weightlessness simulation physiological: Topics by Science.gov

Sample records for weightlessness simulation physiological

Laboratory simulation of the action of weightlessness on the human organism

NASA Technical Reports Server (NTRS)

Genin, A. M.

1977-01-01

A brief history of attemps by the U.S. and the U.S.S.R. to simulate weightlessness in the laboratory is presented. Model for laboratory modeling of weightlessness included the bed regimen, the clinostat, and water immersion. An outline of immediate physiological effects of weightlessness and long term effects is offered.
Objects Mental Rotation under 7 Days Simulated Weightlessness Condition: An ERP Study.

PubMed

Wang, Hui; Duan, Jiaobo; Liao, Yang; Wang, Chuang; Li, Hongzheng; Liu, Xufeng

2017-01-01

During the spaceflight under weightlessness condition, human's brain function may be affected by the changes of physiological effects along with the distribution of blood and body fluids to the head. This variation of brain function will influence the performance of astronauts and therefore create possible harm to flight safety. This study employs 20 male subjects in a 7-day-6° head-down tilted (HDT) bed rest model to simulate physiological effects under weightlessness condition, and use behavioral, electrophysiological techniques to compare the changes of mental rotation ability (MR ability) before and after short-term simulated weightlessness state. Behavioral results suggested that significant linear relationship existed between the rotation angle of stimuli and the reaction time, which means mental rotation process do happen during the MR task in simulated weightlessness state. In the first 3 days, the P300 component induced by object mental rotation followed the "down-up-down" pattern. In the following 4 days it changed randomly. On HDT D2, the mean of the amplitude of the P300 was the lowest, while increased gently on HDT D3. There was no obvious changing pattern of the amplitude of P300 observed after 3 days of HDT. Simulated weightlessness doesn't change the basic process of mental rotation. The effect of simulated weightlessness is neural mechanism of self-adaptation. MR ability didn't bounce back to the original level after HDT test.
Objects Mental Rotation under 7 Days Simulated Weightlessness Condition: An ERP Study

PubMed Central

Wang, Hui; Duan, Jiaobo; Liao, Yang; Wang, Chuang; Li, Hongzheng; Liu, Xufeng

2017-01-01

During the spaceflight under weightlessness condition, human's brain function may be affected by the changes of physiological effects along with the distribution of blood and body fluids to the head. This variation of brain function will influence the performance of astronauts and therefore create possible harm to flight safety. This study employs 20 male subjects in a 7-day−6° head-down tilted (HDT) bed rest model to simulate physiological effects under weightlessness condition, and use behavioral, electrophysiological techniques to compare the changes of mental rotation ability (MR ability) before and after short-term simulated weightlessness state. Behavioral results suggested that significant linear relationship existed between the rotation angle of stimuli and the reaction time, which means mental rotation process do happen during the MR task in simulated weightlessness state. In the first 3 days, the P300 component induced by object mental rotation followed the “down-up-down” pattern. In the following 4 days it changed randomly. On HDT D2, the mean of the amplitude of the P300 was the lowest, while increased gently on HDT D3. There was no obvious changing pattern of the amplitude of P300 observed after 3 days of HDT. Simulated weightlessness doesn't change the basic process of mental rotation. The effect of simulated weightlessness is neural mechanism of self-adaptation. MR ability didn't bounce back to the original level after HDT test. PMID:29270115
Physiological changes in fast and slow muscle with simulated weightlessness

NASA Technical Reports Server (NTRS)

Dettbarn, W. D.; Misulis, K. E.

1984-01-01

A rat hindlimb suspension model of simulated weightlessness was used to examine the physiological characteristics of skeletal muscle. The physiological sequelae of hindlimb suspension were compared to those of spinal cord section, denervation by sciatic nerve crush, and control. Muscle examined were the predominantly slow (Type 1) soleus (SOL) and the predominantly fast (Type 2) extensor digitorum longus (EDL). Two procedures which alter motor unit activity, hindlimb suspension and spinal cord section, produce changes in characteristics of skeletal muscles that are dependent upon fiber type. The SOL develops characteristics more representative of a fast muscle, including smaller Type 1 fiber proportion and higher AChE activity. The EDL, which is already predominantly fast, loses most of its few Type 1 fibers, thus also becoming faster. These data are in agreement with the studies in which rats experienced actual weightlessness.
The Effects of Simulated Weightlessness on Susceptibility to Viral and Bacterial Infections Using a Murine Model

NASA Technical Reports Server (NTRS)

Gould, C. L.

1985-01-01

Certain immunological responses may be compromised as a result of changes in environmental conditions, such as the physiological adaptation to and from the weightlessness which occurs during space flight and recovery. A murine antiorthostatic model was developed to simulate weightlessness. Using this model, the proposed study will determine if differences in susceptibility to viral and bacterial infections exist among mice suspended in an antiorthostatic orientation to simulate weightlessness, mice suspended in an orthostatic orientation to provide a stressful situation without the condition of weightlessness simulation, and non-suspended control mice. Inbred mouse strains which are resistant to the diabetogenic effects of the D variant of encephalomyocarditis virus (EMC-D) and the lethal effects of Salmonella typhimurium will be evaluated. Glucose tolerance tests will be performed on all EMC-D-infected and non-infected control groups. The incidence of EMC-D-induced diabetes and the percentage survival of S. typhimurium-infected animals will be determined in each group. An additional study will determine the effects of simulated weightlessness on murine responses to exogenous interferon.
Physiologic mechanisms of circulatory and body fluid losses in weightlessness identified by mathematical modeling

NASA Technical Reports Server (NTRS)

Simanonok, K. E.; Srinivasan, R. S.; Charles, J. B.

1993-01-01

Central volume expansion due to fluid shifts in weightlessness is believed to activate adaptive reflexes which ultimately result in a reduction of the total circulating blood volume. However, the flight data suggests that a central volume overdistention does not persist, in which case some other factor or factors must be responsible for body fluid losses. We used a computer simulation to test the hypothesis that factors other than central volume overdistention are involved in the loss of blood volume and other body fluid volumes observed in weightlessness and in weightless simulations. Additionally, the simulation was used to identify these factors. The results predict that atrial volumes and pressures return to their prebedrest baseline values within the first day of exposure to head down tilt (HDT) as the blood volume is reduced by an elevated urine formation. They indicate that the mechanisms for large and prolonged body fluid losses in weightlessness is red cell hemoconcentration that elevates blood viscosity and peripheral resistance, thereby lowering capillary pressure. This causes a prolonged alteration of the balance of Starling forces, depressing the extracellular fluid volume until the hematocrit is returned to normal through a reduction of the red cell mass, which also allows some restoration of the plasma volume. We conclude that the red cell mass becomes the physiologic driver for a large 'undershoot' of the body fluid volumes after the normalization of atrial volumes and pressures.
Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions.

PubMed

Clément, Gilles R; Bukley, Angelia P; Paloski, William H

2015-01-01

In spite of the experience gained in human space flight since Yuri Gagarin's historical flight in 1961, there has yet to be identified a completely effective countermeasure for mitigating the effects of weightlessness on humans. Were astronauts to embark upon a journey to Mars today, the 6-month exposure to weightlessness en route would leave them considerably debilitated, even with the implementation of the suite of piece-meal countermeasures currently employed. Continuous or intermittent exposure to simulated gravitational states on board the spacecraft while traveling to and from Mars, also known as artificial gravity, has the potential for enhancing adaptation to Mars gravity and re-adaptation to Earth gravity. Many physiological functions are adversely affected by the weightless environment of spaceflight because they are calibrated for normal, Earth's gravity. Hence, the concept of artificial gravity is to provide a broad-spectrum replacement for the gravitational forces that naturally occur on the Earth's surface, thereby avoiding the physiological deconditioning that takes place in weightlessness. Because researchers have long been concerned by the adverse sensorimotor effects that occur in weightlessness as well as in rotating environments, additional study of the complex interactions among sensorimotor and other physiological systems in rotating environments must be undertaken both on Earth and in space before artificial gravity can be implemented.
Artificial gravity as a countermeasure for mitigating physiological deconditioning during long-duration space missions

PubMed Central

Clément, Gilles R.; Bukley, Angelia P.; Paloski, William H.

2015-01-01

In spite of the experience gained in human space flight since Yuri Gagarin’s historical flight in 1961, there has yet to be identified a completely effective countermeasure for mitigating the effects of weightlessness on humans. Were astronauts to embark upon a journey to Mars today, the 6-month exposure to weightlessness en route would leave them considerably debilitated, even with the implementation of the suite of piece-meal countermeasures currently employed. Continuous or intermittent exposure to simulated gravitational states on board the spacecraft while traveling to and from Mars, also known as artificial gravity, has the potential for enhancing adaptation to Mars gravity and re-adaptation to Earth gravity. Many physiological functions are adversely affected by the weightless environment of spaceflight because they are calibrated for normal, Earth’s gravity. Hence, the concept of artificial gravity is to provide a broad-spectrum replacement for the gravitational forces that naturally occur on the Earth’s surface, thereby avoiding the physiological deconditioning that takes place in weightlessness. Because researchers have long been concerned by the adverse sensorimotor effects that occur in weightlessness as well as in rotating environments, additional study of the complex interactions among sensorimotor and other physiological systems in rotating environments must be undertaken both on Earth and in space before artificial gravity can be implemented. PMID:26136665
A comprehensive Guyton model analysis of physiologic responses to preadapting the blood volume as a countermeasure to fluid shifts

NASA Technical Reports Server (NTRS)

Simanonok, K. E.; Srinivasan, R. S.; Myrick, E. E.; Blomkalns, A. L.; Charles, J. B.

1994-01-01

The Guyton model of fluid, electrolyte, and circulatory regulation is an extensive mathematical model capable of simulating a variety of experimental conditions. It has been modified for use at NASA to simulate head-down tilt, a frequently used analog of weightlessness. Weightlessness causes a headward shift of body fluids that is believed to expand central blood volume, triggering a series of physiologic responses resulting in large losses of body fluids. We used the modified Guyton model to test the hypothesis that preadaptation of the blood volume before weightless exposure could counteract the central volume expansion caused by fluid shifts, and thereby attenuate the circulatory and renal responses that result in body fluid losses. Simulation results show that circulatory preadaptation, by a procedure resembling blood donation immediately before head-down bedrest, is effective in damping the physiologic responses to fluid shifts and reducing body fluid losses. After 10 hours of head-down tilt, preadaptation also produces higher blood volume, extracellular volume, and total body water for 20 to 30 days of bedrest, compared with non-preadapted control. These results indicate that circulatory preadaptation before current Space Shuttle missions may be beneficial for the maintenance of reentry and postflight orthostatic tolerance in astronauts. This paper presents a comprehensive examination of the simulation results pertaining to changes in relevant physiologic variables produced by blood volume reduction before a prolonged head-down tilt. The objectives were to study and develop the countermeasure theoretically, to aid in planning experimental studies of the countermeasure, and to identify potentially disadvantageous physiologic responses that may be caused by the countermeasure.
Osteoblast histogenesis in periodontal ligament and tibial metaphysis during simulated weightlessness

NASA Technical Reports Server (NTRS)

Fielder, Paul J.; Morey, Emily R.; Roberts, W. Eugene

1986-01-01

Utilizing the nuclear morphometric assay for osteoblast histogenesis, the effect of simulated weightlessness (SW) on the relative numbers of the periodontal ligament (PDL) osteoblast progenitors and on the total number of osteogenic cells was determined in rats. Weightlessness was simulated by subjecting rats to continuous 30-deg head-down posture using a modified back-harness device of Morey (1979). The response of a partially unloaded, weight-bearing bone, tibial primary spongiosa (PS), was compared to a normally loaded, nonweight-bearing PDL bone. Data indicated a similar differentiation sequence in PS and PDL, which suggests that these bones might be sensitive to the same systemic factors. Preosteoblast numbers were seen to decrease in both nonweight-bearing and weight-bearing bones during SW (compared with rats not exposed to SW), indicating the importance of systemic mediators, such as cephalad fluid shift, physiological stress, and/or growth retardation.
Analogs of microgravity: head-down tilt and water immersion.

PubMed

Watenpaugh, Donald E

2016-04-15

This article briefly reviews the fidelity of ground-based methods used to simulate human existence in weightlessness (spaceflight). These methods include horizontal bed rest (BR), head-down tilt bed rest (HDT), head-out water immersion (WI), and head-out dry immersion (DI; immersion with an impermeable elastic cloth barrier between subject and water). Among these, HDT has become by far the most commonly used method, especially for longer studies. DI is less common but well accepted for long-duration studies. Very few studies exist that attempt to validate a specific simulation mode against actual microgravity. Many fundamental physical, and thus physiological, differences exist between microgravity and our methods to simulate it, and between the different methods. Also, although weightlessness is the salient feature of spaceflight, several ancillary factors of space travel complicate Earth-based simulation. In spite of these discrepancies and complications, the analogs duplicate many responses to 0 G reasonably well. As we learn more about responses to microgravity and spaceflight, investigators will continue to fine-tune simulation methods to optimize accuracy and applicability. Copyright © 2016 the American Physiological Society.
Computer simulation of preflight blood volume reduction as a countermeasure to fluid shifts in space flight

NASA Technical Reports Server (NTRS)

Simanonok, K. E.; Srinivasan, R.; Charles, J. B.

1992-01-01

Fluid shifts in weightlessness may cause a central volume expansion, activating reflexes to reduce the blood volume. Computer simulation was used to test the hypothesis that preadaptation of the blood volume prior to exposure to weightlessness could counteract the central volume expansion due to fluid shifts and thereby attenuate the circulatory and renal responses resulting in large losses of fluid from body water compartments. The Guyton Model of Fluid, Electrolyte, and Circulatory Regulation was modified to simulate the six degree head down tilt that is frequently use as an experimental analog of weightlessness in bedrest studies. Simulation results show that preadaptation of the blood volume by a procedure resembling a blood donation immediately before head down bedrest is beneficial in damping the physiologic responses to fluid shifts and reducing body fluid losses. After ten hours of head down tilt, blood volume after preadaptation is higher than control for 20 to 30 days of bedrest. Preadaptation also produces potentially beneficial higher extracellular volume and total body water for 20 to 30 days of bedrest.
Physiological responses to environmental factors related to space flight. [hemodynamic and metabolic responses to weightlessness

NASA Technical Reports Server (NTRS)

Pace, N.

1973-01-01

Physiological base line data are established, and physiological procedures and instrumentation necessary for the automatic measurement of hemodynamic and metabolic parameters during prolonged periods of weightlessness are developed.
Physiological responses of women to simulated weightlessness: A review of the first female bed-rest study

NASA Technical Reports Server (NTRS)

Sandler, H.; Winter, D. L.

1978-01-01

Subjects were exposed to centrifugation, to lower body negative pressure (LBNP), and to exericse stress both before and after bed rest. Areas studied were centrifugation tolerance, fluid electrolyte changes and hematology, tolerance to LBNP, physical working capacity, biochemistries, blood fibrinolytic activity, female metabolic and hormonal responses, circadian alterations, and gynecology. Results were compared with the responses observed in similarly bed-rested male subjects. The bed-rested females showed deconditioning responses similar to those of the males, although with some differences. Results indicate that women are capable of coping with exposure to weightlessness and, moreover, that they may be more sensitive subjects for evaluating countermeasures to weightlessness and developing criteria for assessing applicants for shuttle voyages.
[Some problems of space medicine].

PubMed

Gurovskiĭ, N N; Egorov, A D

1976-01-01

The paper discusses the problems to be resolved by space medicine and the main stages in the development of this branch of science, beginning with the vertical launches of rockets and ending with the flights of orbital stations. On the basis of ground-based simulation experiments and real space flights it presents a classification of the major symptomocomplexes that may occur inflight. The paper describes the main stages of adaptation to weightlessness and physiological changes in the weightless state. The paper also outlines further pathways in the development of space medicine.
A systems approach to the physiology of weightlessness

NASA Technical Reports Server (NTRS)

White, Ronald J.; Leonard, Joel I.; Rummel, John A.; Leach, Carolyn S.

1991-01-01

A general systems approach to conducting and analyzing research on the human adaptation to weightlessness is presented. The research is aimed at clarifying the role that each of the major components of the human system plays following the transition to and from space. The approach utilizes a variety of mathematical models in order to pose and test alternative hypotheses concerned with the adaptation process. Certain aspects of the problem of fluid and electrolyte shifts in weightlessnes are considered, and an integrated hypothesis based on numerical simulation studies and experimental data is presented.
An integrative approach to space-flight physiology using systems analysis and mathematical simulation

NASA Technical Reports Server (NTRS)

Leonard, J. I.; White, R. J.; Rummel, J. A.

1980-01-01

An approach was developed to aid in the integration of many of the biomedical findings of space flight, using systems analysis. The mathematical tools used in accomplishing this task include an automated data base, a biostatistical and data analysis system, and a wide variety of mathematical simulation models of physiological systems. A keystone of this effort was the evaluation of physiological hypotheses using the simulation models and the prediction of the consequences of these hypotheses on many physiological quantities, some of which were not amenable to direct measurement. This approach led to improvements in the model, refinements of the hypotheses, a tentative integrated hypothesis for adaptation to weightlessness, and specific recommendations for new flight experiments.
Mechanistic studies on reduced exercise performance and cardiac deconditioning with simulated zero gravity

NASA Technical Reports Server (NTRS)

Tipton, Charles M.

1991-01-01

The primary purpose of this research is to study the physiological mechanisms associated with the exercise performance of rats subjected to conditions of simulated weightlessness. A secondary purpose is to study related physiological changes associated with other systems. To facilitate these goals, a rodent suspension model was developed (Overton-Tipton) and a VO2 max testing procedure was perfected. Three methodological developments occurred during this past year deserving of mention. The first was the refinement of the tail suspension model so that (1) the heat dissipation functions of the caudal artery can be better utilized, and (2) the blood flow distribution to the tail would have less external constriction. The second was the development on a one-leg weight bearing model for use in simulated weightlessness studies concerned with change in muscle mass, muscle enzyme activity, and hind limb blood flow. The chemical body composition of 30 rats was determined and used to develop a prediction equation for percent fat using underwater weighing procedures to measure carcass specific gravity and to calculate body density, body fat, and fat free mass.
Human physiological adaptation to extended Space Flight and its implications for Space Station

NASA Technical Reports Server (NTRS)

Kutyna, F. A.; Shumate, W. H.

1985-01-01

Current work evaluating short-term space flight physiological data on the homeostatic changes due to weightlessness is presented as a means of anticipating Space Station long-term effects. An integrated systems analysis of current data shows a vestibulo-sensory adaptation within days; a loss of body mass, fluids, and electrolytes, stabilizing in a month; and a loss in red cell mass over a month. But bone demineralization which did not level off is seen as the biggest concern. Computer algorithms have been developed to simulate the human adaptation to weightlessness. So far these paradigms have been backed up by flight data and it is hoped that they will provide valuable information for future Space Station design. A series of explanatory schematics is attached.
Actual and Simulated Weightlessness Inhibit Osteogenesis in Long Bone Metaphysis by Different Mechanisms

NASA Technical Reports Server (NTRS)

Roberts, W. E.

1985-01-01

Weightlessness and simulated weightlessness inhibit the rate of periosteal bone formation in long bones. Formation of preosteoblasts is suppressed in periodontal ligament (PDL) of maxillary molars, which suggests a generalized block in osteoblast histogenesis. Growth in length of long bones is decreased by simulated weightlessness, but there are no reliable data on the influence of actual weightlessness on metaphyseal growth. The nuclear size assay for assessing relative numbers of osteoblast precursor cells was utilized in the primary spongiosa of growing long bones subjected to actual and simulated weightlessness. It is found that: (1) Actual weightlessness decreases total number of osteogenic cells and inhibits differentiation of osteoblast precursor cells, (2) Simulated weightlessness suppresses only osteoblast differentation; and (3) The nuclear morphometric assay is an effective means of assessing osteogenic activity in the growing metaphysis or long bones.

Physiological effects of weightlessness: countermeasure system development for a long-term Chinese manned spaceflight.

PubMed

Wang, Linjie; Li, Zhili; Tan, Cheng; Liu, Shujuan; Zhang, Jianfeng; He, Siyang; Zou, Peng; Liu, Weibo; Li, Yinghui

2018-04-25

The Chinese space station will be built around 2020. As a national space laboratory, it will offer unique opportunities for studying the physiological effects of weightlessness and the efficacy of the countermeasures against such effects. In this paper, we described the development of countermeasure systems in the Chinese space program. To emphasize the need of the Chinese space program to implement its own program for developing countermeasures, we reviewed the literature on the negative physiological effects of weightlessness, the challenges of completing missions, the development of countermeasure devices, the establishment of countermeasure programs, and the efficacy of the countermeasure techniques in American and Russian manned spaceflights. In addition, a brief overview was provided on the Chinese research and development on countermeasures to discuss the current status and goals of the development of countermeasures against physiological problems associated with weightlessness.
Certain peculiarities of the functioning of the cardiovascular system in bedrest conditions during horizontal and antiorthostatic body positions

NASA Technical Reports Server (NTRS)

1978-01-01

The adequate modeling of physiological reactions inherent to the state of weightlessness has become a matter of particular urgency in space medicine. This modeling is necessary for studying the phenomenology and degree of disorders, prognostication of the crew's health, and developing the various preventive measures employed in space flights. A comparison is made of the physiological effects brought about by bed rest in a horizontal and antiorthostatic body position. A study is done of the influence of brief antiorthostatic hypokinesia, simulating the acute period of adaptation to weightlessness, on circulation and on a number of involved analytical systems. The basic model accepted is antiorthostatic hypokinesia with a body position declination angle of 4 deg (head lower than feet). The experiment's duration is dictated by the objectives of the research.
Continuous metabolic and cardiovascular measurements on a monkey subject during a simulated 6-day Spacelab mission

NASA Technical Reports Server (NTRS)

Pace, N.; Rahlmann, D. F.; Mains, R. C.; Kodama, A. M.; Mccutcheon, E. P.

1979-01-01

A 10-kg male pig-tailed monkey (Macaca nemestrina) was selected as an optimal species for spaceflight studies on weightlessness. Three days before the simulated launch, the animal was placed in a fiberglass pod system to provide continuous measurement of respiratory gas exchange. Attention is given to examining the effects of weightlessness on several basic parameters of metabolic and cardiovascular function in an adult nonhuman primate. The 10.7-day total simulated-experiment period consisted of preflight 2.6 days, inflight 6.3 days, and postflight 1.8 days. Statistically significant diurnal variation was noted in oxygen consumption and CO2 production rates, body temperature and HR, but not in respiratory quotient or blood pressure. The high quality of the continuous data obtained demonstrates the feasibility of performing sound physiological experimentation on nonhuman primates in the Spacelab environment.
Physiological responses to environmental factors related to space flight

NASA Technical Reports Server (NTRS)

Pace, N.; Grunbaum, B. W.; Kodama, A. M.; Mains, R. C.; Rahlmann, D. F.

1975-01-01

Physiological procedures and instrumentation developed for the measurement of hemodynamic and metabolic parameters during prolonged periods of weightlessness are described along with the physiological response of monkeys to weightlessness. Specific areas examined include: cardiovascular studies; thyroid function; blood oxygen transport; growth and reproduction; excreta analysis for metabolic balance studies; and electrophoretic separation of creatine phosphokinase isoenzymes in human blood.
Spacelab flight simulated by two monkeys at CERMA

NASA Technical Reports Server (NTRS)

Langereux, P.

1980-01-01

A semiautomatic module for two monkeys was designed. The module shelters two Rhesus monkeys seated side by side in a compartment, reducing the emotional stresses caused by isolation. Food pellets, water, and air are supplied and body wastes are automatically removed. Physiological and environmental parameters are continually monitored, making possible the performance of experiments concerning the pathophysiological mechanisms of the disorders of weightlessness. A ten day flight of the module in Spacelab was simulated.
A Systems Approach to the Physiology of Weightlessness

NASA Technical Reports Server (NTRS)

White, Ronald J.; Leonard, Joel I.; Rummel, John A.; Leach, Carolyn S.

1991-01-01

A systems approach to the unraveling of the complex response pattern of the human subjected to weightlessness is presented. The major goal of this research is to obtain an understanding of the role that each of the major components of the human system plays following the transition to and from space. The cornerstone of this approach is the utilization of a variety of mathematical models in order to pose and test alternative hypotheses concerned with the adaptation process. An integrated hypothesis for the human physiological response to weightlessness is developed.
Microbial growth and physiology in space - A review

NASA Technical Reports Server (NTRS)

Cioletti, Louis A.; Mishra, S. K.; Pierson, Duane L.

1991-01-01

An overview of microbial behavior in closed environments is given with attention to data related to simulated microgravity and actual space flight. Microbes are described in terms of antibiotic sensitivity, subcellular structure, and physiology, and the combined effects are considered of weightlessness and cosmic radiation on human immunity to such microorganisms. Space flight results report such effects as increased phage induction, accelerated microbial growth rates, and the increased risk of disease communication and microbial exchange aboard confining spacecraft. Ultrastructural changes are also noted in the nuclei, cell membranes, and cytoplasmic streaming, and it appears that antibiotic sensitivity is reduced under both actual and simulated conditions of spaceflight.
[Effect of aerospace weightlessness on cognitive functions and the relative dialectical analysis of Chinese medicine].

PubMed

Dong, Li; Liu, Xin-Min; Wu, Li-Sha; Yang, Si-Jin; Wang, Qiong

2014-03-01

Aerospace medicine has paid more and more attention to abnormal changes of physiological functions induced by weightlessness and studies on their prevention during space flight. In this paper, the effect of space weightlessness on cognitive functions was introduced. We tried to analyze the correlation between the cognitive function changes and relevant Chinese medical syndromes, thus providing a potential available way to prevent and treat weightlessness induced cognitive deficit during space flight.
[Effects of high +Gx during simulated spaceship emergency return on learning and memory in rats].

PubMed

Xu, Zhi-peng; Sun, Xi-qing; Liu, Ting-song; Wu, Bin; Zhang, Shu; Wu, Ping

2005-02-01

To observe the effects of high +Gx during simulated spaceship emergency return on learning and memory in rats. Thirty two male SD rats were randomly divided into control group, 7 d simulated weightlessness group, +15 Gx/180 s group and +15 Gx/180 s exposure after 7 d simulated weightlessness group, with 8 rats in each group. The changes of learning and memory in rats were measured after stresses by means of Y-maze test and step-through test. In Y-maze test, as compared with control group, percentage of correct reactions decreased significantly (P<0.01) and reaction time increased significantly (P<0.01) in hypergravity after simulated weightlessness group at all time after stress; as compared with +15 Gx group or simulated weightlessness group, percentage of correct reactions decreased significantly (P< 0.05) and reaction time increased significantly (P< 0.05) immediately after stress. In step-through test, as compared with control group, total time increased significantly (P<0.01) in hypergravity after simulated weightlessness group at 1 d after stress; latent time decreased significantly (P<0.01) and number of errors increased significantly (P< 0.01) at all the time after stress. As compared with +15 Gx group, total time increased significantly (P<0.05) immediately, 1 d after stress. As compared with simulated weightlessness group, total time and number of errors increased significantly (P<0.05) immediately after stress. It is suggested that +15 Gx/180 s and simulated weightlessness may affect the ability of learning and memory of rats. Simulated weightlessness for 7 d can aggravate the effect of +Gx on learning and memory ability in rats.
Space Gerontology

NASA Technical Reports Server (NTRS)

Miquel, J. (Editor); Economos, A. C. (Editor)

1982-01-01

Presentations are given which address the effects of space flght on the older person, the parallels between the physiological responses to weightlessness and the aging process, and experimental possibilities afforded by the weightless environment to fundamental research in gerontology and geriatrics.
An optimized index of human cardiovascular adaptation to simulated weightlessness

NASA Technical Reports Server (NTRS)

Wang, M.; Hassebrook, L.; Evans, J.; Varghese, T.; Knapp, C.

1996-01-01

Prolonged exposure to weightlessness is known to produce a variety of cardiovascular changes, some of which may influence the astronaut's performance during a mission. In order to find a reliable indicator of cardiovascular adaptation to weightlessness, we analyzed data from nine male subjects after a 24-hour period of normal activity and after a period of simulated weightlessness produced by two hours in a launch position followed by 20 hours of 6 degrees head-down tilt plus pharmacologically induced diuresis (furosemide). Heart rate, arterial pressure, thoracic fluid index, and radial flow were analyzed. Autoregressive spectral estimation and decomposition were used to obtain the spectral components of each variable from the subjects in the supine position during pre- and post-simulated weightlessness. We found a significant decrease in heart rate power and an increase in thoracic fluid index power in the high frequency region (0.2-0.45 Hz) and significant increases in radial flow and arterial pressure powers in the low frequency region (<0.2 Hz) in response to simulated weightlessness. However, due to the variability among subjects, any single variable appeared limited as a dependable index of cardiovascular adaptation to weightlessness. The backward elimination algorithm was then used to select the best discriminatory features from these spectral components. Fisher's linear discriminant and Bayes' quadratic discriminant were used to combine the selected features to obtain an optimal index of adaptation to simulated weightlessness. Results showed that both techniques provided improved discriminant performance over any single variable and thus have the potential for use as an index to track adaptation and prescribe countermeasures to the effects of weightlessness.
Respiration, respiratory metabolism and energy consumption under weightless conditions

NASA Technical Reports Server (NTRS)

Kasyan, I. I.; Makarov, G. F.

1975-01-01

Changes in the physiological indices of respiration, respiratory metabolism and energy consumption in spacecrews under weightlessness conditions manifest themselves in increased metabolic rates, higher pulmonary ventilation volume, oxygen consumption and carbon dioxide elimination, energy consumption levels in proportion to reduction in neuroemotional and psychic stress, adaptation to weightlessness and work-rest cycles, and finally in a relative stabilization of metabolic processes due to hemodynamic shifts.
Cardiovascular adaptations in weightlessness: The influence of in-flight exercise programs on the cardiovascular adjustments during weightlessness and upon returning to Earth

NASA Technical Reports Server (NTRS)

Bennett, C. H.

1981-01-01

The effect of in-flight exercise programs on astronauts' cardiovascular adjustments during spaceflight weightlessness and upon return to Earth was studied. Physiological changes in muscle strength and volume, cardiovascular responses during the application of lower body negative pressure, and metabolic activities during pre-flight and flight tests were made on Skylab crewmembers. The successful completion of the Skylab missions showed that man can perform submaximal and maximal aerobic exercise in the weightless enviroment without detrimental trends in any of the physiologic data. Exercise tolerance during flight was unaffected. It was only after return to Earth that a tolerance decrement was noted. The rapid postflight recovery of orthostatic and exercise tolerance following two of the three Skylab missions appeared to be directly related to total in-flight exercise as well as to the graded, regular program of exercise performed during the postflight debriefing period.
Characterization of blood drawn rapidly for use in blood volume expansion studies: An animal model for simulated weightlessness

NASA Technical Reports Server (NTRS)

Chenault, V. Michelle; Lynch, Colleen D.; Morris, Mariana; Clodfelter, Jill; Hutchins, Phillip M.

1990-01-01

It was demonstrated that up to 8ml of blood can be drawn from donar rats without significantly increasing volume and stress sensitive hormones, and thus can be used for volume expansion studies. Infusion of whole blood allows more physiological changes that can be seen with volume expansion by saline or other ionic solutions. The infusion of whole blood to induce hypervolemia may provide an improved model to study the fluid balance and control mechanisms operative in weightlessness. Blood samples were drawn as quickly as possible from femoral artery catheters chronically implanted in Sprague Dawley rats and analyzed for hematocrit, plasma sodium, potassium, osmolality, corticosterone, epinepherine, norepinephrine, and vasopressin. The levels were found to be comparable to those of normal rats.
Cardiovascular Consequences of Weightlessness Promote Advances in Clinical and Trauma Care

DTIC Science & Technology

2005-01-01

pressure (LBNP), an experimental procedure used widely in aerospace physiology, induces autonomic and hemodynamic responses that are similar to actual...resistance in response to reductions of arterial blood pressure [23], but only within a finite range of pressures [24]. Once sympa- thetic activation is... orthostatic intolerance has been linked to both hypo- [4, 34] and hyper-adrenergic [35- 37] responses to standing or tilting, or to simulated or
Journal of Gravitational Physiology, Volume 13, No. 1

NASA Technical Reports Server (NTRS)

Fuller, Charles A. (Editor); Cogoli, Augusto (Editor); Hargens, Alan R. (Editor); Smith, Arthur H. (Editor)

2006-01-01

At the outset, the Journal published one issue in 1994. The first number comprised the Proceedings of the 15th Annual International Gravitational Physiology Meeting, held in Barcelona, Spain in October 1993. The Proceedings of the previous 14 Annual Meetings appeared as supplements to The Physiologist from 1979 to 1993. Each year, one issue of the Journal is devoted to the Annual Meeting Proceedings, and up to four more issues are comprised of full-length research papers. Additionally, Supplement Issues are considered by the Editorial Board as they are submitted. The Journal is published for the International Society for Gravitational Physiology by the Galileo Foundation, a 501(c)(3) nonprofit public benefit corporation. This issue, the first number of 2006, comprises the Proceedings of the joint meeting of the International Society for Gravitational Physiology s 27th Annual International Gravitational Physiology Meeting, held in Osaka, Japan 23- 28 April, 2006. The Journal of Gravitational Physiology invites the submission of original experimental or observational papers on subjects in the field of gravitational physiology. Review articles, theoretical papers and historical or biographical articles will also be solicited by the Editor for publication. The wide scientific span of the Journal rests on physiology as its keystone. Gravitational physiology is considered to include the effects of changes in the magnitude and directions of the gravitational force environment on cells and physiological systems and behavior of humans, animals and plants. The effects of weightlessness during space flight, high sustained G forces and chronic acceleration, vibration, impact and the various forms of simulated weightlessness are also included, as well as is consideration of the evolutionary consequences of gravity and the role of gravity in the manifestation of scale effects in animals and plants.
Automated system for integration and display of physiological response data

NASA Technical Reports Server (NTRS)

1975-01-01

The system analysis approach was applied in a study of physiological systems in both 1-g and weightlessness, for short and long term experiments. A whole body, algorithm developed as the first step in the construction of a total body simulation system is described and an advanced biomedical computer system concept including interactive display/command consoles is discussed. The documentation of the design specifications, design and development studies, and user's instructions (which include program listings) for these delivered end-terms; the reports on the results of many research and feasibility studies; and many subcontract reports are cited in the bibliography.
The sympathetic nervous system and the physiologic consequences of spaceflight: a hypothesis

NASA Technical Reports Server (NTRS)

Robertson, D.; Convertino, V. A.; Vernikos, J.

1994-01-01

Many of the physiologic consequences of weightlessness and the cardiovascular abnormalities on return from space could be due, at least in part, to alterations in the regulation of the autonomic nervous system. In this article, the authors review the rationale and evidence for an autonomic mediation of diverse changes that occur with spaceflight, including the anemia and hypovolemia of weightlessness and the tachycardia and orthostatic intolerance on return from space. This hypothesis is supported by studies of two groups of persons known to have low catecholamine levels: persons subjected to prolonged bedrest and persons with syndromes characterized by low circulating catecholamines (Bradbury-Eggleston syndrome and dopamine beta-hydroxylase deficiency). Both groups exhibit the symptoms mentioned. The increasing evidence that autonomic mechanisms underlie many of the physiologic consequences of weightlessness suggests that new pharmacologic approaches (such as administration of beta-blockers and/or sympathomimetic amines) based on these findings may attenuate these unwanted effects.
Physiological problems of weightlessness

NASA Technical Reports Server (NTRS)

Vasilyev, P. V.; Kasyan, I. I.

1975-01-01

A brief review of the compensatory-adjusting body changes observed during and after human exposure to prolonged spaceflight is given. Pathological disturbances caused by increased functional hypokinesia and weightlessness loads affect the cardiovascular system, the nervous and hormonal systems, and the state of the skeletal musculo apparatus.
Preadapting to Weightlessness

NASA Technical Reports Server (NTRS)

Reschke, M. F.; Parker, D. E.; Arrott, A. P.

1986-01-01

Report discusses physiological and physical concepts of proposed training system to precondition astronauts to weightless environment. System prevents motion sickness, often experienced during early part of orbital flight. Also helps prevent seasickness and other forms of terrestrial motion sickness, often experienced during early part of orbital flight. Training affects subject's perception of inner-ear signals, visual signals, and kinesthetic motion perception. Changed perception resembles that of astronauts who spent many days in space and adapted to weightlessness.

Influences of chemical sympathectomy and simulated weightlessness on male and female rats

NASA Technical Reports Server (NTRS)

Woodman, Christopher R.; Stump, Craig S.; Stump, Jane A.; Sebastian, Lisa A.; Rahman, Z.; Tipton, Charles M.

1991-01-01

Consideration is given to a study aimed at determining whether the sympathetic nervous system is associated with the changes in maximum oxygen consumption (VO2max), run time, and mechanical efficiency observed during simulated weightlessness in male and female rats. Female and male rats were compared for food consumption, body mass, and body composition in conditions of simulated weightlessness to provide an insight into how these parameters may influence aerobic capacity and exercise performance. It is concluded that chemical sympathectomy and/or a weight-bearing stimulus will attenuate the loss in VO2max associated with simulated weightlessness in rats despite similar changes in body mass and composition. It is noted that the mechanisms remain unclear at this time.
Description, validation, and modification of the Guyton model for space-flight applications. Part A. Guyton model of circulatory, fluid and electrolyte control. Part B. Modification of the Guyton model for circulatory, fluid and electrolyte control

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1985-01-01

The mathematical model that has been a cornerstone for the systems analysis of space-flight physiological studies is the Guyton model describing circulatory, fluid and electrolyte regulation. The model and the modifications that are made to permit simulation and analysis of the stress of weightlessness are described.
Physiological responses to prolonged bed rest and fluid immersion in man: A compendium of research (1974 - 1980)

NASA Technical Reports Server (NTRS)

Greenleaf, J. E.; Silverstein, L.; Bliss, J.; Langenheim, V.; Rosson, H.; Chao, C.

1982-01-01

Water immersion and prolonged bed rest reproduce nearly all the physiological responses observed in astronauts in the weightless state. Related to actual weightlessness, given responses tend to occur sooner in immersion and later in bed rest. Much research was conducted on humans using these two techniques, especially by Russian scientists. Abstracts and annotations of reports that appeared in the literature from January 1974 through December 1980 are compiled and discussed.
Effect of antiorthostatic bed rest on hepatic blood flow in man.

PubMed

Putcha, L; Cintron, N M; Vanderploeg, J M; Chen, Y; Habis, J; Adler, J

1988-04-01

Physiological changes that occur during exposure to weightlessness may induce alterations in blood flow to the liver. Estimation of hepatic blood flow (HBF) using ground-based weightlessness simulation models may provide insight into functional changes of the liver in crewmembers during flight. In the present study HBF, indirectly estimated by indocyanine green (ICG) clearance, is compared in 10 subjects during the normal ambulatory condition and antiorthostatic (-6 degrees) bed rest. Plasma clearance of ICG was determined following intravenous administration of a 0.5-mg.kg-1 dose of ICG to each subject on two separate occasions, once after being seated for 1 h and once after 24 h of head-down bed rest. After 24 h of head-down bed rest, hepatic blood flow did not change significantly from the respective control value.
Effects of weightlessness on human fluid and electrolyte physiology

NASA Technical Reports Server (NTRS)

Leach, Carolyn S.; Johnson, Philip C., Jr.

1991-01-01

Skylab and Spacelab data on changes occurring in human fluid and electrolyte physiology during the acute and adaptive phases of adaptation to spaceflight are summarized. The combined results for all three Spacelab studies show that hyponatremia developed within 20 h after the onset of weightlessness and continued throughout the flights, and hypokalemia developed by 40 h. Antidiuretic hormone was increased in plasma throughout the flights. Aldosterone decreased by 40 h, but after 7 days it had reached preflight levels.
Results from recent spaceflight experiments (1).

PubMed

Hoffmann, Uwe

2009-10-01

Since the flight of Sputnik 2 in 1957 the effects of weightlessness on the cardiovascular regulation are subject of physiological research. This introduction gives a short summary of the further development of cardiovascular research related to weightlessness which was subject of the contributions to the first part of this workshop.
Three-dimensional ballistocardiography in weightlessness

NASA Technical Reports Server (NTRS)

Scano, A.

1981-01-01

An experiment is described the aim of which is to record a three dimensional ballistocardiogram under the condition of weightlessness and to compare it with tracings recorded on the same subject on the ground as a means of clarifying the meaning of ballistocardiogram waves in different physiological and perphaps pathological conditions. Another purpose is to investigate cardiovascular and possibly fluid adaptations to weightlessness from data collected almost simultaneously on the same subjects during the other cardiovascular during the other cardiovascular and metabolic experiments.
The physiological basis for spacecraft environmental limits

NASA Technical Reports Server (NTRS)

Waligora, J. M. (Compiler)

1979-01-01

Limits for operational environments are discussed in terms of acceptable physiological changes. The environmental factors considered are pressure, contaminants, temperature, acceleration, noise, rf radiation, and weightlessness.
Cardiovascular effects of weightlessness and ground-based simulation

NASA Technical Reports Server (NTRS)

Sandler, Harold

1988-01-01

A large number of animal and human flight and ground-based studies were conducted to uncover the cardiovascular effects of weightlessness. Findings indicate changes in cardiovascular function during simulations and with spaceflight that lead to compromised function on reambulation and/or return to earth. This altered state termed cardiovascular deconditioning is most clearly manifest when in an erect body state. Hemodynamic parameters inidicate the presence of excessive tachnycardia, hypotension (leading to presyncope in one-third of the subjects), decreased heart volume, decreased plasma and circulating blood volumes and loss of skeletal muscle mass, particularly in the lower limbs. No clinically harmful effects were observed to date, but in-depth follow-ups were limited, as was available physiologic information. Available data concerning the causes for the observed changes indicate significant roles for mechanisms involved with body fluid-volume regulation, altered cardiac function, and the neurohumoral control of the control of the peripheral circulation. Satisfactory measures are not found. Return to preflight state was variable and only slightly dependent on flight duration. Future progress awaits availability of flight durations longer than several weeks.
The Effect of Part-simulation of Weightlessness on Human Control of Bilateral Teleoperation: Neuromotor Considerations

NASA Technical Reports Server (NTRS)

Corker, K.; Bejczy, A. K.

1984-01-01

The effect of weightlessness on the human operator's performance in force reflecting position control of remote manipulators was investigated. A gravity compensation system was developed to simulate the effect of weightlessness on the operator's arm. A universal force reflecting hand controller (FRHC) and task simulation software were employed. Two experiments were performed because of anticipated disturbances in neuromotor control specification on the human operator in an orbital control environment to investigate: (1) the effect of controller stiffness on the attainment of a learned terminal position in the three dimensional controller space, and (2) the effect of controller stiffness and damping on force tracking of the contour of a simulated three dimensional cube using the part simulation of weightless conditions. The results support the extension of neuromotor control models, which postulate a stiffness balance encoding of terminal position, to three dimensional motion of a multilink system, confirm the existence of a disturbance in human manual control performance under gravity compensated conditions, and suggest techniques for compensation of weightlessness induced performance decrement through appropriate specification of hand controller response characteristics. These techniques are based on the human control model.
The validity of an animal model for experiments related to weightlessness

NASA Technical Reports Server (NTRS)

Musacchia, X. J.; Steffen, J. M.

1983-01-01

Animal evolution has witnessed morphological and physiological adaptations to gravitational forces. In the rat, hind limb muscles can be used to illustrate a range of load bearing functions: soleus - gastrocnemius = plantaris - extensor digitorum longus (EDL). A harness suspension apparatus is used to induce hypokinesia and hypodynamia (H&H) and to simulate responses comparable to those seen in weightlessness (i.e., COSMOS experiments). After one and two weeks of suspension H&H, there is muscle atrophy with a loss in muscle mass; the result of loss in muscle protein. Concommitantly, there is a decrease in RNA, but not in DNA content. The effects are greatest in the soleus and least in the EDL. These recent findings, in concert with earlier reports of increased nitrogenous excretion, suggest that both decreased protein synthesis and increased protein catabolism are characteristic of muscle atrophy. Recovery is seen in terms of reversal of these effects after removal from suspension.
Some physiological effects of alternation between zero gravity and one gravity

NASA Technical Reports Server (NTRS)

Graybiel, A.

1977-01-01

The anatomy and physiology of the healthy vestibular system and the history of its study, maintenance of muskuloskeletal fitness under low-gravity conditions, tests of motion sickness, and data and techniques on testing subjects in a slow rotation room, are covered. Components of the inner ear labyrinth and their behavior in relation to equilibrium, gravity and inertial forces, motion sickness, and dizziness are discussed. Preventive medicine, the biologically effective force environment, weightlessness per se, activity in a weightless spacecraft, exercizing required to maintain musculoskeletal function, and ataxia problems are dealt with.
Delineating the Impact of Weightlessness on Human Physiology Using Computational Models

NASA Technical Reports Server (NTRS)

Kassemi, Mohammad

2015-01-01

Microgravity environment has profound effects on several important human physiological systems. The impact of weightlessness is usually indirect as mediated by changes in the biological fluid flow and transport and alterations in the deformation and stress fields of the compliant tissues. In this context, Fluid-Structural and Fluid-Solid Interaction models provide a valuable tool in delineating the physical origins of the physiological changes so that systematic countermeasures can be devised to reduce their adverse effects. In this presentation, impact of gravity on three human physiological systems will be considered. The first case involves prediction of cardiac shape change and altered stress distributions in weightlessness. The second, presents a fluid-structural-interaction (FSI) analysis and assessment of the vestibular system and explores the reasons behind the unexpected microgravity caloric stimulation test results performed aboard the Skylab. The last case investigates renal stone development in microgravity and the possible impact of re-entry into partial gravity on the development and transport of nucleating, growing, and agglomerating renal calculi in the nephron. Finally, the need for model validation and verification and application of the FSI models to assess the effects of Artificial Gravity (AG) are also briefly discussed.
Space flight nutrition research: platforms and analogs

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Uchakin, Peter N.; Tobin, Brian W.

2002-01-01

Conducting research during actual or simulated weightlessness is a challenging endeavor, where even the simplest activities may present significant challenges. This article reviews some of the potential obstacles associated with performing research during space flight and offers brief descriptions of current and previous space research platforms and ground-based analogs, including those for human, animal, and cell-based research. This review is intended to highlight the main issues of space flight research analogs and leave the specifics for each physiologic system for the other papers in this section.
The Automated Primate Research Laboratory (APRL)

NASA Technical Reports Server (NTRS)

Pace, N.; Smith, G. D.

1972-01-01

A description is given of a self-contained automated primate research laboratory to study the effects of weightlessness on subhuman primates. Physiological parameters such as hemodynamics, respiration, blood constituents, waste, and diet and nutrition are analyzed for abnormalities in the simulated space environment. The Southeast Asian pig-tailed monkey (Macaca nemistrina) was selected for the experiments owing to its relative intelligence and learning capacity. The objective of the program is to demonstrate the feasibility of a man-tended primate space flight experiment.
Acetylcholinesterase activity in soleus muscle intrafusal and extrafusal fibres in tail suspended rats.

