Work and rest organization for the cosmonauts on a long flight

Proper arrangement of work-rest cycles of crewmembers in long-duration space flight is a practically important task of space ergonomics, a field of science studying man's work capacity and methods of its increase. The basic principle of space ergonomics assuring high efficiency of space crewmembers is to cover every aspect of their activities. Of particular importance is the use of laws of biorhythmology, in order to select candidates least susceptible to desynchronosis and closely resembling each other in their biorhythmological status. At the present time, work-rest cycles in a prolonged space flight should be arranged on a 24-hour basis with a normal day-night alternation, including 8-hour night sleep and 2-hour day rest. Optimization of cosmonauts' activities in space demands that they strictly adhere to the recommended work-rest cycle; this can be achieved through their highly motivated desire only.     

Sanatorium-health resort stage of medical rehabilitation of astronauts after long-term space flight

This paper presents observations over 18 cosmonauts who participated in space flights of 75 days to 12 months and stayed in a sanatorium in the city of Kislovodsk thereafter. The rehabilitation stage continued for 30-40 days. The early stage of rehabilitation lasted 2-3 weeks at the cosmodrome or Gagarin Cosmonaut Training Center. They were taken to a sanatorium for further medical rehabilitation when they showed residual phenomena of postflight fatigue, incomplete recovery of the cardiovascular and musculoskeletal systems, hematological, biochemical and immunological changes. Rehabilitation measures included physical training, terrain cure, balneological procedures. Medical monitoring was performed using physical examinations, arterial pressure and heart rate measurement, ECG, Holter monitoring during terrain cure, and blood and urine clinical analysis. The results showed a beneficial development of readaptation, increase of functional capabilities and physical work capacity of crewmembers. Final physical examinations gave evidence that most physiological parameters returned to the preflight level. Increase of flight duration to 11-12 months did not cause increase of post-recovery duration.     

Psychophysiological characteristics of the organization and regulation of the daily work-rest cycles for the crew on a prolonged space flight

This paper presents the results of analysis of work-rest cycles of the Salyut-6 and Salyut-7 prime crewmembers. The distribution of work-rest cycles within the day, week, month and the flight as a whole, their relation with other components of the time schedule, the effect of various factors involved on the health status and work capacity were studied. It was shown that specified work-rest cycles should be rigorously adhered to. It was demonstrated that proper planning and realization of work-rest cycles, as well as their correction during actual flight with respect to psychophysiological and biorhythmological variations are required to maintain good health condition and high work capacity of crewmembers.     

Anthropometric studies of crew members of Salyut-6 and Salyut-7

The paper presents body mass and leg volume measurements of 21 prime crewmembers of Salyut-6 and Salyut-7 flights. It was found that body mass variations were different in sign. In most crewmembers body mass decreased by 1.2-2.0 to 6.0 kg. In some crewmembers this parameter increased by 1.0 to 4.5 kg during the entire flight or at certain flight stages. This observation confirms the concept that metabolism produces an important effect on body mass variations. It also points out that the space diets used are adequate to metabolic requirements. Leg volume of all cosmonauts decreased in the following manner: the decrease was the greatest during the first flight day, slightly less during the first flight month and still less during the subsequent 2 or 3 months of flight. Exercises that were performed at a larger workload, especially during the second half of flight, seemed to help stabilize or occasionally increase leg volume.     

Dynamics of the body liquids and composition in long-duration space flight (bio-impedance analysis)]

Bio-impedancemetiy was used to study dynamics of the human hydration status and body composition aboard the International space station (ISS). Body liquids in 12 Russian crewmembers were found reduced in different periods of space flight: the total, intra- and extracellular liquid volumes became less by 5.2 to 10.4% on the group average as compared with baseline values. In-flight changes in body composition also displayed a consistent pattern. While the lean mass loss was insignificant averaging 1.9-4.0%, the fatty mass gain averaged 4.6 to 8.2% in the initial three months on flight. We conclude that the human body hydration status falls along with the muscular mass reduction and fatty mass gain during long-duration space flight.     

