematocrit) were recorded on a special form in the logbook and transmitted to the control centre for processing. Results showed that the diuretic weakened the sensation of discomfort and improved the cosmonauts' general condition. Objective indices of the correction test indicate an increased work ability of cosmonauts. After hypohydration, circulating plasma volumes in the group were reduced by 6.8 + 1.0% on average.     

Psychological adaptation and salutogenesis in space: Lessons from a series of studies

Individuals who adapt positively to an inhospitable or extreme environment can derive benefit from their experiences. This positive effect may include an initial improvement in mental health as someone adjusts to the environment (adaptation) as well as more sustained personal growth during the mission (salutogenesis). We review relevant findings from our prior work, including two post-mission surveys of astronauts and cosmonauts, and three studies of crewmembers during missions in a space station simulator, the Mir space station, and the International Space Station (ISS). We also present new analyses showing evidence for adaptation to ISS missions. This finding replicates our previous results from the simulation study, but this effect was not found on the Mir. A better understanding of psychological adaptation and salutogenesis during space flight should help us develop strategies to enhance crewmembers’ in-flight stress tolerance and post-flight adjustment.     

Operational life improvement of SSME high-pressure turbopumps

The current Space Shuttle Main Engine Phase I engine has demonstrated excellent flight performance at power levels up to 104% of rated power level. Early certification testing at 109% power level showed the operational life of the high pressure turbopumps to be limited. A development program, Phase II, has been under way since 1983 to increase the operational life and provide additional margin. The history of the SSME Phase I engine and the design and results of the SSME Phase II Program are presented. Operational life limits and high-maintenance areas of the high-pressure turbopumps are identified. The Phase II design improvements, supporting analyses, and test results are described. The formal certification test program is discussed. Modifications have been made to the high-pressure fuel turbopump to reduce turbine operating temperature, to extend the life of the first- and second-stage turbine blades, and to reduce sheet metal maintenance. Modifications have been made to the high-pressure oxidizer turbopump to improve bearing life and to eliminate subsynchronous whirl. These are discussed in detail, as is the design and use of special instrumentation to provide for rapid evaluation of merit.     

Blood volume regulating hormones, fluid and electrolyte modifications during 21 and 198-day space flights (Altair-MIR 1993)

During the Altair MIR' 93 mission we studied several parameters involved in blood volume regulation. The experiment was done on two cosmonauts before (B-60, B-30), during (D6, D12, D18 for French and D7, D12, D17 for Russian) and after the flight (R+1, R+3 and R+7). Space flight durations were different for two cosmonauts: for the Russian the flight duration was 198 days and for the French 21 days. On board the MIR station only urinary (volume and electrolytes, atrial natriuretic peptide (ANP), cyclic guanosine monophosphate (cGMP) and catecholamines) and salivary (cGMP and cortisol) samples were collected, centrifuged and stored in freezer. Lithium was used as a tracer to know exactly the 24 h urine output (CNES urine collection Kit). Before and after flight, blood was drawn with an epicite needle and vacutainer system for hormonal assays (renin, antidiuretic hormone, cGMP, ANP and aldosterone) in two positions: after 30 min rest in upright seated position and after 90 min of supine position. Salivary samples were collected simultaneously. During flight a decrease of diuresis and ANP and an increase of osmolality were found. No modifications of hematocrit, but an increase of salivary cGMP and cortisol were also observed. The decrease of urinary ANP is in favor of hypovolemia as described in previous flights. The postflight examinations revealed changes in fluid-electrolyte metabolism which indicate a hypohydration status and a stimulation of hormonal system responsible for water and electrolyte retention in order to readapt to the normal gravity.     

Main medical results of extended flights on space station Mir in 1986-1990

During 1986-1990 seven prime spacecrews (16 cosmonauts) have flown on-board the Mir orbital complex. The longest space mission duration was 366 days The principal objectives of the medical tasks were the maintenance of good health and performance of the spacecrews and conducting medical research programs which included study of the cardiovascular, motor, endocrine, blood, immune, and metabolic systems. Results obtained point to the ability of humans to readily adapt to a year-long stay in space and maintain good health and performance. Readaptation had a similar course as after other previous long-term space flights of up to 8 months in duration. Primary body system changes were not qualitatively different from findings after flights aboard the Salyut 6 and 7 space stations. In this case, during and after an 11-12 month flight, body system alterations were even less severe which was a result of adequate countermeasure use, their systematic and creative employment and maintenance of required environments to support life and work in space.     

Influence of graviceptives cues at different level of visual information processing: the effect of prolonged weightlessness

We evaluated the influence of prolonged weightlessness on the performance of visual tasks in the course of the Russian-French missions ANTARES, Post-ANTARES and ALTAIR aboard the MIR station. Eight cosmonauts were subjects in two experiments executed pre-flight, in-flight and post-flight sessions.

In the first experiment, cosmonauts performed a task of symmetry detection in 2-D polygons. The results indicate that this detection is locked in a head retinal reference frame rather than in an environmentally defined one as meridional orientations of symmetry axis (vertical and horizontal) elicited faster response times than oblique ones. However, in weightlessness the saliency of a retinally vertical axis of symmetry is no longer significantly different from an horizontal axis. In the second experiment, cosmonauts performed a mental rotation task in which they judged whether two 3-D objects presented in different orientations were identical. Performance on this task is basically identical in weightlessness and normal gravity.