PubMed

Tang, Bin; Fan, Xiao-li; Wu, Su-di

2002-10-01

Objective. To explore the mechanisms involved in muscle atrophy and conversion of the fiber types induced by simulated weightlessness. Method. Weightlessness was simulated by tail suspension of female rats. Intrafusal and extrafusal fibers of soleus muscles in the rat were examined histochemically for their activity of acetylcholinesterase (AChE) and succinic dehydrogenase (SDH) in 7 d, 14 d, 21 d tail-suspended groups and control groups. Result. Staining for succinic dehydrogenase showed that simulated weightlessness caused obvious atrophy and change in fiber type composition in soleus muscle, with decrease of the proportion of type I fiber and increase of type II fiber. Acetylcholinesterase activities of intrafusal and extrafusal fibers were both decreased significantly after 21 d tail suspension. Conclusion. Simulated weightlessness could induce decrease of AChE activity in neuromuscular junctions, which might be linked with decrease in motor neuron activity.
Alterations in gut transport of minerals and in binding proteins during simulated weightlessness

NASA Technical Reports Server (NTRS)

Bikle, D. D.

1984-01-01

The structural components of the skeleton develop and are maintained in a 1 g environment, shaped by the mechanical load to which they are constantly exposed. Altering such a mechanical load by reducing the gravitational force imposed on the system, as in space flight, has profound effects on the skeleton and permits an exploration of the molecular events which regulate normal skeletal homeostasis. The objective was to determine whether simulated weightlessness reduced intestinal calcium transport, and if so, to determine the molecular mechanisms for such an effect. A nonstressful tail suspension in which the rats gained weight normally while suspended was used to simulate weightlessness. A significant change in intestinal calcium transport was not demonstrated. However, a cyclic change in bone formation with suspension was shown. Based on these observations, the objective changed to determination of the hormonal regulation of bone formation during simulated weightlessness.
A mathematical and experimental simulation of the hematological response to weightlessness

NASA Technical Reports Server (NTRS)

Kimzey, S. L.; Leonard, J. I.; Johnson, P. C.

1979-01-01

A mathematical model of erythropoiesis control was used to simulate the effects of bedrest and zero-g on the circulating red cell mass. The model incorporates the best current understanding of the dynamics of red cell production and destruction and the associated feedback regulation. Specifically studied were the hemodynamic responses of a 28-day bedrest study devised to simulate Skylab experience. The results support the hypothesis that red cell loss during supine bedrest is a normal physiological feedback process in response to hemoconcentration enhanced tissue oxygenation and suppression of red cell production. Model simulation suggested the possibilities that this period was marked by some combination of increased oxygen-hemoglobin affinity, small reduction in mean red cell life span, ineffective erythropoiesis, or abnormal reticulocytosis.
Influence of stress, weightlessness, and simulated weightlessness on differentiation of preosteoblasts

NASA Technical Reports Server (NTRS)

Roberts, W. E.

1984-01-01

The effects of 18.5 days of weightlessness aboard a satellite, stress of restricted feeding, stress of noise and vibration to simulate space flight and 21 days of head down suspension via the Morey-Holton model for simulated weightlessness was studied. Nuclear size of fibroblastlike cells in PDL on the anterior surface of maxillary first molars was classified as: (1) A-cells, self perpetuating precursors with a nuclear volume 80 micron B-cells, nonosteogenic fibroblasts with a nuclear volume of 80-119 micron 3, C-cells, preosteoblasts that are in G1 stage of the cell cycle with a nuclear size of 120-170 micro, and D-cells, preosteoblasts that are in G2 stage of the cell cycle with a nuclear size 170 micro.
[Research on the Kosmos biosatellites].

PubMed

Il'in, E A

1984-01-01

In the last decade the USSR has launched six biosatellites of the Cosmos series. The duration of the first flight was 6 days and of the five subsequent flights 18 to 21 days. The major goals of the flight studies were: investigation of adaptation of living systems to weightlessness, identification of the modifying effect of weightlessness on radiosensitivity, and detection of the biological effect of artificial gravity. The examinations were performed on 37 biological species, with most of them on rats. The exposure to weightlessness gave rise to moderate stress reactions and specific changes, particularly in the musculo-skeletal system (muscle atrophy, reduced bone strength, etc). Artificial gravity of 1 g generated inflight helped maintain the normal function of most physiological systems. The exposure of mammals (rats) to 137Ce irradiation did not reveal a modifying effect of weightlessness on radiation sickness. Distinct manifestations of the effects of weightlessness on intracellular processes were not observed. Dissimilar results were obtained with respect to the growth and development of living organisms in weightlessness.

Aerospace gerontology

NASA Technical Reports Server (NTRS)

Comfort, A.

1982-01-01

The relevancy of gerontology and geriatrics to the discipline of aerospace medicine is examined. It is noted that since the shuttle program gives the facility to fly passengers, including specially qualified older persons, it is essential to examine response to acceleration, weightlessness, and re-entry over the whole adult lifespan, not only its second quartile. The physiological responses of the older person to weightlessness and the return to Earth gravity are reviewed. The importance of the use of the weightless environment to solve critical problems in the fields of fundamental gerontology and geriatrics is also stressed.
The effect of simulated weightlessness on hypobaric decompression sickness

NASA Technical Reports Server (NTRS)

Balldin, Ulf I.; Pilmanis, Andrew A.; Webb, James T.

2002-01-01

BACKGROUND: A discrepancy exists between the incidence of ground-based decompression sickness (DCS) during simulated extravehicular activity (EVA) at hypobaric space suit pressure (20-40%) and crewmember reports during actual EVA (zero reports). This could be due to the effect of gravity during ground-based DCS studies. HYPOTHESIS: At EVA suit pressures of 29.6 kPa (4.3 psia), there is no difference in the incidence of hypobaric DCS between a control group and group exposed to simulated weightlessness (supine body position). METHODS: Male subjects were exposed to a hypobaric pressure of 29.6 kPa (4.3 psi) for up to 4 h. The control group (n = 26) pre-oxygenated for 60 min (first 10 min exercising) before hypobaric exposure and walking around in the altitude chamber. The test group (n = 39) remained supine for a 3 h prior to and during the 60-min pre-oxygenation (also including exercise) and at hypobaric pressure. DCS symptoms and venous gas emboli (VGE) at hypobaric pressure were registered. RESULTS: DCS occurred in 42% in the control and in 44% in simulated weightlessness group (n.s.). The mean time for DCS to develop was 112 min (SD +/- 61) and 123 min (+/- 67), respectively. VGE occurred in 81% of the control group subjects and in 51% of the simulated weightlessness subjects (p = 0.02), while severe VGE occurred in 58% and 33%, respectively (p = 0.08). VGE started after 113 min (+/- 43) in the control and after 76 min (+/- 64) in the simulated weightlessness group. CONCLUSIONS: No difference in incidence of DCS was shown between control and simulated weightlessness conditions. VGE occurred more frequently during the control condition with bubble-releasing arm and leg movements.
The effects of prolonged weightlessness and reduced gravity environments on human survival.

PubMed

Taylor, R L

1993-03-01

The manned exploration of the solar system and the surfaces of some of the smaller planets and larger satellites requires that we are able to keep the adverse human physiological response to long term exposure to near zero and greatly reduced gravity environments within acceptable limits consistent with metabolic function. This paper examines the physiological changes associated with microgravity conditions with particular reference to the weightless demineralizatoin of bone (WDB). It is suggested that many of these changes are the result of physical/mechanical processes and are not primarily a medical problem. There are thus two immediately obvious and workable, if relatively costly, solutions to the problem of weightlessness. The provision of a near 1 g field during prolonged space flights, and/or the development of rapid transit spacecraft capable of significant acceleration and short flight times. Although these developments could remove or greatly ameliorate the effects of weightlessness during long-distance space flights there remains a problem relating to the long term colonization of the surfaces of Mars, the Moon, and other small solar system bodies. It is not yet known whether or not there is a critical threshold value of 'g' below which viable human physiological function cannot be sustained. If such a threshold exists permanent colonization may only be possible if the threshold value of 'g' is less than that at the surface of the planet on which we wish to settle.
Bedrest in healthy women: Effects of menstrual function and oral contraceptives

NASA Technical Reports Server (NTRS)

Fortney, Suzanne M.; Beckett, William B.; Vroman, Neil B.; Davis, John; Rock, John; Kimbell, Allyn; Lafrance, Norman; Drew, Helen

1986-01-01

With the development of the space shuttle program, space flight for the first time is available to individuals who have not been specially selected and trained to be astronauts. In addition, women are being actively recruited into the space program, both as mission specialists and as career astronauts. One purpose of this project was to examine some of the physiological responses of women to a simulated weightlessness program (12 day horizontal bedrest), to compare their responses to those reported in men during similar programs, and to test whether menstrual function might alter some of the physiological changes which occur during bedrest, specifically changes in the plasma volume, exercise tolerance, and venous compliance before and after bedrest.
Effect of simulated weightlessness on the immune system in rats

NASA Technical Reports Server (NTRS)

Caren, L. D.; Mandel, A. D.; Nunes, J. A.

1980-01-01

Rats suspended in a model system designed to simulate many aspects of weightlessness were immunized with sheep red blood cells. Parameters measured on these and control rats included titers of anti-sheep red blood cell antibodies, serum immunoglobulin levels, spleen and thymus weights, hematocrits, and leukocyte differential counts on peripheral blood. No significant differences were found between test and weight-bearing, harnessed controls; however, the thymuses of animals in both these groups were significantly smaller than untreated cage controls. The lack of an effect of simulated weightlessness on the immune system is an interesting result, and its significance is discussed.
Logistic Risk Model for the Unique Effects of Inherent Aerobic Capacity on (+)G(sub z) Tolerance Before and After Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Ludwig, David A.; Convertino, Victor A.; Goldwater, Danielle J.; Sandler, Harold

1987-01-01

Small sample size (n less than 1O) and inappropriate analysis of multivariate data have hindered previous attempts to describe which physiologic and demographic variables are most important in determining how long humans can tolerate acceleration. Data from previous centrifuge studies conducted at NASA/Ames Research Center, utilizing a 7-14 d bed rest protocol to simulate weightlessness, were included in the current investigation. After review, data on 25 women and 22 men were available for analysis. Study variables included gender, age, weight, height, percent body fat, resting heart rate, mean arterial pressure, Vo(sub 2)max and plasma volume. Since the dependent variable was time to greyout (failure), two contemporary biostatistical modeling procedures (proportional hazard and logistic discriminant function) were used to estimate risk, given a particular subject's profile. After adjusting for pro-bed-rest tolerance time, none of the profile variables remained in the risk equation for post-bed-rest tolerance greyout. However, prior to bed rest, risk of greyout could be predicted with 91% accuracy. All of the profile variables except weight, MAP, and those related to inherent aerobic capacity (Vo(sub 2)max, percent body fat, resting heart rate) entered the risk equation for pro-bed-rest greyout. A cross-validation using 24 new subjects indicated a very stable model for risk prediction, accurate within 5% of the original equation. The result for the inherent fitness variables is significant in that a consensus as to whether an increased aerobic capacity is beneficial or detrimental has not been satisfactorily established. We conclude that tolerance to +Gz acceleration before and after simulated weightlessness is independent of inherent aerobic fitness.
Unique life sciences research facilities at NASA Ames Research Center

NASA Technical Reports Server (NTRS)

Mulenburg, G. M.; Vasques, M.; Caldwell, W. F.; Tucker, J.

1994-01-01

The Life Science Division at NASA's Ames Research Center has a suite of specialized facilities that enable scientists to study the effects of gravity on living systems. This paper describes some of these facilities and their use in research. Seven centrifuges, each with its own unique abilities, allow testing of a variety of parameters on test subjects ranging from single cells through hardware to humans. The Vestibular Research Facility allows the study of both centrifugation and linear acceleration on animals and humans. The Biocomputation Center uses computers for 3D reconstruction of physiological systems, and interactive research tools for virtual reality modeling. Psycophysiological, cardiovascular, exercise physiology, and biomechanical studies are conducted in the 12 bed Human Research Facility and samples are analyzed in the certified Central Clinical Laboratory and other laboratories at Ames. Human bedrest, water immersion and lower body negative pressure equipment are also available to study physiological changes associated with weightlessness. These and other weightlessness models are used in specialized laboratories for the study of basic physiological mechanisms, metabolism and cell biology. Visual-motor performance, perception, and adaptation are studied using ground-based models as well as short term weightlessness experiments (parabolic flights). The unique combination of Life Science research facilities, laboratories, and equipment at Ames Research Center are described in detail in relation to their research contributions.
Simulated Space Radiation and Weightlessness: Vascular-Bone Coupling Mechanisms to Preserve Skeletal Health

NASA Technical Reports Server (NTRS)

Globus, R. K.; Alwood, J.; Tahimic, C.; Schreurs, A.-S.; Shirazi-Fard, Y.; Terada, M.; Zaragoza, J.; Truong, T.; Bruns, K.; Castillo, A.;

2018-01-01

We examined experimentally the effects of radiation and/or simulated weightlessness by hindlimb unloading on bone and blood vessel function either after a short period or at a later time after transient exposures in adult male, C57Bl6J mice. In sum, recent findings from our studies show that in the short term, ionizing radiation and simulate weightlessness cause greater deficits in blood vessels when combined compared to either challenge alone. In the long term, heavy ion radiation, but not unloading, can lead to persistent, adverse consequences for bone and vessel function, possibly due to oxidative stress-related pathways.

Effects of simulated weightlessness on mammalian development. Part 1: Development of clinostat for mammalian tissue culture and use in studies on meiotic maturation of mouse oocytes

NASA Technical Reports Server (NTRS)

Wolegemuth, D. J.; Grills, G. S.

1984-01-01

The effects of weightlessness on three aspects of mammalian reproduction: oocyte development, fertilization, and early embryogenesis was studied. Zero-gravity conditions within the laboratory by construction of a clinostat designed to support in vitro tissue culture were simulated and the effects of simulated weightlessness on meiotic maturation in mammalian oocytes using mouse as the model system were studied. The timing and frequency of germinal vesicule breakdown and polar body extrusion, and the structural and numerical properties of meiotic chromosomes at Metaphase and Metaphase of meiosis are assessed.
[Morphological changes on cochlear hair cells of rats in simulated weightlessness and inboard noise].

PubMed

2017-06-18

To observe the morphological changes on cochlear hair cells of rats in simulated weightlessness and inboard noise and to investigate the different changes in three turns of hair cells. Thirty-two healthy SD rats, all males, were randomly divided into four groups: control group, weightlessness group, noise group and weightlessness+noise groups (n=8). Then rats were exposed to -30° head down tilt as simulated weightlessness and inboard noise including steady-state noise which was (72±2) dB SPL and impulse noise up to 160 dB SPL in spaceship environment. The control group was kept in normal condition for 8 weeks. Bilateral auditory brainstem response (ABR) thresholds were tested before and after exposure respectively, and immunofluorescence staining and scanning electron microscopy (SEMs) of basilar membrane were applied after exposure. ABR threshold shifts of each group were higher after exposure. There was difference between ABRs of the experiment groups before and after exposure (P<0.05). IF showed that the inner hair cells (IHCs) missing was the main damage in the basal turn of weightlessness group, the hair cells in the middle turn were swell and in the top turn, the hair cells were not clear. In noise group, the main loss happened in the outer hair cells (OHCs) of the outermost layer. In weightlessness+noise group, the nuclear missing in the basal turn was apparent, and mainly happened at the outermost layer. Meanwhile, the missing of hair cells in the middle turn and top turn was seen at the innermost layer. SEM showed that the cilia in the basal turn of weightlessness group were serious lodging, and occasional absence. Furthermore, the basal cilia in noise group became lodged and absent, and the other two turns were seriously missing. And in weightlessness+noise group, the cilia missing in the basal turn was apparently seen. The damage degree of the four groups: weightlessness+noise group>noise group>weightlessness group>control group and the damage degree of the four turns of hair cells: basal turn>mid turn>top turn. The rats exposed to the above environment for 2 weeks displayed obvious changes in cochlea morphology, and the weightlessness +noise group had the most obvious damage.
Changes in muscles accompanying non-weight-bearing and weightlessness

NASA Technical Reports Server (NTRS)

Tischler, M. E.; Henriksen, E. J.; Jaspers, S. R.; Jacob, S.; Kirby, C.

1989-01-01

Results of hindlimb suspension and space flight experiments with rats examine the effects of weightlessness simulation, weightlessness, and delay in postflight recovery of animals. Parameters examined were body mass, protein balance, amino acid metabolism, glucose and glycogen metabolism, and hormone levels. Tables show metabolic responses to unweighting of the soleus muscle.
Blood circulation under conditions of weightlessness

NASA Technical Reports Server (NTRS)

Kastyan, I. I.; Kopanev, V. I.

1980-01-01

Experimental materials and published data on the problem of blood circulation in man and animals under conditions of short and long term weightlessness are summarized. The data obtained allow the conclusion, that when humans spent 5 days in a weightless state their blood circulation was not essentially distributed. Some features of the functioning of the cardiovascular system are pointed out: delay of adaptation rate, increase in lability, etc. There is a discussion of the physiological mechanisms for the direct and indirect effect of weightlessness. The direct effect comprise the complex of reactions caused by the significant fall in hydrostatic pressure and the indirect embraces all the reactions arising in the organism resulting from disturbance of the systematic character of the analyzers that take part in the analysis of space realtions and the body's orientation in space.
The regulation of fluid and electrolyte metabolism in weightlessness

NASA Technical Reports Server (NTRS)

Leach, C. S.; Johnson, P. C.; Cintron, N. M.

1986-01-01

Endocrine and biochemical changes in astronauts caused by weightlessness are discussed. Translocation of fluid from the extremities to the head and chest at the onset of weightlessness is thought to lead to the establishment of a lower blood volume as an adaptation to microgravity. Results of Skylab experiments indicate that several other regulatory systems have lower homeostatic set points during space flight. Inflight blood samples from three Spacelab flights show increased antidiuretic hormone throughout these short flights and decreased aldosterone and cortisol after 3 days. Results help to explain blood hypoosmolality and hyponatremia but do not explain what happens between the onset of weightlessness and hormone changes. Other factors such as natriuretic peptides and changes in renal function are being studied to elucidate the physiologic adaptation mechanisms.
Evaluation of positive G sub Z tolerance following simulated weightlessness (bedrest)

NASA Technical Reports Server (NTRS)

Jacobson, L. B.; Hyatt, K. H.; Sullivan, R. W.; Cantor, S. A.; Sandler, H.; Rositano, S. A.; Mancini, R. E.

1973-01-01

The magnitude of physiologic changes which are known to occur in human subjects exposed to varying levels of + G sub Z acceleration following bed rest simulation of weightlessness was studied. Bed rest effects were documented by fluid and electrolyte balance studies, maximal exercise capability, 70 deg passive tilt and lower body negative pressure tests and the ability to endure randomly prescribed acceleration profiles of +2G sub Z, +3G sub Z, and +4G sub Z. Six healthy male volunteers were studied during two weeks of bed rest after adequate control observations, followed by two weeks of recovery, followed by a second two-week period of bed rest at which time an Air Force cutaway anti-G suit was used to determine its effectiveness as a countermeasure for observed cardiovascular changes during acceleration. Results showed uniform and significant changes in all measured parameters as a consequence of bed rest including a reduced ability to tolerate +G sub Z acceleration. The use of anti-G suits significantly improved subject tolerance to all G exposures and returned measured parameters such as heart rate and blood pressure towards or to pre-bed-rest (control) values in four of the six cases.
Low-G simulation in mammalian research

NASA Technical Reports Server (NTRS)

Sandler, H.

1982-01-01

After a review of space-flight research concerning the effects of weightlessness on mammals, the paper reviews various methods of low-G simulation. Consideration is given to water immersion; bed rest, chair rest, and confinement; immobilization; and partial body-support systems. Countermeasures to offset the effects of weightlessness are also discussed.
Effects of simulated weightlessness on the kinase activity of MEK1 induced by bone morphogenetic protein-2 in rat osteosarcoma cells

NASA Astrophysics Data System (ADS)

Zhang, S.; Wang, B.; Cao, X. S.; Yang, Z.

Objective The mRNA expression of alpha 1 chain of type I collagen COL-I alpha 1 in rat osteosarcoma ROS17 2 8 cells induced by bone morphogenetic protein-2 BMP-2 was reduced under simulated microgravity The protein kinase MEK1 of MAPK signal pathway plays an important role in the expression of COL-I alpha 1 mRNA The purpose of this study is to investigate the effects of simulated weightlessness on the activity of MEK1 induced by BMP-2 in ROS17 2 8 cells Methods ROS17 2 8 cells were cultured in 1G control and rotating clinostat simulated weightlessness for 24 h 48 h and 72 h BMP-2 500 ng ml was added into the medium 1 h before the culture ended There was a control group in which ROS17 2 8 cells were cultured in 1G condition without BMP-2 Then the total protein of cells was extracted and the expression of phosphated-ERK1 2 p-ERK1 2 protein was detected by means of Western Blotting to show the kinase activity of MEK1 Results There were no significant differences in the expression of total ERK1 2 among all groups The expression of p-ERK1 2 was unconspicuous in the control group without BMP-2 but increased significantly when BMP-2 was added P 0 01 The level of p-ERK1 2 in simulated weightlessness group was much more lower than that in 1G group in every time point P 0 01 The expression of p-ERK1 2 gradually decreased along with the time of weightlessness simulation P 0 01 Conclusions The kinase activity of MEK1 induced by BMP-2 in rat osteosarcoma cells was reduced under simulated weightlessness
Effects of weightlessness on the development of the vestibular apparatus and ocular nystagmus in the rat

NASA Technical Reports Server (NTRS)

Clark, D. L.

1972-01-01

The chronic 2g centrifuge was constructed for testing weightlessness effects on development of vestibular apparatus and ocular nystagmus in the rat. Both the stationary and rotating rail tests were performed. A physiological review is presented on vestibular apparatus, along with a system analysis. Time constants and input threshold level of the system are also considered.
Alteration of Electro-Cortical Activity in Microgravity

NASA Astrophysics Data System (ADS)

Schneider, Stefan; Brummer, Vera; Carnahan, Heather; Askew, Christopher D.; Guardiera, Simon; Struder, Heiko K.

2008-06-01

There is growing interest in the effects of weightlessness on central nervous system (CNS) activity. Due to technical and logistical limitations it presently seems impossible to apply imaging techniques as fMRI or PET in weightless environments e.g. on ISS or during parabolic flights. Within this study we evaluated changes in brain cortical activity using low resolution brain electromagnetic tomography (LORETA) during parabolic flights. Results showed a distinct inhibition of right frontal area activity >12Hz during phases of microgravity compared to normal gravity. We conclude that the inhibition of high frequency frontal activity during microgravity may serve as a marker of emotional anxiety and/or indisposition associated with weightlessness. This puts a new light on the debate as to whether cognitive and sensorimotor impairments are attributable to primary physiological effects or secondary psychological effects of a weightless environment.
The first dedicated life sciences mission - Spacelab 4

NASA Astrophysics Data System (ADS)

Cramer, D. R.; Reid, D. H.; Klein, H. P.

Spacelab is a large versatile laboratory carried in the bay of the Shuttle Orbiter. The first Spacelab mission dedicated entirely to Life Sciences is known as Spacelab 4. It is scheduled for launch in late 1985 and will remain aloft for seven days. This payload consists of 25 tentatively selected investigations combined into a comprehensive integrated exploration of the effects of acute weightlessness on living systems. An emphasis is placed on studying physiological changes that have been previously observed in manned space flight. This payload has complementary designs in the human and animal investigations in order to validate animal models of human physiology in weightlessness. The experimental subjects include humans, squirrel monkeys, laboratory rats, several species of plants, and frog eggs. The primary scientific objectives include study of the acute cephalic fluid shift, cardiovascular adaptation to weightlessness, including postflight reductions in orthostatic tolerance and exercise capacity, and changes in vestibular function, including space motion sickness, associated with weightlessness. Secondary scientific objectives include the study of red cell mass reduction, negative nitrogen balance, altered calcium metabolism, suppressed in vitro lymphocyte reactivity, gravitropism and photropism in plants, and fertilization and early development in frog eggs. The rationale behind this payload, the selection process, and details of the individual investigations are presented in this paper.
Effects of simulated weightlessness on regional blood flow specifically during cardiovascular stress

NASA Technical Reports Server (NTRS)

Harrison, D. C.

1986-01-01

Significant changes in the cardiovasular system of humans and animals have been observed following exposure to prolonged periods of weightlessness during space flight. Although adaption to weightlessness is relatively uncomplicated, marked changes in cardiovascular deconditioning become evident upon return to normal gravity, including orthostatic hypotension and tachycardia. Some evidence that myocardial degeneration occurs has been demonstrated in animals who have been immobilized for two months. Also, evidence of possible loss of myocardial mass following manned space flight has been obtained by means of echocardiographic studies. These findings have serious implications in light of the increasing frequency and duration of Space Shuttle missions and the prospect of extended space station missions in the future. A number of both military and civilian investigators, including middle-aged scientists, will probably encounter prolonged periods of weightlessness. It has been imperative, therefore, to determine the effects of prolonged weightlessness on cardiovascular deconditioning and whether such effects are cumulative or reversible. The research project conducted under NASA Cooperative Agreement NCC 2-126 was undertaken to determine the effects of prolonged simulated weightlessness on regional blood flow. Research results are reported in the three appended publications.

Effect of simulated weightlessness and chronic 1,25-dihydroxyvitamin D administration on bone metabolism

NASA Technical Reports Server (NTRS)

Halloran, B. P.; Bikle, D. D.; Globus, R. K.; Levens, M. J.; Wronski, T. J.; Morey-Holton, E.

1985-01-01

Weightlessness, as experienced during space flight, and simulated weightlessness induce osteopenia. Using the suspended rat model to simulate weightlessness, a reduction in total tibia Ca and bone formation rate at the tibiofibular junction as well as an inhibition of Ca-45 and H-3-proline uptake by bone within 5-7 days of skeletal unloading was observed. Between days 7 and 15 of unloading, uptake of Ca-45 and H-3-proline, and bone formation rate return to normal, although total bone Ca remains abnormally low. To examine the relationship between these characteristic changes in bone metabolism induced by skeletal unloading and vitamin D metabolism, the serum concentrations of 25-hydroxyvitamin D (25-OH-D), 24, 25-dihydroxyvitamin D (24,25(OH)2D) and 1,25-dihydroxyvitamin D (1,25(OH)2D) at various times after skeletal unloading were measured. The effect of chronic infusion of 1,25(OH)2D3 on the bone changes associated with unloading was also determined.
Do the design concepts used for the space flight hardware directly affect cell structure and/or cell function ground based simulations

NASA Technical Reports Server (NTRS)

Chapman, David K.

1989-01-01

The use of clinostats and centrifuges to explore the hypogravity range between zero and 1 g is described. Different types of clinostat configurations and clinostat-centrifuge combinations are compared. Some examples selected from the literature and current research in gravitational physiology are presented to show plant responses in the simulated hypogravity region of the g-parameter (0 is greater than g is greater than 1). The validation of clinostat simulation is discussed. Examples in which flight data can be compared to clinostat data are presented. The data from 3 different laboratories using 3 different plant species indicate that clinostat simulation in some cases were qualitatively similar to flight data, but that in all cases were quantitatively different. The need to conduct additional tests in weightlessness is emphasized.
Physiologic adaptation of man in space; Proceedings of the Seventh International Man in Space Symposium, Houston, TX, Feb. 10-13, 1986

NASA Technical Reports Server (NTRS)

Holland, Albert W. (Editor)

1987-01-01

Topics discussed in this volume include space motion sickness, cardiovascular adaptation, fluid shifts, extravehicular activity, general physiology, perception, vestibular response modifications, vestibular physiology, and pharmacology. Papers are presented on the clinical characterization and etiology of space motion sickness, ultrasound techniques in space medicine, fluid shifts in weightlessness, Space Shuttle inflight and postflight fluid shifts measured by leg volume changes, and the probability of oxygen toxicity in an 8-psi space suit. Consideration is also given to the metabolic and hormonal status of crewmembers in short-term space flights, adaptive changes in perception of body orientation and mental image rotation in microgravity, the effects of a visual-vestibular stimulus on the vestibulo-ocular reflex, rotation tests in the weightless phase of parabolic flight, and the mechanisms of antimotion sickness drugs.
Hybrid water immersion simulation of manual IVA performance in weightlessness

NASA Technical Reports Server (NTRS)

Loats, H. L., Jr.; Mattingly, G. S.

1971-01-01

A description is given of the development, tests, and analysis of a manual simulator. The simulator was developed to test mass handling and translation under weightlessness conditions by a test subject. The system is composed of a hybrid simulator with a combination of water immersion and mechanical, Peter Pan, simulation. The concept operates on the equivalence principle, with the subject and the cargo remaining quasi-stationary. Movement is effected through a moving device controlled through force by the subject. Motion response is determined through computations of the inertial movement under such conditions.
Cardiovascular, renal, electrolyte, and hormonal changes in man during gravitational stress, weightlessness, and simulated weightlessness: Lower body positive pressure applied by the antigravity suit. Thesis - Oslo Univ.

NASA Technical Reports Server (NTRS)

Kravik, Stein E.

1989-01-01

Because of their erect posture, humans are more vulnerable to gravitational changes than any other animal. During standing or walking man must constantly use his antigravity muscles and his two columns, his legs, to balance against the force of gravity. At the same time, blood is surging downward to the dependent portions of the body, draining blood away from the brain and heart, and requiring a series of complex cardiovascular adjustments to maintain the human in a bipedal position. It was not until 12 April 1961, when Yuri Gagarin became the first human being to orbit Earth, that we could confirm man's ability to maintain vital functions in space -- at least for 90 min. Nevertheless, man's adaptation to weightlessness entails the deconditioning of various organs in the body. Muscles atrophy, and calcium loss leads to loss of bone strength as the demands on the musculoskeletal system are almost nonexistent in weightlessness. Because of the lack of hydrostatic pressures in space, blood rushes to the upper portions of the body, initiating a complex series of cardioregulatory responses. Deconditioning during spaceflight, however, first becomes a potentially serious problem in humans returning to Earth, when the cardiovascular system, muscles and bones are suddenly exposed to the demanding counterforce of gravity -- weight. One of the main purposes of our studies was to test the feasibility of using Lower Body Positive Pressure, applied with an antigravity suit, as a new and alternative technique to bed rest and water immersion for studying cardioregulatory, renal, electrolyte, and hormonal changes in humans. The results suggest that Lower Body Positive Pressure can be used as an analog of microgravity-induced physiological responses in humans.
A systems analysis of the erythropoietic responses to weightlessness. Volume 1: Mathematical model simulations of the erythropoietic responses to weightlessness

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1985-01-01

Theoretical responses to weightlessness are summarized. The studies include development and validation of a model of erythropoiesis regulation, analysis of the behavior of erythropoiesis under a variety of conditions, simulations of bed rest and space flight, and an evaluation of ground-based animal studies which were conducted as analogs of zero-g. A review of all relevant space flight findings and a set of testable hypotheses which attempt to explain how red cell mass decreases in space flight are presented. An additional document describes details of the mathematical model used in these studies.
Gravity, weightlessness and the genetic structures of organisms.

PubMed

Dubinin, N P; Vaulina, E N

1974-01-01

The whole evolution of life on earth has proceeded under the action of earth's gravity which must have influenced the structure and function of organisms. During space flights organisms are exposed to the entirely new condition of weightlessness, and to variations in gravity that produce various changes. Current flight data suggest that organisms most often respond to weightlessness by disturbances in physiological function, which are reversible after the brief exposures that have at present been possible. Only longer space flights will show whether these changes will be compensated, or will lead to alterations in the more important systems of organisms including their hereditary properties. There is evidence that weightlessness has a direct effect on genetic properties. Thus, in microspores of Tradescantia abnormal mitoses (that were not observed in the ground-based control) were recorded to an extent of 3%. The numerous changes in various vital systems suggest that for terrestrial organisms weightlessness is a factor which, if administered for a long time, may bring about serious disturbances in their activities and heredity. The higher the evolutionary position of the organism, the more pronounced the effect is likely to be.
Responses of Cardiac Tissue to Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Steczina, Sonette; Terada, Masahiro; Shirazi-Fard, Yasaman; Schreurs, Ann-Sofie; Goukassian, David; Globus, Ruth

2017-01-01

Our current study aims to determine the molecular mechanisms that underlie these cardiac changes in response to spaceflight. The central hypothesis of our study is that long duration simulated weightlessness and subsequent recovery causes select and persistent changes in gene expression and oxidative defense-related pathways. In this study, we will first conduct general analyses of three-month old male and female animals, focusing on two key long-duration time points, (i.e. after 90 days of simulated weightlessness (HU) and after 90 days recovery from 90 days of HU. Both rat-specific gene arrays and qPCR will be performed focusing on genes already implicated in oxidative stress responses and cardiac disease. Gene expression analyses will be complemented by biochemical tests of frozen tissue lysates for select markers of oxidative damage.
Effects of simulated weightlessness on fish otolith growth: Clinostat versus Rotating-Wall Vessel

NASA Astrophysics Data System (ADS)

Brungs, Sonja; Hauslage, Jens; Hilbig, Reinhard; Hemmersbach, Ruth; Anken, Ralf

2011-09-01

Stimulus dependence is a general feature of developing sensory systems. It has been shown earlier that the growth of inner ear heavy stones (otoliths) of late-stage Cichlid fish ( Oreochromis mossambicus) and Zebrafish ( Danio rerio) is slowed down by hypergravity, whereas microgravity during space flight yields an opposite effect, i.e. larger than 1 g otoliths, in Swordtail ( Xiphophorus helleri) and in Cichlid fish late-stage embryos. These and related studies proposed that otolith growth is actively adjusted via a feedback mechanism to produce a test mass of the appropriate physical capacity. Using ground-based techniques to apply simulated weightlessness, long-term clinorotation (CR; exposure on a fast-rotating Clinostat with one axis of rotation) led to larger than 1 g otoliths in late-stage Cichlid fish. Larger than normal otoliths were also found in early-staged Zebrafish embryos after short-term Wall Vessel Rotation (WVR; also regarded as a method to simulate weightlessness). These results are basically in line with the results obtained on Swordtails from space flight. Thus, the growth of fish inner ear otoliths seems to be an appropriate parameter to assess the quality of "simulated weightlessness" provided by a particular simulation device. Since CR and WVR are in worldwide use to simulate weightlessness conditions on ground using small-sized specimens, we were prompted to directly compare the effects of CR and WVR on otolith growth using developing Cichlids as model organism. Animals were simultaneously subjected to CR and WVR from a point of time when otolith primordia had begun to calcify both within the utricle (gravity perception) and the saccule (hearing); the respective otoliths are the lapilli and the sagittae. Three such runs were subsequently carried out, using three different batches of fish. The runs were discontinued when the animals began to hatch. In the course of all three runs performed, CR led to larger than normal lapilli, whereas WVR had no effect on the growth of these otoliths. Regarding sagittae, CR resulted in larger than normal stones in one of the three runs. The other CR runs and all WVR runs had no effect on sagittal growth. These results clearly indicate that CR rather than WVR can be regarded as a device to simulate weightlessness using the Cichlid as model organism. Since WVR has earlier been shown to affect otolith growth in Zebrafish, the lifestyle of an animal (mouth-breeding versus egg-laying) seems to be of considerable importance. Further studies using a variety of simulation techniques (including, e.g. magnetic levitation and random positioning) and various species are needed in order to identify the most appropriate technique to simulate weightlessness regarding a particular model organism.
'Weightless' acrylic painting by Jack Kroehnke

NASA Technical Reports Server (NTRS)

1987-01-01

'Weightless' acrylic painting by Jack Kroehnke depicts STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers participating in extravehicular activity (EVA) simulation in JSC Weightless Environment Training Facility (WETF) Bldg 29. In the payload bay (PLB) mockup, Hilmers, wearing extravehicular mobility unit (EMU), holds onto the mission-peculiar equipment support structure in foreground while SCUBA-equipped diver monitors activity overhead and camera operator records EVA procedures. Copyrighted art work for use by NASA.
Effect of simulated weightlessness on the expression of Cbfα1 induced by fluid shear stress in MG-63 osteosarcoma cells.

NASA Astrophysics Data System (ADS)

Yang, Z.; Zhang, S.; Wang, B.; Sun, X. Q.

Objective The role of mechanical load in the functional regulation of osteoblasts becomes an emphasis in osseous biomechanical researches recently This study was aim to explore the effect of flow shear stress on the expression of Cbf alpha 1 in human osteosarcoma cells and to survey its functional alteration in simulated weightlessness Method After cultured for 72 h in two different gravitational environments i e 1G terrestrial gravitational condition and simulated weightlessness condition human osteosarcoma cells MG-63 were treated with 0 5 Pa or 1 5 Pa fluid shear stress FSS in a flow chamber for 15 30 60 min respectively The total RNA in cells was isolated Transcription PCR analysis was made to examine the gene expression of Cbf alpha 1 And the total protein of cells was extracted and the expression of Cbf alpha 1 protein was detected by means of Western Blotting Results MG-63 cultured in 1G condition reacted to FSS treatment with an enhanced expression of Cbf alpha 1 Compared with no FSS control group Cbf alpha 1 mRNA and protein expression increased significantly at 30 and 60 min with the treatment of FSS P 0 01 And there was remarkable difference on the Cbf alpha 1 mRNA and protein expression between the treatments of 0 5 Pa and 1 5 Pa FSS at 30 min or 60 min P 0 01 As to the osteoblasts cultured in simulated weightlessness by using clinostat the expression of Cbf alpha 1 was significantly different between 1G and simulated weightlessness conditions at each test time P 0 05 Compared with no FSS
Urea, sugar, nonesterified fatty acid and cholesterol content of the blood in prolonged weightlessness

NASA Technical Reports Server (NTRS)

Balakhovskiy, I. S.; Orlova, T. A.

1975-01-01

Biochemical blood composition studies on astronauts during weightlessness flight simulation tests and during actual space flights showed some disturbances of metabolic processes. Increases in blood sugar, fatty acid and cholesterol, and urea content are noted.
Biochemical and physiological consequences of the Apollo flight diet.

NASA Technical Reports Server (NTRS)

Hander, E. W.; Leach, C. S.; Fischer, C. L.; Rummel, J.; Rambaut, P.; Johnson, P. C.

1971-01-01

Six male subjects subsisting on a typical Apollo flight diet for five consecutive days were evaluated for changes in biochemical and physiological status. Laboratory examinations failed to demonstrate any significant changes of the kind previously attributed to weightlessness, such as in serum electrolytes, endocrine values, body fluid, or hematologic parameters.
Influence of single hindlimb support during simulated weightlessness in the rat

NASA Technical Reports Server (NTRS)

Stump, Craig S.; Overton, J. Michael; Tipton, Charles M.

1990-01-01

A study was carried out to develop and evaluate a hindlimb suspension model, making it possible to differentiate the effects of non-weight bearing by hindlimbs per se from the systemic influence of simulated weightlessness. A support platform was designed which allowed the animal to maintain one hindlimb in a posture similar to the hindlimbs of the control animals at rest and to maintain one hindlimb in a posture similar to the hindlimbs of the control animals, providing a support for the animal to contract or stretch hindlimb muscles against at any time during suspension. The results of this study indicated that hindlimb support during head-down suspension will maintain muscle-mass/body-mass ratios, glycogen concentration, and blood flow. However, it will not prevent the loss in citrate synthase activity associated with conditions of simulated weightlessness.
Proceedings of the 1973 Lyndon B. Johnson Space Center Endocrine Program Conference

NASA Technical Reports Server (NTRS)

1975-01-01

Papers given at the conference are presented. Subjects covered include the following: biochemical changes during 28 days of space flight, modulating the pituitary-adrenal response to stress, the significance of biorhythms in space flight, the importance of the rein-angiotensin system in normal cardiovascular homeostasis, a progress report of stress-induced changes in corticosteroid metabolism, recent studies of physiological factors involved in the regulation of serotonin content and turnover in the brain, the role of brain biogenic amines in the control of pituitary-adrenocortical activity, application of the water immersion model to man by studies of acid-base homeostasis during simulated weightlessness, the present status of physiological studies and analysis of calcium homeostasis in the Apollo and Skylab programs, and endocrine considerations in the red-cell-mass and plasma-volume changes of Skylab 2 and 3 crews.
Jumping in simulated and true microgravity: response to maximal efforts with three landing types

NASA Technical Reports Server (NTRS)

D'Andrea, Susan E.; Perusek, Gail P.; Rajulu, Sudhakar; Perry, Julie; Davis, Brian L.

2005-01-01

BACKGROUND: Exercise is a promising countermeasure to the physiological deconditioning experienced in microgravity, but has not proven effective in eliminating the ongoing loss of bone mineral, most likely due to the lack of high-impact forces and loading rates during in-flight activity. We wanted to determine lower-extremity response to high-impact jumping exercises in true and simulated microgravity and establish if 1-G force magnitudes can be achieved in a weightless environment. METHODS: Jumping experiments were performed in a ground-based zero-gravity simulator (ZGS) in 1 G, and during parabolic flight with a gravity-replacement system. There were 12 subjects who participated in the study, with 4 subjects common to both conditions. Force, loading rates, jump height, and kinematics were analyzed during jumps with three distinct landings: two-footed toe-heel, one-footed toe-heel, and flat-footed. Gravity replacement loads of 45%, 60%, 75%, and 100% bodyweight were used in the ZGS; because of time constraints, these loads were limited to 60% and 75% bodyweight in parabolic flight. RESULTS: Average peak ground-reaction forces during landing ranged between 1902+/-607 and 2631+/-663 N in the ZGS and between 1683+/-807 and 2683+/-1174 N in the KC-135. No significant differences were found between the simulated and true microgravity conditions, but neither condition achieved the magnitudes found in 1 G. CONCLUSION: Data support the hypothesis that jumping exercises can impart high-impact forces during weightlessness and that the custom-designed ZGS will replicate what is experienced in true microgravity.
Simulated Space Radiation and Weightlessness: Vascular-Bone Coupling Mechanisms to Preserve Skeletal Health

NASA Technical Reports Server (NTRS)

Alwood, J. S.; Limoli, C. L.; Delp, M. D.; Castillo, A. B.; Globus, R. K.

2012-01-01

Weightlessness causes a cephalad fluid shift and reduction in mechanical stimulation, adversely affecting both cortical and trabecular bone tissue in astronauts. In rodent models of weightlessness, the onset of bone loss correlates with reduced skeletal perfusion, reduced and rarified vasculature and lessened vasodilation, which resembles blood-bone symbiotic events that can occur with fracture repair and aging. These are especially serious risks for long term, exploration class missions when astronauts will face the challenge of increased exposure to space radiation and abrupt transitions between different gravity environments upon arrival and return. Previously, we found using the mouse hindlimb unloading model and exposure to heavy ion radiation, both disuse and irradiation cause an acute bone loss that was associated with a reduced capacity to produce bone-forming osteoblasts from the bone marrow. Together, these findings led us to hypothesize that exposure to space radiation exacerbates weightlessness-induced bone loss and impairs recovery upon return, and that treatment with anti-oxidants may mitigate these effects. The specific aims of this recently awarded grant are to: AIM 1 Determine the functional and structural consequences of prolonged weightlessness and space radiation (simulated spaceflight) for bone and skeletal vasculature in the context of bone cell function and oxidative stress. AIM 2 Determine the extent to which an anti-oxidant protects against weightlessness and space radiation-induced bone loss and vascular dysfunction. AIM 3 Determine how space radiation influences later skeletal and vasculature recovery from prolonged weightlessness and the potential of anti-oxidants to preserve adaptive remodeling.
The first dedicated life sciences mission - Spacelab 4

NASA Technical Reports Server (NTRS)

Cramer, D. R.; Reid, D. H.; Klein, H. P.

1983-01-01

The details of the payload and the experiments in Spacelab 4, the first Spacelab mission dedicated entirely to the life sciences, are discussed. The payload of Spacelab 4, carried in the bay of the Shuttle Orbiter, consists of 25 tentatively selected investigations combined into a comprehensive integrated exploration of the effects of acute weightlessness on living systems. The payload contains complementary designs in the human and animal investigations in order to validate animal models of human physiology in weightlessness. Animals used as experimental subjects will include squirrel monkeys, laboratory rats, several species of plants, and frog eggs. The main scientific objectives of the investigations include the study of the acute cephalic fluid shift, cardiovascular adaptation to weightlessness, including postflight reductions in orthostatic tolerance and exercise capacity, and changes in vestibular function, including space motion sickness, associated with weightlessness. Other scientific objective include the study of red cell mass reduction, negative nitrogen balance, altered calcium metabolism, suppressed in vitro lymphocyte reactivity, gravitropism and photropism in plants, and fertilization and early development in frog eggs.
The role of depressed metabolism in increased radio-resistance

NASA Technical Reports Server (NTRS)

Musacchia, X. J.

1975-01-01

The results of experiments on hamsters and rats to determine physiological responses to various temperature conditions are presented. The experimental methods described are considered to be applicable to future mammalian experiments in space. Renal function was examined in the golden hamster as a function of body temperature. Hamsters were also acclimated to heat and metabolic rates, body temperature, skin temperature, cardiac distribution and whole body hematocrits were measured. In addition, the effects of heat stress on the intestinal transport of sugars in the hamster and rat were studied. The biological effects of prolonged space flight and methods of simulating weightlessness are also discussed.
Research in human performance related to space: A compilation of three projects/proposals

NASA Technical Reports Server (NTRS)

Hasson, Scott M.

1989-01-01

Scientific projects were developed in order to maximize performance in space and assure physiological homeostatis upon return. Three projects that are related to this common goal were either initiated or formulated during the Faculty Fellowship Summer Program. The projects were entitled: (1) Effect of simulated weightlessness (bed rest) on muscle performance and morphology; (2) Effect of submaximal eccentric muscle contractions on muscle injury, soreness and performance: A grant proposal; and (3) Correlation between isolated joint dynamic muscle strength to end-effector strength of the push and pull extravehicular activity (EVA) ratchet maneuver. The purpose is to describe each of these studies in greater detail.

Predictions of cardiovascular responses during STS reentry using mathematical models

NASA Technical Reports Server (NTRS)

Leonard, J. I.; Srinivasan, R.