Preliminary results of medical studies during the 5-month space flight aboard the "Saliut-7"--"Soiuz-T" orbital complex

The medical examinations carried out in the 150-day flight were a continuation of the previous studies in terms of the approaches and methods used. The novel approach was a biochemical study of body fluids collected during flight. An important place was occupied by during EVA. The medical results of the 150-day flight were in consistency with the data obtained during previous space flights of similar duration. The health condition and work capacity of the crewmembers throughout the flight (including two EVA events) were good. The changes seen during and after flight were adaptive and disappeared after a relatively short readaptation period.     

Cardiovascular deconditioning during space flight and the use of saline as a countermeasure to orthostatic intolerance

Alterations in the physiology of the cardiovascular system have been noted during all exposures to the microgravity experienced in space flight. Of most importance to the operational function of Space Shuttle crewmembers is orthostatic intolerance. Although complex changes occur as a result of adaptation to weightlessness, the redistribution and loss of body fluid apparently plays a substantial role. Utilizing ground-based bed rest data as an analog to the absence of gravitational force encountered in orbital flight, a saline loading countermeasure was developed. In this study, 17 crewmembers consumed various amounts of salt and fluid prior to the reentry phase of Space Shuttle flights; 9 other astronauts served as control subjects. The countermeasure reduced the heart rate response to orthostatic stress 29% and reversed the fall in mean blood pressure. A Cardiovascular Index of Deconditioning (defined as CID = delta HR - delta SBP + delta DBP) equalled 21 in those who utilized the countermeasure, a significant improvement toward baseline (p less than 0.003) when compared to the control group CID = 49. The encouraging results of these investigations have led to the adoption of the countermeasure as an operational procedure by Shuttle crewmembers.     

From Vostok to Mir: psychological aspects

Based on achievements in clinical medicine, medical expertise of the flying personnel, ergonomics, human engineering and other life sciences, as well as on the experience gained by Intercosmos researchers, space psychology transformed during 1960-1988 into an independent scientific discipline. This new branch of science has the capability to formulate and resolve important theoretical and applied problems of crew selection and training, assessment of emotional status and work capacity, prevention and optimization of crew activities. The findings and observations made it possible for space psychology to develop psychological reliability criteria and consequently to maintain good mental health and high work capacity of crewmembers in long-term space missions.     

Psychological adaptation and work capacity during simulated weightlessness

In two-head-down tilt studies of 7 and 8 days in duration variations in the work capacity of 24 test subjects were examined and the following stages were distinguished: habituation, stable work capacity, and unstable compensation. Among the test subjects two groups were discriminated: those with plastic and those with inert types of adaptation to a changed environment. It is concluded that the plastic-type people can better and faster adapt to head-down tilt and therefore can work more efficiently during an acute stage of adaptation to weightlessness.     

Review of main medical results of a one-year manned space mission on "Mir"

The objective of medical investigations during and after the 366-day manned mission was to accumulate information about human responses to long-term effects of microgravity. To do this, cardiovascular and other systems were examined in detail during and after exposure. The results gave evidence that the crewmembers well adapted to the long-term flight effects. Their good health condition and high work capacity were supported by adequate medical procedures. Postflight readaptation developed similarly to what was seen after previous flights of shorter duration (6-11 months). No qualitatively new changes in the physiological systems were detected during or after this mission.     

Immunological analyses of U.S. Space Shuttle crewmembers

We have previously reported changes in the immunoresponsiveness of "T" lymphocytes following space flight. Additional data collected before and after 11 Shuttle space flights show that absolute lymphocyte numbers, lymphocyte blastogenic capability, and eosinophil percent in the peripheral blood of crewmembers are generally depressed postflight. These responses resemble those associated with physical and emotional stress and may not be related to flight per se. Additional data from Space Shuttle flights 41B and 41D, involving 11 crewmembers, indicate a postflight decrease in cells reacting with "B" lymphocyte and monocyte monoclonal antibody tags. Further, the loss of "T" lymphocyte blast capability interacts with the decreased monocyte count (correlation coefficient = 0.697). This finding implies that the previously reported loss of blastogenic capability may be a function of decreased monocyte control, as noted in several non-spaceflight related studies.     