1985-01-01

The physiological adaptation to weightless exposure includes cardiovascular deconditioning arising in part from a loss of total circulating blood volume and resulting in a reduction of orthostatic tolerance. The crew of the Shuttle orbiter are less tolerant to acceleration forces in the head-to-foot direction during the reentry phase of the flight at a time they must function at a high level of performance. The factors that contribute to orthostatic intolerance during and following reentry and to predict the likelihood of impaired crew performance are evaluated. A computer simulation approach employing a mathematical model of the cardiovascular system is employed. It is shown that depending on the severity of blood volume loss, the reentry acceleration stress may be detrimental to physiologic function and may place the physiologic status of the crew near the borderline of some type of impairment. They are in agreement with conclusions from early ground-based experiments and from observations of early Shuttle flights.
The Exercise and Environmental Physiology of Extravehicular Activity

NASA Technical Reports Server (NTRS)

Cowell, S. A.; Stocks, J. M.; Evans, D. G.; Simonson, S. R.; Greenleaf, J. E.; Dalton, Bonnie P. (Technical Monitor)

2000-01-01

Over the history of human expansion into space, extravehicular activity (EVA) has become indispensable for both daily living in weightlessness and for further space exploration. The physiological factors involved in the performance of extensive EVA, necessary for construction and maintenance of the International Space Station and during future human interplanetary missions, require further examination. An understanding of the physiological aspects of exercise and thermoregulation in the EVA environment will help to insure the health, safety, and efficiency of working astronauts. To that end, this review will focus on the interaction of the exercise and environmental aspects of EVA, as well as exercise during spaceflight and ground-based simulations such as bed-rest deconditioning. It will examine inflight exercise thermoregulation, and exercise, muscular strength, supine vs. seated exercise, exercise thermoregulation, and exercise in a hypobaric environment. Due to the paucity of data from controlled human research in this area, it is clear that more scientific studies are needed to insure safe and efficient extravehicular activity.
Continuous 30-day measurements utilizing the monkey metabolism pod. [study of weightlessness effects

NASA Technical Reports Server (NTRS)

Pace, N.; Kodama, A. M.; Mains, R. C.; Rahlmann, D. F.; Grunbaum, B. W.

1977-01-01

A fiberglass system was previously described, using which quantitative physiological measurements could be made to study the effects of weightlessness on 10 to 14 kg adult monkeys maintained in comfortable restraint under space flight conditions. Recent improvements in the system have made it possible to obtain continuous measurements of respiratory gas exchange, cardiovascular function, and mineral balance for periods of up to 30 days on pig-tailed monkeys. It has also been possible to operate two pods which share one set of instrumentation, thereby permitting simultaneous measurements to be made on two animals by commutating signal outputs from the pods. In principle, more than two pods could be operated in this fashion. The system is compatible with Spacelab design. Representative physiological data from ground tests of the system are presented.
Effects of simulated weightlessness on bone mineral metabolism

NASA Technical Reports Server (NTRS)

Globus, R. K.; Bikle, D. D.; Morey-Holton, E.

1984-01-01

It is pointed out that prolonged space flight, bedrest, and immobilization are three factors which can produce a negative calcium balance, osteopenia, and an inhibition of bone formation. It is not known whether the effects of gravity on bone mineral metabolism are mediated by systemic endocrine factors which affect all bones simultaneously, or by local factors which affect each bone individually. The present investigation has the objective to test the relative importance of local vs. systemic factors in regulating the bone mineral response to conditions simulating weightlessness. Experiments were conducted with male Sprague-Dawley rats. The test conditions made it possible to compare the data from weighted and unweighted bones in the same animal. The obtained findings indicate that a decrease in bone mass relative to control value occurs rapidly under conditions which simulate certain aspects of weightlessness. However, this decrease reaches a plateau after 10 days.
Simulated weightlessness - Effects on bioenergetic balance

NASA Technical Reports Server (NTRS)

Jordan, J. P.; Sykes, H. A.; Crownover, J. C.; Schatte, C. L.; Simmons, J. B., II; Jordan, D. P.

1980-01-01

As a prelude to a flight experiment, an attempt was made to separate energy requirements associated with gravity from all other metabolic needs. The biological effects of weightlessness were simulated by suspending animals in a harness so that antigravity muscles were not supporting the body. Twelve pairs of rats were allowed to adapt to wearing a harness for 5 d. Experimental animals were then suspended in harness for 7 d followed by recovery for 7 d. Control animals were harnessed but never suspended. Oxygen consumption, carbon dioxide production and rate of (C-14)O2 expiration from radio-labeled glucose were monitored on selected days. Food intake and body mass were recorded daily. Metabolic rate decreased in experimental animals during 7 d of suspension and returned to normal during recovery. Although some of the metabolic changes may have related to variation in food intake, simulated weightlessness appears to directly affect bioenergetic balance.
Mathematical modeling of fluid-electrolyte alterations during weightlessness

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1984-01-01

Fluid electrolyte metabolism and renal endocrine control as it pertains to adaptation to weightlessness were studied. The mathematical models that have been particularly useful are discussed. However, the focus of the report is on the physiological meaning of the computer studies. A discussion of the major ground based analogs of weightlessness are included; for example, head down tilt, water immersion, and bed rest, and a comparison of findings. Several important zero g phenomena are described, including acute fluid volume regulation, blood volume regulation, circulatory changes, longer term fluid electrolyte adaptations, hormonal regulation, and body composition changes. Hypotheses are offered to explain the major findings in each area and these are integrated into a larger hypothesis of space flight adaptation. A conceptual foundation for fluid electrolyte metabolism, blood volume regulation, and cardiovascular regulation is reported.
Results of intravehicular manned cargo-transfer studies in simulated weightlessness

NASA Technical Reports Server (NTRS)

Spady, A. A., Jr.; Beasley, G. P.; Yenni, K. R.; Eisele, D. F.

1972-01-01

A parametric investigation was conducted in a water immersion simulator to determine the effect of package mass, moment of inertia, and size on the ability of man to transfer cargo in simulated weightlessness. Results from this study indicate that packages with masses of at least 744 kg and moments of inertia of at least 386 kg-m2 can be manually handled and transferred satisfactorily under intravehicular conditions using either one- or two-rail motion aids. Data leading to the conclusions and discussions of test procedures and equipment are presented.
Medical considerations for extending human presence in space

NASA Technical Reports Server (NTRS)

Leach, C. S.; Dietlein, L. F.; Pool, S. L.; Nicogossian, A. E.

1990-01-01

The prospects for extending the length of time that humans can safely remain in space depend partly on resolution of a number of medical issues. Physiologic effects of weightlessness that may affect health during flight include loss of body fluid, functional alterations in the cardiovascular system, loss of red blood cells and bone mineral, compromised immune system function, and neurosensory disturbances. Some of the physiologic adaptations to weightlessness contribute to difficulties with readaptation to Earth's gravity. These include cardiovascular deconditioning and loss of body fluids and electrolytes; red blood cell mass; muscle mass, strength, and endurance; and bone mineral. Potentially harmful factors in space flight that are not related to weightlessness include radiation, altered circadian rhythms and rest/work cycles, and the closed, isolated environment of the spacecraft. There is no evidence that space flight has long-term effects on humans, except that bone mass lost during flight may not be replaced, and radiation damage is cumulative. However, the number of people who have spent several months or longer in space is still small. Only carefully-planned experiments in space preceded by thorough ground-based studies can provide the information needed to increase the amount of time humans can safely spend in space.
Effects of weightlessness in man.

NASA Technical Reports Server (NTRS)

Berry, C. A.

1973-01-01

The program for the Apollo 16 flight was designed to include both safeguards against and investigations of the physiological problems arising from increase in the period of manned space flight. Precautions included the provision of a controlled diet with high potassium content, carefully controlled work loads and work-rest cycles, and an emergency cardiology consultation service, and investigations were made to enable preflight vs postflight comparisons of metabolic, cardiovascular, and central nervous system data. Results of these investigations indicate that adjustment to weightlessness can be satisfactorily assisted by appropriate countermeasures, including attention to diet.
Changes in renal function and fluid and electrolyte regulation in space flight

NASA Technical Reports Server (NTRS)

Leach, C. S.

1992-01-01

The cephalad fluid redistribution resulting from weightlessness has a number of physiologic consequences. Plasma volume is reduced soon after weightlessness is reached, and red blood cell mass reduction follows. Plasma atrial natriuretic peptide, which inhibits aldosterone secretion, was elevated during space flight while plasma aldosterone was below preflight levels. Serum sodium was also reduced and potassium was elevated. Antidiuretic hormone (ADH) was markedly elevated at almost all measurement times in the first eight days of flight, but plasma volume did not return to preflight levels.
Considerations in prescribing preflight aerobic exercise for astronauts

NASA Technical Reports Server (NTRS)

Frey, Mary Anne Bassett

1987-01-01

The physiological effects of prolonged exposure to weightlessness are discussed together with the effects of aerobic exercise on human characteristics affected by weightlessness. It is noted that, although early data on orthostatic intolerance after spaceflight led to a belief that a high level of aerobic fitness for astronauts was detrimental to orthostatic tolerance on return to earth, most of the data available today do not suport this contention. Aerobic fitness was found to be beneficial to cardiovascular function and to mental performance; therefore, it may be important in performing extravehicular activities during flight.
French research program on the physiological problems caused by weightlessness. Use of the primate model

NASA Astrophysics Data System (ADS)

Pesquies, P. C.; Milhaud, C.; Nogues, C.; Klein, M.; Cailler, B.; Bost, R.

The need to acquire a better knowledge of the main biological problems induced by microgravity implies—in addition to human experimentation—the use of animal models, and primates seem to be particularly well adapted to this type of research. The major areas of investigation to be considered are the phospho-calcium metabolism and the metabolism of supporting tissues, the hydroelectrolytic metabolism, the cardiovascular function, awakeness, sleep-awakeness cycles, the physiology of equilibrium and the pathophysiology of space sickness. Considering this program, the Centre d'Etudes et de Recherches de Medecine Aerospatiale, under the sponsorship of the Centre National d'Etudes Spatiales, developed both a program of research on restrained primates for the French-U.S. space cooperation (Spacelab program) and for the French-Soviet space cooperation (Bio-cosmos program), and simulation of the effects of microgravity by head-down bedrest. Its major characteristics are discussed in the study.
Exercise countermeasures for spaceflight.

PubMed

Convertino, V A; Sandler, H

1995-01-01

The authors present a physiological basis for the use of exercise as a weightlessness countermeasure, outline special considerations for the development of exercise countermeasures, review and evaluate exercise used during space flight, and provide new approaches and concepts for the implementation of novel exercise countermeasures for future space flight. The discussion of the physiological basis for countermeasures examines maximal oxygen uptake, blood volume, metabolic responses to work, muscle function, bone loss, and orthostatic instability. The discussion of considerations for exercise prescriptions during space flight includes operational considerations, type of exercise, fitness considerations, age and gender, and psychological considerations. The discussion of exercise currently used in space flight examines cycle ergometry, the treadmill, strength training devices, electrical stimulation, and the Penguin suit worn by Russian crews. New approaches to exercise countermeasures include twin bicycles, dynamic resistance exercisers, maximal exercise effects, grasim (gravity simulators), and the relationship between exercise and LBNP.
[Remodeling simulation of human femur under bed rest and spaceflight circumstances based on three dimensional finite element analysis].

PubMed

Yang, Wenting; Wang, Dongmei; Lei, Zhoujixin; Wang, Chunhui; Chen, Shanguang

2017-12-01

Astronauts who are exposed to weightless environment in long-term spaceflight might encounter bone density and mass loss for the mechanical stimulus is smaller than normal value. This study built a three dimensional model of human femur to simulate the remodeling process of human femur during bed rest experiment based on finite element analysis (FEA). The remodeling parameters of this finite element model was validated after comparing experimental and numerical results. Then, the remodeling process of human femur in weightless environment was simulated, and the remodeling function of time was derived. The loading magnitude and loading cycle on human femur during weightless environment were increased to simulate the exercise against bone loss. Simulation results showed that increasing loading magnitude is more effective in diminishing bone loss than increasing loading cycles, which demonstrated that exercise of certain intensity could help resist bone loss during long-term spaceflight. At the end, this study simulated the bone recovery process after spaceflight. It was found that the bone absorption rate is larger than bone formation rate. We advise that astronauts should take exercise during spaceflight to resist bone loss.
The Interaction of the Space Shuttle Launch and Entry Suits and Sustained Weightless on Astronaut Egress Locomotion

NASA Technical Reports Server (NTRS)

Greenisen, M. C.; Bishop, P. A.; Sothmann, M.

2008-01-01

The purpose of this study was to determine the consequences of extended periods of weightlessness during space missions on astronauts f ability to perform a simulated contingency egress while wearing either of the Launch and Entry suits immediately after space flight. In our previous lab-based study of simulated contingency egress, we found only 4 of 12 non-astronauts wearing the Launch and Entry Suit (LES) successfully completed the simulated egress. However, 4 of 4 of the previous failures (when tested wearing the LES), were then successful in completing the test wearing the Advanced Crew Escape Suit (ACES). Therefore, this study tested 21 Astronaut Volunteers wearing either the LES or ACES while performing a simulated egress on a treadmill (TM) onboard the Crew Transportation Vehicle immediately after space flight at either the Kennedy Space Center or Edwards AFB. Astronauts walked for 400 meters at 1.6m/sec with g-suit inflation level set to preflight testing levels, visor down, breathing from the suit emergency O2 supply. Metabolic, heartrate, and perceived exertion data were collected during these post-flight tests. Exactly the same preflight simulated egress tests on a TM were performed in the lab at NASA/JSC by each crewmember at L-60. Preflight testing found 2 of the 21 crewmembers were unable to complete the simulated contingency egress. Postflight, 9 crew (8 ACES, 1 LES) completed the simulated contingency egress of 400 meters at 1.6m/sec. and 12 failed to meet that standard (7 ACES, 5 LES). Preflight physiological response tests failed to identify crew capable of performing the egress vs. those who failed. However, 18 of the 21 crew did make at least 2.67 minutes into the postflight egress testing. At that point in time, heartrate was higher (P <=.20) for the failures compared to the finishers. These findings indicate that NASA fs switch to the ACES for space flight crews should be expedited.
Advanced research to qualify man for long term weightlessness.

NASA Technical Reports Server (NTRS)

Jones, W. L.

1972-01-01

NASA is in the process of conducting a broad program of research and development of technology to qualify, support, and permit the successful use of man in long-term space flight. The technological tasks include human engineering, extravehicular engineering, life support, and human research to assess the effect of space stresses on human physiology and psychology. Various testing techniques that are being used may have future relevance to world health. These include a biocybernetic approach to the study of cardiovascular stresses, measurement of blood flow by means of the Doppler effect, and a device for simulating radiation dosages similar to those produced in solar flares. The planned program includes a study of both humans and animals.
Bone density in limb-immobilized beagles: An animal model for bone loss in weightlessness

NASA Technical Reports Server (NTRS)

Wolinsky, Ira

1987-01-01

Prolonged weightlessness is man in space flight results in a slow progressive demineralization of bone accompanied by an increased calcium output in the urine resulting in negative calcium balances. This possibly irreversible bone loss may constitute a serious limiting factor to long duration manned space flight. In order to seek and test preventative measures an appropriate ground based animal model simulating weightlessness is necessary. Use of the mature Beagle in limb immobilization has been documented as an excellent model for orthopedic research since this animal most closely simulates the phenomenom of bone loss with regards to growth, remodeling, structure, chemistry and mineralization. The purpose of this project is to develop a research protocol for the study of bone loss in Beagles during and after cast immobilization of a hindleg; research will then be initiated.
Study of physiological and behavioral response to transitions between rotating and nonrotating environments

NASA Technical Reports Server (NTRS)

Brady, J. F.

1972-01-01

Future manned space missions may require transition between artificial gravity and weightlessness environments. The frequency and rate of such transition will influence the psychophysiological responses of man. Abrupt transfers are examined between such rotating and nonrotating environments to determine the physiological and behavioral responses of man. Five subjects were tested using rates of rotation up to 5 rpm.
[Effects of simulated weightlessness on pressure-volume relationships of femoral vein of New Zealand Rabbits].

PubMed

Yue, Yong; Yao, Yong-jie; Xie, Xiao-ping; Wang, Bing; Zhu, Qing-sheng; Wu, Xing-yu

2002-12-01

Objective. To observe the changes of pressure-volume relationships of rabbit femoral veins and their structural changes caused by simulated weightlessness. Method. Head-Down Tilt (HDT) -20 degrees rabbit model was used to simulate weightlessness. Twenty four healthy male New Zealand Rabbits were randomly divided into 21 d HDT group,10 d HDT group and control group, (8 in each group). Pressure-volume (P-V) relationship of rabbits femoral veins was measured and the microstructure of the veins was observed. Result. The femoral vein P-V relationship curves of HDT groups showed a larger volume change ratio than that of control group. This change was that 21 d HDT group was even more obvious than that of HDT-10 d group. B1 and B2 in quadratic equations of 21 d HDT group were significantly higher than the values of both 10 d HDT group and control group during expansion (inflow) and collapse (outflow) (P<0.01). The result of histological examination showed that the contents and structure of femoral vein wall of HDT-rabbits changed significantly. Endothelial cells of femoral vein became short and columnar or cubic, some of which fell off. Smooth muscle layer became thinner. Conclusion. Femoral venous compliance increased after weightlessness-simulation and the femoral venous compliance in 21 d-HDT rabbits increased more obviously than that in 10 d-HDT rabbits. The structure of femoral vein wall had changed obviously.
Cardiovascular and other dynamic systems in long-term space flight

NASA Technical Reports Server (NTRS)

Tipton, David A.

1987-01-01

The paper examines the physiology of the cardiovascular system, and to a lesser extent the endocrine, renal, and hematopoietic systems. The paper highlights the aspects of these areas that are most pertinent to space manufacturing, i.e., working in space. Areas covered include the physiological costs of working in microgravity and partial gravity (e.g., the moon or Mars), countermeasures to potentially adverse physiological adaptations, and problems associated with return to earth after long periods of weightlessness.

Physiology of the sensory sphere under spaceflight conditions

NASA Technical Reports Server (NTRS)

Yuganov, Y. M.; Kopanev, V. I.

1975-01-01

Information regarding the influence on sensory perception of certain space flight factors, including weightlessness, acceleration, and vibration, is presented. Several illusions which occur under these conditions are described. The results of ground based experiments are also discussed.
Regulation of body fluid and salt homeostasis--from observations in space to new concepts on Earth.

PubMed

Gerzer, R; Heer, M

2005-08-01

The present manuscript summarizes recent discoveries that were made by studying salt and fluid homeostasis in weightlessness. These data indicate that 1. atrial natriuretic peptide appears not to play an important role in natriuresis in physiology, 2. the distribution of body fluids appears to be tightly coupled with hunger and thirst regulation, 3. intrathoracic pressure may be an important co-regulator of body fluid homeostasis, 4. a so far unknown low-affinity, high capacity osmotically inactive sodium storage mechanism appears to be present in humans that is acting through sodium/hydrogen exchange on glycosaminoglycans and might explain the pathophysiology, e.g., of salt sensitive hypertension. The surprising and unexpected data underline that weightlessness is an excellent tool to investigate the physiology of our human body: If we knew it, we should be able to predict changes that occur when gravity is absent. But, as data from space demonstrate, we do not.
Gravity as a probe for understanding pattern specification

NASA Technical Reports Server (NTRS)

Malacinski, George M.; Neff, Anton W.

1993-01-01

Amphibian eggs from Xenopus laevis were employed as a model system. Xenopus embryos were demonstrated to be sensitive to novel force fields. Under clinostat-simulated weightlessness the location of the third cleavage furrow was shifted towards the equator; the dorsal lip was shifted closer to the vegetal pole; and head and eye dimensions of hatching tadpoles were enlarged. Effects of centrifuge-simulated hypergravity were the opposite of those of simulated weightlessness. Those morphological alterations had their own force-sensitive period, and a substantial spawning-to-spawning variation in sensitivity was observed. Despite those dramatic differences in embryogenesis, tadpoles at the feeding stage were largely indistinguishable from controls.
Skylab

NASA Image and Video Library

1973-05-01

This photograph was taken during testing of an emergency procedure to free jammed solar array panels on the Skylab workshop. A metal strap became tangled over one of the folded solar array panels when Skylab lost its micrometeoroid shield during the launch. This photograph shows astronauts Schweickart and Gibson in the Marshall Space Flight Center (MSFC) Neutral Buoyancy Simulator (NBS) using various cutting tools and methods developed by the MSFC to free the jammed solar wing. Extensive testing and many hours of practice in simulators such as the NBS tank helped prepare the Skylab crewmen for extravehicular performance in the weightless environment. This huge water tank simulated the weightless environment that the astronauts would encounter in space.
Gravity as a probe for understanding pattern specification

NASA Astrophysics Data System (ADS)

Malacinski, George M.; Neff, Anton W.

1993-08-01

Amphibian eggs from Xenopus laevis were employed as a model system. Xenopus embryos were demonstrated to be sensitive to novel force fields. Under clinostat-simulated weightlessness the location of the third cleavage furrow was shifted towards the equator; the dorsal lip was shifted closer to the vegetal pole; and head and eye dimensions of hatching tadpoles were enlarged. Effects of centrifuge-simulated hypergravity were the opposite of those of simulated weightlessness. Those morphological alterations had their own force-sensitive period, and a substantial spawning-to-spawning variation in sensitivity was observed. Despite those dramatic differences in embryogenesis, tadpoles at the feeding stage were largely indistinguishable from controls.
From "Below Dignity" to "Above It All": Origins and Early History of Underwater Neutral Buoyancy Simulation of Weightlessness for EVA Procedures Development and Training

NASA Technical Reports Server (NTRS)

Charles, John B.

2013-01-01

An attempt to clarify some vague memories of underwater studies of astronaut capabilities in space led Dr. John Charles to become acquainted with Sam Mattingly, one of the pioneers in the field, and to greater insights into Mattingly's work simulating Gemini EVAs in the mid-1960s. Charles recounted major accomplishments by Environmental Research Associates (ERA), Mattingly's company for contracting with NASA Langley on several early studies. ERA's work was considered within the context of contemporary efforts to simulate weightlessness and the widespread development of neutral buoyancy facilities after ERA's successful demonstration for Gemini 12.
Influence of simulated weightlessness on the rate of anomalies of the flour beetle Tribolium confusum.

PubMed

Briegleb, W; Neubert, J; Schatz, A; Sinapius, F

1975-01-01

Experiments with Tribolium confusum showed that the morphological characteristics of the beetles are modified by simulated weightlessness (fast running clinostat). Because of possible side effects due to differences in fertility of inbred lines, the first experiments were made with a genetically heterogeneous stock. Thereafter experiments were confirmed with inbred beetles. For both stocks a rise of mainly wing anomalies resulted from rotation of whole cultures of beetles within horizontal tubes. The extent to which these anomalies are teratogenetic or genetic has not yet been analysed in detail.
Eccentric and concentric muscle performance following 7 days of simulated weightlessness

NASA Technical Reports Server (NTRS)

Hayes, Judith C.; Roper, Mary L.; Mazzocca, Augustus D.; Mcbrine, John J.; Barrows, Linda H.; Harris, Bernard A.; Siconolfi, Steven F.

1992-01-01

Changes in skeletal muscle strength occur in response to chronic disuse or insufficient functional loading. The purpose of this study was to examine changes in muscle performance of the lower extremity and torso prior to and immediately after 7 days of simulated weightlessness (horizontal bed rest). A Biodex was used to determine concentric and eccentric peak torque and angle at peak torque for the back, abdomen, quadriceps, hamstring, soleus, and tibialis anterior. A reference angle of 0 degrees was set at full extension. Data were analyzed by ANOVA.
Stress, workload and physiology demand during extravehicular activity: a pilot study.

PubMed

Rai, Balwant; Kaur, Jasdeep; Foing, Bernard H

2012-06-01

Extravehicular activity (EVA), such as exercise performed under unique environmental conditions, is essential for supporting daily living in weightlessness and for further space exploration like long Mars mission. The study was planned stress, workload, and physiological demands of simulated Mars exploration. In this study, the six-person crew lived (24 hours) for 14 days during a short-term stay at the Mars Desert Research Station. The heart rates, salivary cortisol, workload, peak oxygen uptake or maximal aerobic capacity of the crew are measured before, during and after an EVA. Data for heart rate showed the same trend as peak oxygen uptake or maximal aerobic capacity, with a maximal increase to 85% of peak. The rating of subscale showed a significant increase in EVA as compared to run. Salivary cortisol levels and heart rates were increased in both groups, although significant increased of cortisol levels and heart rates more in EVA as compared to hill running crew members. Further study is required on large scale taken into account of limitations of this study and including other physiological and psychological parameters in Mars analog environment.
Skeletal Responses to Long-Duration Simulated Weightlessness in Rats

NASA Technical Reports Server (NTRS)

Adams, Julia; Torres, Samantha; Schreurs, Ann-Sofie; Alwood, Joshua S.; Shirazi-Fard, Yasaman; Tahimic, Candice; Globus, Ruth

2017-01-01

Damaging effects due to spaceflight and long-duration weightlessness are seen in the musculoskeletal system, specifically with regards to bone loss, bone resorption, and changes in overall bone structure. These adverse effects are all seen with indicators of oxidative stress and a variation in the levels of oxidative gene expression. Once gravity is restored, however, the recovery is slow and incomplete. Despite this, few reports have investigated the correlation between oxidative damage and general modifications within the bone. In this project, we will make use of a ground-based model of simulated weightlessness (hindlimb unloading, HU) in order to observe skeletal changes in response to induced microgravity due to changes in oxidative pressures. With this model we will analyze samples at 14-day and 90-day time points following HU for the determination of acute and chronic effects, each with corresponding controls. We hypothesize that simulated microgravity will lead to skeletal adaptations including time-dependent activation of pro-oxidative processes and pro-osteoclastogenic signals related to the progression, plateau, and recovery of the bone. Microcomputed tomography techniques will be utilized to measure skeletal changes in response to HU. With the results of this study, we hope to further the understanding of skeletal affects as a result of long-duration weightlessness and develop countermeasures to combat bone loss in spaceflight and osteoporosis on Earth.
Next Steps Toward Understanding Human Habitation of Space: Environmental Impacts and Mechanisms

NASA Technical Reports Server (NTRS)

Globus, Ruth

2016-01-01

Entry into low earth orbit and beyond causes profound shifts in environmental conditions that have the potential to influence human productivity, long term health, and even survival. We now have evidence that microgravity, radiation and/or confinement in space can lead to demonstrably detrimental changes in the cardiovascular (e.g. vessel function, orthostatic intolerance), musculoskeletal (muscle atrophy, bone loss) and nervous (eye, neurovestibular) systems of astronauts. Because of both the limited number of astronauts who have flown (especially females) and the high degree of individual variability in the human population, important unanswered questions about responses to the space environment remain: What are the sex differences with respect to specific physiological systems? Are the responses age-dependent and/or reversible after return to Earth? Do observed detrimental changes that resemble accelerated aging progress continuously over time or plateau? What are the mechanisms of the biological responses? Answering these important questions certainly demands a multi-pronged approach, and the study of multicellular model organisms (such as rodents and flies) already has provided opportunities for exploring those questions in some detail. Recent long duration spaceflight experiments with rodents show that mice in space provide a mammalian model that uniquely combines the influence of reduced gravitational loading with increased physical activity. In addition, multiple investigators have shown that ground-based models that simulate aspects of spaceflight (including rodent hind limb unloading to mimic weightlessness and exposure to ionizing radiation), cause various transient and persistent detrimental consequences in multiple physiological systems. In general, we have found that adverse skeletal effects of simulated weightlessness and space radiation when combined, can be quantitatively, if not qualitatively, different from the influence of each environmental factor alone implying at least some shared underlying mechanisms. Thus, both ground based and spaceflight research utilizing model organisms provide the opportunity to better understand environmental factors and biological mechanisms that contribute to human health and survival in space.
Evaluation of Treadmill Exercise in a Lower Body Negative Pressure Chamber as a Countermeasure for Weightlessness-Induced Bone Loss: a Bed Rest Study with Identical Twins

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Davis-Street, Janis E.; Fesperman, J. Vernell; Calkins, D. S.; Bawa, Maneesh; Macias, Brandon R.; Meyer, R. Scott; Hargens, Alan R.

2003-01-01

Counteracting bone loss is required for future space exploration. We evaluated the ability of treadmill exercise in a LBNP chamber to counteract bone loss in a 30-day bed rest study. Eight pairs of identical twins were randomly assigned to sedentary control or exercise groups. Exercise within LBNP decreased the bone resorption caused by bed rest and may provide a countermeasure for spaceflight. INTRODUCTION: Bone loss is one of the greatest physiological challenges for extended-duration space missions. The ability of exercise to counteract weightlessness-induced bone loss has been studied extensively, but to date, it has proven ineffective. We evaluated the effectiveness of a combination of two countermeasures-treadmill exercise while inside a lower body negative pressure (LBNP) chamber-on bone loss during a 30-day bed rest study. MATERIALS AND METHODS: Eight pairs of identical twins were randomized into sedentary (SED) or exercise/LBNP (EX/LBNP) groups. Blood and urine samples were collected before, several times during, and after the 30-day bed rest period. These samples were analyzed for markers of bone and calcium metabolism. Repeated measures ANOVA was used to determine statistical significance. Because identical twins were used, both time and group were treated as repeated variables. RESULTS: Markers of bone resorption were increased during bed rest in samples from sedentary subjects, including the collagen cross-links and serum and urinary calcium concentrations. For N-telopeptide and deoxypyridinoline, there were significant (p < 0.05) interactions between group (SED versus EX/LBNP) and phase of the study (sample collection point). Pyridinium cross-links were increased above pre-bed rest levels in both groups, but the EX/LBNP group had a smaller increase than the SED group. Markers of bone formation were unchanged by bed rest in both groups. CONCLUSIONS: These data show that this weight-bearing exercise combined with LBNP ameliorates some of the negative effects of simulated weightlessness on bone metabolism. This protocol may pave the way to counteracting bone loss during spaceflight and may provide valuable information about normal and abnormal bone physiology here on Earth.
The exercise and environmental physiology of extravehicular activity

NASA Technical Reports Server (NTRS)

Cowell, Stephenie A.; Stocks, Jodie M.; Evans, David G.; Simonson, Shawn R.; Greenleaf, John E.

2002-01-01

Extravehicular activity (EVA), i.e., exercise performed under unique environmental conditions, is indispensable for supporting daily living in weightlessness and for further space exploration. From 1965-1996 an average of 20 h x yr(-1) were spent performing EVA. International Space Station (ISS) assembly will require 135 h x yr(-1) of EVA, and 138 h x yr(-1) is planned for post-construction maintenance. The extravehicular mobility unit (EMU), used to protect astronauts during EVA, has a decreased pressure of 4.3 psi that could increase astronauts' risk of decompression sickness (DCS). Exercise in and repeated exposure to this hypobaria may increase the incidence of DCS, although weightlessness may attenuate this risk. Exercise thermoregulation within the EMU is poorly understood; the liquid cooling garment (LCG), worn next to the skin and designed to handle thermal stress, is manually controlled. Astronauts may become dehydrated (by up to 2.6% of body weight) during a 5-h EVA, further exacerbating the thermoregulatory challenge. The EVA is performed mainly with upper body muscles; but astronauts usually exercise at only 26-32% of their upper body maximal oxygen uptake (VO2max). For a given ground-based work task in air (as opposed to water), the submaximal VO2 is greater while VO2max and metabolic efficiency are lower during ground-based arm exercise as compared with leg exercise, and cardiovascular responses to exercise and training are also different for arms and legs. Preflight testing and training, whether conducted in air or water, must account for these differences if ground-based data are extrapolated for flight requirements. Astronauts experience deconditioning during microgravity resulting in a 10-20% loss in arm strength, a 20-30% loss in thigh strength, and decreased lower-body aerobic exercise capacity. Data from ground-based simulations of weightlessness such as bed rest induce a 6-8% decrease in upper-body strength, a 10-16% loss in thigh extensor strength, and a 15-20% decrease in lower-body aerobic exercise capacity. Changes in EVA support systems and training based on a greater understanding of the physiological aspects of exercise in the EVA environment will help to insure the health, safety, and efficiency of working astronauts.
The exercise and environmental physiology of extravehicular activity.

PubMed

Cowell, Stephenie A; Stocks, Jodie M; Evans, David G; Simonson, Shawn R; Greenleaf, John E

2002-01-01

Extravehicular activity (EVA), i.e., exercise performed under unique environmental conditions, is indispensable for supporting daily living in weightlessness and for further space exploration. From 1965-1996 an average of 20 h x yr(-1) were spent performing EVA. International Space Station (ISS) assembly will require 135 h x yr(-1) of EVA, and 138 h x yr(-1) is planned for post-construction maintenance. The extravehicular mobility unit (EMU), used to protect astronauts during EVA, has a decreased pressure of 4.3 psi that could increase astronauts' risk of decompression sickness (DCS). Exercise in and repeated exposure to this hypobaria may increase the incidence of DCS, although weightlessness may attenuate this risk. Exercise thermoregulation within the EMU is poorly understood; the liquid cooling garment (LCG), worn next to the skin and designed to handle thermal stress, is manually controlled. Astronauts may become dehydrated (by up to 2.6% of body weight) during a 5-h EVA, further exacerbating the thermoregulatory challenge. The EVA is performed mainly with upper body muscles; but astronauts usually exercise at only 26-32% of their upper body maximal oxygen uptake (VO2max). For a given ground-based work task in air (as opposed to water), the submaximal VO2 is greater while VO2max and metabolic efficiency are lower during ground-based arm exercise as compared with leg exercise, and cardiovascular responses to exercise and training are also different for arms and legs. Preflight testing and training, whether conducted in air or water, must account for these differences if ground-based data are extrapolated for flight requirements. Astronauts experience deconditioning during microgravity resulting in a 10-20% loss in arm strength, a 20-30% loss in thigh strength, and decreased lower-body aerobic exercise capacity. Data from ground-based simulations of weightlessness such as bed rest induce a 6-8% decrease in upper-body strength, a 10-16% loss in thigh extensor strength, and a 15-20% decrease in lower-body aerobic exercise capacity. Changes in EVA support systems and training based on a greater understanding of the physiological aspects of exercise in the EVA environment will help to insure the health, safety, and efficiency of working astronauts.
Suspension restraint - Induced hypokinesia and antiorthostasis as a simulation of weightlessness

NASA Technical Reports Server (NTRS)

Musacchia, X. J.; Steffen, J. M.; Deavers, D. R.

1982-01-01

Muscle, renal, fluid and electrolyte responses were measured in suspended rats; the hind limbs are non-load bearing and the front limbs can be used for feeding and grooming. Hind limb hypokinesia reverses after removal from the suspension harness. This suspension system is adjustable for a head-down tilt to produce antiorthostatic responses which are also reversible. Responses to hypokinesia or antiorthostatic hypokinesia for up to 14 days were measured, e.g., muscle atrophy: soleus greater than gastrocnemius equals plantaris greater than extensor digitorum longus, kaliuresis, and increased excretion of urea, NH3, and 3 methylhistidine. Muscle protein loss, a response to a reduction in RNA, is also reversible. A head-down tilt for 7-14 days results in diuresis and natriuresis. These changes are reversed within 24 hours after removal from the restraint harness. Physiological effects of suspension restraint can be used to simulate and predict responses to microgravity exposure.
Report of 14-day bedrest simulation of Skylab

NASA Technical Reports Server (NTRS)

Johnson, P. C. (Compiler); Mitchell, C. (Compiler)

1976-01-01

Part one of a two-phase bedrest project in which the physiological effects of weightlessness were simulated is presented. The project was designed to approximate the medical testing and dietary control of Skylab. The test period included a three week pre-flight period, a two week bedrest period and a two week post-flight period. The test subjects ate measured amounts of the Skylab diet and drank deionized water to recreate the metabolic balance studies of Skylab. The medical testing program, pre- and postbedrest, was similar to that of Skylab including: lower body negative pressure testing the orthostatic intolerance noted after both spaceflights and bedrest, bicycle ergometry testing the cardiovascular response to graded exercise, postural equilibrium, vestibular studies and electromyograms. Fluid and electrolyte shifts and balance were documented with intake and output records and radionuclide studies. The subjects were observed by a psychiatrist who watched for signs of mental stress in the test environment and changes in mental status.
Observation of arterial blood pressure of the primate

NASA Technical Reports Server (NTRS)

Meehan, J. P.; Henry, J. P.

1973-01-01

The developments are reported in physiological instrumentation, surgical procedures, measurement and data analysis techniques, and the definition of flight experiments to determine the effects of prolonged weightlessness on the cardiovascular system of subhuman primates. The development of an implantable telemetric data acquisition system is discussed along with cardiovascular research applications in renal hemodynamics. It is concluded that the implant technique permits a valid interpretation, free of emotional response, for the manipulated variable on physiological functions. It also allows a better definition of normal physiological baseline conditions.
[Effect of Electroacupuncture Intervention at Different Time-points on Levels of HSP 70, MDA, SOD and GSH-PX of Liver in Rats with Simulated Weightlessness].

PubMed

Song, Yan; Zhao, Guo-zhen; Zhao, Bai-xiao; Ji, Bo; Wang, De-sheng; Zhang, He; Mao, Ying-qiu; Zhang, Ping; Xu, Yong-si; Liu, Ya-li; Lu, Ya-wen; Dai, Jian; Li, Ying-hui

2015-10-01

To observe the effect of acupuncture intervention at different time-points on the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), the content of malonaldehyde (MDA) and expression of heat shock protein 70 (HSP 70) of liver tissue in rats with simulated weightlessness, so as to explore its mechanism underlying improvement of liver injury in rats with simulated weightlessness. Twenty male Wistar rats were randomly divided into control group, model group, pre-acupuncture group and EA group, 5 rats in each. The model of simulated weightlessness was established by tail suspension for 4 week. One week before the tail suspension, the rats in the pre-acupuncture group were treated with electroacupuncture (EA) at "Shenshu" (BL 23), "Pishu"(BL 20) and "Sanyinjiao" (SP 6) for 30 min before treatment, once a day for 7 days. The rats in the EA group received tail suspension and acupuncture intervention at the same time. EA was applied for 30 min per treatment, once every other day for 14 times. Immunohistochemical staining was used to assay the expression of HSP 70 in the liver tissue. The activities of SOD and GSH-PX and content of MDA in liver tissues were examined by means of colourimetric method. Results Compared with the control group,the expression of HSP 70 and the content of MDA in the liver tissue were increased significantly (P < 0.01), and the activity of SOD and GSH-PX was notably reduced (P < 0.05) in the model group. Compared with the model group, the content of HSP 70 was significantly reduced in the pre-acupuncture group (P < 0.01). There were no significant changes in the levels of SOD, GSH-PX, MDA and HSP 70 in the EA group (P > 0.05). In comparison with the pre-acupuncture group, the activity of GSH-PX was lower (P < 0.05) and the content of MDA was higher (P < 0.05) in the EA group. EA-pretreatment can suppress the increase of liver HSP 70 immunoactivity in rats with simulated weightlessness, being likely to improve the antioxidant ability of liver.
Role of muscle spindle in weightlessness-induced amyotrophia and muscle pain.

PubMed

Ali, Umar; Fan, Xiao-Li; You, Hao-Jun

2009-10-01

To date, the medium and long-term space flight is urgent in need and has become a major task of our manned space flight program. There is no doubt that medium and long-term space flight has serious damaging impact upon human physiological systems. For instance, atrophy of the lower limb anti-gravity muscle can be induced during the space flight. Muscle atrophy significantly affects the flight of astronauts in space. Most importantly, it influences the precise manipulation of the astronauts and their response capacity to emergencies on returning to the atmosphere from space. Muscle atrophy caused by weightlessness may also seriously disrupt the normal life and work of the astronauts during the re-adaptation period. Here we summarize the corresponding research concentrating on weightlessness-induced changes of muscular structure and function. By combining research on muscle pain, which is a common clinical pain disease, we further provide a hypothesis concerning a dynamic feedback model of "weightlessness condition right triple arrow muscular atrophy <--> muscle pain". This may be useful to explore the neural mechanisms underlying the occurrence and development of muscular atrophy and muscle pain, through the key study of muscle spindle, and furthermore provide more effective therapy for clinical treatment.
Influences of Vestibular System on Sympathetic Nervous System. Implications for countermeasures.

NASA Astrophysics Data System (ADS)

Denise, Pr Pierre

As gravity is a direct and permanent stress on body fluids, muscles and bones, it is not surpris-ing that weightlessness has important effects on cardiovascular and musculo-skeletal systems. However, these harmful effects do not totally result from the removal of the direct stress of gravity on these organs, but are also partially and indirectly mediated by the vestibular sys-tem. Besides its well known crucial role in spatial orientation and postural equilibrium, it is now clear that the vestibular system is also involved in the regulation of other important physi-ological systems: respiratory and cardiovascular systems, circadian regulation, food intake and even bone mineralization. The neuroanatomical substrate for these vestibular-mediated reg-ulations is still poorly defined, but there is much evidence that vestibular system has strong impacts not only on brainstem autonomic centers but on many hypothalamic nuclei as well. As autonomic nervous system controls almost all body organs, bringing into play the vestibular system by hypergravity or microgravity could virtually affects all major physiological func-tions. There is experimental evidence that weightlessness as well as vestibular lesion induce sympathetic activation thus participating in space related physiological alterations. The fact that some effects of weightlessness on biological systems are mediated by the vestibular system has an important implication for using artificial gravity as a countermeasure: artificial gravity should load not only bones and the cardiovascular system but the vestibular system as well. In short-arm centrifuges, the g load at the head level is low because the head is near the axis of rotation. If the vestibular system is involved in cardiovascular deconditioning and bone loss during weightlessness, it would be more effective to significantly stimulate it and thus it would be necessary to place the head off-axis. Moreover, as the otolithic organs are non longer stimu-lated in term of gravity during space flight, and because of the plasticity of the brain, it might be possible that their inputs be progressively interpreted as resulting from translational move-ment with no gravity related activation. Therefore, on return to Earth the effect of the otoliths on cardiovascular regulation might be temporarily lost leading to orthostatic intolerance.

Distributed automatic control of technological processes in conditions of weightlessness

NASA Technical Reports Server (NTRS)

Kukhtenko, A. I.; Merkulov, V. I.; Samoylenko, Y. I.; Ladikov-Royev, Y. P.

1986-01-01

Some problems associated with the automatic control of liquid metal and plasma systems under conditions of weightlessness are examined, with particular reference to the problem of stability of liquid equilibrium configurations. The theoretical fundamentals of automatic control of processes in electrically conducting continuous media are outlined, and means of using electromagnetic fields for simulating technological processes in a space environment are discussed.
Spacelab Life Sciences 1: Reprints of Background Life Sciences Publications

NASA Technical Reports Server (NTRS)

White, Ronald (Editor); Leonard, Joel I. (Editor)

1991-01-01

The research being conducted on SLS-1 is primarily concerned with the short-term adaptation of physiological systems to weightlessness. A comprehensive overview of the various disciplines being studied on SLS-1 is presented. Citations and abstracts of all the papers submitted by the SLS-1 investigator teams are contained. The physiological systems studied include: cardiovascular and cardiopulmonary, musculoskeletal, neurovestibular, renal and endocrine, hematological, and immunological.
The control of calcium metabolism by parathyroid hormone, calcitonin and vitamin D

NASA Technical Reports Server (NTRS)

Potts, J. T., Jr.

1976-01-01

Advances in analysis of chemistry and physiology of parathyroid hormone, calcitonin, and Vitamin D are described along with development of techniques in radioassay methods. Emphasis is placed on assessment of normal and abnormal patterns of secretion of these hormones in specific relation to the physiological adaptations of weightlessness and space flight. Related diseases that involve perturbations in normal skeletal and calcium homeostasis are also considered.
Parathyroid hormone, calcitonin, and vitamin D 1974: Present status of physiological studies and analysis of calcium homeostasis

NASA Technical Reports Server (NTRS)

Potts, J. T., Jr.; Swenson, K. G.

1975-01-01

The role of parathyroid hormone, calcitonin, and vitamin D in the control of calcium and bone metabolism was studied. Particular emphasis was placed on the physiological adaptation to weightlessness and, as a potential model for this purpose, on the immobilization characteristic of space flight or prolonged bed rest. The biosynthesis, control of secretion, and metabolism of these hormonal agents is considered.
Current concepts of space flight induced changes in hormonal control of fluid and electrolyte metabolism

NASA Technical Reports Server (NTRS)

Leach, C. S.; Johnson, P. C.; Suki, W. N.

1983-01-01

A systematic analysis of body fluid and renal dynamics during simulated space flight (head-down bedrest) was undertaken to increase understanding of the physiologic effects of acute cephalad fluid shifts. The earliest effects were increases in central venous pressure and decreases in plasma aldosterone, epinephrine and norepinephrine and glomerular filtration rate, 2 h after the beginning of bedrest. Decreases in plasma angiotensin I at 6 h may have resulted from the increased effective pressure and decreased sympathetic activity seen earlier in bedrest. The early decrease in aldosterone and ADH is thought to contribute to an increase, by 6 h, in urinary excretion of salt and water. Fluid and electrolyte losses occur during space flight, and analysis of body fluids from Space Shuttle crewmembers has indicated that conservation of these substances is begun almost immediately upon cessation of weightlessness. Operational medicine measures to counteract dehydration and electrolyte loss resulted in a less extreme physiologic response to the flight.
Leg Vascular Responsiveness During Acute Orthostasis Following Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Blamick, Cynthia A.; Goldwater, Danielle J.; Convertino, Victor A.

1988-01-01

Ten men (35-49 years old) underwent lower body negative pressure (LBNP) exposures before and offer 10 d of continuous 6 degrees head-down bedrest in order to predict the effect of weightlessness on the responsiveness of leg vasculature to an orthostatic stress. Heart rate (HR), mean arterial blood pressure (MAP), and Impedance rheographic indices of arterial pulse volume (APV) of the legs were measured during rest and at 1 min at -30 mm Hg LBNP. Bedrest-induced deconditioning was manifested by decreases (p less than 0.06) in plasma volume (17%), peak oxygen uptake (16%), and LBNP tolerance (17%). Resting HR was unchanged after bedrest, but HR was higher (p less than 0.05) at 1 min of -30 mm Hg LBNP after, compared with before bedrest. Responses of MAP to -30 mm Hg LBNP were not altered by bodrest. Resting APV was decreased (p less than 0.05) by simulated weightlessness. However, APV was reduced (p less than 0.05) from rest to 1 min -30 mm Hg LBNP by the same relative magnitude before and after bodrest (-21.4 +/- 3.4% and -20.5 +/- 2.7%, respectively). We conclude that peripheral arterial vasoconstriction, as indicated by reductions in APV during LBNP, was not affected by bedrest. These results suggest that there was no apparent alteration in responsiveness of the leg vasculature following simulated weightlessness. Therefore, it appears unlikely that control mechanisms of peripheral resistance contribute significantly to reduced orthostatic tolerance following space-flight.
Offsetting Gravity

NASA Technical Reports Server (NTRS)

1976-01-01

The Coastal Center and the NASA Biomedical Team are working together to adapt a suspension device that simulates weightlessness. Attempts to approximate weightlessness have led astronauts underwater and into harnesses that suspend all or part of their weight. One such device, built at Langley Research Center, is being transferred to rehabilitation work. It can help a person walk and re-learn muscular coordination following a stroke. Hospitals could use it to lift handicapped persons.
[Counteracting effects of intermittent head-up tilt on simulated-weightlessness induced atrophy of anti-gravity muscles].

PubMed

Liu, C; Zhang, L F; Zhang, L N; Ni, H Y; Zhang, Y Q; Sun, L

2000-12-01

Objective. To study the efficacy of intermittent + Gz (45 degrees head-up tilt, HUT) exposures in preventing or alleviating atrophic changes in hind limb muscles induced by simulated weightlessness. Method. Male Sprague-Dawley (SD) rats were assigned randomly to one of three groups: simultaneous control (CON), simulated weightlessness (SUS), and SUS plus 6 h/d HUT (SUS + HUT). Muscles examined included soleus (SOL), medial gastrocnemius (correction from grastrocnemius) (MG), lateral gastrocnemius (LG) and extensor digitorum longus (EDL). Sections were treated with an adenosinetriphosphatase (ATPase) stain or alkaline phosphatase stain. The cross-sectional areas (CSA) of fibers, the relative proportion of type I fiber and the ratio of capillaries/fibers (C/F) were measured using Leica image analysis system. Result. Compared with CON, the wet weight of hind limb muscles in SUS were significantly reduced. The changes of wet weight in different groups were various. The C/F ratios of all muscles were significantly reduced. SUS + HUT rats showed significant increases in SOL and MG wet weight, and the relative counter-effects of intermittent HUT were 93.4% and 34.8%, respectively. In SUS + HUT group, the CSA of both type I and II fibers and relative proportion of type I fibers were completely recovered in SOL, and partially recovered in MG, while the counter-effects were much less obvious in the fibers of LG and EDL. However, HUT resulted in a significant recovery of the C/F ratios in all muscles. Conclusion. The present study demonstrated that intermittent HUT is effective in counteracting the atrophy induced by simulated weightlessness. The result that reactivity to HUT varied among different muscles suggests that the intermittent artificial gravity should be complemented with other countermeasures.
A comparison of autonomic responses in humans induced by two simulation models of weightlessness: lower body positive pressure and 6 degrees head-down tilt.

PubMed

Fu, Q; Sugiyama, Y; Kamiya, A; Mano, T

2000-04-12

Six-degree head-down tilt (HDT) is well accepted as an effective weightlessness model in humans. However, some researchers utilized lower body positive pressure (LBPP) to simulate the cardiovascular and renal effects of a decreased gravitational stress. In order to determine whether LBPP was a suitable model for simulated weightlessness, we compared the differences between these two methods. Ten healthy males, aged 21-41 years, were subjected to graded LBPP at 10, 20 and 30 mmHg, as well as 6 degrees HDT. Muscle sympathetic nerve activity (MSNA) was microneurographically recorded from the tibial nerve along with cardiovascular variables. We found that MSNA decreased by 27% to a similar extent both at low levels of LBPP (10 and 20 mmHg) and HDT. However, at a high level of LBPP (30 mmHg), MSNA tended to increase. Mean arterial pressure was elevated significantly by 11% (10 mmHg) at 30 mmHg LBPP, but remained unchanged at low levels of LBPP and HDT. Heart rate did not change during the entire LBPP and HDT procedures. Total peripheral resistance markedly increased by 36% at 30 mmHg LBPP, but decreased by 9% at HDT. Both stroke volume and cardiac output tended to decrease at 30 mmHg LBPP, but increased at HDT. These results suggest that although both LBPP and HDT induce fluid shifts from the lower body toward the thoracic compartment, autonomic responses are different, especially at LBPP greater than 20 mmHg. We note that high levels of LBPP (>20 mmHg) activate not only cardiopulmonary and arterial baroreflexes, but also intramuscular mechanoreflexes, while 6 degrees HDT only activates cardiopulmonary baroreflexes. We conclude that LBPP is not a suitable model for simulated weightlessness in humans.
Ground experiments for finding principles and working out methods for preventing adverse effects of weightlessness on the human organism

NASA Technical Reports Server (NTRS)

Kakurin, L. I.; Gregoryev, A. I.; Mikhailov, V. M.; Tishler, V. A.

1980-01-01

A comparative assessment of the effectiveness of different prophylactic procedures to prevent the adverse effects of weightlessness is presented. It is concluded that: physical training is most effective but no single method by itself produces the full effect, and an adjustment of regimes to one another enhances the effect. The approved complex of prophylactic procedures affected basic changes occurring in hypokinesia: deficit of muscular activity, no or reduced BP hydrostatic component, reduced volume of blood circulation, reduced hydration level, and the application of various prophylactic complexes during 49 day antiorthostatic hypodynamia eliminated or reduced the adverse effects of weightlessness in simulation.
Maximizing information from space data resources: a case for expanding integration across research disciplines.

PubMed

Goswami, Nandu; Batzel, Jerry J; Clément, Gilles; Stein, T Peter; Hargens, Alan R; Sharp, M Keith; Blaber, Andrew P; Roma, Peter G; Hinghofer-Szalkay, Helmut G

2013-07-01

Regulatory systems are affected in space by exposure to weightlessness, high-energy radiation or other spaceflight-induced changes. The impact of spaceflight occurs across multiple scales and systems. Exploring such interactions and interdependencies via an integrative approach provides new opportunities for elucidating these complex responses. This paper argues the case for increased emphasis on integration, systematically archiving, and the coordination of past, present and future space and ground-based analogue experiments. We also discuss possible mechanisms for such integration across disciplines and missions. This article then introduces several discipline-specific reviews that show how such integration can be implemented. Areas explored include: adaptation of the central nervous system to space; cerebral autoregulation and weightlessness; modelling of the cardiovascular system in space exploration; human metabolic response to spaceflight; and exercise, artificial gravity, and physiologic countermeasures for spaceflight. In summary, spaceflight physiology research needs a conceptual framework that extends problem solving beyond disciplinary barriers. Administrative commitment and a high degree of cooperation among investigators are needed to further such a process. Well-designed interdisciplinary research can expand opportunities for broad interpretation of results across multiple physiological systems, which may have applications on Earth.
Biomedical research on the International Space Station postural and manipulation problems of the human upper limb in weightlessness

NASA Astrophysics Data System (ADS)

Neri, Gianluca; Zolesi, Valfredo

2000-01-01

Accumulated evidence, based on information gathered on space flight missions and ground based models involving both humans and animals, clearly suggests that exposure to states of microgravity conditions for varying duration induces certain physiological changes; they involve cardiovascular deconditioning, balance disorders, bone weakening, muscle hypertrophy, disturbed sleep patterns and depressed immune responses. The effects of the microgravity on the astronauts' movement and attitude have been studied during different space missions, increasing the knowledge of the human physiology in weightlessness. The purpose of the research addressed in the present paper is to understand and to assess the performances of the upper limb, especially during grasp. Objects of the research are the physiological changes related to the long-term duration spaceflight environment. Specifically, the changes concerning the upper limb are investigated, with particular regard to the performances of the hand in zero-g environments. This research presents also effects on the Earth, improving the studies on a number of pathological states, on the health care and the rehabilitation. In this perspective, a set of experiments are proposed, aimed at the evaluation of the effects of the zero-g environments on neurophysiology of grasping movements, fatigue assessment, precision grip. .
Basic results of medical examinations of Soyuz spacecraft crew members

NASA Technical Reports Server (NTRS)

Gurovskiy, N. N.; Yegorov, A. D.; Kakurin, L. I.; Nefedov, Y. G.

1975-01-01

Weightlessness, hypokinesia and intense activity of crew members caused changes in human physiological functions during prolonged space flight as expressed in unusual diurnal rhythms. Microclimate, radiation and the nervous emotional state were not of significance in emergence of human body response reactions.
Foundations of space biology and medicine. Volume 2, book 1: Ecological and physiological bases of space biology and medicine

NASA Technical Reports Server (NTRS)

Calvin, M. (Editor); Gazenko, O. G. (Editor)

1975-01-01

Barometric pressure, gas composition, toxicity, and thermal exchange of spacecraft cabin atmospheres are discussed. Effects of gravitation, acceleration, weightlessness, noise, and vibration on human behavior and performance during space flight are also described.
EPM - The European Facility for human physiology research on ISS.

PubMed

Rieschel, Mats; Nasca, Rosario; Junk, Peter; Gerhard, Ingo

2002-07-01

The European Physiology Modules (EPM) Facility is one of the four major Space Station facilities being developed within the framework of ESA's Microgravity Facilities for Columbus (MFC) programme. In order to allow a wide spectrum of physiological studies in weightlessness conditions, the facility provides the infrastructure to accommodate a variable set of scientific equipment. The initial EPM configuration supports experiments in the fields of neuroscience, bone & muscle research, cardiovascular research and metabolism. The International Space Life Science Working Group (ISLSWG) has recommended co-locating EPM with the 2 NASA Human Research Facility racks.
NASA-Ames Life Sciences Flight Experiments program - 1980 status report

NASA Technical Reports Server (NTRS)

Berry, W. E.; Dant, C. C.; Macleod, G.; Williams, B. A.

1980-01-01

The paper deals with the ESA's Spacelab LSFE (Life Sciences Flight Experiments) program which, once operational, will provide new and unique opportunities to conduct research into the effects of spaceflight and weightlessness on living organisms under conditions approximating ground-based laboratories. Spacelab missions, launched at 18-month intervals, will enable scientists to test hypotheses from such disciplines as vestibular physiology, developmental biology, biochemistry, cell biology, plant physiology, and similar life sciences.
Skylab

NASA Image and Video Library

1973-05-01

This photograph was taken in the Marshall Space Flight Center (MSFC) Neutral Buoyancy Simulator (NBS) during the testing of an emergency procedure to deploy a twin-pole sunshade to protect the orbiting workshop from overheating due to the loss of its thermal shield. The spacecraft suffered damage to its sunshield during its launch on May 14, 1973. This photograph shows the base plate used to hold the twin-pole in place, the bag to hold the fabric sail, and the lines that were used to draw the sail into place. Extensive testing and many hours of practice in simulators, such as the NBS, helped prepare the Skylab crewmen for extravehicular performance in the weightless environment. This huge water tank simulated the weightless environment that the astronauts would encounter in space.
Simulated weightlessness in fish and neurophysiological studies on memory storage

NASA Technical Reports Server (NTRS)

Vonbaumgarten, R. J.

1973-01-01

Simulated weightlessness was used to study the different types of gravity responses in blind fish. It was found that a shift in the direction of low magnitude acceleration in weightlessness causes a rapid 180 deg turn in the blind fish, while a shift in the direction of the applied acceleration in the earth's gravitational field is not significant because of a higher acceleration magnitude threshold than during the zero g condition. This increased responsiveness seems to be explained by a combination of directional sensitivity with a Weber-Fechner relationship of increased receptor sensitivity at diminished levels of background stimulation. Neurophysical studies of the statocyst nerve of the gastropod Mollusc Pleurobranchaea Californica were undertaken in order to understand how complex otolith systems operate. Information storage was investigated on relatively simple neuronal networks in the mollusc Aplysia. Intracellular electrical stimulation of isolated neurons show that a manipulation of autoditonous rhymicity is possible. It was also found that glycolysis and oxidative phosphorylation are involved in inherent rhymicity of Aplysis neurons.
Light as a chronobiologic countermeasure for long-duration space operations

NASA Technical Reports Server (NTRS)

Samel, Alexander (Editor); Gander, Philippa (Editor); Evans, Julie; Graeber, R. Curtis; Hackett, Elizabeth; Keil, Lanny; Maab, Hartmut; Raabe, Wolfgang; Rosekind, Mark; Rountree, Mike

1991-01-01

Long-duration space missions require adaptation to work-rest schedules which are substantially shifted with respect to earth. Astronauts are expected to work in two-shift operations and the environmental synchronizers (zeitgebers) in a spacecraft differ significantly from those on earth. A study on circadian rhythms, sleep, and performance was conducted by exposing four subjects to 6 deg head-down tilt bedrest (to simulate the effects of the weightless condition) and imposing a 12-h shift (6 h delay per day for two days). Bright light was tested in a cross-over design as a countermeasure for achieving faster resynchronization and regaining stable conditions for sleep and circadian rhythmicity. Data collection included objective sleep recording, temperature, heart rate, and excretion of hormones and electrolytes as well as performance and responses to questionnaires. Even without a shift in the sleep-wake cycle, the sleep quantity, circadian amplitudes and 24 h means decreased in many functions under bedrest conditions. During the shift days, sleepiness and fatigue increased, and alertness decreased. However, sleep quantity was regained, and resynchronization was completed within seven days after the shift for almost all functions, irrespective of whether light was administered during day-time or night-time hours. The time of day of light exposure surprisingly appeared not to have a discriminatory effect on the resynchronization speed under shift and bedrest conditions. The results indicate that simulated weightlessness alters circadian rhythms and sleep, and that schedule changes induce additional physiological disruption with decreased subjective alertness and increased fatigue. Because of their operational implications, these phenomena deserve additional investigation.
The simulation of microgravity conditions on the ground.

PubMed

Albrecht-Buehler, G

1992-10-01

This chapter defines weightlessness as the condition where the acceleration of an object is independent of its mass. Applying this definition to the clinostat, it argues that the clinostat is very limited as a simulator of microgravity because it (a) generates centrifugal forces, (b) generates particle oscillations with mass-dependent amplitudes of speed and phase shifts relative to the clinorotation, (c) is unable to remove globally the scalar effects of gravity such as hydrostatic pressure, which are independent of the direction of gravity in the first place, and, (d) generates more convective mixing of the gaseous or liquid environment of the test object, rather than eliminating it, as would true weightlessness. It is proposed that attempts to simulate microgravity must accept the simulation of one aspect of microgravity at a time, and urges that the suppression of convective currents be a major feature of experimental methods that simulate microgravity.

Gravity effects on reproduction, development, and aging

NASA Technical Reports Server (NTRS)

Miquel, Jaime; Souza, Kenneth A.

1991-01-01

The effects of various levels of gravity force (obtained by rotation in clinostats or by centrifugation) and the near-weightlessness condition aboard orbiting spacecraft on the fertilization, embryonic development, maturation, and aging of animals are examined. Results obtained from the American and Soviet spaceborne biology experiments are presented including those on mammals, amphibians, fish, birds, invertebrates, and protozoa. Theoretical issues related to the effect of gravity on various physiological systems are discused together with the future research goals concerning human life in space. It is noted that life in space (after adaptation to near-weightlessness) might be significantly prolonged due to a reduction in metabolic rate and a concomitant decrease in oxygen radical reactions.
Increased hematuria following hypergravic exposure in middle-aged women

NASA Technical Reports Server (NTRS)

Goldwater, D. J.; Ohara, D. B.; Sandler, H.

1982-01-01

The effects of simulated weightlessness on orthostatic tolerance were studied in 9 women (55 to 65 years old) who underwent acceleration and lower body negative pressure before and after 10 days of horizontal bed rest. The results of this study show the first known association of microscopic hematuria with hypergravic and orthostatic stress which suggests similarities to the 'stress hematuria syndrome' previously seen with heavy exercise (Boileau et al., 1980). In addition, the sporadic occurrence of this phenomenon indicates a multifactorial etiology in predisposed individuals. Bedrest or weightlessness simulation per se does not seem to significantly alter renal function, but may decrease microscopic hematuria with an orthostatic component.
Research opportunities in muscle atrophy

NASA Technical Reports Server (NTRS)

Herbison, G. J. (Editor); Talbot, J. M. (Editor)

1984-01-01

Muscle atrophy in a weightless environment is studied. Topics of investigation include physiological factors of muscle atrophy in space flight, biochemistry, countermeasures, modelling of atrophied muscle tissue, and various methods of measurement of muscle strength and endurance. A review of the current literature and suggestions for future research are included.
Stress, Workload and Physiology Demand During Extravehicular Activity: A Pilot Study

PubMed Central

Rai, Balwant; Kaur, Jasdeep; Foing, Bernard H

2012-01-01

Background: Extravehicular activity (EVA), such as exercise performed under unique environmental conditions, is essential for supporting daily living in weightlessness and for further space exploration like long Mars mission. Aim: The study was planned stress, workload, and physiological demands of simulated Mars exploration. Materials and Methods: In this study, the six-person crew lived (24 hours) for 14 days during a short-term stay at the Mars Desert Research Station. The heart rates, salivary cortisol, workload, peak oxygen uptake or maximal aerobic capacity of the crew are measured before, during and after an EVA. Results: Data for heart rate showed the same trend as peak oxygen uptake or maximal aerobic capacity, with a maximal increase to 85% of peak. The rating of subscale showed a significant increase in EVA as compared to run. Salivary cortisol levels and heart rates were increased in both groups, although significant increased of cortisol levels and heart rates more in EVA as compared to hill running crew members. Conclusion: Further study is required on large scale taken into account of limitations of this study and including other physiological and psychological parameters in Mars analog environment. PMID:22754877
Proceedings of the 1972 Lyndon B. Johnson Space Center Endocrine Program Conference

NASA Technical Reports Server (NTRS)

1974-01-01

Subjects covered during the Endocrine Program Conference include the following: (1) endocrine/metabolic studies on the Apollo 16 crewmen; (2) changes in glucose, insulin, and growth hormone levels associated with bed rest; (3) circadian rhythms of heart rate and body temperature during 56 days of bed rest; (4) stress-induced changes in corticosteroid metabolism in man; (5) present status of physiological studies on parathyroid hormone and vitamin D; (6) antagonistic effect of lithium on antidiuretic hormone action; (7) proposed Skylab body-fluid volumes study; (8) daily rhythmic changes in serotonin content in areas of the mouse brain and norepinephrine content in areas of the hamster brain; (9) studies of sodium homeostasis during simulated weightlessness; and (10) application of the water immersion model to man.
A long term model of circulation. [human body

NASA Technical Reports Server (NTRS)

White, R. J.

1974-01-01

A quantitative approach to modeling human physiological function, with a view toward ultimate application to long duration space flight experiments, was undertaken. Data was obtained on the effect of weightlessness on certain aspects of human physiological function during 1-3 month periods. Modifications in the Guyton model are reviewed. Design considerations for bilateral interface models are discussed. Construction of a functioning whole body model was studied, as well as the testing of the model versus available data.
Space Resources for Teachers: Biology, Including Suggestions for Classroom Activities and Laboratory Experiments.

ERIC Educational Resources Information Center

Lee, Tom E.; And Others

This compilation of resource units concerns the latest developments in space biology. Some of the topics included are oxygen consumption, temperature, radiation, rhythms, weightlessness, acceleration and vibration stress, toxicity, and sensory and perceptual problems. Many of the topics are interdisciplinary and relate biology, physiology,…
Computer simulation analysis of the behavior of renal-regulating hormones during hypogravic stress

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1982-01-01

A computer simulation of a mathematical circulation model is used to study the alterations of body fluids and their electrolyte composition that occur in weightlessness. The behavior of the renal-regulating hormones which control these alterations is compared in simulations of several one-g analogs of weightlessness and space flight. It is shown that the renal-regulating hormones represent a tightly coupled system that responds acutely to volume disturbances and chronically to electrolyte disturbances. During hypogravic conditions these responses lead to an initial suppression of hormone levels and a long-term effect which varies depending on metabolic factors that can alter the plasma electrolytes. In addition, it is found that if pressure effects normalize rapidly, a transition phase may exist which leads to a dynamic multiphasic endocrine response.
Magnetic levitation in two-dimensional geometry with translational invariance

NASA Astrophysics Data System (ADS)

Lorin, C.; Mailfert, A.

2008-11-01

The development of activities in space and of the corresponding technologies requires research on the behavior of both matter and biological organisms under weightless conditions. Various methods have been invented in order to simulate weightlessness, for example, drop towers, sounding rockets, or parabolic flights. Magnetic field ground-based devices have also been developed. This paper introduces an optimization method of the magnetic field so as to obtain magnetic levitation in a two-dimensional cylindrical geometry.
Space colonization - Some physiological perspectives

NASA Technical Reports Server (NTRS)

Winkler, L. H.

1978-01-01

Physiological criteria determining the design of the habitat for a space colony with 10,000 people are discussed. Centrifugally generated earth-normal gravity, maximum ionizing radiation dose standards less than or equal to 0.5 rem/year (obtained with passive shielding), and an atmosphere with reduced nitrogen partial pressures were established as design requirements for the habitat. However, further research is needed to determine whether humans experience complete adaptation to weightlessness and whether there are long-term effects of breathing various atmospheric mixtures and pressures.
Dr. von Braun Tries Out the Neutral Buoyancy Simulator (NBS)

NASA Technical Reports Server (NTRS)

1967-01-01

Marshall Space Flight Center (MSFC) Director, Dr. von Braun, submerges after spending some time under water in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.
Endocrine and metabolic changes in payload specialist (L-1)

NASA Technical Reports Server (NTRS)

Matsui, Nobuo

1993-01-01

The endocrine system plays an important role in the adaptation to unusual environments by secreting hormones to control metabolism. Since human beings have long evolved on the surface of the Earth under a gravity environment, the weightless environment must be quite unusual for them. The purpose of this experiment is to study the mechanisms of human adaptation to a weightless environment from endocrine and metabolic changes. Our study plan is focused on four major physiological changes which were reported during past space flights or which may be expected to occur under that condition: (1) hormone and metabolic changes associated with fluid shift; (2) bone demineralization and muscle atrophy; (3) altered circadian rhythm; and (4) stress reaction during space flight.
MSFC Skylab neutral buoyancy simulator

NASA Technical Reports Server (NTRS)

1974-01-01

The use of a neutral buoyancy simulator for developing extravehicular activity systems and for training astronauts in weightless activities is discussed. The construction of the facility and the operations are described. The types of tests and the training activities conducted in the simulator are reported. Photographs of the components of the simulator and actual training exercises are included.
Axial jet mixing of ethanol in spherical containers during weightlessness

NASA Technical Reports Server (NTRS)

Audelott, J. C.

1976-01-01

An experimental program was conducted to examine the liquid flow patterns that result from the axial jet mixing of ethanol in 10-centimeter-diameter spherical containers in weightlessness. Complete liquid circulation flow patterns were easily established in containers that were less than half full of liquid, while for higher liquid fill conditions, vapor was drawn into the inlet of the simulated mixer unit. Increasing the liquid-jet or lowering the position at which the liquid jet entered the container caused increasing turbulence and bubble formation.
Selection of an appropriate animal model for study of bone loss in weightlessness

NASA Technical Reports Server (NTRS)

Wolinsky, I.

1986-01-01

Prolonged weightlessness in space flight results in a slow progressive demineralization of bone accompanied by an increased calcium output in the urine resulting in negative calcium balances. This possibly irreversible bone loss may constitute a serious limiting factor to long duration manned space flight. A number of preventative measures have been suggested, i.e., exercise during flight, dietary calcium supplements, use of specific prophylactic drugs. In order to facilitate research in these areas it is necessary to develop appropriate ground-based animal models that simulate the human condition of osteoporsis. An appropriate animal model would permit bone density studies, calcium balance studies, biochemical analyses, ground-based simulation models of weightlessness (bed rest, restraint, immobilization) and the planning of inflight experiments. Several animal models have been proposed in the biomedical research literature, but have inherent deficiencies. The purpose of this project was to evaluate models in the literature and determine which of these most closely simulates the phenomenon of bone loss in humans with regard to growth, bone remodeling, structural, chemical and mineralization similarities to human. This was accomplished by a comprehensive computer assisted literature search and report. Three animal models were examined closely for their relative suitability: the albino rat, monkey, and Beagle.
Loading Configurations and Ground Reaction Forces During Treadmill Running in Weightlessness

NASA Technical Reports Server (NTRS)

DeWitt, John; Schaffner, Grant; Blazine, Kristi; Bentley, Jason; Laughlin, Mitzi; Loehr, James; Hagan, Donald

2003-01-01

Studies have shown losses in bone mineral density of 1-2% per month in critical weight bearing areas such as the proximal femur during long-term space flight (Grigoriev, 1998). The astronauts currently onboard the International Space Station (ISS) use a treadmill as an exercise countermeasure to bone loss that occurs as a result of prolonged exposure to weightlessness. A crewmember exercising on the treadmill is attached by a harness and loading device. Ground reaction forces are obtained through the loading device that pulls the crewn1ember towards the treadmill surface during locomotion. McCrory et al. (2002) found that the magnitude of the peak ground reaction force (pGRF) during horizontal suspension running, or simulated weightlessness, was directly related to the load applied to the subject. It is thought that strain magnitude and strain rate affects osteogenesis, and is a function of the magnitude and rate of change of the ground reaction force. While it is not known if a minimum stimulus exists for osteogenesis, it has been hypothesized that in order to replicate the bone formation occurring in normal gravity (1 G), the exercise in weightlessness should mimic the forces that occur on earth. Specifically, the pGRF obtained in weightlessness should be comparable to that achieved in 1 G.
Preadaptation to the stimulus rearrangement of weightlessness: Preliminary studies and concepts for trainer designs

NASA Technical Reports Server (NTRS)

Parker, D. E.; Reschke, M. F.

1988-01-01

An effort to develop preflight adaptation training (PAT) apparatus and procedures to adapt astronauts to the stimulus rearrangement of weightless spaceflight is being pursued. Based on the otolith tilt-translation reinterpretation model of sensory adaptation to weightlessness, two prototype preflight adaptation trainers (PAT) have been developed. These trainers couple pitch movement of the subject with translation of the visual surround. Subjects were exposed to this stimulus rearrangement for periods of 30 m. The hypothesis is that exposure to the rearrangement would attenuate vertical eye movements was supported by two experiments using the Miami University Seesaw (MUS) PAT prototype. The Dynamic Environment Simulator (DES) prototype failed to support this hypothesis; this result is attributed to a pecularity of the DES apparatus. A final experiment demonstrated that changes in vertical eye movements were not a consequence of fixation on an external target during exposure to a control condition. Together these experiments support the view that preflight adaptation training can alter eye movements in a manner consistent with adaptation to weightlessness. Following these initial studies, concepts for development of operational preflight trainers were proposed. The trainers are intended to: demonstrate the stimulus rearrangement of weightlessness; allow astronauts to train in altered sensory environment; modify sensory motor reflexes; and reduce/eliminate space motion sickness symptoms.
USSR Space Life Sciences Digest

NASA Technical Reports Server (NTRS)

Lewis, C. S. (Editor); Donnelly, K. L. (Editor)

1980-01-01

Research in exobiology, life sciences technology, space biology, and space medicine and physiology, primarily using data gathered on the Salyut 6 orbital space station, is reported. Methods for predicting, diagnosing, and preventing the effects of weightlessness are discussed. Psychological factors are discussed. The effects of space flight on plants and animals are reported. Bioinstrumentation advances are noted.
NASA space biology accomplishments, 1983-84

NASA Technical Reports Server (NTRS)

Halstead, T. W.; Dutcher, F. R.; Pleasant, L. G.

1984-01-01

Approximately 42 project summaries from NASA's Space Biology Program are presented. Emphasis is placed on gravitational effects on plant and animal life. The identification of gravity perception; the effects of weightlessness on genetic integrity, cellular differentiation, reproduction, development, growth, maturation, and senescence; and how gravity affects and controls physiology, morphology, and behavior of organisms are studied.
Bringing Gravity to Space

NASA Technical Reports Server (NTRS)

Norsk, P.; Shelhamer, M.

2016-01-01

This panel will present NASA's plans for ongoing and future research to define the requirements for Artificial Gravity (AG) as a countermeasure against the negative health effects of long-duration weightlessness. AG could mitigate the gravity-sensitive effects of spaceflight across a host of physiological systems. Bringing gravity to space could mitigate the sensorimotor and neuro-vestibular disturbances induced by G-transitions upon reaching a planetary body, and the cardiovascular deconditioning and musculoskeletal weakness induced by weightlessness. Of particular interest for AG during deep-space missions is mitigation of the Visual Impairment Intracranial Pressure (VIIP) syndrome that the majority of astronauts exhibit in space to varying degrees, and which presumably is associated with weightlessness-induced fluid shift from lower to upper body segments. AG could be very effective for reversing the fluid shift and thus help prevent VIIP. The first presentation by Dr. Charles will summarize some of the ground-based and (very little) space-based research that has been conducted on AG by the various space programs. Dr. Paloski will address the use of AG during deep-space exploration-class missions and describe the different AG scenarios such as intra-vehicular, part-of-vehicle, or whole-vehicle centrifugations. Dr. Clement will discuss currently planned NASA research as well as how to coordinate future activities among NASA's international partners. Dr. Barr will describe some possible future plans for using space- and ground-based partial-G analogs to define the relationship between physiological responses and G levels between 0 and 1. Finally, Dr. Stenger will summarize how the human cardiovascular system could benefit from intermittent short-radius centrifugations during long-duration missions.

Biological effects of weightlessness and clinostatic conditions registered in cells of root meristem and cap of higher plants

NASA Astrophysics Data System (ADS)

Sytnik, K. M.; Kordyum, E. L.; Belyavskaya, N. A.; Nedukha, E. M.; Tarasenko, V. A.

Research in cellular reproduction, differentiation and vital activity, i.e. processes underlying the development and functioning of organisms, plants included, is essential for solving fundamental and applied problems of space biology. Detailed anatomical analysis of roots of higher plants grown on board the Salyut 6 orbital research station show that under conditions of weightlessness for defined duration mitosis, cytokinesis and tissue differentiation in plant vegetative organs occur essentially normally. At the same time, certain rearrangements in the structural organization of cellular organelles - mainly the plastid apparatus, mitochondria, Golgi apparatus and nucleus - are established in the root meristem and cap of the experimental plants. This is evidence for considerable changes in cellular metabolism. The structural changes in the subcellular level arising under spaceflight conditions are partially absent in clinostat experiments designed to simulate weightlessness. Various clinostatic conditions have different influences on the cell structural and functional organization than does space flight. It is suggested that alterations of cellular metabolism under weightlessness and clinostatic conditions occur within existing genetic programs.
Biomedical study on combined effects of simulated weightlessness and emergent depressurization of spacecraft

NASA Astrophysics Data System (ADS)

Yang, T. D.; Zhang, R. G.; Wang, C. M.; Fu, H. W.; Zhang, B. L.; Zhang, J. X.

1999-01-01

Cabin emergent depressurization (CED) may occur in spacecraft during manned space flight. The purpose of this paper was to study the combined effects of simulated weightlessness (SW) and CED factors on humans and animals. It was found that the amplitude of T wave of human electrocardiograms (ECG) significantly decreased in bed rest and hypoxia compared with the control condition (P<0.05), and that suspension with pure O2 induced severer edema in the lungs of rats than that in only a pure O2 environment. SW and pure O2 caused middle ear congestion and decreased the barofunction during pressure changes. These results indicate that human response to CED factors become more serious under SW because of the blood redistribution.
[Effects of space-flight factors on cytochemical characteristics of the motor analyzer neurons].

PubMed

Gorbunova, A V

2010-01-01

The work was designed to study metabolism of motoneurons in anterior horns of the spinal cord and sensorimotor cortex of Wistar rats after flights on Earth's satellites for 22.5 days (Kosmos-605), 19.5 days (Kosmos-782), and 18.5 days (Kosmos-936). Control rats underwent simulated space-flight factors under laboratory conditions excepting weightlessness. Rats placed in Kosmos-936 were subjected to artificial gravity (AG). They showed complete recovery of motoneuronal metabolism 25 days after landing unlike animals that had experienced weightlessness in which enhanced functional activity of the genetic apparatus was manifest as increased RNA level, protein content, and nuclei size. These finding may reflect differences of neuronal metabolism in animals experiencing weightlessness and AG. We believe they may be due to reduced static load on the locomotor system during the space flight.
Dr. von Braun Tries Out the Neutral Buoyancy Simulator (NBS)

NASA Technical Reports Server (NTRS)

1967-01-01

Marshall Space Flight Center (MSFC) Director, Dr. von Braun, is shown leaving the suiting-up van wearing a pressure suit prepared for a tryout in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.
Specialized physiological studies in support of manned space flight

NASA Technical Reports Server (NTRS)

Luft, U. C.

1980-01-01

The reversible changes that take place in the cardiovascular system during weightlessness were investigated. Particular attention was given to the assessment of cardiovascular functions during and after space missions. One of the most important of these functions is the amount of blood pumped by the heart per min at rest and during exercise of gravitational stress.
Development and testing of a mouse simulated space flight model

NASA Technical Reports Server (NTRS)

Sonnenfeld, G.

1985-01-01

The development and testing of a mouse model for simulating some aspects of weightlessness that occur during space flight, and the carrying out of immunological flight experiments on animals was discussed. The mouse model is an antiorthostatic, hypokinetic, hypodynamic suspension model similar to the one used with rats. It is shown that this murine model yield similar results to the rat model of antiorthostatic suspension for simulating some aspects of weightlessness. It is also shown that mice suspended in this model have decreased interferon-alpha/beta production as compared to control, nonsuspended mice or to orthostatically suspended mice. It is suggested that the conditions occuring during space flight could possibly affect interferon production. The regulatory role of interferon in nonviral diseases is demonstrated including several bacterial and protozoan infections indicating the great significance of interferon in resistance to many types of infectious diseases.
A review of the consequences of fluid and electrolyte shifts in weightlessness

NASA Technical Reports Server (NTRS)

Leach, C. S.

1979-01-01

This review describes the renal-endocrine mechanisms related to the early losses of fluid-electrolytes from the body during weightlessness as well as their contribution to longer term adaptation of fluid-electrolyte balance. The hypotheses presented were generated by a systematic analysis of body fluid and renal dynamics observed under conditions of actual and simulated spaceflight. These have increased our understanding of the effects of acute headward fluid shifts on renal excretion, the factors promoting excess sodium excretion and the regulation of extracellular fluid composition.
A review of the consequences of fluid and electrolyte shifts in weightlessness

NASA Technical Reports Server (NTRS)

Leach, C. S.

1978-01-01

This review describes the renal-endocrine mechanisms related to the early losses of fluid-electrolytes from the body during weightlessness as well as their contribution to longer term adaptation of fluid-electrolyte balance. The hypotheses presented were generated by a systematic analysis of body fluid and renal dynamics observed under conditions of actual and simulated spaceflight. These have increased our understanding of the effects of acute headward fluid shifts on renal excretion, the factors promoting excess sodium excretion and the regulation of extracellular fluid composition.
Bion 11 Spaceflight Project: Effect of Weightlessness on Single Muscle Fiber Function in Rhesus Monkeys

NASA Technical Reports Server (NTRS)

Fitts, Robert H.; Romatowski, Janell G.; Widrick, Jeffrey J.; DeLaCruz, Lourdes

1999-01-01

Although it is well known that microgravity induces considerable limb muscle atrophy, little is known about how weightlessness alters cell function. In this study, we investigated how weightlessness altered the functional properties of single fast and slow striated muscle fibers. Physiological studies were carried out to test the hypothesis that microgravity causes fiber atrophy, a decreased peak force (Newtons), tension (Newtons/cross-sectional area) and power, an elevated peak rate of tension development (dp/dt), and an increased maximal shortening velocity (V(sub o)) in the slow type I fiber, while changes in the fast-twitch fiber are restricted to atrophy and a reduced peak force. For each fiber, we determined the peak force (P(sub o)), V(sub o), dp/dt, the force-velocity relationship, peak power, the power-force relationship, the force-pCa relationship, and fiber stiffness. Biochemical studies were carried out to assess the effects of weightlessness on the enzyme and substrate profile of the fast- and slow-twitch fibers. We predicted that microgravity would increase resting muscle glycogen and glycolytic metabolism in the slow fiber type, while the fast-twitch fiber enzyme profile would be unaltered. The increased muscle glycogen would in part result from an elevated hexokinase and glycogen synthase. The enzymes selected for study represent markers for mitochondrial function (citrate synthase and 0-hydroxyacyl-CoA dehydrogenase), glycolysis (Phosphofructokinase and lactate dehydrogenase), and fatty acid transport (Carnitine acetyl transferase). The substrates analyzed will include glycogen, lactate, adenosine triphosphate, and phosphocreatine.
A "Bony" Proposition: Pathways Mediating Responses to Simulated Weightlessness and Radiation

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Globus, Ruth

2016-01-01

There is evidence that weightlessness and radiation, two elements of the spaceflight environment, can lead to detrimental changes in human musculoskeletal tissue, including bone loss and muscle atrophy. This bone loss is thought to be brought about by the increased activity of bone-resorbing osteoclasts and functional changes in bone-forming osteoblasts, cells that give rise to mature osteocytes. My current area of research focuses on understanding the mechanistic basis for the responses of bone to the spaceflight environment using earth-based animal and cellular models. The overarching goal is to identify molecular targets to prevent bone loss in space exploration and earth-based scenarios of radiotherapy, accidental radiation exposure and reduced mobility. In this talk, I will highlight two signaling pathways that potentially play a role in the response of bone to spaceflight-like conditions. Firstly, I will discuss the role of insulin-like growth factor 1 (IGF1) signaling as it pertains to the recovery of bone from simulated weightlessness (rodent hindlimb unloading model). Secondly, I will share recent findings from our study that aims to understand the emerging role of autophagy in maintaining the balance between bone formation and resorption (bone homeostasis) as well as normal skeletal structure.
Cardiovascular and fluid volume control in humans in space.

PubMed

Norsk, Peter

2005-08-01

The human cardiovascular system and regulation of fluid volume are heavily influenced by gravity. When decreasing the effects of gravity in humans such as by anti-orthostatic posture changes or immersion into water, venous return is increased by some 25%. This leads to central blood volume expansion, which is accompanied by an increase in renal excretion rates of water and sodium. The mechanisms for the changes in renal excretory rates include a complex interaction of cardiovascular reflexes, neuroendocrine variables, and physical factors. Weightlessness is unique to obtain more information on this complex interaction, because it is the only way to completely abolish the effects of gravity over longer periods. Results from space have been unexpected, because astronauts exhibit a fluid and sodium retaining state with activation of the sympathetic nervous system, which subjects during simulations by head-down bed rest do not. Therefore, the concept as to how weightlessness affects the cardiovascular system and modulates regulation of body fluids should be revised and new simulation models developed. Knowledge as to how gravity and weightlessness modulate integrated fluid volume control is of importance for understanding pathophysiology of heart failure, where gravity plays a strong role in fluid and sodium retention.
Use of bed rest and head-down tilt to simulate spaceflight-induce immune system changes

NASA Technical Reports Server (NTRS)

Schmitt, D. A.; Schaffar, L.; Taylor, G. R.; Loftin, K. C.; Schneider, V. S.; Koebel, A.; Abbal, M.; Sonnenfeld, G.; Lewis, D. E.; Reuben, J. R.;

1996-01-01

Bed rest, both with and without head-down tilt, has been extensively used as an earth-bound analog to study physiologic effects mimicking those occurring in weightlessness during spaceflight. We have been able to show in six subjects that 4 weeks of head-down tilt bed rest induces a significant decrease in interleukin-2 secretion by PHA-stimulated T lymphocytes. Another study, lasting 113 days, with two subjects showed a decreased interleukin-2 receptor expression in PHA-stimulated peripheral blood mononuclear cells but a decreased interleukin-2 production in one subject only. Under the same conditions, interleukin-1 production was largely increased in both subjects. Several other immune parameters were also analyzed. Increased interleukin-1 production could contribute to bone mineral loss encountered during bed rest and decreased interleukin-2 secretion could play a role in the appearance of infectious diseases often observed during bed red.

Cardiovascular dynamics during the initial period of head-down tilt

NASA Technical Reports Server (NTRS)

Tomaselli, Clare Marie; Kenney, Richard A.; Frey, Mary Anne Bassett; Hoffler, G. Wyckliffe

1987-01-01

The cardiovascular response to 1 h of 60-deg head-down tilt was studied in 12 male subjects, ages 30-39 years, to simulate the early effects of weightlessness. Fluid shifts, hemodynamic variables, and indices of myocardial contractility were evaluated by utilizing electrocardiography, systolic time intervals, impedance cardiography, sphygmomanometry, and measurement of calf circumference. Most cardiovascular variables remained stable throughout the initial 30 min of the protocol, even though translocation of fluid from the legs to the thorax commenced immediately with the onset of head-down tilt. In contrast, minutes 30-60 were characterized by reduced stroke volume, cardiac output, mean stroke ejection rate, and Heather index concomitant with an elevation in mean arterial pressure. Intrathoracic fluid volume continued to increase, while leg volume continued to decrease. This latter physiological response suggests intrathoracic sequestration of fluid volume; blood was apparently redistributed to the pulmonary circulation rather than being retained in the great veins.
The influence of different space-related physiological variations on exercise capacity determined by oxygen uptake kinetics.

PubMed

Stegemann, J

1992-07-01

Oxygen uptake kinetics, following defined variations of work load changes allow to estimate the contribution of aerob and anaerob energy supply which is the base for determining work capacity. Under the aspect of long duration missions with application of adequate dosed countermeasures, a reliable estimate of the astronaut's work capacity is important to adjust the necessary inflight training. Since the kinetics of oxygen uptake originate in the working muscle group itself, while measurements are performed at the mouth, various influences within the oxygen transport system might disturb the determinations. There are not only detraining effects but also well-known other influences, such as blood- and fluid shifts induced by weightlessness. They might have an impact on the circulatory system. Some of these factors have been simulated by immersion, blood donation, and changing of the body position.
The influence of different space-related physiological variations on exercise capacity determined by oxygen uptake kinetics

NASA Astrophysics Data System (ADS)

Stegemann, J.

Oxygen uptake kinetics, following defined variations of work load changes allow to estimate the contribution of aerob and anaerob energy supply which is the base for determining work capacity. Under the aspect of long duration missions with application of adequate dosed countermeasures, a reliable estimate of the astronaut's work capacity is important to adjust the necessary inflight training. Since the kinetics of oxygen uptake originate in the working muscle group itself, while measurements are performed at the mouth, various influences within the oxygen transport system might disturb the determinations. There are not only detraining effects but also well-known other influences, such as blood- and fluid shifts induced by weightlessness. They might have an impact on the circulatory system. Some of these factors have been simulated by immersion, blood donation, and changing of the body position.
Main results of the experiments conducted during the flight of the Kosmos-1129 Biosatellite and the status of preparation of studies on the next biosatllite

NASA Technical Reports Server (NTRS)

Ilin, E. A.

1980-01-01

Experiments included studies on the biological effects of weightlessness. Space flight stress, disorientation, and physiological factors are discussed for each experimental subject. The subjects included rats, drosophila flies, and plants. Metabolic rates were monitored along with other changes in the subject's activity cycles.
Nutrition in space

NASA Technical Reports Server (NTRS)

Smith, S. M.; Davis-Street, J.; Rice, B. L.; Lane, H. W.

1997-01-01

The authors review studies conducted to define nutritional requirements for astronauts during space flight and to assess nutrition before, during, and after space flight. Topics include space food systems, research and limitations on spacecraft, physiological adaptation to weightlessness, energy requirements, dietary intake during space flight, bone demineralization, gastrointestinal function, blood volume, and nutrition requirements for space flight. Benefits of space-related nutrition research are highlighted.
Biochemical Assessment of Stress in Cardiac Tissue in Response to Weightless Space Travel

NASA Technical Reports Server (NTRS)

Brunton, Laurence L.; Meszaros, J. Gary; Lio, Francisco M.

1997-01-01

The absence of unit gravity may cause physiological changes in the cardiovascular system. For instance, in the absence of Earth's gravity, venous return to the heart may increase due, in pan, to decreased pooling of the blood in the extremities. We hypothesize that this would produce an increase in the heart's work load ultimately resulting in hypertrophy.
Journal of Gravitational Physiology, Volume 12, Number 1

NASA Technical Reports Server (NTRS)

Fuller, Charles A. (Editor); Cogoli, Augusto (Editor); Hargens, Alan R. (Editor); Smith, Arthur H. (Editor)

2005-01-01

The following topics were covered: System Specificity in Responsiveness to Intermittent -Gx Gravitation during Simulated Microgravity in Rats; A Brief Overview of Animal Hypergravity Studies; Neurovestibular Adaptation to Short Radius Centrifugation; Effect of Artificial Gravity with Exercise Load by Using Short-Arm Centrifuge with Bicycle Ergometer as a Countermeasure Against Disused Osteoporosis; Perception of Body Vertical in Microgravity during Parabolic Flight; Virtual Environment a Behavioral and Countermeasure Tool for Assisted Gesture in Weightlessness: Experiments during Parabolic Flight; Artificial Gravity: Physiological Perspectives for Long-Term Space Exploration; Comparison of the Effects of DL-threo-Beta-Benzyloxyaspartate on the Glutamate Release from Synaptosomes before and after Exposure of Rats to Artificial Gravity; Do Perception and Postrotatory Vestibulo-Ocular Reflex Share the Same Gravity Reference?; Vestibular Adaptation to Changing Gravity Levels and the Orientation of Listing's Plane; Compound Mechanism Hypothesis on +Gz - Induced Brain Injury and Dysfunction of Learning and Memory; Environmental Challenge Impairs Prefrontal Brain Functions; Effect of 6-Days of Support Withdrawal on Characteristics of Balance Function; Hypergravity-Induced Changes of Neuronal Activities in CA1 Region of Rat Hippocampus; Audiological Findings in Antiorthostatic Position Modelling Microgravitation; Investigating Human Cognitive Performance during Spaceflight; The Relevance of the Minimization of Torque Exchange with the Environment in Weightlessness is Confirmed by Asimulation Study; Characteristics of the Eyes Pursuit Function during Readaptation to Terrestrial Gravity after Prolonged Flights Aboard the International Space Station; Comparison of Cognitive Performance Tests for Promethazine Pharmacodynamics in Human Subjects; Structural Reappraisal of Dendritic Tree of Cerebellar Purkinje Cell for Novel Functional Modeling of Elementary Sensorimotor Adaptive Processes; Orpheus 0 G or Ear in Microgravity to Establish Symptoms Concomittant of Inner and Middle Ear and Osteoporosis in Microgravity; Understanding Visual Perception in the Perspective of Gravity; Cortical Regions Associated with Orthostatic Stress in Conscious Humans; Restoration of Central Blood Volume: Application of a Simple Concept and Simple Device to Counteract Cardiovascular Instability in Syncope and Hemorrhage; WISE-2005: Integrative Cardiovascular Responses with LBNP during 60-Day Bed Rest in Women; Intracranial Pressure Increases during Weightlessness. A Parabolic Flights Study; Lower Limb & Portal Veins Echography for Predicting Risk of Thrombosis during a 90-D Bed Rest; Calf Tissue Liquid Stowage and Muscular and Deep Vein Distension in Orthostatic Tests after a 90-Day Head Down Bed Rest; Morphology of Brain Vessels in the Tail Suspended Rats Exposed to Intermittent 2 G; Alterations in Vasoreactivity of Femoral Artery Induced by Hindlimb Unweighting are Related to the Changes of Contractile Protein in Rats; and Respiratory Sinus Arrhythmia: A Marker of Decreased Parasympathetic Modulation after Short Duration.
Potential benefits of maximal exercise just prior to return from weightlessness

NASA Technical Reports Server (NTRS)

Convertino, Victor A.