Off-duty preparation for overnight work in rotor wing air medical programs

INTRODUCTION: Air medical teams provide around-the-clock critical care, risking performance-altering fatigue from circadian disruption and sleep deprivation. Although safety is an essential issue in the air medical industry, there is little understanding of off-duty preparation for overnight shifts. METHODS: An anonymous survey was distributed to pilots and medical team members at participating programs with variable program, staffing, and shift models. Eighty responses from crewmembers working 12-hour night shifts (12N) were analyzed with appropriate t-tests and nonparametric tests. RESULTS: 12N crewmembers sleep significantly less in off-duty periods than before night shifts: 7.3 +/- 1.2 hours versus 4.8 +/- 1.9 hours (P < 0.01). Preshift sleep does not differ between crewmembers permitted on-duty rest and those for whom it is prohibited. 34.1% of 12N crewmembers permitted on-duty rest say they report to work planning to sleep. The minimum preshift sleep reported by 12N crewmembers before any shift in the past month averaged 2.4 +/- 2.3 hours, with 36.3% having worked overnight in the past month with no sleep before their shift On-duty rest permission was not a significant factor. Fifty-five percent of 12N crewmembers report outside employment (OE) in addition to their flight position. 12N crewmembers with OE averaged significantly less preshift sleep than those without OE: 4.4 +/- 2.1 hours versus 5.3 +/- 1.6 hours (P < 0.05). 54.5% of 12N crewmembers with OE described reporting to a flight shift within 8 hours of leaving their other job at least once within the past month. OE was more common when the flight program permitted on-duty rest (P < 0.01). CONCLUSION: Air medical team members report for 12N shifts with a significant sleep debt that does not differ between crewmembers permitted on-duty rest and those with on-duty rest prohibitions. More than half of flight team members surveyed have OE and many report for flight duty within 8 hours of leaving their other job. 12N shift crewmembers are at a particularly high risk for the consequences of fatigue. This is an important consideration as the industry develops on-duty rest guidelines to optimize safe operations.     

The right and wrong stuff in civil aviation

Aircrewmembers (ACMs) enter a mortally hostile environment when they take off from Earth in their flying machines. Their physiological adaptation has been augmented and supported through ergonomics, avionics, and engineering, but no such technological aid helps them adapt their minds to that atypical condition. They must rely upon their own psychic resources, i.e. "aeronautical motivation" in the three levels of consciousness, and defense mechanisms to counteract their "aeronautical anxiety." Various relationships of motivation and defense give rise either to the flying adaptation syndrome or the various forms of the secondary flying disadaptation syndrome when ACMs must face the dangers of flight. These alterations of the ACMs' psychic balance may cause temporary or permanent medical disqualification due to the impairment of safety which they provoke. This paper proposes an analysis of the interplay between motivation, psychic defenses, and aviation stress to explain the manifestations of flight adaptation and disadaptation seen in some aircrewmembers.     

Preliminary results of studies of the cardiovascular system in members of the 2d expedition in the Mir orbital station

Three crewmembers of the second expedition onboard Mir were examined. Their physiological data (bioelectric activity of the heart, phasic structure of the cardiac cycle, circulation parameters at rest and circulation responses to exercise ergometry tests and LBNP tests) were monitored and transmitted to the Earth. This paper presents the physiological data obtained, their interpretation and conclusion that the Commander during his longest-term flight remained in best shape. Individual responses of each cosmonaut in terms of adaptation to flight conditions are discussed.     

Medical results from STS 1-4: analysis of body fluids

Venous blood was drawn from the eight crewmembers of Space Shuttle flights STS-1 through STS-4 three times before lift-off and twice after landing, and the characteristics of biomedical blood components were evaluated. Twenty-four-hour urine pools were collected 30 days before flight and on landing day or day 4 after landing, and electrolytes, selected hormones and other components were measured. The results indicated that although fluid and electrolyte losses occur during space flight, conservation of these substances is begun almost immediately upon cessation of weightlessness. Enzyme and hormone measurements indicated that landing may have caused some stress on crewmembers.     