1987-01-01

The purpose of this study was to determine whether performance of a single maximal bout of exercise during weightlessness within hours of return to earth would enhance recovery of aerobic fitness and physical work capacities under a 1G environment. Ten healthy men were subjected to a 10-d bedrest period in the 6-deg headdown position. A graded maximal supine cycle ergometer test was performed before and at the end of bedrest to simulate exercise during weightlessness. Following 3 h of resumption of the upright posture, a second maximal exercise test was performed on a treadmill to measure work capacity under conditions of 1G. Compared to before bedrest, peak oxygen consumption, V(O2), decreased by 8.7 percent and peak heart rate (HR) increased by 5.6 percent in the supine cycle test at the end of bedrest. However, there were no significant changes in peak V(O2) and peak HR in the upright treadmill test following bedrest. These data suggest that one bout of maximal leg exercise prior to return from 10 d of weightlessness may be adequate to restore preflight aerobic fitness and physical work capacity.

Leaf senescence under various gravity conditions: relevance to the dynamics of plant hormones

NASA Astrophysics Data System (ADS)

Miyamoto, K.; Yuda, T.; Shimazu, T.; Ueda, J.

Effects of simulated microgravity and hypergravity on the senescence of oat leaf segments excised from the primary leaves of 8-d-old green seedlings were studied using a 3-dimensional (D) clinostat as a simulator of weightlessness and a centrifuge, respectively. During the incubation with water under 1-g conditions at 25 °C in the dark, the loss of chlorophyll of the segments was found dramatically immediately after leaf excision, and leaf color completely turned to yellow after 3-d to 4-d incubation. In this case kinetin (10 μM) was effective in retarding senescence. The application of simulated microgravity conditions on a 3-D clinostat enhanced chlorophyll loss in the presence or absence of kinetin. The loss of chlorophyll was also enhanced by hypergravity conditions (ca. 8 to 16 g), but the effect was smaller than that of simulated microgravity conditions on the clinostat. Jasmonates (JAs) and abscisic acid (ABA) promoted senescence under simulated microgravity conditions on the clinostat as well as under 1-g conditions. After 2-d incubation with water or 5-d incubation with kinetin, the endogenous levels of JAs and ABA of the segments kept under simulated microgravity conditions on the clinostat remained higher than those kept under 1-g conditions. These findings suggest that physiological processes of leaf senescence and the dynamics of endogenous plant hormone levels are substantially affected by gravity.
Jernigan and Wolf in Neutral Buoyancy Simulator (NBS)

NASA Technical Reports Server (NTRS)

1995-01-01

Astronauts Tamara Jernigan (#1) and David Wolf (#2) are training in the Neutral Buoyancy Simulator (NBS) at Marshall Space Flight center with an exercise for International Space Station Alpha. The NBS provided the weightless environment encountered in space needed for testing and the practices of Extravehicular Activities (EVA).
Dr. von Braun Tries Out the NBS

NASA Technical Reports Server (NTRS)

1967-01-01

Marshall Space Flight Center (MSFC) Director, Dr. von Braun, is shown fitted with suit and diving equipment as he prepares for a tryout in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.
Weight simulator

NASA Technical Reports Server (NTRS)

Howard, W. H.; Young, D. R.

1972-01-01

Device applies compressive force to bone to minimize loss of bone calcium during weightlessness or bedrest. Force is applied through weights, or hydraulic, pneumatic or electrically actuated devices. Device is lightweight and easy to maintain and operate.
Gravity as a biochemical determinant

NASA Technical Reports Server (NTRS)

Siegel, S. M.

1979-01-01

The existence of obvious morphological and physiological changes in living systems exposed to altered gravity immediately informs us that prior changes have taken place in the chemistry of exposed cells, tissues and organs. These changes include transients that return more or less promptly to the norm when the system is restored to the terrestrial g-field. For example, altered serum hormone and electrolyte levels in man, which appear to reflect successful adaptation to the conditions of orbital weightlessness, disappear shortly after return to Earth. Other changes--in mineral and protein constituents of the skeletal system in man, and cell wall composition in plants--are more persistent or even permanent. Hypogravitational departures from the norm include not only "weightlessness" as achieved in orbit, but also experimental modes of compensation, on the clinostat or by flotation. These techniques are useful in the study of hypogravity but cannot replace fully the weightless environment. Plant ethylene and peroxidase both increase under orbital, clinostat and/or flotation conditions whereas 3-phosphoglyceraldehyde-dehydrogenase increases under orbital but not clinostat conditions; cytochrome reductase and malic dehydrogenase levels are affected by the clinostat, but not by actual weightless conditions. How do the altered organismal biochemistries induced by the centrifuge and the clinostat relate to one another? Does gravity operate on living systems as a continuous variable from 0 to superterrestrial values, or do deviations from g(earth) generate non-uniform, discontinuous stress responses, irrespective of sign? In plants, measurements of wall lignin content and peroxidase activity yield opposite answers. Given the limited data so far available we will consider the meaning of these contradictions.
Biorhythms and space experiments with nonhuman primates

NASA Technical Reports Server (NTRS)

Winget, C. M.

1977-01-01

Man's response to exposure to spaceflight and weightlessness is expressed in physiological adjustments which involve his health and ability to function. The amplitude and periodicity of fluctuations in biological processes affect various functions and responses to provocative stimuli. Primates and other species are subjected to tests to determine the consequences of an altered biorhythm on work and performance, emotional stability, biomedical evaluation in space, the ability to cope with the unexpected, and susceptibility to infection, toxicity, radiation, drugs, and stress. Factors in the environment or operational setup which can change the physiological baseline must be determined and controlled.
Effects of simulated weightlessness and sympathectomy on maximum VO2 of male rats

NASA Technical Reports Server (NTRS)

Woodman, C. R.; Stump, C. S.; Beaulieu, S. M.; Rahman, Z.; Sebastian, L. A.

1989-01-01

The effects of simulated weightlessness (hind-limb suspension) and chemical sympathectomy (by repeated injections with guanethidine sulfate) on the maximum oxygen consumption (VO2 max) of female rats were investigated in rats assigned for 14 days to one of three groups: a head-down hind-limb suspension, a horizontal suspension with hind limbs weight bearing, or the caged control. The VO2 max values were assessed by having rats run on a treadmill enclosed in an airtight chamber. The hind-limb-suspended sympathectomized rats were found to exhibit shorter run times and lower mechanical efficiencies, compared to their presuspension values or the values from saline-injected suspended controls. On the other hand, the suspended sympathectomized rats did not demonstrate a decrease in the VO2 max values that was observed in saline-injected controls.
Ground-facilities at the DLR Institute of Aerospace Medicine for preparation of flight experiments

NASA Astrophysics Data System (ADS)

Hemmersbach, Ruth; Hendrik Anken, Ralf; Hauslage, Jens; von der Wiesche, Melanie; Baerwalde, Sven; Schuber, Marianne

In order to investigate the influence of altered gravity on biological systems and to identify gravisensitive processes, various experimental platforms have been developed, which are useful to simulate weightlessness or are able to produce hypergravity. At the Institute of Aerospace Medicine, DLR Cologne, a broad spectrum of applications is offered to scientists: clinostats with one rotation axis and variable rotation speeds for cultivation of small objects (including aquatic organisms) in simulated weightlessness conditions, for online microscopic observations and for online kinetic measurements. Own research concentrates on comparative studies with other kinds of methods to simulate weightlessness, also available at the institute: Rotating Wall Vessel (RWV) for aquatic studies, Random Positioning Machine (RPM; manufactured by Dutch Space, Leiden, The Netherlands). Correspondingly, various centrifuge devices are available to study different test objects under hypergravity conditions -such as NIZEMI, a slow rotating centrifuge microscope, and MUSIC, a multi-sample centrifuge. Mainly for experiments with human test subjects (artificial gravity), but also for biological systems or for testing various kinds of (flight-) hardware, the SAHC, a short arm human centrifuge -loaned by ESA -was installed in Cologne and completes our experimental scenario. Furthermore, due to our specific tasks such as providing laboratories during the German Parabolic Flight Experiments starting from Cologne and being the Facility Responsible Center for BIOLAB, a science rack in the Columbus module aboard the ISS, scientists have the possibility for an optimal preparation of their flight experiments.
Hypoxia, gas narcosis, and metabolic response to argon and nitrous oxide

NASA Technical Reports Server (NTRS)

1972-01-01

Studies of the mechanism of inert gas influence on metabolism are reported. The studies reported include: metabolic response of hamsters to argon and nitrous oxide, membrane fatty acids and susceptability to narcotic gas influence, narcosis-induced histotoxic hypoxia, biochemical study of inert gas narcosis, hypoxia-induced protection against cardiovascular deterioration in the weightless state, and acute metabolic and physiologic response of goats to narcosis.
The effect of dynamic factors of space flight on animal organisms

NASA Technical Reports Server (NTRS)

Genin, A. M. (Editor)

1979-01-01

Physiological, biochemical and morphological studies made on the Cosmos-782 biosatellite are presented. Rats, which were exposed on the biosatellite for 19.5 days, were examined immediately after completion of the flight and also during the 25 day period of readaptation to earth's conditions. The effect of factors of space flight, primarily weightlessness, on the organism was investigated for all systems of the body.
The Effect of Hindlimb Suspension on the Reproductive System of Young Male Rats

NASA Technical Reports Server (NTRS)

Tou, Janet; Grindeland, R.; Baer, L.; Guran, G.; Fung, C.; Wade, C.; Dalton, Bonnie P. (Technical Monitor)

2001-01-01

Colonization of space requires the ability to reproduce in reduced gravity. Following spaceflight, astronauts and male rats exhibit decreased testosterone (T). This has important implications as T effects the testes and accessory sex glands. To our knowledge no studies have examined the effects of spaceflight on accessory sex glands. Due to the rarity of spaceflight opportunities, ground models have been used to simulate weightlessness. The objective of this study was to determine the effect of long-term (21 d) weightlessness on the reproductive system of male rats. Weightlessness was simulated using the Morey-Holton hindlimb suspension (HLS) model. Age 10 week old, male Sprague-Dawley rats weighing (209.0 +9.7g) were randomly assigned (n=10/group) to either HLS or ambulatory control. In HLS rats, testes mass was 33% lower (p<0.05) than ambulatory controls. However, HLS had no effect on prostate (0.65 +0.09g vs 0.69 +0.12g) or seminal vesicles (1.01 +0.35g vs 0.75 +0.22g) weights compared to controls. The absence of effects on plasma T in this study contrasts previous reports of reduced plasma T in HLS male rats. This discrepancy may have been due to the age of animal and timing of sampling. T levels vary dramatically during testes development as well as within normal diurnal cycles. In young HLS rats, testes weight was reduced but not plasma T. Subsequently there was no effect on accessory sex glands. However, this may not be the case in older rats. More studies using standardized methods are needed to gain a better understanding of male reproduction function and capability in weightlessness. Funding provided by NASA.
Correlation of macro and micro cardiovascular function during weightlessness and simulated weightlessness

NASA Technical Reports Server (NTRS)

Hutchins, P. M.; Marshburn, T. H.; Smith, T. L.; Osborne, S. W.; Lynch, C. D.; Moultsby, S. J.

1988-01-01

The investigation of cardiovascular function necessarily involves a consideration of the exchange of substances at the capillary. If cardiovascular function is compromised or in any way altered during exposure to zero gravity in space, then it stands to reason that microvascular function is also modified. We have shown that an increase in cardiac output similar to that reported during simulated weightlessness is associated with a doubling of the number of post-capillary venules and a reduction in the number of arterioles by 35%. If the weightlessness of space travel produces similar changes in cardiopulmonary volume and cardiac output, a reasonable expectation is that astronauts will undergo venous neovascularization. We have developed an animal model in which to correlate microvascular and systemic cardiovascular function. The microcirculatory preparation consists of a lightweight, thermo-neutral chamber implanted around intact skeletal muscle on the back of a rat. Using this technique, the performed microvasculature of the cutaneous maximus muscle may be observed in the conscious, unanesthetized animal. Microcirculatory variables which may be obtained include venular and arteriolar numbers, lengths and diameters, single vessel flow velocities, vasomotion, capillary hematocrit anastomoses and orders of branching. Systemic hemodynamic monitoring of cardiac output by electromagnetic flowmetry, and arterial and venous pressures allows correlation of macro- and microcirculatory changes at the same time, in the same animal. Observed and calculated hemodynamic variables also include pulse pressure, heart rate, stroke volume, total peripheral resistance, aortic compliance, minute work, peak aortic flow velocity and systolic time interval. In this manner, an integrated assessment of total cardiovascular function may be obtained in the same animal without the complicating influence of anesthetics.
Dr. von Braun Tries Out the Neutral Buoyancy Simulator (NBS)

NASA Technical Reports Server (NTRS)

1967-01-01

Astronaut L. Gordon Cooper checks the neck ring of a space suit worn by Marshall Space Flight Center (MSFC) Director, Dr. von Braun before he submerges into the water of the MSFC Neutral Buoyancy Simulator (NBS). Wearing a pressurized suit and weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.
Fungi in space--literature survey on fungi used for space research.

PubMed

Kern, V D; Hock, B

1993-09-01

A complete review of the scientific literature on experiments involving fungi in space is presented. This review begins with balloon experiments around 1935 which carried fungal spores, rocket experiments in the 1950's and 60's, satellite and moon expeditions, long-time orbit experiments and Spacelab missions in the 1980's and 90's. All these missions were aimed at examining the influence of cosmic radiation and weightlessness on genetic, physiological, and morphogenetic processes. During the 2nd German Spacelab mission (D-2, April/May 1993), the experiment FUNGI provided the facilities to cultivate higher basidiomycetes over a period of 10 d in orbit, document gravimorphogenesis and chemically fix fruiting bodies under weightlessness for subsequent ultrastructural analysis. This review shows the necessity of space travel for research on the graviperception of higher fungi and demonstrates the novelty of the experiment FUNGI performed within the framework of the D-2 mission.
Effects of restraint and cabin environment on skin temperature, sleep-wake, feeding and drinking circadian rhythms in Macaca mulatta during spacelab flight simulation.

PubMed

Demaria-Pesce, V H; Balzamo, E

1994-05-01

Exposure to a weightless environment such as in spaceflight, leads to a number of physiological responses to assure the survival of an organism in this new environment. However, the real effect of microgravity itself has not been clearly established yet. Considering the environmental and operational characteristics of a spaceflight, and as it has been shown in previous flights, the use of animals, and more particularly the non-human primates, takes on importance in understanding the mechanisms and factors involved in the adaptation to changes in gravitational loading. The SLS-3 flight of the American shuttle, scheduled for launch in early 1996, will be the first flight of the Rhesus project, a joint program of C.N.E.S. and N.A.S.A. which will carry out experiments in various physiological disciplines using the Rhesus monkey as a human surrogate. This 16 day orbital flight will be the longest flight accomplished by the shuttle to date. A number of feasibility studies have already been conducted on Macaca mulatta in order to simulate flight conditions to obtain ground data and to test the technical characteristics of the Rhesus Research Facility which have been described elsewhere. Microgravity might be the main factor inducing the physiological changes observed during spaceflights. However, these responses could also be influenced by other factors related to the spaceflight environment such as the life support systems of the spacecraft. Thus, the main purpose of the present study was to determine the impact of specific restraint and cabin environment on the circadian rhythms of body temperature, feeding, drinking, and sleep-waking in order to separate them from the real impact of microgravity.
Effects of chronic acceleration on body composition

NASA Technical Reports Server (NTRS)

Pitts, G. C.

1982-01-01

Studies of the centrifugation of adult rats showed an unexpected decrease in the mass of fat-free muscle and bone, in spite of the added load induced by centrifugation. It is suggested that the lower but constant fat-free body mass was probably regulated during centrifugation. Rats placed in weightless conditions for 18.5 days gave indirect but strong evidence that the muscle had increased in mass. Other changes in the rats placed in weightless conditions included a smaller fraction of skeletal mineral, a smaller fraction of water in the total fat-free body, and a net shift of fluid from skin to viscera. Adult rats centrifuged throughout the post-weaning growth period exhibited smaller masses of bone and central nervous system (probably attributable to slower growth of the total body), and a larger mass of skin than controls at 1 G. Efforts at simulating the effects of weightlessness or centrifugation on the body composition of rats by regimens at terrestrial gravity were inconclusive.
Research on the properties of circadian systems amenable to study in space. [using pocket mice in Skylab experiment S-071 for the study of the effects of prolonged weightlessness

NASA Technical Reports Server (NTRS)

Lindberg, R. G.; Hayden, P.

1974-01-01

Three areas of inquiry are reported for the Skylab Experiment S-071 whose objective was to study the circadian system of a mammal during space flight. The thermoregulatory behavior of the Perognathus longimembris, or little pocket mouse, was studied under conditions of constant dark and constant temperature in the prolonged weightless environment of Skylab. The following specific questions were studied: (1) the effects of weightlessness on circadian periodicity in the little pocket mouse; (2) stability of the free-running circadian period of body temperature of the little pocket mouse exposed to simulated launch stress; and (3) characteristics of the circadian rhythm of body temperature in the little pocket mouse. Diagrams of the electronic circuitry and hardware used in the experiment are shown and results are given in both graphical and tabular form. The methods used in the experiment are fully documented, along with conclusions and recommendations for future research.
Changes of brain response induced by simulated weightlessness

NASA Astrophysics Data System (ADS)

Wei, Jinhe; Yan, Gongdong; Guan, Zhiqiang

The characteristics change of brain response was studied during 15° head-down tilt (HDT) comparing with 45° head-up tilt (HUT). The brain responses evaluated included the EEG power spectra change at rest and during mental arithmetic, and the event-related potentials (ERPs) of somatosensory, selective attention and mental arithmetic activities. The prominent feature of brain response change during HDT revealed that the brain function was inhibited to some extent. Such inhibition included that the significant increment of "40Hz" activity during HUT arithmetic almost disappeared during HDT arithmetic, and that the positive-potential effect induced by HDT presented in all kinds of ERPs measured, but the slow negative wave reflecting mental arithmetic and memory process was elongated. These data suggest that the brain function be affected profoundly by the simulated weightlessness, therefore, the brain function change during space flight should be studied systematically.
Rheoceptive mediators of graviperception in a water flea: Morphological implications of antennal-socket setae in daphnia magna

NASA Technical Reports Server (NTRS)

Meyers, D. G.

1984-01-01

Aquatic microcrustaceans of the genus Daphnia are known to orient to light during the day. At night, in the absence of visual cues, daphnids were suspected of maintaining equilibrium by monitoring the direction of gravity through their swimming antennae. Recent investigations using simulated, weightlessness conditions coupled with absence of illumination revealed hair like structures or setae on the basal, articulating socket of the antennae that, when surgically removed, resulted in disorientation. Given the simulated weightlessness or neutrally buoyant condition that eliminated sinking of the normally negatively buoyant Daphnia, it was proposed that the antennal socket setae function as rheoceptors stimulated by the upward rush of water currents during gravity induced, sinking phase of daphnid swimming movements. This rheoceptively mediated, gravity perception hypothesis is further supported by morphological investigations. Scanning electron micrographs indicate that antennal socket setae are anatomically similar to proprioceptors used by higher crustaceans to monitor gravitational direction.
Effect of simulated weightlessness on energy metabolism in the rat

NASA Technical Reports Server (NTRS)

Jordan, J. P.; Sykes, H. A.; Crownover, J. C.; Schatte, C. L.; Simmons, J. B., II; Jordan, D. P.

1982-01-01

Results of measurements of food uptake and body weight changes occurring in rats suspended from a harness so that the antigravity muscles were not used for locomotion are presented. The rats were tested in pairs, with both in a harness but only one suspended off its hind legs; this section lasted 7 days. A second phase of the experiment involved feeding the nonsuspended rat the same amount of food the experimental rat had consumed the previous day. All rats experienced decreased in body weight and food intake in the first stage, while in the second stage the suspended rat lost more weight. The total oxygen uptake, CO2 output, and rate of C-14O2 production were depressed in the suspended rats, then returned to normal levels once the rats were back on the ground. It is concluded that the gross metabolic processes are unaffected by simulated weightlessness.

The effects of horizontal body casting on blood volume, drug responsiveness, and +Gz tolerance in the rhesus monkey

NASA Technical Reports Server (NTRS)

Dickey, D. T.; Billman, G. E.; Teoh, K.; Sandler, H.; Stone, H. L.

1982-01-01

To simulate the weightless condition, eight rhesus monkeys, instrumented with solid-state pressure transducers, were horizontally restrained in body casts for 28 days. Blood volume decreased an average of 13% after 14 days of restraint, due mainly to a drop in plasma volume. Aortic pressure and heart rate responses to norepinephrine and phenylephrine decreased after 14 days of restraint. The monkeys did not show a statistically significant decreased tolerance to a 90 deg sudden upright tilt after horizontal restraint. During the fifth week of casting, four animals were subjected to +Gz acceleration tests on a centrifuge. The acceleration tolerance of the casted monkeys was significantly reduced compared to four similarly instrumented control animals. These findings indicate that the cardiovascular deconditioning associated with simulated weightlessness results from an inability to maintain central blood volume during orthostatic stress.
Group Housing During Hindlimb Unloading to Simulate Weightlessness

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Lowe, Moniece; Steczina, Sonette; Torres, Samantha; Terada, Masahiro; Schreurs, Ann-Sofie; Ronca, April; Alwood, Joshua; Globus, Ruth K.

2017-01-01

The rodent hindlimb unloading (HU) model was developed in the 1980s to faciliate the study of mechanisms, responses, and treatments for the adverse effects of spaceflight. A number of variations on unloading systems and cage designs have been developed, although most entail individually housing the HU animals. In this study, we performed hindlimb unloading under group housing conditions. Our preliminary results indicate that HU animals that were group housed for 30 days, displayed musculoskeletal decrements associated with disuse, and further, body weights did not differ compared to age-matched controls. In conclusion, group housing of HU mice provides a novel means to simulate weightlessness under conditions that more closely resemble living conditions of Rodent Research Project ISS flight hardware habitats, and minimizes the social stress of isolation, which is consistent with current animal welfare standards (Guide for the Care and Use of Laboratory Animals: Eighth Edition, National Research Council).
Clinostats and bioreactors.

PubMed

Klaus, D M

2001-06-01

The environment created on Earth within a clinostat or Rotating Wall Vessel (RWV) bioreactor is often referred to as "simulated microgravity". Both devices utilize constant reorientation to effectively nullify cumulative sedimentation of particles. Neither, however, can fully reproduce the concurrent lack of structural deformation, displacement of intercellular components and/or reduced mass transfer in the extracellular fluid that occur in actual weightlessness. Parameters including density, viscosity, and even container geometry must each be considered to determine the overall gravity-dependent effects produced by either a clinostat or the RWV bioreactor; in addition, the intended application of these two devices differs considerably. A state of particle "motionlessness" relative to the surrounding bulk fluid, which is nearly analogous to the extracellular environment encountered under weightless conditions, can theoretically be achieved through clinorotation. The RWV bioreactor, on the other hand, while similarly maintaining cells in suspension as they continually "fall" through the medium under 1 g conditions, can also purposefully induce a perfusion of nutrients to and waste from the culture. A clinostat, therefore, is typically used in an attempt to reproduce the quiescent, unstirred fluid conditions achievable on orbit; while the RWV bioreactor ideally creates a low shear, but necessarily mixed, fluid environment that is optimized for suspension culture and tissue growth. Other techniques for exploring altered inertial environments, such as freefall, neutral buoyancy and electromagnetic levitation, can also provide unique insight into how gravity affects biological systems. Ultimately, all underlying biophysical principles thought to give rise to gravity-dependent physiological responses must be identified and thoroughly examined in order to accurately interpret data from flight experiments or ground-based microgravity analogs.
Intake of Fish and Omega-3 (N-3) Fatty Acid: Effect on Humans during Actual and Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Mehta, Satish K.; Pierson, Duane L.; Zwart, Sara R.

2009-01-01

Space flight has many negative effects on human physiology, including bone and muscle loss. These are some of the systems on which intakes of fish and n-3 fatty acids have positive effects. These effects are likely to occur through inhibition of inflammatory cytokines (such as TNFalpha) and thus inhibition of downstream NF-KB activation. We documented this effect in a 3D cell culture model, where NF-KB activation in osteoclasts was inhibited by eicosapentaenoic acid, an n-3 fatty acid. We have extended these studies and report here (a) NF-KB expression in peripheral blood mononuclear cells of Space Shuttle crews on 2-wk missions, (b) the effects of n-3 fatty acid intake after 60 d of bed rest (a weightlessness analog), and (c) the effects of fish intake in astronauts after 4 to 6 mo on the International Space Station. After Shuttle flights of 2 wk, NFKB p65 expression at landing was increased (P less than 0.001). After 60 d of bed rest, higher intake of n-3 fatty acids was associated with less N-telopeptide excretion (Pearson r = -0.62, P less than 0.05). Higher consumption of fish during flight was associated with higher bone mineral density (Pearson r = -0.46, P less than 0.05). Together with our earlier findings, these data provide mechanistic cellular and preliminary human evidence of the potential for n-3 fatty acids to counteract bone loss associated with spaceflight. This study was supported by the NASA Human Research Program.
Space flight research relevant to health, physical education, and recreation: With particular reference to Skylab's life science experiments

NASA Technical Reports Server (NTRS)

Vanhuss, W. D.; Heusner, W. W.

1979-01-01

Data collected in the Skylab program relating to physiological stresses is presented. Included are routine blood measures used in clinical medicine as research type endocrine analyses to investigate the metabolic/endocrine responses to weightlessness. The daily routine of physical exercise, coupled with appropriate dietary intake, sleep, work, and recreation periods were considered essential in maintaining the crew's health and well being.
Study of Histopathological and Molecular Changes of Rat Kidney under Simulated Weightlessness and Resistance Training Protective Effect

PubMed Central

Li, Zhili; Tian, Jijing; Abdelalim, Saed; Du, Fang; She, Ruiping; Wang, Desheng; Tan, Cheng; Wang, Huijuan; Chen, Wenjuan; Lv, Dongqiang; Chang, Lingling

2011-01-01

To explore the effects of long-term weightlessness on the renal tissue, we used the two months tail suspension model to simulate microgravity and investigated the simulated microgravity on the renal morphological damages and related molecular mechanisms. The microscopic examination of tissue structure and ultrastructure was carried out for histopathological changes of renal tissue morphology. The immunohistochemistry, real-time PCR and Western blot were performed to explore the molecular mechanisms associated the observations. Hematoxylin and eosin (HE) staining showed severe pathological kidney lesions including glomerular atrophy, degeneration and necrosis of renal tubular epithelial cells in two months tail-suspended rats. Ultrastructural studies of the renal tubular epithelial cells demonstrated that basal laminas of renal tubules were rough and incrassate with mitochondria swelling and vacuolation. Cell apoptosis in kidney monitored by the expression of Bax/Bcl-2 and caspase-3 accompanied these pathological damages caused by long-term microgravity. Analysis of the HSP70 protein expression illustrated that overexpression of HSP70 might play a crucial role in inducing those pathological damages. Glucose regulated protein 78 (GRP78), one of the endoplasmic reticulum (ER) chaperones, was up-regulated significantly in the kidney of tail suspension rat, which implied that ER-stress was associated with apoptosis. Furthermore, CHOP and caspase-12 pathways were activated in ER-stress induced apoptosis. Resistance training not only reduced kidney cell apoptosis and expression of HSP70 protein, it also can attenuate the kidney impairment imposed by weightlessness. The appropriate optimization might be needed for the long term application for space exploration. PMID:21625440
Research on the effects of altered gravity and other factors on the growth and development of higher plants

NASA Technical Reports Server (NTRS)

Brown, A. H.

1973-01-01

The establishment, maintenance and use of the NASA-UCSC Botanical Centrifuge is discussed. The broad goals of this project were: (1) to establish facilities for conducting experiments under conditions of sustained centrifugation; (2) to pursue research on the gravitational physiology of higher plants; (3) to develop experimental hardware suitable for studies of plant development in the weightless condition; and (4) to accommodate visiting investigators whose researches are of interest to the NASA Biomedical Program and who may require for some limited time, the use of a medium size centrifuge with associated facilities appropriate for plant physiological studies.
Pharmacokinetics and Pharmacodynamics in Space

NASA Technical Reports Server (NTRS)

Putcha, Lakshmi; Cintron, Nitza M.

1990-01-01

The Pharmacokinetics and Pharmacodynamics Panel met on 29-30 Aug. 1988 at the Lunar and Planetary Institute in Houston, Texas to discuss pharmacokinetic and pharmacodynamic implications of space flight and make recommendations for operational and research strategies. Based on the knowledge available on the physiological changes that occur during space flight, the dependence of pharmacokinetics on physiological factors, and the therapeutic requirements for future space missions, the panel made several recommendations for research. It was suggested that using medications available with a large (wide) therapeutic window will avoid unforeseen therapeutic consequences during flight. The sequence for conducting research was outlined as follows: (1) identify ground-based simulation models (e.g., antiorthostatic bed rest) for conducting pharmacokinetic and pharmacodynamic research; (2) estimate parametric changes in these models using pharmacologic agents that have different pharmacokinetic characteristics and a narrow therapeutic index; (3) verify these findings during flight; and (4) develop and identify appropriate and effective drug delivery systems, dosage forms, and regimens. The panel recommended gaining a thorough understanding of the pharmacokinetic deviations of medications that have a narrow therapeutic index (e.g. cardiovascular drugs and sedative hypnotics) in order to ensure safe and effective treatment during flight with these agents. It was also suggested that basic information on physiological factors such as organ blood flow, protein composition and binding, tissue distribution, and metabolism by hepatic enzymes must be accumulated by conducting ground-based animal and human studies using models of weightlessness. This information will be useful to construct and identify physiologically based pharmacokinetic models that can provide valuable information on the pharmacodynamic consequences of space flight and aid in identifying appropriate therapeutic regimens.
Skeletal Micro-RNA Responses to Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Thomas, Nicholas J.; Choi, Catherine Y.; Alwood, Joshua S.

2016-01-01

Astronauts lose bone structure during long-duration spaceflight. These changes are due, in part, to insufficient bone formation by the osteoblast cells. Little is known about the role that small (approximately 22 nucleotides), non-coding micro-RNAs (miRNAs) play in the osteoblast response to microgravity. We hypothesize that osteoblast-lineage cells alter their miRNA status during microgravity exposure, contributing to impaired bone formation during weightlessness. To simulate weightlessness, female mice (C57BL/6, Charles River, 10 weeks of age, n = 7) were hindlimb unloaded up to 12 days. Age-matched and normally ambulating mice served as controls (n=7). To assess the expression of miRNAs in skeletal tissue, the tibia was collected ex vivo and cleaned of soft-tissue and marrow. Total RNA was collected from tibial bone and relative abundance was measured for miRNAs of interest using quantitative real time PCR array looking at 372 unique and well-characterized mature miRNAs using the delta-delta Ct method. Transcripts of interest were normalized to an average of 6 reference RNAs. Preliminary results show that hindlimb unloading decreased the expression of 14 miRNAs to less than 0.5 times that of the control levels and increased the expression of 5 miRNAs relative to the control mice between 1.2-1.5-fold (p less than 0.05, respectively). Using the miRSystem we assessed overlapping target genes predicted to be regulated by multiple members of the 19 differentially expressed miRNAs as well as in silico predicted targets of our individual miRNAs. Our miRsystem results indicated that a number of our differentially expressed miRNAs were regulators of genes related to the Wnt-Beta Catenin pathway-a known regulator of bone health-and, interestingly, the estrogen-mediated cell-cycle regulation pathway, which may indicate that simulated weightlessness modulated systemic hormonal levels or hormonal transduction that additionally contributed to bone loss. We plan to follow up these findings by measuring gene expression of miRNA-regulated genes within these two pathways with the aim of furthering our understanding of the function of miRNAs in the skeletal response to spaceflight.
Effects of Simulated Microgravity on Otolith Growth of Larval Zebrafish using a Rotating-Wall Vessel: Appropriate Rotation Speed and Fish Developmental Stage

NASA Astrophysics Data System (ADS)

Li, Xiaoyan; Anken, Ralf; Liu, Liyue; Wang, Gaohong; Liu, Yongding

2017-02-01

Stimulus dependence is a general feature of developing animal sensory systems. In this respect, it has extensively been shown earlier that fish inner ear otoliths can act as test masses as their growth is strongly affected by altered gravity such as hypergravity obtained using centrifuges, by (real) microgravity achieved during spaceflight or by simulated microgravity using a ground-based facility. Since flight opportunities are scarce, ground-based simulators of microgravity, using a wide variety of physical principles, have been developed to overcome this shortcoming. Not all of them, however, are equally well suited to provide functional weightlessness from the perspective of the biosystem under evaluation. Therefore, the range of applicability of a particular simulator has to be extensively tested. Earlier, we have shown that a Rotating-Wall Vessel (RWV) can be used to provide simulated microgravity for developing Zebrafish regarding the effect of rotation on otolith development. In the present study, we wanted to find the most effective speed of rotation and identify the appropriate developmental stage of Zebrafish, where effects are the largest, in order to provide a methodological basis for future in-depth analyses dedicated to the physiological processes underlying otolith growth at altered gravity. Last not least, we compared data on the effect of simulated microgravity on the size versus the weight of otoliths, since the size usually is measured in related studies due to convenience, but the weight more accurately approximates the physical capacity of an otolith. Maintaining embryos at 10 hours post fertilization for three days in the RWV, we found that 15 revolutions per minute (rpm) yielded the strongest effects on otolith growth. Maintenance of Zebrafish staged at 10 hpf, 1 day post fertilization (dpf), 4 dpf, 7 dpf and 14 dpf for three days at 15 rpm resulted in the most prominent effects in 7 dpf larvae. Weighing versus measuring the size of otoliths yielded basically similar results, but the data gained by weighing were more distinct. Overall, our results clearly support the concept that the environmental gravity vector regulates fish otolith growth in terms of the pendulum model of otolith test masses, and that wall vessel rotation is a valuable means to provide functional weightlessness from the perspective of developing Zebrafish. We recommend that Zebrafish embryos staged 7 dpf (or possibly slightly elder) are rotated at 15 rpm in a Rotating-Wall Vessel as used in the present study for further experiments designed to elucidate the mechanisms underlying (altered gravity affected) otolith growth.
Venous gas emboli and exhaled nitric oxide with simulated and actual extravehicular activity.

PubMed

Karlsson, Lars L; Blogg, S Lesley; Lindholm, Peter; Gennser, Mikael; Hemmingsson, Tryggve; Linnarsson, Dag

2009-10-01

The decompression experienced due to the change in pressure from a space vehicle (1013hPa) to that in a suit for extravehicular activity (EVA) (386hPa) was simulated using a hypobaric chamber. Previous ground-based research has indicated around a 50% occurrence of both venous gas emboli (VGE) and symptoms of decompression illness (DCI) after similar decompressions. In contrast, no DCI symptoms have been reported from past or current space activities. Twenty subjects were studied using Doppler ultrasound to detect any VGE during decompression to 386hPa, where they remained for up to 6h. Subjects were supine to simulate weightlessness. A large number of VGE were found in one subject at rest, who had a recent arm fracture; a small number of VGE were found in another subject during provocation with calf contractions. No changes in exhaled nitric oxide were found that can be related to either simulated EVA or actual EVA (studied in a parallel study on four cosmonauts). We conclude that weightlessness appears to be protective against DCI and that exhaled NO is not likely to be useful to monitor VGE.
Water immersion and its computer simulation as analogs of weightlessness

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1982-01-01

Experimental studies and computer simulations of water immersion are summarized and discussed with regard to their utility as analogs of weightlessness. Emphasis is placed on describing and interpreting the renal, endocrine, fluid, and circulatory changes that take place during immersion. A mathematical model, based on concepts of fluid volume regulation, is shown to be well suited to simulate the dynamic responses to water immersion. Further, it is shown that such a model provides a means to study specific mechanisms and pathways involved in the immersion response. A number of hypotheses are evaluated with the model related to the effects of dehydration, venous pressure disturbances, the control of ADH, and changes in plasma-interstitial volume. By inference, it is suggested that most of the model's responses to water immersion are plausible predictions of the acute changes expected, but not yet measured, during space flight. One important prediction of the model is that previous attempts to measure a diuresis during space flight failed because astronauts may have been dehydrated and urine samples were pooled over 24-hour periods.
Space research on organs and tissues

NASA Technical Reports Server (NTRS)

Tischler, Marc E.; Morey-Holton, Emily

1992-01-01

The effects of microgravity on various physiological systems are reviewed focusing on muscle, bone, cardiovascular, pulmonary, neurovestibular, liver, and endocrine systems. It is noted that certain alterations of organs and tissues caused by microgravity are not reproducible in earth-bound animal or human models. Thus space research on organs and tissues is essential for both validating the earth-bound models used in laboratories and studying the adaptations to weightlessness which cannot be mimicked on earth.
Astronaut Bonnie Dunbar watches crewmates during training

NASA Technical Reports Server (NTRS)

1994-01-01

Astronaut Bonnie J. Dunbar, STS-71 mission specialist, smiles as she watches a crew mate (out of frame) make a simulated parachute landing in nearby water. The action came as part of an emergency bailout training session in the JSC Weightless Environment
Cosmonaut Vladimir Titov participates in bail-out training for STS-60

NASA Technical Reports Server (NTRS)

1993-01-01

Cosmanaut Vladimir Titov, an alternate mission specialist for STS-60, simulates a parachute glide into water during a bailout training exercise at JSC. This phase of emergency egress training took place in JSC's Weightless Environment Training Facility (WETF).
Cosmonaut Vladimir Titov participates in bail-out training for STS-60

NASA Image and Video Library

1993-07-16

Cosmanaut Vladimir Titov, an alternate mission specialist for STS-60, simulates a parachute glide into water during a bailout training exercise at JSC. This phase of emergency egress training took place in JSC's Weightless Environment Training Facility (WETF).
[Electron microscope analysis of cardiomyocytes in the rat left ventricle under simulation of weightlessness effects and artificial gravitation].

PubMed

Varenik, E N; Lipina, T V; Shornikova, M V; Krasnov, I B; Chentsov, Iu S

2012-01-01

Electron microscopic study of left ventricle cardiomyocytes and quantitative analysis of their mitochondriom was performed in rats exposed to tail-suspension, as a model of weightlessness effects, to artificial gravity produced by intermittent 2G centrifugation and a combination of these effects. It was found that the cardiomyocytes ultrastructure changed slightly after tail-suspension and after intermittent 2G influence, as well as under a combination of these effects. However, the number of intermitochondrial junctions increased significantly in the interfibrillar zone of cardiomyocytes under a combination of tail-suspension and intermittent 2G influence, which agrees with the cell hypertrophy described earlier.
Validation of a model for investigating red cell mass changes during weightlessness

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1976-01-01

The model, both the conceptual model and simulation model, provided a convenient framework on which to demonstrate the commonality between such diverse stresses as descent from altitude, red cell infusions, bed rest, and weightlessness. The results suggest that all of these stresses induce an increased blood hematocrit leading to tissue hyperoxia and eventual inhibition of the erythyocyte producing circuit until the hyperoxic condition is relieved. The erythropoietic system was acting, in these situations, as if it were an hematocrit sensor and regulator. In these terms the decreases in red cell mass during Skylab may be explained in terms of normal feedback regulation of the erythropoietic system in the face of sustained decreases in plasma colume.
Neurovestibular and Sensorimotor Studies in Space and Earth Benefits

NASA Technical Reports Server (NTRS)

Clement, Gilles; Reschke, Millard; Wood, Scott

2005-01-01

This review summarizes what has been learned from studies of human neurovestibular system in weightless conditions, including balance and locomotion, gaze control, vestibular-autonomic function and spatial orientation, and gives some examples of the potential Earth benefits of this research. Results show that when astronauts and cosmonauts return from space flight, both the peripheral and central neural processes are physiologically and functionally altered. There are clear distinctions between the virtually immediate adaptive compensations to weightlessness and those that require longer periods of time to adapt. However, little is known to date about the adaptation of sensory-motor functions to long-duration space missions in weightlessness and to the transitions between various reduced gravitational levels, such as on the Moon and Mars. Results from neurovestibular research in space have substantially enhanced our understanding of the mechanisms and characteristics of postural, gaze, and spatial orientation deficits, analogous to clinical cases of labyrinthine-defective function. Also, space neurosciences research has participated in the development and application of significant new technologies, such as video recording and processing of three-dimensional eye movements and posture, hardware for the unencumbered measurement of head and body movement, and procedures for investigating otolith function on Earth. In particular, devices such as centrifugation or off-vertical axis rotation could enhance clinical neurological testing because it provides linear acceleration which specifically stimulates the otolith organs in a frequency range close to natural head and body movement.
Neurovestibular and sensorimotor studies in space and Earth benefits.

PubMed

Clément, Gilles; Reschke, Millard; Wood, Scott

2005-08-01

This review summarizes what has been learned from studies of human neurovestibular system in weightless conditions, including balance and locomotion, gaze control, vestibular-autonomic function and spatial orientation, and gives some examples of the potential Earth benefits of this research. Results show that when astronauts and cosmonauts return from space flight both the peripheral and central neural processes are physiologically and functionally altered. There are clear distinctions between the virtually immediate adaptive compensations to weightlessness and those that require longer periods of time to adapt. However, little is known to date about the adaptation of sensory-motor functions to long-duration space missions in weightlessness and to the transitions between various reduced gravitational levels, such as on the Moon and Mars. Results from neurovestibular research in space have substantially enhanced our understanding of the mechanisms and characteristics of postural, gaze, and spatial orientation deficits, analogous to clinical cases of labyrinthine-defective function. Also, space neurosciences research has participated in the development and application of significant new technologies, such as video recording and processing of three-dimensional eye movements and posture, hardware for the unencumbered measurement of head and body movement, and procedures for investigating otolith function on Earth. In particular, devices such as centrifugation or off-vertical axis rotation could enhance clinical neurological testing because it provides linear acceleration which specifically stimulates the otolith organs in a frequency range close to natural head and body movement.

Physiological monitoring of team and task stressors

NASA Astrophysics Data System (ADS)

Orasanu, Judith; Tada, Yuri; Kraft, Norbert; Fischer, Ute

2005-05-01

Sending astronauts into space, especially on long-durations missions (e.g. three-year missions to Mars), entails enormous risk. Threats include both physical dangers of radiation, bone loss and other consequences of weightlessness, and also those arising from interpersonal problems associated with extended life in a high-risk isolated and confined environment. Before undertaking long-duration missions, NASA seeks to develop technologies to monitor indicators of potentially debilitating stress at both the individual and team level so that countermeasures can be introduced to prevent further deterioration. Doing so requires a better understanding of indicators of team health and performance. To that end, a study of team problem solving in a simulation environment was undertaken to explore effects of team and task stress. Groups of four males (25-45 yrs) engaged in six dynamic computer-based Antarctic search and rescue missions over four days. Both task and team stressors were manipulated. Physiological responses (ECG, respiration rate and amplitude, SCL, EMG, and PPG); communication (voice and email); individual personality and subjective team dynamics responses were collected and related to task performance. Initial analyses found that physiological measures can be used to identify transient stress, predict performance, and reflect subjective workload. Muscle tension and respiration were the most robust predictors. Not only the level of arousal but its variability during engagement in the task is important to consider. In general, less variability was found to be associated with higher levels of performance. Individuals scoring high on specific personality characteristics responded differently to task stress.
Six-Degree Head-Down Tilt Bed Rest: Forty Years of Development as a Physiological Analog for Weightlessness

NASA Technical Reports Server (NTRS)

Smith, Jeffrey D.; Cromwell, Ronita L.; Kundrot, Craig E.; Charles, John B.

2011-01-01

Early on, bed rest was recognized as a method for inducing many of the physiological changes experienced by spaceflight. Head-down tilt (HDT) bed rest was first introduced as an analog for spaceflight by a Soviet team led by Genin and Kakurin. Their study was performed in 1970 (at -4 degrees) and lasted for 30 days; results were reported in the Russian Journal of Space Biology (Kosmicheskaya Biol. 1972; 6(4): 26-28 & 45-109). The goal was to test physiological countermeasures for cosmonauts who would soon begin month-long missions to the Salyut space station. HDT was chosen to produce a similar sensation of blood flow to the head reported by Soyuz cosmonauts. Over the next decade, other tilt angles were studied and comparisons with spaceflight were made, showing that HDT greater than 4 degrees was superior to horizontal bed rest for modeling acute physiological changes observed in space; but, at higher angles, subjects experienced greater discomfort without clearly improving the physiological comparison to spaceflight. A joint study performed by US and Soviet investigators, in 1979, set the goal of standardization of baseline conditions and chose 6-degrees HDT. This effectively established 6-degree HDT bed rest as the internationally-preferred analog for weightlessness and, since 1990, nearly all further studies have been conducted at 6-degrees HDT. A thorough literature review (1970-2010) revealed 534 primary scientific journal articles which reported results from using HDT as a physiological analog for spaceflight. These studies have ranged from as little as 10 minutes to the longest duration of 370 days. Long-term studies lasting four weeks or more have resulted in over 170 primary research articles. Today, the 6-degree HDT model provides a consistent, thoroughly-tested, ground-based analog for spaceflight and allows the proper scientific controls for rigorous testing of physiological countermeasures; however, all models have their strengths and limits. The 6-degrees HDT model must continue to be scrutinized, re-examined, validated and compared to other analog environments whenever possible. Only by understanding the strengths and limits of this model, will it continue to serve as a critical physiological analog to spaceflight for many more years to come.
Testing of the Japanese Experimental Module in NBS

NASA Technical Reports Server (NTRS)

1993-01-01

This photograph was taken in the Marshall Space Flight Center (MSFC) Neutral Buoyancy Simulator (NBS) during the testing of the Japanese Experimental Module. The NBS provided the weightless environment encountered in space needed for testing and the practices of extra-vehicular activities.
Astronaut Bonnie Dunbar wearing extravehicular mobility unit

NASA Technical Reports Server (NTRS)

1985-01-01

Astronaut Bonnie J. Dunbar, wearing an extravehicular mobility unit (EMU), is about to be submerged in the weightless environment training facility (WETF) to simulate a contingency extravehicular activity (EVA) for STS 61-A. In this portrait view, Dunbar is not wearing a helmet.
Effects of weightlessness on body composition in the rat

NASA Technical Reports Server (NTRS)

Pitts, G. C.; Ushakov, A. S.; Pace, N.; Smith, A. H.; Rahlmann, D. F.; Smirnova, T. A.

1983-01-01

The effects of weightlessness on the body composition of rats were investigated using 5 male rats exposed to 18.5 days of weightlessness on the COSMOS 1129 biosatellite and killed after reentry. The animals were immediately dissected and the three major body divisions (musculoskeletal system, skin, and pooled viscera) were analyzed for fat, water, solids, and six elements. These results were determined as percentages of the fat-free body or its components and then compared with two groups of terrestrial controls, one of which was subjected to a flight simulation in a spacecraft mock-up while the other was under standard vivarium conditions. Compared with the control groups, the flight group was found to exhibit a reduced fraction of total body water, a net shift of body water from skin to viscera, a marked diminution in the fraction of extracellular water in the fat-free body, a marked reduction in the fraction of bone mineral, no change in the quantity of stored fat or adrenal masses, and a net increase in total muscle mass as indicated by total body creatine, protein, and body cell mass.
STS-26 Pilot Covey floats in life raft during JSC WETF exercises

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing newly designed launch and entry suit (LES), floats in single-occupant life raft during simulations in the JSC Weightless Environment Training Facility Bldg 29 pool. During the simulation of escape and rescue operations, the crew escape system (CES) pole mode of egress from the Space Shuttle was utilized.
Synergistic Effects of Incubation in Rotating Bioreactors and Cumulative Low Dose 60Co γ-ray Irradiation on Human Immortal Lymphoblastoid Cells

NASA Astrophysics Data System (ADS)

Wei, Lijun; Han, Fang; Yue, Lei; Zheng, Hongxia; Yu, Dan; Ma, Xiaohuan; Cheng, Huifang; Li, Yu

2012-11-01

The complex space environments can influence cell structure and function. The research results on space biology have shown that the major mutagenic factors in space are microgravity and ionizing radiation. In addition, possible synergistic effects of radiation and microgravity on human cells are not well understood. In this study, human immortal lymphoblastoid cells were established from human peripheral blood lymphocytes and the cells were treated with low dose (0.1, 0.15 and 0.2 Gy) cumulative 60Co γ-irradiation and simulated weightlessness [obtained by culturing cells in the Rotating Cell Culture System (RCCS)]. The commonly used indexes of cell damage such as micronucleus rate, cell cycle and mitotic index were studied. Previous work has proved that Gadd45 (growth arrest and DNA-damage-inducible protein 45) gene increases with a dose-effect relationship, and will possibly be a new biological dosimeter to show irradiation damage. So Gadd45 expression is also detected in this study. The micronucleus rate and the expression of Gadd45α gene increased with irradiation dose and were much higher after incubation in the rotating bioreactor than that in the static irradiation group, while the cell proliferation after incubation in the rotating bioreactor decreased at the same time. These results indicate synergetic effects of simulated weightlessness and low dose irradiation in human cells. The cell damage inflicted by γ-irradiation increased under simulated weightlessness. Our results suggest that during medium- and long-term flight, the human body can be damaged by cumulative low dose radiation, and the damage will even be increased by microgravity in space.
Orbiting Frog Otolith experiment (OFO-A): Data reduction and control experimentation

NASA Technical Reports Server (NTRS)

Gualtierotti, T.; Bracchi, F.; Rocca, E.

1972-01-01

The OFO-A mission was prepared as a part of a special program of vestibular physiology with the purpose of studying in which way the lack of the gravity pull will affect the functioning of that part of the labyrinth which controls balance. The gravitational components corresponded to the different head positions, namely, the gravity sensitive or positioning receptors. It is evident that in weightlessness the gravity sensitive receptors are deprived of their primary input.
Intake of Fish and Omega-3 (n-3) Fatty Acids: Effect on Humans During Actual and Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Smith, S. M.; Pierson, D. L.; Mehta, S. K.; Zwart, S. R.

2011-01-01

Space flight has many negative effects on human physiology, including bone and muscle loss. Bone and muscle are two systems that are positively affected by dietary intake of fish and n-3 fatty acids. The mechanism is likely to be related to inhibition by n-3 fatty acids of inflammatory cytokines (such as TNF) and thus inhibition of downstream NF-kB activation. We have documented this effect in a 3-dimensional cell culture model, where NF-kB activation in osteoclasts was inhibited by eicosapentaenoic acid, an n-3 fatty acid. We have also indentified that NF-kB activation in peripheral blood mononuclear cells of Space Shuttle crews. We found that after Shuttle flights of 2 wk, expression of the protein p65 (evidence of NF-kB activation) was increased at landing (P less than 0.001). When evaluating the effects of n-3 fatty acid intake on bone breakdown after 60 d of bed rest (a weightlessness analog). We found that after 60 d of bed rest, greater intake of n-3 fatty acids was associated with less N-telopeptide excretion (Pearson r = -0.62, P less than 0.05). We also evaluated the relationship of fish intake and bone loss in astronauts after 4 to 6 mo missions on the International Space Station. Higher consumption of fish during flight was associated with higher bone mineral density (Pearson r = 0.46, P less than 0.05). Together, these findings provide evidence of the cellular mechanism by which n-3 fatty acids can inhibit bone loss, and preliminary human evidence of the potential for n-3 fatty acids to counteract bone loss associated with space flight. This study was supported by the NASA Human Research Program.
Astronaut James Buchli wearing extravehicular mobility unit

NASA Technical Reports Server (NTRS)

1985-01-01

Astronaut James F. Buchli, wearing an extravehicular mobility unit (EMU), is about to be submerged in the weightless environment training facility (WETF) to simulate a contingency extravehicular activity (EVA) for STS 61-A. In this portrait view, Buchli is wearing a communications carrier assembly (CCA).
Underwater EVA training in the WETF with astronaut Robert L. Stewart

NASA Technical Reports Server (NTRS)

1983-01-01

Underwater extravehicular activity (EVA) training in the weightless environment training facility (WETF) with astronaut Robert L. Stewart. Stewart is simulating a planned EVA using the mobile foot restraint device and a one-G version of the Canadian-built remote manipulator system.
Residual nutational activity of the sunflower hypocotyl in simulated weightlessness

NASA Technical Reports Server (NTRS)

Chapman, D. K.; Brown, A. H.

1979-01-01

The gravity dependence of circumnutational activity in the sunflower hypocotyl is investigated under conditions of simulated weightlessness. Seedling cultures of the sunflower Helianthus annuus were placed four days after planting in clinostats rotating at a rate of 1.0 rpm in the horizontal or somersaulting configurations, and plant movements around their growth axes were recorded in infrared light by a time-lapse closed-circuit video system. The amplitudes and mean cycle durations of the plant nutations in the horizontal and tumbling clinostats are observed to be 20% and 72%, and 32% and 74%, respectively, of the values observed in stationary plants; extrapolations to a state of zero g by the imposition of small centripetal forces on horizontally clinostated plants also indicate some nutational motion in the absence of gravity. It is concluded that the results are incompatible with the model of Israelsson and Johnsson (1967) of geotropic response with overshoot for sunflower circumnutation; however, results of the Spacelab 1 mission experiment are needed to unambiguously define the role of gravitation.
Changes in bone structure and metabolism during simulated weightlessness: Endocrine and dietary factors

NASA Technical Reports Server (NTRS)

Halloran, B. P.; Wronski, T. J.

1985-01-01

The role of vitamin D, PTH and corticosterone in the skeletal alterations induced by simulated weightlessness was examined. The first objective was to determine if changes in the serum concentrations of Ca, P sub i, osteocalcin, 25-OH-D, 24,25(OH)2D or 1,25(OH)2D also occur following acute skeletal unloading. Animals were either suspended or pair fed for 2, 5, 7, 10, 12 and 15 days and the serum concentrations of Ca, P sub i, osteocalcin and the vitamin D metabolites measured. Bone histology was examined at day 5 after suspension. Acute skeletal unloading produced a transient hypercalcemia, a significant fall in serum osteocalcin and serum 1,25(OH)2D, a slight rise in serum 24,25(OH)2D, but did not affect the serum concentrations of P sub i or 25-OH-D. At the nadir in serum 1,25(OH)2D serum osteocalcin was reduced by 22%, osteoblast surface by 32% and longitudinal bone growth by 21%.
A unique problem of muscle adaptation from weightlessness: The deceleration deficiency

NASA Technical Reports Server (NTRS)

Stauber, William T.

1989-01-01

Decelerator problems of the knee are emphasized since the lower leg musculature is known to atrophy in response to weightlessness. However, other important decelerator functions are served by the shoulder muscles, in particular the rotator cuff muscles. Problems in these muscles often result in tears and dislocations as seen in baseball pitchers. It is noteworthy that at least one device currently exists that can measure concentric and eccentric muscle loading including a submaximal simulated free weight exercise (i.e., force-controlled) and simultaneously record integrated EMG analysis appropriate for assessment of all muscle functional activities. Studies should be undertaken to provide information as to the performance of maximal and submaximal exercise in space travelers to define potential problems and provide rationale for prevention.
Ground Reaction Forces During Locomotion in Simulated Microgravity

NASA Technical Reports Server (NTRS)

Davis, B. L.; Cavanagh, Peter R.; Sommer, H. J., III; Wu, G.

1996-01-01

Significant losses in bone density and mineral, primarily in the lower extremities have been reported following exposure to weightlessness. Recent investigations suggest that mechanical influences such as bone deformation and strain rate may be critically important in stimulating new bone formation. It was hypothesized that velocity, cadence and harness design would significantly affect lower limb impact forces during treadmill exercise in simulated zero gravity (0G). A ground-based hypogravity simulator was used to investigate which factors affect limb loading during tethered treadmill exercise. A fractional factorial design was used and 12 subjects were studied. The results showed that running on active and passive treadmills in the simulator with a tethering force close to the maximum comfortable level produced similar magnitudes for the peak ground reaction force. It was also found that these maximum forces were significantly lower than those obtained during overground trials, even when the speeds of locomotion in the simulator were 66 % greater than those in 1 G. Cadence had no effect on any of the response variables. The maximum rate of force application (DFDT-Max) was similar for overground running and exercise in simulated 0G, provided that the "weightless subjects ran on a motorized treadmill. These findings have implications for the use of treadmill exercise as a countermeasure for hypokinetic osteoporosis. As the relationship between mechanical factors and osteogenesis becomes better understood, results from human experiments in 0G simulators will help to design in-flight exercise programs that are more closely targeted to generate appropriate mechanical stimuli.
Early development of Xenopus embryos is affected by simulated gravity

NASA Technical Reports Server (NTRS)

Yokota, Hiroki; Neff, Anton W.; Malacinski, George M.

1994-01-01

Early amphibian (Xenopus laevis) development under clinostat-simulated weightlessness and centrifuge-simulated hypergravity was studied. The results revealed significant effects on (i) 'morphological patterning' such as the cleavage furrow pattern in the vegetal hemisphere at the eight-cell stage and the shape of the dorsal lip in early gastrulae and (ii) 'the timing of embryonic events' such as the third cleavage furrow completion and the dorsal lip appearance. Substantial variations in sensitivity to simulated force fields were observed, which should be considered in interpreting spaceflight data.
Low-g simulation testing of propellant systems using neutral buoyancy

NASA Technical Reports Server (NTRS)

Balzer, D. L.; Lake, R. J., Jr.

1972-01-01

A two liquid, neutral buoyancy technique is being used to simulate propellant behavior in a weightless environment. By equalizing the density of two immiscible liquids within a container (propellant tank), the effect of gravity at the liquid interface is balanced. Therefore the surface-tension forces dominate to control the liquid/liquid system configuration in a fashion analogous to a liquid/gas system in a zero gravity environment.
Physiological Health Challenges for Human Missions to Mars

NASA Technical Reports Server (NTRS)

Norsk, Peter

2015-01-01

During the next decades, manned space missions are expected to be aiming at the Lagrange points, near Earth asteroids, and Mars flyby and/or landing. The question is therefore: Are we ready to go? To answer this with a yes, we are currently using the International Space Station to develop an integrated human physiological countermeasure suite. The integrated countermeasure suite will most likely encounter: 1) Exercise devices for aerobic, dynamic and resistive exercise training; 2) sensory-motor computer training programs and anti-motion sickness medication for preparing EVAs and G-transitions; 3) lower limb bracelets for preventing and/or treating the VIIP (vision impairment and intracranial pressure) syndrome; 4) nutritional components for maintenance of bone, muscle, the cardiovascular system and preventing oxidative stress and damage and immune deficiencies (e. g. omega-3 fatty acids, PRO/K, anti-oxidants and less salt and iron); 5) bisphosphonates for preventing bone degradation.; 6) lower body compression garment and oral salt and fluid loading for landing on a planetary surface to combat orthostatic intolerance; 7) laboratory analysis equipment for individualized monitoring of biomarkers in blood, urine and saliva for estimation of health status in; 8) advanced ultrasound techniques for monitoring bone and cardiovascular health; and 9) computer modeling programs for individual health status assessments of efficiency and subsequent adjustments of countermeasures. In particular for future missions into deep space, we are concerned with the synergistic effects of weightlessness, radiation, operational constraints and other spaceflight environmental factors. Therefore, increased collaboration between physiological, behavioral, radiation and space vehicle design disciplines are strongly warranted. Another venue we are exploring in NASA's Human Research Program is the usefulness of artificial gravity for mitigating the health risks of long duration weightlessness.
Combining ergometer exercise and artificial gravity in a compact-radius centrifuge

NASA Astrophysics Data System (ADS)

Diaz, Ana; Trigg, Chris; Young, Laurence R.

2015-08-01

Humans experience physiological deconditioning during space missions, primarily attributable to weightlessness. Some of these adverse consequences include bone loss, muscle atrophy, sensory-motor deconditioning, and cardiovascular alteration, which may lead to orthostatic intolerance when astronauts return to Earth. Artificial gravity could provide a comprehensive countermeasure capable of challenging all the physiological systems at once, particularly if combined with exercise, thereby maintaining overall health during extended exposure to weightlessness. A new Compact Radius Centrifuge (CRC) platform was designed and built on the existing Short Radius Centrifuge (SRC) at the Massachusetts Institute of Technology (MIT). The centrifuge has been constrained to a radius of 1.4 m, the upper radial limit for a centrifuge to fit within an International Space Station (ISS) module without extensive structural alterations. In addition, a cycle ergometer has been added for exercise during centrifugation. The CRC now includes sensors of foot forces, cardiovascular parameters, and leg muscle electromyography. An initial human experiment was conducted on 12 subjects to analyze the effects of different artificial gravity levels (0 g, 1 g, and 1.4 g, measured at the feet) and ergometer exercise intensities (25 W warm-up, 50 W moderate and 100 W vigorous) on the musculoskeletal function as well as motion sickness and comfort. Foot forces were measured during the centrifuge runs, and subjective comfort and motion sickness data were gathered after each session. Preliminary results indicate that ergometer exercise on a centrifuge may be effective in improving musculoskeletal function. The combination is well tolerated and motion sickness is minimal. The MIT CRC is a novel platform for future studies of exercise combined with artificial gravity. This combination may be effective as a countermeasure to space physiological deconditioning.
Red blood cell and iron metabolism during space flight

NASA Technical Reports Server (NTRS)

Smith, Scott M.

2002-01-01

Space flight anemia is a widely recognized phenomenon in astronauts. Reduction in circulating red blood cells and plasma volume results in a 10% to 15% decrement in circulatory volume. This effect appears to be a normal physiologic adaptation to weightlessness and results from the removal of newly released blood cells from the circulation. Iron availability increases, and (in the few subjects studied) iron stores increase during long-duration space flight. The consequences of these changes are not fully understood.

Scientific experiments in the flight of the 1977 biological satellite (draft plan)

NASA Technical Reports Server (NTRS)

1977-01-01

The physiological, biological, radiobiological and radiophysical experiments planned for the 1977 biological satellite are described. The biological experiments will involve rats, higher and lower plants, insects and other biological specimens carried on the biosatellite. The responses of these organisms to weightlessness, artificial gravity, cosmic radiation particles and general flight factors will be studied. The radiophysical experiments will investigate certain properties of cosmic radiation as well as the possibility of creating electrostatic and dielectric radiation shields under actual space-flight conditions.
Noninvasive methods in space cardiology.

PubMed

Baevsky, R M

1997-01-01

The development and application of noninvasive methods in space cardiology is discussed. These methods are used in astronautics both to gain new insights into the impact of weightlessness conditions on the human organism and to help solve problems involved in the medical monitoring of space crew members. The cardiovascular system is a major target for the action of microgravity. Noninvasive methods used to examine the cardiovascular system during space flights over the past 30 years are listed. Special attention is given to methods for studying heart rate variability and contactless recording of physiologic functions during night sleep. Analysis of heart rate variability highlights an important principle of space cardiology-gaining the maximum amount of information while recording as little data as possible. With this method, the degree of strain experienced by the systems of autonomic regulation and the adaptational capabilities of the body can be assessed at various stages of a space flight. Discriminant analysis of heart rate variability data enables the psycho-emotional component of stress to be separated from the component associated with the impact of weightlessness. A major advance in space medicine has been the development of techniques for contactless recording of pulse rates, breathing frequency, myocardial contractility, and motor activity during sleep using a sensor installed on the cosmonaut's sleeping bag. The data obtained can be used to study ultradian rhythms, which reflect the activity of higher autonomic centers. An important role of these centers in mobilizing functional reserves of the body to ensure its relatively stable adaptation to weightless conditions is shown.
Prediction of space sickness in astronauts from preflight fluid, electrolyte, and cardiovascular variables and Weightless Environmental Training Facility (WETF) training

NASA Technical Reports Server (NTRS)

Simanonok, K.; Mosely, E.; Charles, J.

1992-01-01

Nine preflight variables related to fluid, electrolyte, and cardiovascular status from 64 first-time Shuttle crewmembers were differentially weighted by discrimination analysis to predict the incidence and severity of each crewmember's space sickness as rated by NASA flight surgeons. The nine variables are serum uric acid, red cell count, environmental temperature at the launch site, serum phosphate, urine osmolality, serum thyroxine, sitting systolic blood pressure, calculated blood volume, and serum chloride. Using two methods of cross-validation on the original samples (jackknife and a stratefied random subsample), these variables enable the prediction of space sickness incidence (NONE or SICK) with 80 percent sickness and space severity (NONE, MILD, MODERATE, of SEVERE) with 59 percent success by one method of cross-validation and 67 percent by another method. Addition of a tenth variable, hours spent in the Weightlessness Environment Training Facility (WETF) did not improve the prediction of space sickness incidences but did improve the prediction of space sickness severity to 66 percent success by the first method of cross-validation of original samples and to 71 percent by the second method. Results to date suggest the presence of predisposing physiologic factors to space sickness that implicate fluid shift etiology. The data also suggest that prior exposure to fluid shift during WETF training may produce some circulatory pre-adaption to fluid shifts in weightlessness that results in a reduction of space sickness severity.
Effects of hypercapnia and bedrest on psychomotor performance

NASA Technical Reports Server (NTRS)

Storm, W. F.; Giannetta, C. L.

1974-01-01

Two weeks of continuous exposure to simulated weightlessness (bedrest) and/or an elevated (30 torr) CO2 environment had no detrimental effect on complex tracking performance, eye-hand coordination, or problem-solving ability. These results were consistent with previously reported behavioral findings which investigated these two factors only as independent stressors.
Antigravity Suits For Studies Of Weightlessness

NASA Technical Reports Server (NTRS)

Kravik, Stein E.; Greenleaf, John

1992-01-01

Report presents results of research on use of "antigravity" suit, one applying positive pressure to lower body to simulate some effects of microgravity. Research suggests lower-body positive pressure is alternative to bed rest or immersion in water in terrestrial studies of cardioregulatory, renal, electrolyte, and hormonal changes induced in humans by microgravity.
STS-81 crewmembers participate in bailout training in Bldg 29 WETF

NASA Image and Video Library

1996-09-26

S96-15407 (26 Sept. 1996) --- In the Johnson Space Center's weightless environment training facility, astronaut Peter J.K. (Jeff) Wisoff, STS-81 mission specialist, simulates a parachute drop into water. Five STS-81 crewmates, out of frame, joined him for the bailout training exercises.
STS-81 crewmembers participate in bailout training in Bldg 29 WETF

NASA Image and Video Library

1996-09-26

S96-15402 (26 Sept. 1996) --- In the Johnson Space Center's weightless environment training facility, astronaut John M. Grunsfeld, STS-81 mission specialist, prepares to simulate a parachute drop into water. Five STS-81 crewmates, out of frame, joined him for the bailout training exercises.
Nutrition and human physiological adaptations to space flight

NASA Technical Reports Server (NTRS)

Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

1993-01-01

Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.
Magnetic Field Is the Dominant Factor to Induce the Response of Streptomyces avermitilis in Altered Gravity Simulated by Diamagnetic Levitation

PubMed Central

Shang, Peng; Zhou, Xianlong; Ashforth, Elizabeth; Zhuo, Ying; Chen, Difei; Ren, Biao; Liu, Zhiheng; Zhang, Lixin

2011-01-01

Background Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to simulate an altered gravity environment, as in space. In this study, using Streptomyces avermitilis as the test organism, we investigate whether changes in magnetic field and altered gravity induce changes in morphology and secondary metabolism. We find that a strong magnetic field (12T) inhibit the morphological development of S. avermitilis in solid culture, and increase the production of secondary metabolites. Methodology/Principal Findings S. avermitilis on solid medium was levitated at 0 g*, 1 g* and 2 g* in an altered gravity environment simulated by diamagnetic levitation and under a strong magnetic field, denoted by the asterix. The morphology was obtained by electromicroscopy. The production of the secondary metabolite, avermectin, was determined by OD245 nm. The results showed that diamagnetic levitation could induce a physiological response in S. avermitilis. The difference between 1 g* and the control group grown without the strong magnetic field (1 g), showed that the magnetic field was a more dominant factor influencing changes in morphology and secondary metabolite production, than altered gravity. Conclusion/Significance We have discovered that magnetic field, rather than altered gravity, is the dominant factor in altered gravity simulated by diamagnetic levitation, therefore care should to be taken in the interpretation of results when using diamagnetic levitation as a technique to simulate altered gravity. Hence, these results are significant, and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena. PMID:22039402
Space flight rehabilitation.

PubMed

Payne, Michael W C; Williams, David R; Trudel, Guy

2007-07-01

The weightless environment of space imposes specific physiologic adaptations on healthy astronauts. On return to Earth, these adaptations manifest as physical impairments that necessitate a period of rehabilitation. Physiologic changes result from unloading in microgravity and highly correlate with those seen in relatively immobile terrestrial patient populations such as spinal cord, geriatric, or deconditioned bed-rest patients. Major postflight impairments requiring rehabilitation intervention include orthostatic intolerance, bone demineralization, muscular atrophy, and neurovestibular symptoms. Space agencies are preparing for extended-duration missions, including colonization of the moon and interplanetary exploration of Mars. These longer-duration flights will result in more severe and more prolonged disability, potentially beyond the point of safe return to Earth. This paper will review and discuss existing space rehabilitation plans for major postflight impairments. Evidence-based rehabilitation interventions are imperative not only to facilitate return to Earth but also to extend the safe duration of exposure to a physiologically hostile microgravity environment.
SLS-1 flight experiments preliminary significant results

NASA Technical Reports Server (NTRS)

1992-01-01

Spacelab Life Sciences-1 (SLS-1) is the first of a series of dedicated life sciences Spacelab missions designed to investigate the mechanisms involved in the physiological adaptation to weightlessness and the subsequent readaptation to 1 gravity (1 G). Hypotheses generated from the physiological effects observed during earlier missions led to the formulation of several integrated experiments to determine the underlying mechanisms responsible for the observed phenomena. The 18 experiments selected for flight on SLS-1 investigated the cardiovascular, cardiopulmonary, regulatory physiology, musculoskeletal, and neuroscience disciplines in both human and rodent subjects. The SLS-1 preliminary results gave insight to the mechanisms involved in the adaptation to the microgravity environment and readaptation when returning to Earth. The experimental results will be used to promote health and safety for future long duration space flights and, as in the past, will be applied to many biomedical problems encountered here on Earth.
STS-37 MS Jerome Apt during water egress exercise in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1990-01-01

STS-37 Mission Specialist (MS) Jerome Apt, wearing launch and entry suit (LES) and launch and entry helmet (LEH), is suspended above pool via a parachute harness during water egress exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Apt simulates emergency egress from a Space Shuttle. The WETF's 25-ft pool served as a simulated ocean into which a parachute landing might be made.
STS-37 MS Linda M. Godwin during water egress exercise in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1990-01-01

STS-37 Mission Specialist (MS) Linda M. Godwin, wearing launch and entry suit (LES) and launch and entry helmet (LEH), is suspended above pool via a parachute harness during water egress exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Godwin simulates emergency egress from a Space Shuttle. The WETF's 25-ft pool served as a simulated ocean into which a parachute landing might be made.
Estrous Cyclicity of Mice During Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Moyer, Eric; Talyansky, Yuli; Scott, Ryan; Tash, Joseph; Christenson, Lane; Alwood, Joshua; Ronca, April

2017-01-01

Hindlimb unloading (HU) is a rodent model system used to simulate weightlessness experienced in space. However, some effects of this approach on rodent physiology are under-studied, specifically the effects on ovarian estrogen production which drives the estrous cycle. To resolve this deficiency, we conducted a ground-based validation study using the HU model, while monitoring estrous cycles in 16-weeks-old female C57BL6 mice. Animals were exposed to HU for 12 days following a 3 day HU cage acclimation period, and estrous cycling was analyzed in HU animals (n22), normally loaded HU Cage Pair-Fed controls (CPF; n22), and Vivarium controls fed ad libitum (VIV; n10). Pair feeding was used to control for potential nutritional deficits on ovarian function. Vaginal cells were sampled daily in all mice via saline lavage. Cells were dried and stained with crystal violet, and the smears evaluated using established vaginal cytology techniques by two individuals blinded to the animal treatment group. Estrous cyclicity was disrupted in nearly all HU and CPF mice, while those maintained in VIV had an average normal cycle length of 4.8 0.5 days, with all stages in the cycle visibly observed. CPF and HU animals arrested in the diestrous phase, which precedes the pre-ovulatory estrogen surge. Additionally, infection-like symptoms characterized by vaginal discharge and swelling arose in several HU animals, which we suspect was due to an inability of these mice to properly groom themselves, andor due to the change in the gravity vector relative to the vaginal opening, which prevented drainage of the lavage solution. Pair-feeding resulted in similar weight gains of HU and CPF (1.5 vs 3.0, respectively). The current results indicate that pair-feeding controlled weight gain and that the HU cage alone influenced estrous cyclicity. Thus, longer acclimation needs to be tested to determine if and when normal estrous cycling resumes in non-loaded mice in HU cages prior to HU testing. Future studies might also examine whether modifications to the vaginal lavage procedure might prevent the onset of the infection-like symptoms, and allow estrous cyclicity to be measured in this model system.
Effects of spaceflight and simulated weightlessness on longitudinal bone growth

NASA Technical Reports Server (NTRS)

Sibonga, J. D.; Zhang, M.; Evans, G. L.; Westerlind, K. C.; Cavolina, J. M.; Morey-Holton, E.; Turner, R. T.

2000-01-01

Indirect measurements have suggested that spaceflight impairs bone elongation in rats. To test this possibility, our laboratory measured, by the fluorochrome labeling technique, bone elongation that occurred during a spaceflight experiment. The longitudinal growth rate (LGR) in the tibia of rats in spaceflight experiments (Physiological Space Experiments 1, 3, and 4 and Physiological-Anatomical Rodent Experiment 3) and in two models of skeletal unloading (hind-limb elevation and unilateral sciatic neurotomy) were calculated. The effects of an 11 day spaceflight on gene expression of cartilage matrix proteins in rat growth plates were also determined by northern analysis and are reported for the first time in this study. Measurements of longitudinal growth indicate that skeletal unloading generally did not affect LGR, regardless of age, strain, gender, duration of unloading, or method of unloading. There was, however, one exception with 34% suppression in LGR detected in slow-growing, ovariectomized rats skeletally unloaded for 8 days by hind-limb elevation. This detection of reduced LGR by hind-limb elevation is consistent with changes in steady-state mRNA levels for type II collagen (-33%) and for aggrecan (-53%) that were detected in rats unloaded by an 11 day spaceflight. The changes detected in gene expression raise concern that spaceflight may result in changes in the composition of extracellular matrix, which could have a negative impact on conversion of growth-plate cartilage into normal cancellous bone by endochondral ossification.
Models to study gravitational biology of Mammalian reproduction

NASA Technical Reports Server (NTRS)

Tou, Janet; Ronca, April; Grindeland, Richard; Wade, Charles

2002-01-01

Mammalian reproduction evolved within Earth's 1-g gravitational field. As we move closer to the reality of space habitation, there is growing scientific interest in how different gravitational states influence reproduction in mammals. Habitation of space and extended spaceflight missions require prolonged exposure to decreased gravity (hypogravity, i.e., weightlessness). Lift-off and re-entry of the spacecraft are associated with exposure to increased gravity (hypergravity). Existing data suggest that spaceflight is associated with a constellation of changes in reproductive physiology and function. However, limited spaceflight opportunities and confounding effects of various nongravitational factors associated with spaceflight (i.e., radiation, stress) have led to the development of ground-based models for studying the effects of altered gravity on biological systems. Human bed rest and rodent hindlimb unloading paradigms are used to study exposure to hypogravity. Centrifugation is used to study hypergravity. Here, we review the results of spaceflight and ground-based models of altered gravity on reproductive physiology. Studies utilizing ground-based models that simulate hyper- and hypogravity have produced reproductive results similar to those obtained from spaceflight and are contributing new information on biological responses across the gravity continuum, thereby confirming the appropriateness of these models for studying reproductive responses to altered gravity and the underlying mechanisms of these responses. Together, these unique tools are yielding new insights into the gravitational biology of reproduction in mammals.
Effect of magnetically simulated zero-gravity and enhanced gravity on the walk of the common fruitfly†

PubMed Central

Hill, Richard J. A.; Larkin, Oliver J.; Dijkstra, Camelia E.; Manzano, Ana I.; de Juan, Emilio; Davey, Michael R.; Anthony, Paul; Eaves, Laurence; Medina, F. Javier; Marco, Roberto; Herranz, Raul

2012-01-01

Understanding the effects of gravity on biological organisms is vital to the success of future space missions. Previous studies in Earth orbit have shown that the common fruitfly (Drosophila melanogaster) walks more quickly and more frequently in microgravity, compared with its motion on Earth. However, flight preparation procedures and forces endured on launch made it difficult to implement on the Earth's surface a control that exposed flies to the same sequence of major physical and environmental changes. To address the uncertainties concerning these behavioural anomalies, we have studied the walking paths of D. melanogaster in a pseudo-weightless environment (0g*) in our Earth-based laboratory. We used a strong magnetic field, produced by a superconducting solenoid, to induce a diamagnetic force on the flies that balanced the force of gravity. Simultaneously, two other groups of flies were exposed to a pseudo-hypergravity environment (2g*) and a normal gravity environment (1g*) within the spatially varying field. The flies had a larger mean speed in 0g* than in 1g*, and smaller in 2g*. The mean square distance travelled by the flies grew more rapidly with time in 0g* than in 1g*, and slower in 2g*. We observed no other clear effects of the magnetic field, up to 16.5 T, on the walks of the flies. We compare the effect of diamagnetically simulated weightlessness with that of weightlessness in an orbiting spacecraft, and identify the cause of the anomalous behaviour as the altered effective gravity. PMID:22219396
Effect of magnetically simulated zero-gravity and enhanced gravity on the walk of the common fruitfly.

PubMed

Hill, Richard J A; Larkin, Oliver J; Dijkstra, Camelia E; Manzano, Ana I; de Juan, Emilio; Davey, Michael R; Anthony, Paul; Eaves, Laurence; Medina, F Javier; Marco, Roberto; Herranz, Raul

2012-07-07

Understanding the effects of gravity on biological organisms is vital to the success of future space missions. Previous studies in Earth orbit have shown that the common fruitfly (Drosophila melanogaster) walks more quickly and more frequently in microgravity, compared with its motion on Earth. However, flight preparation procedures and forces endured on launch made it difficult to implement on the Earth's surface a control that exposed flies to the same sequence of major physical and environmental changes. To address the uncertainties concerning these behavioural anomalies, we have studied the walking paths of D. melanogaster in a pseudo-weightless environment (0g*) in our Earth-based laboratory. We used a strong magnetic field, produced by a superconducting solenoid, to induce a diamagnetic force on the flies that balanced the force of gravity. Simultaneously, two other groups of flies were exposed to a pseudo-hypergravity environment (2g*) and a normal gravity environment (1g*) within the spatially varying field. The flies had a larger mean speed in 0g* than in 1g*, and smaller in 2g*. The mean square distance travelled by the flies grew more rapidly with time in 0g* than in 1g*, and slower in 2g*. We observed no other clear effects of the magnetic field, up to 16.5 T, on the walks of the flies. We compare the effect of diamagnetically simulated weightlessness with that of weightlessness in an orbiting spacecraft, and identify the cause of the anomalous behaviour as the altered effective gravity.
The flights before the flight - An overview of shuttle astronaut training

NASA Technical Reports Server (NTRS)

Sims, John T.; Sterling, Michael R.

1989-01-01

Space shuttle astronaut training is centered at NASA's Johnson Space Center in Houston, Texas. Each astronaut receives many different types of training from many sources. This training includes simulator training in the Shuttle Mission Simulator, in-flight simulator training in the Shuttle Training Aircraft, Extravehicular Activity training in the Weightless Environment Training Facility and a variety of lectures and briefings. Once the training program is completed each shuttle flight crew is well-prepared to perform the normal operations required for their flight and deal with any shuttle system malfunctions that might occur.
Spacsuit donning and doffing in zero-g training for Don Peterson STS-6

NASA Technical Reports Server (NTRS)

1982-01-01

Spacsuit donning and doffing in zero-g training for Don Peterson of the STS-6 crew. The training is being held aboard the KC-135 to simulate weightlessness. He is being assisted to don the lower torso of the extravehicular mobility unit (EMU) by an ILC technician.

Hematology/immunology (M110 series). [human hemodynamic response to weightlessness simulation

NASA Technical Reports Server (NTRS)

1973-01-01

The hematology/immunology experiments in the Skylab mission study various aspects of the red blood cell, including its metabolism and life span, and blood volume changes under zero gravity conditions to determine the precise mechanism of the transient changes which have been seen on the relatively brief missions of the past.
Fluid shifts and muscle function in humans during acute simulated weightlessness

NASA Technical Reports Server (NTRS)

Hargens, A. R.; Tipton, C. M.; Gollnick, P. D.; Mubarak, S. J.; Tucker, B. J.; Akeson, W. H.

1983-01-01

The acute effects of simulated weightlessness on transcapillary fluid balance, tissue fluid shifts, muscle function, and triceps surface reflex time were studied in eight supine human subjects who were placed in a 5 degrees head-down tilt position for 8 hr. Results show a cephalic fluid shift from the legs as indicated by facial edema, nasal congestion, increased urine flow, decreased creatinine excretion, reduced calf girth, and decreased lower leg volume. The interstitial fluid pressure in the tibialis anterior muscle and subcutaneous tissue of the lower leg was found to fall significantly, while other transcapillary pressures (capillary and interstitial fluid colloid osmotic pressures) were relatively unchanged. The total water content of the soleus muscle was unchanged during the head-down tilt. After head-down tilt, isometric strength and isokinetic strength of the plantar flexors were unchanged, while the triceps surae reflex time associated with plantar flexion movement slowed slightly. These results demonstrate a dehydration effect of head-down tilt on muscle and subcutaneous tissue of the lower leg that may affect muscle function.
The temporal response of bone to unloading

NASA Technical Reports Server (NTRS)

Globus, R. K.; Bikle, D. D.; Morey-Holton, E.

1984-01-01

Rats were suspended by their tails with the forelimbs bearing the weight load to simulate the weightlessness of space flight. Growth in bone mass ceased by 1 week in the hindlimbs and lumbar vertebrae in growing rats, while growth in the forelimbs and cervical vertebrae remained unaffected. The effects of selective skeletal unloading on bone formation during 2 weeks of suspension was investigated using radio iostope incorporation (with Ca-45 and H-3 proline) and histomorphometry (with tetracycline labeling). The results of these studies were confirmed by histomorphometric measurements of bone formation using triple tetracycline labeling. This model of simulated weightlessness results in an initial inhibition of bone formation in the unloaded bones. This temporary cessation of bone formation is followed in the accretion of bone mass, which then resumes at a normal rate by 14 days, despite continued skeletal unloading. This cycle of inhibition and resumption of bone formation has profound implication for understanding bone dynamics durng space flight, immobilization, or bed rest and offers an opportunity to study the hormonal and mechanical factors that regulate bone formation.
Body composition changes in men and women after 2-3 weeks of bed rest

NASA Technical Reports Server (NTRS)

Pace, N.; Kodama, A. M.; Grunbaum, B. W.; Rahlmann, D. F.; Price, D. C.; Newsom, B. D.

1976-01-01

Several parameters of body composition were measured in eight men before and after 14 days of continuous recumbency, and in eight women before and after 17 days of recumbency. The parameters measured included body weight, body water, body potassium, plasma volume, and plasma protein concentrations. From these, values were derived for body fat content, lean body mass, body mass, and circulating plasma proteins. In general, the men and women responded similarly to continuous recumbency. Characteristically, there was significant reduction of plasma volume and body potassium in both groups. The women showed a significant reduction in circulating plasma protein, entirely in the albumin fraction; a similar change was observed in the men. The women, but not the men, showed a significant increase in circulating fibrinogen. Both men and women lost body cell mass, while body fat content remained the same or tended to increase slightly. It is expected that similar changes would occur in weightlessness. It is further concluded that women should tolerate the weightlessness of space flight physiologically as well as men.
State of spermatogenesis in rats flown aboard Kosmos-690 biosatellite. [Effects of space flight factors on. gamma. radiosensitivity of germ cells in male rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plakhuta-Plakutina, G.I.

1978-10-26

In studying the modifying effects of space flight factors on radiosensitivity of various physiological systems of the body, of definite interest is the reaction of critical organs, in particular the testes, which have a high degree of heterogenic sensitivity of spermatogenic epithelium. Impairment of proliferative activity of testicular epithelium is largely related to the radiovulnerability of cells of the stem type, spermatogonia. In determining the modifying effects of weightlessness and other factors of space flights, it is necessary to compare the cytological state and quantitative evaluation of the incidence of spermatogonia, spermatocytes, spermatids, and spermatozoa in order to determine themore » possible injury to specific stages of spectrogenesis, depending on the radiation doses during space flights and in ground-based model experiments. The effects of radiation under weightless conditions on the reproductive glands of 30 male Wistar rats flown aboard Kosmos-690 and submitted to prolonged ..gamma.. radiation on the 10th day of the flight were investigated.« less
Athletes, astronauts and orthostatic tolerance.

PubMed

Harrison, M H

1986-01-01

Specific alterations in autonomic functions induced by endurance training may lead to a reduced ability to withstand orthostatic stress. This possibility has caused some authorities to suggest that, because of potentially greater pooling of blood in the lower extremities during gravitational loading, endurance-trained athletes may make poor astronauts. Although results from spaceflight studies have provided little evidence to support this suggestion, data from water-immersion studies indicate that endurance-trained athletes do become more orthostatically intolerant following a few hours of simulated weightlessness. Unfortunately, other evidence supporting the hypothesis that endurance training reduces orthostatic tolerance has not received adequate publication in the open scientific literature. On the other hand, a number of studies which have been openly reported clearly refute this hypothesis. Nevertheless, the established physiological differences between endurance athletes and non-athletes are themselves sufficient to suggest that the hypothesis could be tenable. Consequently, it has to be concluded that the presently available information is both qualitatively and quantitatively inadequate to permit any definite statement regarding a possible relationship between aerobic power (VO2max) and orthostatic tolerance.
Our experience in the evaluation of the thermal comfort during the space flight and in the simulated space environment

NASA Astrophysics Data System (ADS)

Novák, Ludvik

The paper presents the results of the mathematical modelling the effects of hypogravity on the heat output by the spontaneous convection. The theoretical considerations were completed by the experiments "HEAT EXCHANGE 1" performed on the biosatellite "KOSMOS 936". In the second experiment "HEAT EXCHANGE 2" acomplished on the board of the space laboratory "SALYUT 6" was studied the effect of the microgravity on the thermal state of a man during the space flight. Direct measurement in weightlessness prowed the capacity of the developed electric dynamic katathermometer to check directly the effect of the microgravity on the heat output by the spontaneous convection. The role of the heat partition impairment's in man as by the microgravity, so by the inadequate forced convection are clearly expressed in changes of the skin temperature and the subjective feeling of the cosmonaut's thermal comfort. The experimental extension of the elaborated methods for the flexible adjustment of the thermal environment to the actual physiological needs of man and suggestions for the further investigation are outlined.
STS-37 Mission Specialist (MS) Godwin floating in life raft in JSC WETF pool

NASA Technical Reports Server (NTRS)

1990-01-01

STS-37 Mission Specialist (MS) Linda M. Godwin, wearing launch and entry suit (LES) and launch and entry helmet (LEH), floats in a one-person life raft during a training session in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. She was simulating steps involved in emergency egress from a Space Shuttle. The WETF's 25-ft deep pool served as a simulated ocean into which a parachute landing might be made.
Biomedical systems analysis program

NASA Technical Reports Server (NTRS)

1979-01-01

Biomedical monitoring programs which were developed to provide a system analysis context for a unified hypothesis for adaptation to space flight are presented and discussed. A real-time system of data analysis and decision making to assure the greatest possible crew safety and mission success is described. Information about man's abilities, limitations, and characteristic reactions to weightless space flight was analyzed and simulation models were developed. The predictive capabilities of simulation models for fluid-electrolyte regulation, erythropoiesis regulation, and calcium regulation are discussed.
Simulated weightlessness and synbiotic diet effects on rat bone mechanical strength

NASA Astrophysics Data System (ADS)

Sarper, Hüseyin; Blanton, Cynthia; DePalma, Jude; Melnykov, Igor V.; Gabaldón, Annette M.

2014-10-01

This paper reports results on exposure to simulated weightlessness that leads to a rapid decrease in bone mineral density known as spaceflight osteopenia by evaluating the effectiveness of dietary supplementation with synbiotics to counteract the effects of skeletal unloading. Forty adult male rats were studied under four different conditions in a 2 × 2 factorial design with main effects of diet (synbiotic and control) and weight condition (unloaded and control). Hindlimb unloading was performed at all times for 14 days followed by 14 days of recovery (reambulation). The synbiotic diet contained probiotic strains Lactobacillus acidophilus and Lactococcus lactis lactis and prebiotic fructooligosaccharide. This paper also reports on the development of a desktop three-point bending device to measure the mechanical strength of bones from rats subjected to simulated weightlessness. The importance of quantifying bone resistance to breakage is critical when examining the effectiveness of interventions against osteopenia resulting from skeletal unloading, such as astronauts experience, disuse or disease. Mechanical strength indices provide information beyond measures of bone density and microarchitecture that enhance the overall assessment of a treatment's potency. In this study we used a newly constructed three-point bending device to measure the mechanical strength of femur and tibia bones from hindlimb-unloaded rats fed an experimental synbiotic diet enriched with probiotics and fermentable fiber. Two calculated outputs for each sample were Young's modulus of elasticity and fracture stress. Bone major elements (calcium, magnesium, and phosphorous) were quantified using ICP-MS analysis. Hindlimb unloading was associated with a significant loss of strength in the femur, and with significant reductions in major bone elements. The synbiotic diet did not protect against these unloading effects. Tibia strength and major elements were not reduced by hindlimb unloading, as was the case for femur, but tibia bone strength was negatively affected by the synbiotic diet. Thus, unexpectedly, the synbiotic diet was associated with null or detrimental effects on bone strength.
Electromyographic analysis of skeletal muscle changes arising from 9 days of weightlessness in the Apollo-Soyuz space mission

NASA Technical Reports Server (NTRS)

Lafevers, E. V.; Nicogossian, A. E.; Hursta, W. N.

1976-01-01

Both integration and frequency analyses of the electromyograms from voluntary contractions were performed in one crewman of the Apollo-Soyuz Test Project mission. Of particular interest were changes in excitability, electrical efficiency, and fatigability. As a result of 9 days of weightlessness, muscle excitability was shown to increase; muscle electrical efficiency was found to decrease in calf muscles and to increase in arm muscles; and fatigability was found to increase significantly, as shown by spectral power shifts into lower frequencies. It was concluded from this study that skeletal muscles are affected by the disuse of weightlessness early in the period of weightlessness, antigravity muscles seem most affected by weightlessness, and exercise may abrogate the weightlessness effect. It was further concluded that electromyography is a sensitive tool for measuring spaceflight muscle effects.
The rhesus monkey (Macaca mulatta) as a flight candidate

NASA Technical Reports Server (NTRS)

Debourne, M. N. G.; Bourne, G. H.; Mcclure, H. M.

1977-01-01

The intelligence and ruggedness of rhesus monkeys, as well as the abundance of normative data on their anatomy, physiology, and biochemistry, and the availability of captive bred animals qualify them for selection as candidates for orbital flight and weightlessness studies. Baseline data discussed include: physical characteristics, auditory thresholds, visual accuity, blood, serological taxomony, immunogenetics, cytogenics, circadian rhythms, respiration, cardiovascular values, corticosteroid response to charr restraint, microscopy of tissues, pathology, nutrition, and learning skills. Results from various tests used to establish the baseline data are presented in tables.
Aerospace medicine and biology: A continuing bibliography with indexes (supplement 395)

NASA Technical Reports Server (NTRS)

1994-01-01

This bibliography lists 82 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during Nov. 1992. Subject coverage includes: general life sciences; aerospace medicine (including physiological factors, biological effects of radiation, and effects of weightlessness on man and animals); behavioral sciences (including psychological factors, individual and group behavior, crew training and evaluation, and psychic research); man/system technology and life support (including human engineering, biotechnology, and space suits and protective clothing) and space biology (including exobiology, planetary biology, and extraterrestrial life).
Effects of prolonged weightlessness on self-motion perception and eye movements evoked by roll and pitch

NASA Technical Reports Server (NTRS)

Reschke, Millard F.; Parker, Donald E.

1987-01-01

Seven astronauts reported translational self-motion during roll simulation 1-3 h after landing following 5-7 d of orbital flight. Two reported strong translational self-motion perception when they performed pitch head motions during entry and while the orbiter was stationary on the runway. One of two astronauts from whom adequate data were collected exhibited a 132-deg shift in the phase angle between roll stimulation and horizontal eye position 2 h after landing. Neither of two from whom adequate data were collected exhibited increased horizontal eye movement amplitude or disturbance of voluntary pitch or roll body motion immediately postflight. These results are generally consistent with an otolith tilt-translation reinterpretation model and are being applied to the development of apparatus and procedures intended to preadapt astronauts to the sensory rearrangement of weightlessness.
Metabolic changes observed in astronauts

NASA Technical Reports Server (NTRS)

Leach, Carolyn S.; Cintron, N. M.; Krauhs, J. M.