Fear of flying in civil aviation personnel.

Included in a multi-faceted questionnaire concerning the work environment within a commercial airline were questions on flight anxiety and exposure for critical incidents. A total of 1,147 respondents were included in the sample. Results show that 9.2% of the aircrew members feel anxious or afraid of flying monthly or more often. The cockpit crewmembers were less anxious than the cabin crewmembers, and female cabin crewmembers were more anxious than male. Aircrew who had experienced critical situations and had not sufficiently worked through their experiences, reported more anxiety than those with adequate work-through. We recommend that the cabin crewmembers be provided with better information on how the flight deck operates, and that more stable work crews and co-training of cabin and cockpit crewmembers be facilitated. A formal debriefing routine after critical incidents is advised. Personnel with flight anxiety should be offered help to reduce their fear level.     

Effect of flight factors on changes in blood coagulation and anticoagulation indices in crew members]

A total of 105 flight qualified crewmembers, aged 20 to 40, were taken under observation. Coagulographic and thromboelastographic parameters of the venous blood were studied. The most significant changes (an increase in the coagulation time as related to the time of plasma recalcification, a decrease of the plasma tolerance to heparin, R, K, R plus K, a decrease in the coagulation index Si with respect to the thromboelastogram, a significant increase in the fibrinolytic activity and the heparin number) were noted postflight in commanders, pilots and navigators. Less significant variations of the coagulographic parameters were observed in other crewmembers. The above changes (an increase in endogenous heparin, an acceleration of the fibrinolytic activity) can be regarded as the protective-adaptive reaction of the anticoagulatory system aimed at reducing hypercoagulation during the emotional stress-effect of the flight.     

Features of changes in blood pressure and blood flow in the common carotid artery of monkeys exposed aboard the biosatellite Cosmos-1514

Preflight the rhesus-monkey Bion was implanted with sensors and transducers to measure blood pressure and linear flow velocity in the common carotid artery and to compare these parameters with central circulation. At the early flight stage blood pressure increased, blood flow decreased and resistance in the area grew. The last change can be regarded as a compensatory reaction that can provide rapid adaptation of regional circulation to changes in systemic circulation. At later flight stages blood pressure showed distinct circadian oscillations and blood flow, a significant increase when compared to the ground-based 36-hour control study. Regulatory mechanisms of the cardiovascular system changed to the greatest extent on flight day 2. This manifested as a decrease of the amplitude of circadian oscillations of the above circulation parameters. Signs of cardiovascular adaptation to the effects of microgravity were discerned on flight days 3 to 5.     

Space motion sickness during 24 flights of the space shuttle

The incidence and severity of Space Motion Sickness (SMS) were determined from 24 flights of the Space Shuttle. A standardized questionnaire developed at the NASA-Johnson Space Center (JSC) was administered to all crewmembers postflight during an oral debriefing with the examining flight surgeon. Cases of SMS were graded mild, moderate or severe using criteria developed at the JSC. The incidence of SMS during a first Shuttle flight for 85 crewmembers was 67% (57 cases). There were 26 mild cases (30%), 20 moderate (24%), and 11 severe (13%). Differences were found between males and females, crew positions (Commander, Pilot, Mission Specialist, etc.), and age groups, which were not statistically significant (p greater than 0.05), but would suggest future research into the mechanism, prevention, and treatment of SMS. The 26 crewmembers with a second flight showed a reduction in SMS incidence to 46%, but the change was not significant compared with the first flight. Nine crewmembers (35%) showed a reduction in SMS severity comparing first and second flights, yet there was no significant difference in the mean time between flights for crewmembers with SMS versus asymptomatic crewmembers. Variability in crewmember training and flight experience may explain some of the differences observed.     

A method of central electroanalgesia for correcting the functional status of pilots during intensive flights

Optimal levels of the health status of pilots performing an intensive flight program can be maintained by rational work and rest schedules and correction methods. The effectiveness of central electroanalgesia as a correction method was determined. The course of treatment which consisted of 4-5 sessions, each 40-50 min long, produced a beneficial effect on the health status and work capacity of pilots as measured by direct and indirect methods.