1991-01-01

Results of medical experiments with astronauts reveal rapid loss of volume (2 l) from the legs and a transient early increase in left ventricular volume index. These findings indicate that, during space flight, fluid is redistributed from the legs toward the head. In about 2 days, total body water decreases 2 to 3 percent. Increased levels of plasma renin activity and antidiuretic hormone while blood sodium and plasma volume are reduced suggest that space flight-associated factors are influencing the regulatory systems. In addition to fluid and electrolyte loss, Skylab astronauts lost an estimated 0.3 kg of protein. Endocrine factors, including increased cortisol and thyroxine and decreased insulin, are favorable for protein catabolism. The body appears to adapt to weightlessness at some physiologic cost. Readaptation to earth's gravity at landing becomes another physiologic challenge.
Astronaut Curtis Brown suspended by simulated parachute gear during training

NASA Image and Video Library

1994-06-28

S94-37516 (28 June 1994) --- Astronaut Curtis L. Brown is suspended by a simulated parachute gear during an emergency bailout training exercise in the Johnson Space Center's (JSC) Weightless Environment Training Facility (WET-F). Making his second flight in space, Brown will join four other NASA astronauts and a European mission specialist for a week and a half in space aboard the Space Shuttle Atlantis in support of the Atmospheric Laboratory for Applications and Science (ATLAS-3) mission.
STS-37 MS Linda M. Godwin during water egress exercise in JSC's WETF Bldg 29

NASA Image and Video Library

1990-06-25

S90-45238 (25 June 1990) ---- Astronaut Linda M. Godwin, STS 37 mission specialist, simulates emergency egress from a Space Shuttle. The training session was held in the Johnson Space Center's (JSC) weightless environment training facility (WET-F). The 25-ft. pool in the facility served as a simulated ocean into which a parachute landing might be made. Early next year, Godwin, along with four other astronauts, will fly onboard Atlantis for a five-day mission.
STS-37 Mission Specialist (MS) Jerome Apt floats in raft in JSC's WETF pool

NASA Technical Reports Server (NTRS)

1990-01-01

STS-37 Mission Specialist (MS) Jerome Apt, wearing launch and entry suit (LES) and launch and entry helmet (LEH), propels his one-person life raft by splashing water during emergency egress exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Apt, floating in the life raft, was simulating the steps involved in emergency egress from a Space Shuttle. The WETF's 25-ft pool served as a simulated ocean into which a parachute landing might be made.
Angular velocities, angular accelerations, and coriolis accelerations

NASA Technical Reports Server (NTRS)

Graybiel, A.

1975-01-01

Weightlessness, rotating environment, and mathematical analysis of Coriolis acceleration is described for man's biological effective force environments. Effects on the vestibular system are summarized, including the end organs, functional neurology, and input-output relations. Ground-based studies in preparation for space missions are examined, including functional tests, provocative tests, adaptive capacity tests, simulation studies, and antimotion sickness.
Astronaut Bonnie Dunbar watches crewmates during training

NASA Image and Video Library

1994-10-13

S94-47256 (13 Oct 1994) --- Astronaut Bonnie J. Dunbar, STS-71 mission specialist, smiles as she watches a crew mate (out of frame) make a simulated parachute landing in nearby water. The action came as part of an emergency bailout training session in the Johnson Space Center's (JSC) Weightless Environment Training Facility's (WET-F) 25-feet-deep pool.

STS-53 MS Clifford, in EMU, dons gloves with technicians' assistance at JSC

NASA Technical Reports Server (NTRS)

1992-01-01

STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Michael R.U. Clifford, wearing extravehicular mobility unit (EMU) and communications carrier assembly (CCA), dons gloves with assistance from two technicians. Clifford is preparing for an underwater contingency extravehicular activity (EVA) simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.
STS-53 MS Voss,in EMU, dons gloves with technicians' assistance at JSC's WETF

NASA Technical Reports Server (NTRS)

1992-01-01

STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) James S. Voss, wearing extravehicular mobility unit (EMU) and communications carrier assembly (CCA), dons his gloves with assistance from two technicians. Voss is preparing for an underwater contingency extravehicular activity (EVA) simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.
Astronaut William S. McArthur in training for contingency EVA in WETF

NASA Technical Reports Server (NTRS)

1993-01-01

Astronaut William S. McArthur, mission specialist, participates in training for contingency extravehicular activity (EVA) for the STS-58 mission. He is wearing the extravehicular mobility unit (EMU) minus his helmet. For simulation purposes, McArthur was about to be submerged to a point of neutral buoyancy in the JSC Weightless Environment Training Facility (WETF).
Morphology and Molecular Mechanisms of Hepatic Injury in Rats under Simulated Weightlessness and the Protective Effects of Resistance Training.

PubMed

Du, Fang; Ding, Ye; Zou, Jun; Li, Zhili; Tian, Jijing; She, Ruiping; Wang, Desheng; Wang, Huijuan; Lv, Dongqiang; Chang, Lingling

2015-01-01

This study investigated the effects of long-term simulated weightlessness on liver morphology, enzymes, glycogen, and apoptosis related proteins by using two-month rat-tail suspension model (TS), and liver injury improvement by rat-tail suspension with resistance training model (TS&RT). Microscopically the livers of TS rats showed massive granular degeneration, chronic inflammation, and portal fibrosis. Mitochondrial and endoplasmic reticulum swelling and loss of membrane integrity were observed by transmission electron microscopy (TEM). The similar, but milder, morphological changes were observed in the livers of TS&RT rats. Serum biochemistry analysis revealed that the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly higher (p<0.05) in TS rats than in controls. The levels of ALT and AST in TS&RT rats were slightly lower than in RT rats, but they were insignificantly higher than in controls. However, both TS and TS&RT rats had significantly lower levels (p<0.05) of serum glucose and hepatic glycogen than in controls. Immunohistochemistry demonstrated that the expressions of Bax, Bcl-2, and active caspase-3 were higher in TS rats than in TS&RT and control rats. Real-time polymerase chain reaction (real-time PCR) showed that TS rats had higher mRNA levels (P < 0.05) of glucose-regulated protein 78 (GRP78) and caspase-12 transcription than in control rats; whereas mRNA expressions of C/EBP homologous protein (CHOP) and c-Jun N-terminal kinase (JNK) were slightly higher in TS rats. TS&RT rats showed no significant differences of above 4 mRNAs compared with the control group. Our results demonstrated that long-term weightlessness caused hepatic injury, and may trigger hepatic apoptosis. Resistance training slightly improved hepatic damage.
Morphology and Molecular Mechanisms of Hepatic Injury in Rats under Simulated Weightlessness and the Protective Effects of Resistance Training

PubMed Central

Zou, Jun; Li, Zhili; Tian, Jijing; She, Ruiping; Wang, Desheng; Wang, Huijuan; Lv, Dongqiang; Chang, Lingling

2015-01-01

This study investigated the effects of long-term simulated weightlessness on liver morphology, enzymes, glycogen, and apoptosis related proteins by using two-month rat-tail suspension model (TS), and liver injury improvement by rat-tail suspension with resistance training model (TS&RT). Microscopically the livers of TS rats showed massive granular degeneration, chronic inflammation, and portal fibrosis. Mitochondrial and endoplasmic reticulum swelling and loss of membrane integrity were observed by transmission electron microscopy (TEM). The similar, but milder, morphological changes were observed in the livers of TS&RT rats. Serum biochemistry analysis revealed that the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly higher (p<0.05) in TS rats than in controls. The levels of ALT and AST in TS&RT rats were slightly lower than in RT rats, but they were insignificantly higher than in controls. However, both TS and TS&RT rats had significantly lower levels (p<0.05) of serum glucose and hepatic glycogen than in controls. Immunohistochemistry demonstrated that the expressions of Bax, Bcl-2, and active caspase-3 were higher in TS rats than in TS&RT and control rats. Real-time polymerase chain reaction (real-time PCR) showed that TS rats had higher mRNA levels (P < 0.05) of glucose-regulated protein 78 (GRP78) and caspase-12 transcription than in control rats; whereas mRNA expressions of C/EBP homologous protein (CHOP) and c-Jun N-terminal kinase (JNK) were slightly higher in TS rats. TS&RT rats showed no significant differences of above 4 mRNAs compared with the control group. Our results demonstrated that long-term weightlessness caused hepatic injury, and may trigger hepatic apoptosis. Resistance training slightly improved hepatic damage. PMID:26000905
Creating a Lunar EVA Work Envelope

NASA Technical Reports Server (NTRS)

Griffin, Brand N.; Howard, Robert; Rajulu, Sudhakar; Smitherman, David

2009-01-01

A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks. For weightless operations, this process is well developed, but planetary EVA is different and no work envelope has been defined. The primary difference between weightless and planetary work envelopes is gravity. It influences anthropometry, horizontal and vertical mobility, and reaction load paths and introduces effort into doing "overhead" work. Additionally, the use of spacesuits other than the EMU, and their impacts on range of motion, must be taken into account. This paper presents the analysis leading to a concept for a planetary EVA work envelope with emphasis on lunar operations. There is some urgency in creating this concept because NASA has begun building and testing development hardware for the lunar surface, including rovers, habitats and cargo off-loading equipment. Just as with microgravity operations, a lunar EVA work envelope is needed to guide designers in the formative stages of the program with the objective of avoiding difficult and costly rework.
The importance of weightlessness and tides in teaching gravitation

NASA Astrophysics Data System (ADS)

Galili, I.; Lehavi, Y.

2003-11-01

We examine the presentation of the weight, weightlessness, and tides in university-level physics textbooks. Introductory textbooks often do not discuss tidal forces even though their understanding would be useful for understanding weightlessness. The explanations of tides often miss the free gravitational motion of both interacting objects, which is essential for the symmetry of tidal deformation. The shortcomings in the explanations of weightlessness and tides as provided by students and teachers are compared to textbook discussions. We suggest that an explicit discussion of the different definitions of weight and a synergetic presentation of weightlessness and tides might lead to a better understanding of gravitation. Our approach is illustrated by examples of tidal effects appropriate for introductory courses.
Interplanetary Transit Simulations Using the International Space Station

NASA Technical Reports Server (NTRS)

Charles, J. B.; Arya, Maneesh

2010-01-01

It has been suggested that the International Space Station (ISS) be utilized to simulate the transit portion of long-duration missions to Mars and near-Earth asteroids (NEA). The ISS offers a unique environment for such simulations, providing researchers with a high-fidelity platform to study, enhance, and validate technologies and countermeasures for these long-duration missions. From a space life sciences perspective, two major categories of human research activities have been identified that will harness the various capabilities of the ISS during the proposed simulations. The first category includes studies that require the use of the ISS, typically because of the need for prolonged weightlessness. The ISS is currently the only available platform capable of providing researchers with access to a weightless environment over an extended duration. In addition, the ISS offers high fidelity for other fundamental space environmental factors, such as isolation, distance, and accessibility. The second category includes studies that do not require use of the ISS in the strictest sense, but can exploit its use to maximize their scientific return more efficiently and productively than in ground-based simulations. In addition to conducting Mars and NEA simulations on the ISS, increasing the current increment duration on the ISS from 6 months to a longer duration will provide opportunities for enhanced and focused research relevant to long-duration Mars and NEA missions. Although it is currently believed that increasing the ISS crew increment duration to 9 or even 12 months will pose little additional risk to crewmembers, additional medical monitoring capabilities may be required beyond those currently used for the ISS operations. The use of the ISS to simulate aspects of Mars and NEA missions seems practical, and it is recommended that planning begin soon, in close consultation with all international partners.
Second All-Union Seminar on Hydromechanics and Heat-Mass Transfer in Weightlessness. Abstracts of reports: Table of contents

NASA Technical Reports Server (NTRS)

Gershuni, G. Z.; Zhukhovitskiy, Y. M.

1984-01-01

Abstracts of reports are given which were presented at the Second All Union Seminar on Hydromechanics and Heat-Mass Transfer in Weightlessness. Topics inlcude: (1) features of crystallization of semiconductor materials under conditions of microacceleration; (2) experimental results of crystallization of solid solutions of CDTE-HGTE under conditions of weightlessness; (3) impurities in crystals cultivated under conditions of weightlessness; and (4) a numerical investigation of the distribution of impurities during guided crystallization of a melt.
Second All-Union Seminar on Hydromechanics and Heat-Mass Transfer in Weightlessness. Abstracts of reports: Table of contents

NASA Astrophysics Data System (ADS)

Gershuni, G. Z.; Zhukhovitskiy, Y. M.

1984-01-01

s of reports are given which were presented at the Second All Union Seminar on Hydromechanics and Heat-Mass Transfer in Weightlessness. Topics inlcude: (1) features of crystallization of semiconductor materials under conditions of microacceleration; (2) experimental results of crystallization of solid solutions of CDTE-HGTE under conditions of weightlessness; (3) impurities in crystals cultivated under conditions of weightlessness; and (4) a numerical investigation of the distribution of impurities during guided crystallization of a melt.
Second All-Union Seminar on Hydromechanics and Heat and Mass Exchange in Weightlessness, summaries of reports

NASA Astrophysics Data System (ADS)

Gershuni, G. Z.; Zhukhovitskiy, Y. M.

1984-07-01

s of reports are given which were presented at the Second All Union Seminar on Hydromechanics and Heat-Mass Transfer in Weightlessness. Topics include: (1) features of crystallization of semiconductor materials under conditions of microacceleration; (2) experimental results of crystallization of solid solutions of CDTE-HGTE under conditions of weightlessness; (3) impurities in crystals cultivated under conditions of weightlessness; and (4) a numerical investigation of the distribution of impurities during guided crystallization of a melt.
Second All-Union Seminar on Hydromechanics and Heat and Mass Exchange in Weightlessness, summaries of reports

NASA Technical Reports Server (NTRS)

Gershuni, G. Z. (Editor); Zhukhovitskiy, Y. M. (Editor)

1984-01-01

Abstracts of reports are given which were presented at the Second All Union Seminar on Hydromechanics and Heat-Mass Transfer in Weightlessness. Topics include: (1) features of crystallization of semiconductor materials under conditions of microacceleration; (2) experimental results of crystallization of solid solutions of CDTE-HGTE under conditions of weightlessness; (3) impurities in crystals cultivated under conditions of weightlessness; and (4) a numerical investigation of the distribution of impurities during guided crystallization of a melt.
Calcitonin control of calcium metabolism during weightlessness

NASA Technical Reports Server (NTRS)

Soliman, Karam F. A.

1993-01-01

The main objective of this proposal is to elucidate calcitonin role in calcium homeostasis during weightlessness. In this investigation our objectives are to study: the effect of weightlessness on thyroid and serum calcitonin, the effect of weightlessness on the circadian variation of calcitonin in serum and the thyroid gland, the role of light as zeitgeber for calcitonin circadian rhythm, the circadian pattern of thyroid sensitivity to release calcitonin in response to calcium load, and the role of serotonin and norepinephrine in the control of calcitonin release. The main objective of this research/proposal is to establish the role of calcitonin in calcium metabolism during weightlessness condition. Understanding the mechanism of these abnormalities will help in developing therapeutic means to counter calcium imbalance in spaceflights.
Reactions of animals and people under conditions of brief weightlessness

NASA Technical Reports Server (NTRS)

Kitayev-Smik, L. A.

1975-01-01

It has been shown that under brief weightlessness sensory reactions arise in a number of people, mainly those under these conditions for the first time, in the form of spatial and visual illusions, motor excitation, in which tonic and motor components can be distinguished, and vestibular-vegetative disturbances (nausea, vomiting, etc.). In repeated flights with creation of weightlessness, a decrease in the extent of expression and, then, disappearance of these reactions occurred in a significant majority of those studied. Experiments in weightlessness with the vision cut off and with the absence of vestibular functions in the subjects confirm the hypothesis that spatial conceptions of people in weightlessness depend on predominance of gravireceptor or visual afferent signals under these conditions.
NASA's Biomedical Research Program

NASA Technical Reports Server (NTRS)

Ahn, Chung-Hae

1981-01-01

The biomedical research program has been established to investigate the major physiological and psychological problems encountered by man when he undertakes spaceflight. The program seeks to obtain a better definition of each problem, an understanding of its underlying mechanism, and ultimately a means of prevention. In pursuing these goals the program also includes a major effort to develop the research tools and procedures it needs where these are not being developed elsewhere. After almost twenty years of manned spaceflight activities and after a much longer period of space related ground-based research, the program now recognizes two characteristics of spaceflight which are truly unique to space. These are weightlessness and one specific form of radiation. In its present stage of maturity much of the research focuses on mechanisms underlying the basic responses of man and animals to weightlessness. The program consists of nine elements. Eight of these are referable to specific physiological problems that have either been encountered in previous manned spaceflight or which are anticipated to occur as spaceflights last longer, traverse steeper orbital inclinations, or are otherwise different from previous missions. The ninth addresses problems that have neither arisen nor can be reasonably predicted but are suspected on the basis of theoretical models, ground-based animal research, or for other reasons. The program's current emphasis is directed toward the motion sickness problem because of its relevance to Space Shuttle operations. Increased awareness and understanding of the radiation hazard has resulted in more emphasis being placed on the biological effects of high energy, high mass number particulate radiation and upon radiation protection . Cardiovascular and musculoskeleta1 studies are pursued in recognition of the considerable fundamental knowledge that must be acquired in these areas before effective countermeasures to the effects of repetitive or long-term flight can be devised. Major new avenues of research will deal with the psychological accompaniments of spaceflight and with mathematical modelling of physiological systems.
So You Want to Go to Mars: Bones and Matters of the Heart

NASA Technical Reports Server (NTRS)

Tahimic, Candice; Globus, Ruth; Torres, Samantha; Steczina, Sonette

2017-01-01

There is evidence that weightlessness and radiation, two elements of the spaceflight environment, can lead to detrimental changes in human musculoskeletal tissue, including bone loss and muscle atrophy. This bone loss is thought to be brought about by the increased activity of bone-resorbing osteoclasts and functional changes in bone-forming osteoblasts, cells that give rise to mature osteocytes. Collectively, our research team aims to understand the molecular mechanisms underlying the responses of mammalian tissue to the spaceflight environment using earth-based animal and cellular models. The overarching goal is to identify molecular targets to prevent tissue decrements induced by spaceflight and earth-based scenarios of radiotherapy, accidental radiation exposure and reduced mobility. In this talk, I will provide an overview of skeletal and cardiovascular responses to spaceflight and will highlight our research progress on understanding the role of reactive oxygen species (ROS) signaling in skeletal responses to radiation and simulated weightlessness.
Origins and Early History of Underwater Neutral Buoyancy Simulation of Weightlessness for EVA Procedures Development and Training. Part 2; Winnowing and Regrowth

NASA Technical Reports Server (NTRS)

Charles, John B.

2013-01-01

The technique of neutral buoyancy during water immersion was applied to a variety of questions pertaining to human performance factors in the early years of the space age. It was independently initiated by numerous aerospace contractors at nearly the same time, but specific applications depended on the problems that the developers were trying to solve. Those problems dealt primarily with human restraint and maneuverability and were often generic across extravehicular activity (EVA) and intravehicular activity (IVA) worksites. The same groups often also considered fractional gravity as well as weightless settings and experimented with ballasting to achieve lunar and Mars-equivalent loads as part of their on-going research and development. Dr. John Charles reviewed the association of those tasks with contemporary perceptions of the direction of NASA's future space exploration activities and with Air Force assessments of the military value of man in space.
STS-52 Commander Wetherbee, in LES/LEH, during JSC WETF bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Commander James D. Wetherbee, fully outfitted in a launch and entry suit (LES) and launch and entry helmet (LEH), prepares for emergency egress (bailout) training exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. The WETF's 25-ft deep pool will be used to simulate a water landing.
STS-46 ESA MS Nicollier in life raft during water egress training at JSC WETF

NASA Technical Reports Server (NTRS)

1992-01-01

STS-46 Atlantis, Orbiter Vehicle (OV) 104, European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier, wearing launch and entry suit (LES) and launch and entry helmet (LEH), floats in a one-person life raft during a launch emergency egress (bailout) simulation conducted in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.
STS-26 Pilot Covey floats in life raft during JSC WETF exercises

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing the newly designed launch and entry suit (LES), floats in single-occupant life raft in JSC Weightless Environment Training Facility (WETF) Bldg 29 pool. The simulation of the escape and rescue operations utilized the crew escape system (CES) pole method of egress from the Space Shuttle.

STS-46 MS Chang-Diaz floats in life raft during water egress training at JSC

NASA Technical Reports Server (NTRS)

1992-01-01

STS-46 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) Franklin R. Chang-Diaz, wearing launch and entry suit (LES) and launch and entry helmet (LEH), relies on a one-person life raft to get him to 'safety' during a launch emergency egress (bailout) simulation conducted in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool.
The effect of blood volume loss on cardiovascular response to lower body negative pressure using a mathematical model

NASA Technical Reports Server (NTRS)

Karam, E. H.; Srinivasan, R. S.; Charles, J. B.; Fortney, S. M.

1994-01-01

Different mathematical models of varying complexity have been proposed in recent years to study the cardiovascular (CV) system. However, only a few of them specifically address the response to lower body negative pressure (LBNP), a stress that can be applied in weightlessness to predict changes in orthostatic tolerance. Also, the simulated results produced by these models agree only partially with experimental observations. In contrast, the model proposed by Melchior et al., and modified by Karam et al. is a simple representation of the CV system capable of accurately reproducing observed LBNP responses up to presyncopal levels. There are significant changes in LBNP response due to a loss of blood volume and other alterations that occur in weightlessness and related one-g conditions such as bedrest. A few days of bedrest can cause up to 15% blood volume loss (BVL), with consequent decreases in both stroke volume and cardiac output, and increases in heart rate, mean arterial pressure, and total peripheral resistance. These changes are more pronounced at higher levels of LBNP. This paper presents the results of a simulation study using our CV model to examine the effect of BVL on LBNP response.
Skylab

NASA Image and Video Library

1970-11-18

After the end of the Apollo missions, NASA's next adventure into space was the marned spaceflight of Skylab. Using an S-IVB stage of the Saturn V launch vehicle, Skylab was a two-story orbiting laboratory, one floor being living quarters and the other a work room. The objectives of Skylab were to enrich our scientific knowledge of the Earth, the Sun, the stars, and cosmic space; to study the effects of weightlessness on living organisms, including man; to study the effects of the processing and manufacturing of materials utilizing the absence of gravity; and to conduct Earth resource observations. At the Marshall Space Flight Center (MSFC), astronauts and engineers spent hundreds of hours in an MSFC Neutral Buoyancy Simulator (NBS) rehearsing procedures to be used during the Skylab mission, developing techniques, and detecting and correcting potential problems. The NBS was a 40-foot deep water tank that simulated the weightlessness environment of space. This photograph shows astronaut Ed Gibbon (a prime crew member of the Skylab-4 mission) during the neutral buoyancy Skylab extravehicular activity training at the Apollo Telescope Mount (ATM) mockup. One of Skylab's major components, the ATM was the most powerful astronomical observatory ever put into orbit to date.
Plasma volume losses during simulated weightlessness in women

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drew, H.; Fortney, S.; La France, N.

Six healthy women not using oral contraceptives underwent two 11-day intervals of complete bedrest (BR) with the BR periods separated by 4 weeks of ambulatory control. Change in plasma volume (PV) was monitored during BR to test the hypothesis that these women would show a smaller decrease in PV than PV values reported in similarly stressed men due to the water retaining effects of the female hormones. Bedrest periods were timed to coincide with opposing stages of the menstrual cycle in each woman. The menstrual cycle was divided into 4 separate stages; early follicular, ovulatory, early luteal, and late lutealmore » phases. The percent decrease of PV showed a consistent decrease for each who began BR while in stage 1, 3 or 4 of the menstrual cycle. However, the females who began in stage 2 showed a transient attenuation in PV loss. Overall, PV changes seen in women during BR were similar to those reported for men. The water-retaining effects of menstrual hormones were evident only during the high estrogen ovulatory stage. The authors conclude the protective effects of menstrual hormones on PV losses during simulated weightless conditions appear to be only small and transient.« less
The foundations of space biology and medicine. Volume 2: Ecological and physiological bases of space biology and medicine. Part 3: Effect on the organism of dynamic flight factors. Chapter 1: Principles of gravitational biology

NASA Technical Reports Server (NTRS)

Smith, A. H.

1972-01-01

The physical principles of gravitation are discussed, such as gravitational and intertial forces, weight and mass, weightlessness, size and scale effects, scale limits of gravitational effects, and gravity as a biogenic factor. The behavior of the accelerative force gravitation, is described. This law proposes and quantifies the mutual gravitational attraction existing between all bodies of matter, the force being proportional to the product of masses, and inversely related to the square of the distance separating them. Gravity orientation, chronic acceleration, and hematology are examined. Systematic responses, such as circulation and renal functions, are also considered, along with animal response to a decreased acceleration field and physiology of hyper- and hypodynamic fields.
Thought Experiments in Teaching Free-Fall Weightlessness: A Critical Review and an Exploration of Mercury's Behavior in "Falling Elevator"

ERIC Educational Resources Information Center

Balukovic, Jasmina; Slisko, Josip; Cruz, Adrián Corona

2017-01-01

Different "thought experiments" dominate teaching approaches to weightlessness, reducing students' opportunities for active physics learning, which should include observations, descriptions, explanations and predictions of real phenomena. Besides the controversy related to conceptual definitions of weight and weightlessness, we report…
Islet in weightlessness: Biological experiments on board COSMOS 1129 satellite

NASA Technical Reports Server (NTRS)

Zhuk, Y.

1980-01-01

Biological experiments planned as an international venture for COSMOS 1129 satellite include tests of: (1) adaptation of rats to conditions of weightlessness, and readaption to Earth's gravity; (2) possibility of fertilization and embryonic development in weightlessness; (3) heat exchange processes; (4) amount of gravity force preferred by fruit flies for laying eggs (given a choice of three centrifugal zones); (5) growth of higher plants from seeds; (6) effects of weightlessness on cells in culture and (7) radiation danger from heavy nuclei, and electrostatic protection from charged particles.
Body composition data from the rat subjects of Cosmos 1129 experiment K-316

NASA Technical Reports Server (NTRS)

Pace, N.; Smith, A. H.; Pitts, G. C.; Ushakov, A. S.; Smirnova, T. A.

1982-01-01

The effects of 18.5 days of weightlessness on the body composition of young, growing, male laboratory rats were examined. Three groups of 5 rats each were examined. It is indicated that exposure of young, growing, male rats to 18.5 days of weightlessness produces: (1) no effect on the quantity of fat stored by the body; (2) a slight reduction in the quantity of fat free tissue laid down by the body; (3) a small reduction in the fraction of water contained by the fat free body mass; (4) a similar reduction in the fraction of water contained by the fat free skin and fat free carcass; (5) a shift in relative distribution of the total body water from skin to viscera; (6) a diminution in the fraction of extracellular water contained by the fat free body; (7) no effect on the fraction of total skeletal musculature contained by the fat free body, as indicated by body creatine content; (8) a sizeable reduction in the fraction of bone mineral contained by the fat free body, as calculated from body calcium content. The nature of the physiological changes induced by unloading from Earth gravity in the mammalian organism are illustrated.
Personal miniature electrophysiological tape recorder

NASA Astrophysics Data System (ADS)

Green, H.

1981-11-01

The use of a personal miniature electrophysiological tape recorder to measure the physiological reactions of space flight personnel to space flight stress and weightlessness is described. The Oxford Instruments Medilog recorder, a battery-powered, four-channel cassette tape recorder with 24 hour endurance is carried on the person and will record EKG, EOG, EEG, and timing and event markers. The data will give information about heart rate and morphology changes, and document adaptation to zero gravity on the part of subjects who, unlike highly trained astronauts, are more representative of the normal population than were the subjects of previous space flight studies.
Acceleration Tolerance: Effect of Exercise, Acceleration Training; Bed Rest and Weightlessness Deconditioning. A Compendium of Research (1950-1996)

NASA Technical Reports Server (NTRS)

Chou, J. L.; McKenzie, M. A.; Stad, N. J.; Barnes, P. R.; Jackson, C. G. R.; Ghiasvand, F.; Greenleaf, J. E.

1997-01-01

This compendium includes abstracts and annotations of clinical observations and of more basic studies involving physiological mechanisms concerning interaction of acceleration, training and deconditioning. If the author's abstract or summary was appropriate, it was included. In other cases a more detailed annotation of the paper was prepared under the subheadings Purpose, Methods, Results, and Conclusions. Author and keyword indices are provided, plus an additional selected bibliography of related work and of those papers received after the volume was prepared for publication. This volume includes material published from 1950-1996.
Mathematical modeling of acute and chronic cardiovascular changes during Extended Duration Orbiter (EDO) flights

NASA Technical Reports Server (NTRS)

White, Ronald J.; Leonard, Joel I.; Srinivasan, R. Srini; Charles, John B.

1991-01-01

The purpose of NASA's Extended Duration Orbiter program is a gradual extension of the capabilities of the Space Shuttle Orbiter beyond its current 7-10 day limit on mission duration, as warranted by deepening understanding of the long-term physiological effects of weightlessness. Attention is being given to the cardiovascular problem of orthostatic tolerance loss due to its adverse effects on crew performance and health during reentry and initial readaptation to earth gravity. An account is given of the results of the application of proven mathematical models of circulatory and cardiovascular systems under microgravity conditions.
Cosmonaut Yuriy Onufriyenko simulates parachute drop into water

NASA Image and Video Library

1994-10-13

S94-47232 (13 Oct 1994) --- Cosmonaut Yuriy I. Onufriyenko (right), in the United States to participate in training for joint Russia-United States space missions, simulates a parachute drop into water. The training took place in the Johnson Space Center's (JSC) Weightless Environment Training Facility (WET-F) because it contains a 25-feet-deep pool. Onufriyenko, a Mir reserve team member, and a number of other cosmonauts and astronauts participating in the joint program were in Houston, Texas to prepare for upcoming missions which involve crewmembers from the two nations.
Effects of hypodynamic simulations on the skeletal system of monkeys

NASA Technical Reports Server (NTRS)

Young, D. R.; Tremor, J. W.

1977-01-01

A research and development program was undertaken to evaluate the skeletal losses of subhuman primates in hypodynamic environments. The goals of the program are: (1) to uncover the mechanisms by which weightlessness affects the skeletal system; (2) to determine the consequences and reversibility of bone mineral losses; and (3) to acquire a body of data needed to formulate an appropriate countermeasure program for the prevention of skeletal deconditioning. Space flight experiment simulation facilities are under development and will be tested for their capability in supporting certain of the requirements for these investigations.
Astronaut Jones donning EMU during space walk simulations for STS-59

NASA Image and Video Library

1993-08-16

Astronaut Thomas D. Jones, mission specialist, dons a space suit prior to participating in contingency space walk simulations at the JSC Weightless Environment Training Facility (WETF). Jones is assisted by Frank Hernandez (left) and suit technician Charles Hudson of Hamilton Standard. Jones suit is weighted to that he can achieve a neutrally buoyant state once under water. Extravehicular tasks are not planned for the STS-59 mission, but a number of chores are rehearsed in case of failure of remote systems to perform those jobs.
Effects of prolonged weightlessness on the humoral immune response of humans

NASA Technical Reports Server (NTRS)

Voss, E. W., Jr.

1981-01-01

An experiment to examine the possible interrelationship of various classes of immunoglobulins by utilizing the effect of weightlessness as a stress factor and subsequently measuring inhibitory, compensatory, or enhancing interrelationships. A second objective of the experiment is to investigate the state of immune competency under conditions of sustained weightlessness.
Estrous Cyclicity in Mice During Simulated Weightlessness

NASA Technical Reports Server (NTRS)

Moyer, E. L.; Talyansky, Y.; Scott, R. T.; Tash, J. S.; Christenson, L. K.; Alwood, J. S.; Ronca, A. E.

2017-01-01

Hindlimb unloading (HU) is a rodent model system used to simulate weightlessness experienced in space. However, some effects of this approach on rodent physiology are under-studied, specifically the effects on ovarian estrogen production which drives the estrous cycle. To resolve this deficiency, we conducted a ground-based validation study using the HU model, while monitoring estrous cycles in 16-weeks-old female C57BL6 mice. Animals were exposed to HU for 12 days following a 3 day HU cage acclimation period, and estrous cycling was analyzed in HU animals (n=22), normally loaded HU Cage Pair-Fed controls (CPF; n=22), and Vivarium controls fed ad libitum (VIV; n=10). Pair feeding was used to control for potential nutritional deficits on ovarian function. Vaginal cells were sampled daily in all mice via saline lavage. Cells were dried and stained with crystal violet, and the smears evaluated using established vaginal cytology techniques by two individuals blinded to the animal treatment group. Estrous cyclicity was disrupted in nearly all HU and CPF mice, while those maintained in VIV had an average normal cycle length of 4.8+/- 0.5 days, with all stages in the cycle visibly observed. CPF and HU animals arrested in the diestrous phase, which precedes the pre-ovulatory estrogen surge. Additionally, infection-like symptoms characterized by vaginal discharge and swelling arose in several HU animals, which we suspect was due to an inability of these mice to properly groom themselves, and/or due to the change in the gravity vector relative to the vaginal opening, which prevented drainage of the lavage solution. Pair-feeding resulted in similar weight gains of HU and CPF (1.5% vs 3.0%, respectively). The current results indicate that pair-feeding controlled weight gain and that the HU cage alone influenced estrous cyclicity. Thus, longer acclimation needs to be tested to determine if and when normal estrous cycling resumes in non-loaded mice in HU cages prior to HU testing. Future studies might also examine whether modifications to the vaginal lavage procedure might prevent the onset of the infection-like symptoms, and allow estrous cyclicity to be measured in this model system. Research supported by NNX15AB48G to JST.
STS-39 MS Harbaugh is suspended over JSC's WETF Bldg 29 pool via harness

NASA Image and Video Library

1990-12-07

S90-54763 (7 Dec 1990) --- Astronaut Gregory J. Harbaugh. Mission specialist, participates in emergency egress training. Harbaugh and some of his fellow STS 39 astronauts were in JSC's weightless environment training facility (WET-F). Harbaugh is actually suspended over water. This type training uses the WET-F's 25 ft. deep pool to simulate an ocean parachute landing.
STS-46 crewmembers during water egress training in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1992-01-01

STS-46 Atlantis, Orbiter Vehicle (OV) 104, European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier (left) and backup Italian Payload Specialist Umberto Guidoni, seated at the pool's side, relax before participating in a launch emergency egress (bailout) simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29. The two participants are wearing launch and entry suits (LESs) during the pretest briefing.
Mir training Facility view

NASA Image and Video Library

1995-02-22

S95-04319 (22 Feb 1995) --- The neutral buoyancy facility at the Gagarin Cosmonaut Training Center in Star City, Russia, is used for underwater training for missions aboard the Russian Mir Space Station. The facility is similar to NASA's Weightless Environment Training Facility (WET-F) at the Johnson Space Center (JSC) in Houston, Texas, and the Neutral Buoyancy Simulator (NBS) at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama.
STS-47 backup payload specialists participate in JSC WETF bailout exercise

NASA Technical Reports Server (NTRS)

1992-01-01

STS-47 Endeavour, Orbiter Vehicle (OV) 105, backup payload specialists (left to right) Chiaki Naito-Mukai, Takao Doi, and Stan Koszelak, wearing launch and entry suits, sit on the poolside in JSC's Weightless Environment Training Facility (WETF) Bldg 29. These alternates are waiting to participate launch emergency egress (bailout) exercises. The training is conducted in the WETF pool to simulate a water landing.

STS-46 Payload Specialist Malerba in JSC's WETF pool during egress training

NASA Technical Reports Server (NTRS)

1992-01-01

STS-46 Atlantis, Orbiter Vehicle (OV) 104, Italian Payload Specialist Franco Malerba, wearing launch and entry suit (LES) and clamshell helmet, laughes as he floats in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Malerba's flotation vest (life jacket) and two SCUBA-equipped divers keep him afloat after he was dropped into the pool during a launch emergency egress simulation.
STS-52 Commander Wetherbee floats in life raft during JSC bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Commander James D. Wetherbee, wearing launch and entry suit (LES) and launch and entry helmet (LEH), floats in single person life raft during emergency egress (bailout) training exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. The bailout exercises utilize the WETF's 25-foot deep pool as the ocean for this water landing simulation.
BION-M 1: First continuous blood pressure monitoring in mice during a 30-day spaceflight

NASA Astrophysics Data System (ADS)

Andreev-Andrievskiy, Alexander; Popova, Anfisa; Lloret, Jean-Christophe; Aubry, Patrick; Borovik, Anatoliy; Tsvirkun, Daria; Vinogradova, Olga; Ilyin, Eugeniy; Gauquelin-Koch, Guillemette; Gharib, Claude; Custaud, Marc-Antoine

2017-05-01

Animals are an essential component of space exploration and have been used to demonstrate that weightlessness does not disrupt essential physiological functions. They can also contribute to space research as models of weightlessness-induced changes in humans. Animal research was an integral component of the 30-day automated Russian biosatellite Bion-M 1 space mission. The aim of the hemodynamic experiment was to estimate cardiovascular function in mice, a species roughly 3000 times smaller than humans, during prolonged spaceflight and post-flight recovery, particularly, to investigate if mice display signs of cardiovascular deconditioning. For the first time, heart rate (HR) and blood pressure (BP) were continuously monitored using implantable telemetry during spaceflight and recovery. Decreased HR and unchanged BP were observed during launch, whereas both HR and BP dropped dramatically during descent. During spaceflight, BP did not change from pre-flight values. However, HR increased, particularly during periods of activity. HR remained elevated after spaceflight and was accompanied by increased levels of exercise-induced tachycardia. Loss of three of the five mice during the flight as a result of the hardware malfunction (unrelated to the telemetry system) and thus the limited sample number constitute the major limitation of the study. For the first time BP and HR were continuously monitored in mice during the 30-day spaceflight and 7-days of post-flight recovery. Cardiovascular deconditioning in these tiny quadruped mammals was reminiscent of that in humans. Therefore, the loss of hydrostatic pressure in space, which is thought to be the initiating event for human cardiovascular adaptation in microgravity, might be of less importance than other physiological mechanisms. Further experiments with larger number of mice are needed to confirm these findings.
Effects of Hypogravity on Osteoblast Differentiation

NASA Technical Reports Server (NTRS)

Globus, Ruth; Doty, Steven

1997-01-01

Weightbearing is essential for normal skeletal function. Without weightbearing, the rate of bone formation by osteoblasts decreases in the growing rat. Defective formation may account for the decrease in the maturation, strength and mass of bone that is caused by spaceflight. These skeletal defects may be mediated by a combination of physiologic changes triggered by spaceflight, including skeletal unloading, fluid shifts, and stress-induced endocrine factors. The fundamental question of whether the defects in osteoblast function due to weightlessness are mediated by localized skeletal unloading or by systemic physiologic adaptations such as fluid shifts has not been answered. Furthermore, bone-forming activity of osteoblasts during unloading may be affected by paracrine signals from vascular, monocytic, and neural cells that also reside in skeletal tissue. Therefore we proposed to examine whether exposure of cultured rat osteoblasts to spaceflight inhibits cellular differentiation and impairs mineralization when isolated from the influence of both systemic factors and other skeletal cells.
Effect of 5E Teaching Model on Student Teachers' Understanding of Weightlessness

ERIC Educational Resources Information Center

Tural, Guner; Akdeniz, Ali Riza; Alev, Nedim

2010-01-01

Weight is one of the basic concepts of physics. Its gravitational definition accommodates difficulties for students to understand the state of weightlessness. The aim of this study is to investigate the effect of materials based on 5E teaching model and related to weightlessness on science student teachers' learning. The sample of the study was 9…
Electrostatic demonstration of free-fall weightlessness

NASA Astrophysics Data System (ADS)

Balukovic, Jasmina; Slisko, Josip; Corona Cruz, Adrian

2015-05-01

The phenomena of free-fall weightlessness have been demonstrated to students for many years in a number of different ways. The essential basis of all these demonstrations is the fact that in free-falling, gravitationally accelerated systems, the weight force and weight-related forces (for example, friction and hydrostatic forces) disappear. In this article, an original electrostatic demonstration of weightlessness is presented. A charged balloon fixed at the opening of a plastic container cannot lift a light styrofoam sphere sitting on the bottom when the container is at rest. However, while the system is in free-fall, the sphere becomes weightless and the charged balloon is able to lift it electrostatically.
[Basic results of an experiment with mammals on the Kosmos-782 biosatellite].

PubMed

Gazenko, O G; Genin, A M; Il'in, E A; Portugalov, V V; Serova, L V

1978-01-01

The rat experiments carried out onboard the biosatellite Cosmos-782 contributed to our understanding of mechanisms of animal adaption to prolonged weightlessness. Postflight analysis helped to study nonspecific changes related to the stress-reaction accompanying space flight and return to the Earth gravity as well as specific changes associated with functional unloading of the musculoskeletal system in weightlessness. The flight results confirmed the previously made conclusions concerning possible adaptation of mammals to prolonged weightlessness and lack of pathological changes in vital weightlessness. They included: metabolic and hormonal changes, muscle atrophy, osteoporosis and delayed bone growth, decrease of ATPase activity of myocardial myosin, inhibition of erythropoiesis.
Endoscopic surgery in weightlessness: the investigation of basic principles for surgery in space.

PubMed

Campbell, M R; Kirkpatrick, A W; Billica, R D; Johnston, S L; Jennings, R; Short, D; Hamilton, D; Dulchavsky, S A

2001-12-01

Performing a surgical procedure in weightlessness, also called 0-gravity (0-g), has been shown to be no more difficult than in a 1-g environment if the requirements for the restraint of the patient, operator, surgical hardware, are observed. The performance of laparoscopic and thorascopic procedures in weightlessness, if feasible, would offer several advantages over the performance of an open operation. Concerns about the feasibility of performing minimally invasive procedures in weightlessness have included impaired visualization from the absence of gravitational retraction of the bowel (laparoscopy) or thoracic organs (thoracoscopy) as well as obstruction and interference from floating debris such as blood, pus, and irrigation fluid. The purpose of this study was to determine the feasibility of performing laparoscopic and thorascopic procedures and the degree of impaired surgical endoscopic visualization in weightlessness. From 1993 to 2000, laparoscopic and thorascopic procedures were performed on 10 anesthetized adult pigs weighing approximately 50 kg in the National Aeronautics and Space Administration (NASA) Microgravity Program using a modified KC-135 airplane. The parabolic simulation system for advanced life support was used in this project, and 20 to 40 parabolas were used for laparoscopic or thorascopic investigation, each containing approximately 30 s of 0-g alternating with 2-g pullouts. The animal model was restrained in the supine position on a floor-level Crew Medical Restraint System, and the abdominal cavity was insufflated with carbon dioxide. The intraabdominal and intrathoracic anatomy was visualized in the 1-g, 0-g, and 2-g periods of parabolic flight. Bleeding was created in the animals, and the behavior of the blood in the abdominal and thoracic cavities was observed. In the thoracic cavity, gas insufflation and mechanical retraction was used at times unilaterally to decrease pulmonary ventilation enough to increase the thoracic domain. Visualization was improved in laparoscopy, from tethering of the bowel by the elastic mesentery, and from the strong tendency for debris and blood to adhere to the abdominal wall because of surface tension forces. The lack of adequate thoracic domain made thorascopy more difficult. Fluid in the thoracic cavity did not impair visualization because the fluid at 0-g does not loculate posteriorly, but disperses along the thoracic wall and mediastinal reflections. Performing minimally invasive procedures instead of open surgical procedures in a weightless environment has theoretical advantages, especially in the ability to prevent cabin atmosphere contamination from surgical fluids (blood, pus, irrigation). Visualization will become more important and practical as the endoscopic hardware is miniaturized from its current form, as endoscopic technology becomes more advanced, and as more surgically capable medical crew officers are present in future long-duration space exploration missions.
Endoscopic surgery in weightlessness: the investigation of basic principles for surgery in space

NASA Technical Reports Server (NTRS)

Campbell, M. R.; Kirkpatrick, A. W.; Billica, R. D.; Johnston, S. L.; Jennings, R.; Short, D.; Hamilton, D.; Dulchavsky, S. A.

2001-01-01

BACKGROUND: Performing a surgical procedure in weightlessness, also called 0-gravity (0-g), has been shown to be no more difficult than in a 1-g environment if the requirements for the restraint of the patient, operator, surgical hardware, are observed. The performance of laparoscopic and thorascopic procedures in weightlessness, if feasible, would offer several advantages over the performance of an open operation. Concerns about the feasibility of performing minimally invasive procedures in weightlessness have included impaired visualization from the absence of gravitational retraction of the bowel (laparoscopy) or thoracic organs (thoracoscopy) as well as obstruction and interference from floating debris such as blood, pus, and irrigation fluid. The purpose of this study was to determine the feasibility of performing laparoscopic and thorascopic procedures and the degree of impaired surgical endoscopic visualization in weightlessness. METHODS: From 1993 to 2000, laparoscopic and thorascopic procedures were performed on 10 anesthetized adult pigs weighing approximately 50 kg in the National Aeronautics and Space Administration (NASA) Microgravity Program using a modified KC-135 airplane. The parabolic simulation system for advanced life support was used in this project, and 20 to 40 parabolas were used for laparoscopic or thorascopic investigation, each containing approximately 30 s of 0-g alternating with 2-g pullouts. The animal model was restrained in the supine position on a floor-level Crew Medical Restraint System, and the abdominal cavity was insufflated with carbon dioxide. The intraabdominal and intrathoracic anatomy was visualized in the 1-g, 0-g, and 2-g periods of parabolic flight. Bleeding was created in the animals, and the behavior of the blood in the abdominal and thoracic cavities was observed. In the thoracic cavity, gas insufflation and mechanical retraction was used at times unilaterally to decrease pulmonary ventilation enough to increase the thoracic domain. RESULTS: Visualization was improved in laparoscopy, from tethering of the bowel by the elastic mesentery, and from the strong tendency for debris and blood to adhere to the abdominal wall because of surface tension forces. The lack of adequate thoracic domain made thorascopy more difficult. Fluid in the thoracic cavity did not impair visualization because the fluid at 0-g does not loculate posteriorly, but disperses along the thoracic wall and mediastinal reflections. CONCLUSIONS: Performing minimally invasive procedures instead of open surgical procedures in a weightless environment has theoretical advantages, especially in the ability to prevent cabin atmosphere contamination from surgical fluids (blood, pus, irrigation). Visualization will become more important and practical as the endoscopic hardware is miniaturized from its current form, as endoscopic technology becomes more advanced, and as more surgically capable medical crew officers are present in future long-duration space exploration missions.
STS-26 Pilot Covey floats in life raft during JSC WETF exercises

NASA Image and Video Library

1988-07-08

S88-42425 (20 July 1988) --- STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing the newly designed launch and entry suit (LES), floats in single-occupant life raft in JSC Weightless Environment Training Facility (WETF) Bldg 29 pool. The simulation of the escape and rescue operations utilized the crew escape system (CES) pole method of egress from the Space Shuttle.
Gravity, calcium, and bone - Update, 1989

NASA Technical Reports Server (NTRS)

Arnaud, Sara B.; Morey-Holton, Emily

1990-01-01

Recent results obtained on skeletal adaptation, calcium metabolism, and bone browth during short-term flights and ground simulated-microgravity experiments are presented. Results demonstrate that two principal components of calcium metabolism respond within days to changes in body position and to weightlessness: the calcium endocrine system and bone characteristics. Furthermore, results of recent studies imply that bone biomechanics are more severely affected by spaceflight exposures than is the bone mass.
Plant biology in space: proceedings of the International Workshop, Bad Honnef, Germany, June 24-27, 1996

NASA Technical Reports Server (NTRS)

Scott, T. K. (Principal Investigator)

1997-01-01

Papers presented at the International Workshop on Plant Biology in Space include reviews, reports, and perspectives related to plant gravitational biology. Presentations focused on nine subject areas: gravitropism in unicellular plants, gravitropism in fungi, cell development, gravity perception in multicellular plants, gravity responses in multicellular plants, plant reproduction, evaluation of a clinostat for weightlessness simulation, biological life support systems, and future research.
STS-45 backup Payload Specialist Chappell during water egress training at JSC

NASA Technical Reports Server (NTRS)

1991-01-01

STS-45 Atlantis, Orbiter Vehicle (OV) 104, backup Payload Specialist Charles R. Chappell, wearing launch and entry suit (LES), is suspended via his parachute harness above JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Chappell will be dropped into the pool during the exercise which simulates a parachute landing into a body of water. SCUBA-equipped divers swimming in the pool will assist during the training.
STS-52 backup Payload Specialist Tryggvason during JSC bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, backup Payload Specialist Bjarni V. Tryggvason, wearing launch and entry suit (LES), checks his launch and entry helmet (LEH) fitting prior to participating in emergency egress (bailout) training exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. The WETF's 25-ft deep pool will serve as the ocean during this water landing simulation. Tryggvason represents the Canadian Space Agency (CSA).
STS-45 Payload Specialist Frimout prepares for water egress training at JSC

NASA Technical Reports Server (NTRS)

1991-01-01

STS-45 Atlantis, Orbiter Vehicle (OV) 104, Payload Specialist Dirk D. Frimout, a European Space Agency (ESA) crewmember from Belgium, smiles while taking a break from water egress exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. Frimout along with other STS-45 is participating a launch emergency egress simulation during which the crewmembers will be dropped from their parachute harnesses into the pool.
Cosmonaut Sergei Krikalev receives assistance from suit technician

NASA Technical Reports Server (NTRS)

1994-01-01

Sergei Krikalev, alternative mission specialist for STS-63, gets help from Dawn Mays, a Boeing suit technician. The cosmonaut was about to participate in a training session at JSC's Weightless Environment Training Facility (WETF). Wearing the training version of the extravehicular mobility unit (EMU) space suit, weighted to allow neutral buoyancy in the 25 feet deep WETF pool, Krikalev minutes later was underwater simulating a contingency spacewalk, or extravehicular activity (EVA).
STS-26 Pilot Covey floats in life raft during JSC WETF exercises

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing the newly designed launch and entry suit (LES), floats in single-occupant life raft in JSC Weightless Environment Training Facility (WETF) Bldg 29 pool. Covey has paddle-like gloves on his hands. The simulation of the escape and rescue operations utilized the crew escape system (CES) pole method of egress from the Space Shuttle.
STS-46 Pilot Allen and Payload Specialist Malerba in life rafts at JSC's WEFT

NASA Technical Reports Server (NTRS)

1992-01-01

STS-46 Atlantis, Orbiter Vehicle (OV) 104, Pilot Andrew M. Allen (foreground) and Italian Payload Specialist Franco Malerba, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), float in one-person life rafts during a launch emergency egress (bailout) simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. A SCUBA-equipped diver assists in the training activity.
Effect of simulated weightlessness on exercise-induced anaerobic threshold

NASA Technical Reports Server (NTRS)

Convertino, V. A.; Karst, G. M.; Kirby, C. R.; Goldwater, D. J.

1986-01-01

The effect of simulated weightlessness, induced by ten days of continuous bedrest (BR) in the -6 deg head-down position, on the exercise-induced anaerobic threshold (AT) was determined by comparing specific ventilatory and gas-exchange measurements during an incremental ergometer test performed before and after BR. The primary index for determining the exercise-induced AT values of each subject was visual identification of the workrate or oxygen uptake (VO2) at which the ratio of the expired minute ventilation volume (VE) to VO2 exhibited a systematic increase without a concomitant increase in the VE/VCO2 value. Following BR, the mean VO2max of the subjects decreased by 7.0 percent, and the AT decreased from a mean of 1.26 L/min VO2 before BR to 0.95 L/min VO2 after BR. The decrease in AT was manifested by a decrease in both absolute and relative workrates. The change in AT correlated significantly with the change in plasma volume but not with the change in VO2max. The results suggest that the reduction in AT cannot be completely explained by the reduction in VO2, and that the AT decrease is associated with the reduction in intravascular fluid volume.
Effect of weightlessness on mineral saturation of bone tissue

NASA Technical Reports Server (NTRS)

Krasnykh, I. G.

1975-01-01

X-ray photometry of bone density established dynamic changes in mineral saturation of bone tissues for Soyuz spacecraft and Salyut orbital station crews. Calcaneus optical bone densities in all crew members fell below initial values; an increase in spacecrew exposure time to weightlessness conditions also increased the degree of decalcification. Demineralization under weightlessness conditions took place at a higher rate than under hypodynamia.

Influence of gravity on cardiac performance.

PubMed

Pantalos, G M; Sharp, M K; Woodruff, S J; O'Leary, D S; Lorange, R; Everett, S D; Bennett, T E; Shurfranz, T

1998-01-01

Results obtained by the investigators in ground-based experiments and in two parabolic flight series of tests aboard the NASA KC-135 aircraft with a hydraulic simulator of the human systemic circulation have confirmed that a simple lack of hydrostatic pressure within an artificial ventricle causes a decrease in stroke volume of 20%-50%. A corresponding drop in stroke volume (SV) and cardiac output (CO) was observed over a range of atrial pressures (AP), representing a rightward shift of the classic CO versus AP cardiac function curve. These results are in agreement with echocardiographic experiments performed on space shuttle flights, where an average decrease in SV of 15% was measured following a three-day period of adaptation to weightlessness. The similarity of behavior of the hydraulic model to the human system suggests that the simple physical effects of the lack of hydrostatic pressure may be an important mechanism for the observed changes in cardiac performance in astronauts during the weightlessness of space flight.
A method for estimating the mass properties of a manipulator by measuring the reaction moments at its base

NASA Technical Reports Server (NTRS)

West, Harry; Papadopoulos, Evangelos; Dubowsky, Steven; Cheah, Hanson

1989-01-01

Emulating on earth the weightlessness of a manipulator floating in space requires knowledge of the manipulator's mass properties. A method for calculating these properties by measuring the reaction forces and moments at the base of the manipulator is described. A manipulator is mounted on a 6-DOF sensor, and the reaction forces and moments at its base are measured for different positions of the links as well as for different orientations of its base. A procedure is developed to calculate from these measurements some combinations of the mass properties. The mass properties identified are not sufficiently complete for computed torque and other dynamic control techniques, but do allow compensation for the gravitational load on the links, and for simulation of weightless conditions on a space emulator. The algorithm has been experimentally demonstrated on a PUMA 260 and used to measure the independent combinations of the 16 mass parameters of the base and three proximal links.
Spaceflight Nutrition Research: Platforms and Analogs

NASA Technical Reports Server (NTRS)

Smith, Scott M.; Uchakin, Peter N.; Tobin, Brian W.

2002-01-01

Understanding human adaptation to weightlessness requires research in either the true microgravity environment or iii a ground-based model. Over the years, many flight platforms have been available, and many ground models have emerged for both human and animal studies of the effects of spaceflight on physiology. In this review, we provide a brief description of these models and the main points to be considered when choosing a model. We do not intend to provide a comprehensive overview of each platform or model, but rather to provide the reader with an overview of the options available for space nutrition research, and the relative merits and/or drawbacks of each.
Apollo food technology

NASA Technical Reports Server (NTRS)

Smith, M. C., Jr.; Heidelbaugh, N. D.; Rambaut, P. C.; Rapp, R. M.; Wheeler, H. O.; Huber, C. S.; Bourland, C. T.

1975-01-01

Large improvements and advances in space food systems achieved during the Apollo food program are discussed. Modifications of the Apollo food system were directed primarily toward improving delivery of adequate nutrition to the astronaut. Individual food items and flight menus were modified as nutritional countermeasures to the effects of weightlessness. Unique food items were developed, including some that provided nutritional completeness, high acceptability, and ready-to-eat, shelf-stable convenience. Specialized food packages were also developed. The Apollo program experience clearly showed that future space food systems will require well-directed efforts to achieve the optimum potential of food systems in support of the physiological and psychological well-being of astronauts and crews.
An overview of gravitational physiology

NASA Technical Reports Server (NTRS)

Miquel, Jaime; Souza, Kenneth A.

1991-01-01

The focus of this review is on the response of humans and animals to the effects of the near weightless condition occurring aboard orbiting spacecraft. Gravity is an omnipresent force that has been a constant part of our lives and of the evolution of all living species. Emphasis is placed on the general mechanisms of adaptation to altered gravitational fields and vectors, i.e., both hypo- and hypergravity. A broad literature review of gravitational biology was conducted and the general state of our knowledge in this area is discussed. The review is specifically targeted at newcomers to the exciting and relatively new area of space and gravitational biology.
Effects of the Cosmos 1129 Soviet paste diet on body composition in the growing rat

NASA Technical Reports Server (NTRS)

Pace, N.; Rahlmann, D. F.; Smith, A. H.; Pitts, G. C.

1981-01-01

Six Simonsen albino rats (45 days of age) were placed on a regimen of 40 g/day the semipurified Soviet paste diet used in the 18.5 day Cosmos 1129 spacecraft was to support the rats for various experiments on the physiological effects of weightlessness. The animals were maintained on the Soviet paste diet for 35 days, metabolic rate was measured and body composition was determined by direct analysis. The results were compared with a control group of rates of the same age, which had been kept on a standard commercial grain diet during the same period of time.
OFO experimental techniques and preliminary conclusions - Is artificial gravity needed during prolonged weightlessness.

NASA Technical Reports Server (NTRS)

Gualtierotti, T.; Bracchi, F.

1972-01-01

The technique of single unit recording from body systems generating electrical pulses coherent with their basic function (CNS, muscles, sense organs) has been proved feasible during the OFO A orbital flight, an automatic physiological experiment. The results of recording 155 hours of orbital flight of pulses from the nerve fibres of four vestibular gravity sensors in two bull frogs indicate that the vestibular organ adjusts to zero g. As all the other biological changes observed during orbit are due to lack of exercise, it is concluded that artificial gravity might not be necessary during prolonged space missions or on low gravity celestial bodies.
Plant and Animal Gravitational Biology. Part 1

NASA Technical Reports Server (NTRS)

1997-01-01

Session TA2 includes short reports covering: (1) The Interaction of Microgravity and Ethylene on Soybean Growth and Metabolism; (2) Structure and G-Sensitivity of Root Statocytes under Different Mass Acceleration; (3) Extracellular Production of Taxanes on Cell Surfaces in Simulated Microgravity and Hypergravity; (4) Current Problems of Space Cell Phytobiology; (5) Biological Consequences of Microgravity-Induced Alterations in Water Metabolism of Plant Cells; (6) Localization of Calcium Ions in Chlorella Cells Under Clinorotation; (7) Changes of Fatty Acids Content of Plant Cell Plasma Membranes under Altered Gravity; (8) Simulation of Gravity by Non-Symmetrical Vibrations and Ultrasound; and (9) Response to Simulated weightlessness of In Vitro Cultures of Differentiated Epithelial Follicular Cells from Thyroid.
Parabolic flight experience is related to increased release of stress hormones.

PubMed

Schneider, Stefan; Brümmer, Vera; Göbel, Simon; Carnahan, Heather; Dubrowski, Adam; Strüder, Heiko K

2007-06-01

Numerous studies have shown significant effects of weightlessness on adaptational processes of the CNS, cardiovascular and/or muscular system. Most of these studies have been carried out during parabolic flights, using the recurring 20 s of weightlessness at each parabola. Although some of these studies reported on potential influences not only of weightlessness but also of the stressful situation within a parabolic flight, especially provoked by the ongoing changes between 1.8, 1 and 0 G, so far there seems to be only marginal information about objective parameters of stress evoked by parabolic flights. By collecting blood samples from a permanent venous catheter several times during parabolic flights, we were able to show an increase of prolactin, cortisol and ACTH in the course of a 120 min flight. We conclude, therefore, that previous reported effects of weightlessness on adaptational processes may be affected not only by weightlessness but also by the exposure to other stressors experienced within the environment of a Zero-G airbus.
Spaceflight effects on adult rat muscle protein, nucleic acids, and amino acids

NASA Technical Reports Server (NTRS)

Steffen, J. M.; Musacchia, X. J.

1986-01-01

Exposure to conditions of weightlessness has been associated with decrements in muscle mass and strength. The present studies were undertaken to determine muscle responses at the cellular level. Male Sprague-Dawley rats (360-410 g) were exposed to 7 days of weightlessness during the Spacelab-3 shuttle flight (May 1985). Animals were killed 12 h postflight, and soleus (S), gastrocnemius (G), and extensor digitorum longus (EDL) muscles were excised. Muscle protein, RNA, and DNA were extracted and quantified. Differential muscle atrophy was accompanied by a significant (P less than 0.05) reduction in total protein only in S muscles. There were no significant changes in protein concentration (mg/g) in the muscles examined. In S muscles from flight animals, sarcoplasmic protein accounted for a significantly greater proportion of total protein that in ground controls (37.5 vs. 32.5%). Tissue concentrations (nmol/g) of asparagine-aspartate, glutamine-glutamate, glycine, histidine, and lysine were significantly reduced (from 17 to 63%) in S muscles from flight animals, but only glutamine-glutamate levels were decreased in the G and EDL. Muscle DNA content (microgram) was unchanged in the tissues examined, but S muscle DNA concentration (micrograms/mg) increased 27%. RNA content (micrograms) was significantly (P less than 0.025) reduced in S (-28%) and G(-22%) muscles following spaceflight. These results identify specific alterations in rat skeletal muscle during short term (7-day) exposure to weightlessness and compare favorably with observations previously obtained from ground-based suspension simulations.
Possibility of long-distance heat transport in weightlessness using supercritical fluids

NASA Astrophysics Data System (ADS)

Beysens, D.; Chatain, D.; Nikolayev, V. S.; Ouazzani, J.; Garrabos, Y.

2010-12-01

Heat transport over large distances is classically performed with gravity or capillarity driven heat pipes. We investigate here whether the “piston effect,” a thermalization process that is very efficient in weightlessness in compressible fluids, could also be used to perform long-distance heat transfer. Experiments are performed in a modeling heat pipe (16.5 mm long, 3 mm inner diameter closed cylinder), with nearly adiabatic polymethylmethacrylate walls and two copper base plates. The cell is filled with H2 near its gas-liquid critical point (critical temperature: 33 K). Weightlessness is achieved by submitting the fluid to a magnetic force that compensates gravity. Initially the fluid is isothermal. Then heat is sent to one of the bases with an electrical resistance. The instantaneous amount of heat transported by the fluid is measured at the other end. The data are analyzed and compared with a two-dimensional numerical simulation that allows an extrapolation to be made to other fluids (e.g., CO2 , with critical temperature of 300 K). The major result is concerned with the existence of a very fast response at early times that is only limited by the thermal properties of the cell materials. The yield in terms of ratio, injected or transported heat power, does not exceed 10-30% and is limited by the heat capacity of the pipe. These results are valid in a large temperature domain around the critical temperature.
Reactivity of organism in prolonged space flights

NASA Technical Reports Server (NTRS)

Vasilyev, P. V.

1980-01-01

An analysis of published data are presented as well as the results of experiments which show that the state of weightlessness and hypodynamia result in a reduced orthostatic and vestibular resistance, increased sensitivity to infections, decreased endurance of accelerations and physical exercises, and altered reactivity of the organism to drugs. Various consequences of weightlessness on the human body, especially weightlessness combined with other factors linked to long space flights are also considered.
M.I.T./Canadian vestibular experiments on the Spacelab-1 mission. I - Sensory adaptation to weightlessness and readaptation to one-g: An overview

NASA Technical Reports Server (NTRS)

Young, L. R.; Oman, C. M.; Lichtenberg, B. K.; Watt, D. G. D.; Money, K. E.

1986-01-01

Human sensory/motor adaptation to weightlessness and readaptation to earth's gravity are assessed. Preflight and postflight vestibular and visual responses for the crew on the Spacelab-1 mission are studied; the effect of the abnormal pattern of otolith afferent signals caused by weightlessness on the pitch and roll perception and postural adjustments of the subjects are examined. It is observed that body position and postural reactions change due to weightlessness in order to utilize the varied sensory inputs in a manner suited to microgravity conditions. The aspects of reinterpretation include: (1) tilt acceleration reinterpretation, (2) reduced postural response to z-axis linear acceleration, and (3) increased attention to visual cues.
Spaceflight and bone turnover - Correlation with a new rat model of weightlessness

NASA Technical Reports Server (NTRS)

Morey, E. R.

1979-01-01

Earlier manned spaceflight studies have revealed that the near-weightless environment of orbital flight produce certain biological effects in humans, including abnormalities in mineral metabolism. The data collected were compatible with bone mineral loss. Cosmos 782 and 936 experiments have shown a decrease in rat bone formation rate. In this paper, a rat model of weightlessness is described, which is unique in that the animal is free to move about a 360-deg arc. The model meets the requirements for an acceptable system. Data from the model and spaceflight are presented. Many of the responses noted in suspended animals indicate that the model closely mimics results from rats and man exposed to near-weightlessness during orbital spaceflight.
European Space Agency (ESA) Mission Specialist Nicollier trains in JSC's WETF

NASA Technical Reports Server (NTRS)

1987-01-01

European Space Agency (ESA) Mission Specialist (MS) Claude Nicollier (left) is briefed by Randall S. McDaniel on Space Shuttle extravehicular activity (EVA) tools and equipment prior to donning an extravehicular mobility unit and participating in an underwater EVA simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Nicollier is holding the EMU mini workstation. Other equipment on the table includes EVA tool caddies and EVA crewmember safety tethers.
Life sciences and space research 25 (1). Gravitational biology; Interdisciplinary Scientific Commission F of the COSPAR Plenary Meeting, 29th, Washington, DC, Aug. 28-Sep. 5, 1992

NASA Technical Reports Server (NTRS)

Cogoli, A. (Editor); Cogoli-Greuter, M. (Editor); Gruener, R. (Editor); Sievers, A. (Editor); Ubbels, G. A. (Editor); Halstead, T. W. (Editor); Ross, M. D. (Editor); Roux, S. J. (Editor); Oser, H. (Editor); Lujan, B. F. (Editor)

1994-01-01

The conference includes papers describing theories and models of cell biology in microgravity and weightlessness; experimental research on cellular responses to altered gravity in plants and animals, natural and simulated; graviresponses in plants; gravitational effects in developmental biology; mechanisms of gravisensing; effects on animals and humans; and educational programs in Space Life Sciences.
STS-50 Payload Specialist Trinh during JSC WETF Bailout Exercises in Bldg 29

NASA Technical Reports Server (NTRS)

1992-01-01

STS-50 Columbia, Orbiter Vehicle (OV) 102, United States Microgravity Laboratory 1 (USML-1) Payload Specialist Eugene H. Trinh, wearing launch and entry suit (LES), listens to instructions prior to participating in launch emergency egress (bailout) exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. The WETF's 25-foot deep pool will simulate the ocean as crewmembers familiarize themselves with procedures associated with a bailout and subsequent water landing.
STS-52 Pilot Baker, in LES, dons parachute during JSC WETF bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Pilot Michael A. Baker is assisted with a training version of his Shuttle partial-pressure launch and entry suit (LES). A technician adjusts his parachute harness prior to the emergency egress (bailout) training exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. The WETF's 25-ft deep pool will be used in this simulation of a water landing.
STS-52 Mission Specialist Veach, in LES/LEH, during JSC WETF bailout exercise

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist (MS) Charles Lacy Veach, wearing launch and entry suit (LES) and launch and entry helmet (LEH), smiles as he observes emergency egress (bailout) training exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Veach waits his turn to be dropped into the WETF's 25-ft deep pool which will simulate the ocean during of his water landing.
STS-39 MS Hieb prepares for emergency egress exercises in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1990-01-01

STS-39 Mission Specialist (MS) Richard J. Hieb, wearing launch and entry suit (LES), parachute pack, and communications carrier assembly (CCA), listens to instructions prior to emergency egress bailout exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. The WETF's 25 ft deep pool will simulate the ocean. Crewmembers will practice procedures necessary in the event of an emergency onboard the Space Shuttle requiring a water landing.

STS-26 Pilot Covey floats in life raft during JSC WETF exercises

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Pilot Richard O. Covey, wearing the newly designed launch and entry suit (LES), floats in single-occupant life raft in JSC Weightless Environment Training Facility (WETF) Bldg 29 pool. Covey pulls and fastens life raft protective cover over himself. The simulation of the escape and rescue operations utilized the crew escape system (CES) pole method of egress from the Space Shuttle.
STS-52 Mission Specialist Veach in life raft during JSC bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist (MS) Charles Lacy Veach, wearing launch and entry suit (LES) and launch and entry helmet (LEH), floats in a single person life raft during emergency egress (bailout) training exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. SCUBA-equipped divers look on. The bailout exercises utilize the WETF's 25-foot deep pool as the ocean for this water landing simulation.
Space Biology and Aerospace Medicine, Number 4, 1977

DTIC Science & Technology

1977-10-01

using a blood transfusion system. In the presence of diastolic pressure (DP) of 85-95 mm Hg, 6 intravenous injections were ordered in a dosage of 150...submersion in vertical position (see Figure 3b), there is compensation for hydrostatic blood pressure in vessels by the corresponding...7-19]. C. Use of Stands to Simulate Weightlessness The use of special stands , with diminished support reactions, in which a man or animal is
Premission and postmission simulation studies of the foot-controlled maneuvering unit for Skylab experiment T-020. [astronaut maneuvering equipment - space environment simulation

NASA Technical Reports Server (NTRS)

Hewes, D. E.; Glover, K. E.

1975-01-01

A Skylab experiment was conducted to study the maneuvering capabilities of astronauts using a relatively simple self-locomotive device, referred to as the foot-controlled maneuvering unit, and to evaluate the effectiveness of ground-based facilities simulating the operation of this device in weightless conditions of space. Some of the special considerations given in the definition and development of the experiment as related to the two ground-based simulators are reviewed. These simulators were used to train the test subjects and to obtain baseline data which could be used for comparison with the in-flight tests that were performed inside the Skylab orbital workshop. The results of both premission and postmission tests are discussed, and subjective comparisons of the in-flight and ground-based test conditions are presented.
Motor control of landing from a countermovement jump in simulated microgravity.

PubMed

Gambelli, C N; Theisen, D; Willems, P A; Schepens, B

2016-05-15

Landing from a jump implies proper positioning of the lower limb segments and the generation of an adequate muscular force to cope with the imminent collision with the ground. This study assesses how a hypogravitational environment affects the control of landing after a countermovement jump (CMJ). Eight participants performed submaximal CMJs on Earth (1-g condition) and in a weightlessness environment with simulated gravity conditions generated by a pull-down force (1-, 0.6-, 0.4-, and 0.2-g0 conditions). External forces applied to the body, movements of the lower limb segments, and muscular activity of six lower limb muscles were recorded. 1) All subjects were able to jump and stabilize their landing in all experimental conditions, except one subject in 0.2-g0 condition. 2) The mechanical behavior of lower limb muscles switches during landing from a stiff spring to a compliant spring associated with a damper. This is true whatever the environment, on Earth as well as in environments where sensory inputs are altered. 3) The motor control of landing in simulated 1 g0 reveals an increased "safety margin" strategy, illustrated by increased stiffness and damping coefficient compared with landing on Earth. 4) The motor command is adjusted to the task constraints: muscular activity of lower limb extensors and flexors, stiffness and damping coefficient decrease according to the decreased gravity level. Our results show that even if in daily living gravity can be perceived as a constant factor, subjects can cope with altered sensory signals, taking advantage of the remaining information (visual and/or decreased proprioceptive inputs). Copyright © 2016 the American Physiological Society.
Regulation of body fluid volume and electrolyte concentrations in spaceflight.

PubMed

Smith, S M; Krauhs, J M; Leach, C S

1997-01-01

Despite a number of difficulties in performing experiments during weightlessness, a great deal of information has been obtained concerning the effects of spaceflight on the regulation of body fluid and electrolytes. Many paradoxes and questions remain, however. Although body mass, extracellular fluid volume, and plasma volume are reduced during spaceflight and remain so at landing, the changes in total body water are comparatively small. Serum or plasma sodium and osmolality have generally been unchanged or reduced during the spaceflight, and fluid intake is substantially reduced, especially during the first of flight. The diuresis that was predicted to be caused by weightlessness, has only rarely been observed as an increased urine volume. What has been well established by now, is the occurrence of a relative diuresis, where fluid intake decreases more than urine volume does. Urinary excretion of electrolytes has been variable during spaceflight, but retention of fluid and electrolytes at landing has been consistently observed. The glomerular filtration rate was significantly elevated during the SLS missions, and water and electrolyte loading tests have indicated that renal function is altered during readaptation to Earth's gravity. Endocrine control of fluid volumes and electrolyte concentrations may be altered during weightlessness, but levels of hormones in body fluids do not conform to predictions based on early hypotheses. Antidiuretic hormone is not suppressed, though its level is highly variable and its secretion may be affected by space motion sickness and environmental factors. Plasma renin activity and aldosterone are generally elevated at landing, consistent with sodium retention, but inflight levels have been variable. Salt intake may be an important factor influencing the levels of these hormones. The circadian rhythm of cortisol has undoubtedly contributed to its variability, and little is known yet about the influence of spaceflight on circadian rhythms. Atrial natriuretic peptide does not seem to play an important role in the control of natriuresis during spaceflight. Inflight activity of the sympathetic nervous system, assessed by measuring catecholamines and their metabolites and precursors in body fluids, generally seems to be no greater than on Earth, but this system is usually activated at landing. Collaborative experiments on the Mir and the International Space Station should provide more of the data needed from long-term flights, and perhaps help to resolve some of the discrepancies between U.S. and Russian data. The use of alternative methods that are easier to execute during spaceflight, such as collection of saliva instead of blood and urine, should permit more thorough study of circadian rhythms and rapid hormone changes in weightlessness. More investigations of dietary intake of fluid and electrolytes must be performed to understand regulatory processes. Additional hormones that may participate in these processes, such as other natriuretic hormones, should be determined during and after spaceflight. Alterations in body fluid volume and blood electrolyte concentrations during spaceflight have important consequences for readaptation to the 1-G environment. The current assessment of fluid and electrolyte status during weightlessness and at landing and our still incomplete understanding of the processes of adaptation to weightlessness and readaptation to Earth's gravity have resulted in the development of countermeasures that are only partly successful in reducing the postflight orthostatic intolerance experienced by astronauts and cosmonauts. More complete knowledge of these processes can be expected to produce countermeasures that are even more successful, as well as expand our comprehension of the range of adaptability of human physiologic processes.
Regulation of body fluid volume and electrolyte concentrations in spaceflight

NASA Technical Reports Server (NTRS)

Smith, S. M.; Krauhs, J. M.; Leach, C. S.

1997-01-01

Despite a number of difficulties in performing experiments during weightlessness, a great deal of information has been obtained concerning the effects of spaceflight on the regulation of body fluid and electrolytes. Many paradoxes and questions remain, however. Although body mass, extracellular fluid volume, and plasma volume are reduced during spaceflight and remain so at landing, the changes in total body water are comparatively small. Serum or plasma sodium and osmolality have generally been unchanged or reduced during the spaceflight, and fluid intake is substantially reduced, especially during the first of flight. The diuresis that was predicted to be caused by weightlessness, has only rarely been observed as an increased urine volume. What has been well established by now, is the occurrence of a relative diuresis, where fluid intake decreases more than urine volume does. Urinary excretion of electrolytes has been variable during spaceflight, but retention of fluid and electrolytes at landing has been consistently observed. The glomerular filtration rate was significantly elevated during the SLS missions, and water and electrolyte loading tests have indicated that renal function is altered during readaptation to Earth's gravity. Endocrine control of fluid volumes and electrolyte concentrations may be altered during weightlessness, but levels of hormones in body fluids do not conform to predictions based on early hypotheses. Antidiuretic hormone is not suppressed, though its level is highly variable and its secretion may be affected by space motion sickness and environmental factors. Plasma renin activity and aldosterone are generally elevated at landing, consistent with sodium retention, but inflight levels have been variable. Salt intake may be an important factor influencing the levels of these hormones. The circadian rhythm of cortisol has undoubtedly contributed to its variability, and little is known yet about the influence of spaceflight on circadian rhythms. Atrial natriuretic peptide does not seem to play an important role in the control of natriuresis during spaceflight. Inflight activity of the sympathetic nervous system, assessed by measuring catecholamines and their metabolites and precursors in body fluids, generally seems to be no greater than on Earth, but this system is usually activated at landing. Collaborative experiments on the Mir and the International Space Station should provide more of the data needed from long-term flights, and perhaps help to resolve some of the discrepancies between U.S. and Russian data. The use of alternative methods that are easier to execute during spaceflight, such as collection of saliva instead of blood and urine, should permit more thorough study of circadian rhythms and rapid hormone changes in weightlessness. More investigations of dietary intake of fluid and electrolytes must be performed to understand regulatory processes. Additional hormones that may participate in these processes, such as other natriuretic hormones, should be determined during and after spaceflight. Alterations in body fluid volume and blood electrolyte concentrations during spaceflight have important consequences for readaptation to the 1-G environment. The current assessment of fluid and electrolyte status during weightlessness and at landing and our still incomplete understanding of the processes of adaptation to weightlessness and readaptation to Earth's gravity have resulted in the development of countermeasures that are only partly successful in reducing the postflight orthostatic intolerance experienced by astronauts and cosmonauts. More complete knowledge of these processes can be expected to produce countermeasures that are even more successful, as well as expand our comprehension of the range of adaptability of human physiologic processes.
Laparoscopic surgery in weightlessness

NASA Technical Reports Server (NTRS)

Campbell, M. R.; Billica, R. D.; Jennings, R.; Johnston, S. 3rd

1996-01-01

BACKGROUND: Performing a surgical procedure in weightlessness has been shown not to be any more difficult than in a 1g environment if the requirements for the restraint of the patient, operator, and surgical hardware are observed. The feasibility of performing a laparoscopic surgical procedure in weightlessness, however, has been questionable. Concerns have included the impaired visualization from the lack of gravitational retraction of the bowel and from floating debris such as blood. METHODS: In this project, laparoscopic surgery was performed on a porcine animal model in the weightlessness of parabolic flight. RESULTS: Visualization was unaffected due to the tethering of the bowel by the elastic mesentery and the strong tendency for debris and blood to adhere to the abdominal wall due to surface tension forces. CONCLUSIONS: There are advantages to performing a laparoscopic instead of an open surgical procedure in a weightless environment. These will become important as the laparoscopic support hardware is miniaturized from its present form, as laparoscopic technology becomes more advanced, and as more surgically capable crew medical officers are present in future long-duration space-exploration missions.
Physical examination during space flight

NASA Technical Reports Server (NTRS)

Harris, B. A. Jr; Billica, R. D.; Bishop, S. L.; Blackwell, T.; Layne, C. S.; Harm, D. L.; Sandoz, G. R.; Rosenow, E. C. 3rd

1997-01-01

OBJECTIVE: To develop techniques for conducting a physical examination in microgravity and to describe and document the physiologic changes noted with use of a modified basic physical examination. DESIGN: On the basis of data gathered from physical examinations on KC-135 flights, three physical variables were assessed serially in astronauts during two shuttle missions (of 8- and 10-day duration, respectively). Preflight, in-flight, and postflight examinations were conducted by trained physician-astronauts or flight surgeons, who used this modified examination. MATERIAL AND METHODS: Five male and two female crewmembers participated in the "hands-on" physical examination of all physiologic systems except the genitourinary system. Level of edema, intensity of bowel sounds, and peripheral reflexes were assessed and graded. RESULTS: This investigation identified unique elements of a physical examination performed during space flight that will assist in the development of standard methods for conducting examinations of astronauts in weightlessness. In addition, demonstrable changes induced by microgravity were noted in most physiologic systems examined. CONCLUSION: The data support the hypothesis that the microgravity examination differs from that conducted on earth or in a 1g environment. In addition, alterations in the physiologic response can be detected with use of hands-on technique. These data are invaluable in the development of optimal medical care for humans in space.
STS-55 MS3 Harris, wearing EMU and CCA, prepares for EVA simulation at JSC WETF

NASA Technical Reports Server (NTRS)

1991-01-01

STS-55 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist 3 (MS3) Bernard A. Harris, Jr, suited in the extravehicular mobility unit (EMU) upper torso and communications carrier assembly (CCA), smiles as he prepares for an underwater simulation in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. This portrait-like view captures Harris as he checks out his communications equipment. Once fully suited, Harris will be lowered into the WETF's 25-foot deep pool for an underwater contingency extravehicular activity (EVA) simulation. There is no scheduled EVA for the 1993 flight but each spaceflight crew includes astronauts trained for a variety of contingency tasks that could require exiting the shirt-sleeve environment of a Shuttle's cabin.
Materials of the final reports on the joint Soviet-American experiment on the Kosmos-936 biosatellite

NASA Technical Reports Server (NTRS)

Timofeyev-Resolskiy, N. V.; Parfenov, G. P.; Tairbekov, M.; Platonova, R. N.; Rostopshina, A. V.; Zhvalikovskaya, V. P.; Mosgovaya, I. Y.; Shvets, V. N.; Kovalev, Y. Y.; Dudkin, V. Y.

1978-01-01

Biological experiments onboard the Kosmos-936 investigated the effect of weightlessness on the basic components of cells, the genetic structure and energy apparatus. Genetic studies were made on the Drosophila melanogaster. Experiments were made on higher vegetation and fungi as well. The results indicate that weightlessness cannot be the principal barrier for normal development. An experiment with ectopic osteogenesis in weightlessness was carried out. Measurements were made of cosmic radiation inside and outside the biosatellite.
Simulated microgravity affects some biological characteristics of Lactobacillus acidophilus.

PubMed

Shao, Dongyan; Yao, Linbo; Riaz, Muhammad Shahid; Zhu, Jing; Shi, Junling; Jin, Mingliang; Huang, Qingsheng; Yang, Hui

2017-04-01

The effects of weightlessness on enteric microorganisms have been extensively studied, but have mainly been focused on pathogens. As a major component of the microbiome of the human intestinal tract, probiotics are important to keep the host healthy. Accordingly, understanding their changes under weightlessness conditions has substantial value. This study was carried out to investigate the characteristics of Lactobacillus acidophilus, a typical probiotic for humans, under simulated microgravity (SMG) conditions. The results revealed that SMG had no significant impact on the morphology of L. acidophilus, but markedly shortened its lag phase, enhanced its growth rate, acid tolerance ability up to pH < 2.5, and the bile resistance at the bile concentration of <0.05%. SMG also decreased the sensitivity of L. acidophilus to cefalexin, sulfur gentamicin, and sodium penicillin. No obvious effect of SMG was observed on the adhesion ability of L. acidophilus to Caco-2 cells. Moreover, after SMG treatment, both the culture of L. acidophilus and its liquid phase exhibited higher antibacterial activity against S. typhimurium and S. aureus in a time-dependent manner. The SMG treatment also increased the in vitro cholesterol-lowering ability of L. acidophilus by regulating the expression of the key cholesterol metabolism genes CYP7A1, ABCB11, LDLR, and HMGCR in the HepG2 cell line. Thus, the SMG treatment did have considerable influence on some biological activities and characteristics of L. acidophilus related to human health. These findings provided valuable information for understanding the influence of probiotics on human health under simulated microgravity conditions, at least.
Morphological and histochemical studies of bone and cartilage during periods of stimulated weightlessness

NASA Technical Reports Server (NTRS)

Doty, S. B.

1984-01-01

Rats which were subjected to spaceflight for 2-4 weeks showed considerable loss in ability to form new bone. Animals which are placed into nonweight bearing positions, as a model to simulate the absence of gravity here on the Earth's surface. Show a similar decline in new bone formation. It is suggested that the mechanisms underlying these changes may be the result of reduced transmission of gravitational force to the skeletal cells.
SPACESUIT DONNING AND DOFFING - ZERO-G TRAINING - DON PETERSON - STS-6

NASA Image and Video Library

1982-07-14

Spacesuit Donning and Doffing in Zero-G Training for Don Peterson of the STS-6 Crew with Astronaut Jerry Ross assisting; and, apparatus for testing the JSC Mechanically-Induced Settling Technology (MIST) Experiment. The training is being held aboard the KC-135 to simulate weightlessness. He is being assisted to don the lower torso of the Extravehicular Mobility Unit (EMU) by an ILC Technician. 1. ASTRONAUT ROSS, JERRY L. - ZERO-G SUITING 2. SHUTTLE - EXPERIMENTS (MIST)
STS-52 MS Jemison, in LES/LEH, during JSC WETF bailout exercise

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist (MS) Tamara E. Jernigan, wearing launch and entry suit (LES) and launch and entry helmet (LEH), listens to a briefing about water landings during an emergency egress (bailout) training exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. Jernigan waits her turn to be dropped into the WETF's 25-ft deep pool which will simulate the ocean during of her water landing.
STS-47 Commander Gibson and MS Apt in JSC WETF for bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-47 Endeavour, Orbiter Vehicle (OV) 105, Commander Robert L. Gibson, wearing launch and entry suit (LES) and launch and entry helmet (LEH), listens to instructions before participating in launch emergency egress (bailout) exercises in JSC's Weightless Environment Trainining Facility (WETF) Bldg 29. Mission Specialist (MS) Jerome Apt, wearing LES and LES parachute, is seen in the background. This exercise is conducted in the WETF pool to simulate a water landing.
STS-51 astronauts participate in emergency bailout training in WETF

NASA Image and Video Library

1993-03-24

S93-31929 (24 March 1993) --- The three mission specialists for NASA's STS-51 mission watch as a crewmate (out of frame) simulates a parachute jump into water during emergency bailout training exercises at the Johnson Space Center's Weightless Environment Training Facility (WET-F). Left to right are astronauts Daniel W. Bursch, Carl E. Walz and James H. Newman. Out of frame are astronauts Frank L. Culbertson and William F. Readdy, commander and pilot, respectively.
STS-52 Payload Specialist MacLean floats in pool during JSC bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Payload Specialist Steven G. MacLean, wearing launch and entry suit (LES) and clamshell helmet, is assisted by SCUBA-equipped divers as he floats in pool during emergency egress (bailout) training exercises in JSC's Weightless Environment Training Facility Bldg 29. Bailout exercises utilize the WETF's 25-foot deep pool as the ocean during this water landing simulation. MacLean represents the Canadian Space Agency (CSA).
STS-55 MS3 Harris listens to technician during JSC WETF egress exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-55 Columbia, Orbiter Vehicle (OV) 102, Mission Specialist 3 (MS3) Bernard A. Harris, Jr, wearing launch and entry suit (LES), launch and entry helmet (LEH), and parachute, listens to technician Karen Porter's instructions prior to launch emergency egress (bailout) exercises. The session, held in JSC's Weightless Environment Training Facility (WETF) Bldg 29, used the facility's 25-foot deep pool to simulate the ocean as Harris and other crewmembers practiced water bailout procedures.
The Application of Systems Analysis and Mathematical Models to the Study of Erythropoiesis During Space Flight

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1974-01-01

Included in the report are: (1) review of the erythropoietic mechanisms; (2) an evaluation of existing models for the control of erythropoiesis; (3) a computer simulation of the model's response to hypoxia; (4) an hypothesis to explain observed decreases in red blood cell mass during weightlessness; (5) suggestions for further research; and (6) an assessment of the role that systems analysis can play in the Skylab hematological program.

Does Simulated Spaceflight Modify Epigenetic Status During Bone Remodeling?

NASA Technical Reports Server (NTRS)

Thomas, Nicholas J.; Stevick, Rebecca J.; Tran, Luan H.; Nalavadi, Mohit O.; Almeida, Eduardo A.C.; Globus, Ruth K.; Alwood, Joshua S.

2015-01-01

Little is known about the effects of spaceflight conditions on epigenetics. The term epigenetics describes changes to the genome that can affect expression of a gene without changes to the sequence of DNA. Epigenetic processes are thought to underlie cellular differentiation, where transcription of specific genes occurs in response to key stimuli, and may be heritable - passing from one cell to its daughter cell. We hypothesize that the mechanical environment during spaceflight, namely microgravity-induced weightlessness or exercise regulate gene expression in the osteoblast-lineage cells both to control bone formation by osteoblasts and bone resorption by osteoclasts, which continually shapes bone structure throughout life. Similarly we intend to evaluate how radiation regulates these same bone cell activity and differentiation related genes. We further hypothesize that the regulation in bone cell gene expression is at least partially controlled through epigenetic mechanisms of methylation or small non-coding RNA (microRNAs). We have acquired preliminary data suggesting that global genome methylation is modified in response to axial compression of the tibia - a model of exercise. We intend to pursue these hypotheses wherein we will evaluate changes in gene expression and, congruently, changes in epigenetic state in bones from mice subjected to the aforementioned conditions: hindlimb unloading to simulate weightlessness, axial compression of the tibia, or radiation exposure in order to gain insight into the role of epigenetics in spaceflight-induced bone loss.
Identification of specific gravity sensitive signal transduction pathways in human A431 carcinoma cells

NASA Astrophysics Data System (ADS)

Rijken, P. J.; de Groot, R. P.; Kruijer, W.; de Laat, S. W.; Verkleij, A. J.; Boonstra, J.

Epidermal growth factor (EGF) activates a well characterized signal transduction cascade in human A431 epidermoid carcinoma cells. The influence of gravity on EGF-induced EGF-receptor clustering and early gene expression as well as on actin polymerization and actin organization have been investigated. Different signalling pathways induced by the agents TPA, forskolin and A23187 that activate gene expression were tested for sensitivity to gravity. EGF-induced c-fos and c-jun expression were decreased in microgravity. However, constitutive β-2 microglobulin expression remained unaltered. Under simulated weightlessness conditions EGF- and TPA-induced c-fos expression was decreased, while forskolin- and A23187-induced c-fos expression was independent of the gravity conditions. These results suggest that gravity affects specific signalling pathways. Preliminary results indicate that EGF-induced EGF-receptor clustering remained unaltered irrespective of the gravity conditions. Furthermore, the relative filamentous actin content of steady state A431 cells was enhanced under microgravity conditions and actin filament organization was altered. Under simulated weightlessness actin filament organization in steady state cells as well as in EGF-treated cells was altered as compared to the 1 G reference experiment. Interestingly the microtubule and keratin organization in untreated cells showed no difference with the normal gravity samples. This indicates that gravity may affect specific components of the signal transduction circuitry.
Estimating the center of mass of a free-floating body in microgravity.

PubMed

Lejeune, L; Casellato, C; Pattyn, N; Neyt, X; Migeotte, P-F

2013-01-01

This paper addresses the issue of estimating the position of the center of mass (CoM) of a free-floating object of unknown mass distribution in microgravity using a stereoscopic imaging system. The method presented here is applied to an object of known mass distribution for validation purposes. In the context of a study of 3-dimensional ballistocardiography in microgravity, and the elaboration of a physical model of the cardiovascular adaptation to weightlessness, the hypothesis that the fluid shift towards the head of astronauts induces a significant shift of their CoM needs to be tested. The experiments were conducted during the 57th parabolic flight campaign of the European Space Agency (ESA). At the beginning of the microgravity phase, the object was given an initial translational and rotational velocity. A 3D point cloud corresponding to the object was then generated, to which a motion-based method inspired by rigid body physics was applied. Through simulations, the effects of the centroid-to-CoM distance and the number of frames of the sequence are investigated. In experimental conditions, considering the important residual accelerations of the airplane during the microgravity phases, CoM estimation errors (16 to 76 mm) were consistent with simulations. Overall, our results suggest that the method has a good potential for its later generalization to a free-floating human body in a weightless environment.
Physiologic Pressure and Flow Changes During Parabolic Flight (Pilot Study)

NASA Technical Reports Server (NTRS)

Pantalos, George; Sharp, M. Keith; Mathias, John R.; Hargens, Alan R.; Watenpaugh, Donald E.; Buckey, Jay C.

1999-01-01

The objective of this study was to obtain measurement of cutaneous tissue perfusion central and peripheral venous pressure, and esophageal and abdominal pressure in human test subjects during parabolic flight. Hemodynamic data recorded during SLS-I and SLS-2 missions have resulted in the paradoxical finding of increased cardiac stroke volume in the presence of a decreased central venous pressure (CVP) following entry in weightlessness. The investigators have proposed that in the absence of gravity, acceleration-induced peripheral vascular compression is relieved, increasing peripheral vascular capacity and flow while reducing central and peripheral venous pressure, This pilot study seeks to measure blood pressure and flow in human test subjects during parabolic flight for different postures.
Final science results: Spacelab J

NASA Technical Reports Server (NTRS)

Leslie, Fred (Editor)

1995-01-01

This report contains a brief summary of the mission science conducted aboard Spacelab J (SL-J), a joint venture between the National Aeronautics and Space Administration (NASA) and the National Space Development Agency (NASDA) of Japan. The scientific objectives of the mission were to conduct a variety of material and life science experiments utilizing the weightlessness and radiation environment of an orbiting Spacelab. All 43 experiments were activated; 24 in microgravity sciences (material processing, crystal growth, fluid physics, and acceleration measurement) and 19 in life sciences (physiology, developmental biology, radiation effects, separation processes, and enzyme crystal growth). In addition, more than a dozen experiments benefited from the extra day through either additional experiment runs or extended growth time.
STS-78 Flight Day 8

NASA Technical Reports Server (NTRS)

1996-01-01

On this eighth day of the STS-78 mission, the flight crew, Cmdr. Terence T. Henricks, Pilot Kevin R. Kregel, Payload Cmdr. Susan J. Helms, Mission Specialists Richard M. Linnehan, Charles E. Brady, Jr., and Payload Specialists Jean-Jacques Favier, Ph.D. and Robert B. Thirsk, M.D., continue to conduct experiments primarily focusing on the effects of weightlessness on human physiology. Results from the studies of muscle activity, task performance, and sleep will help future mission planners organize crew schedules for greater efficiency and productivity. For a second consecutive day, Henricks, Kregel, Thirsk, and Favier continue to enter responses to a battery of problem-solving tasks on the Performance Assessment Work Station, a laptop computer.
Effects of weightlessness on tissue proliferation

NASA Technical Reports Server (NTRS)

Crosby, W. H.; Tavassoli, M.

1975-01-01

The repair of bone marrow stroma following mechanical injury was studied to obtain baseline data for a proposed space experiment regarding the effect of weightlessness on marrow stroma and other proliferating cell systems.
[Analysis of possible causes activation a stomach and pancreas excretory and incretory function after completion of space flight on the international space station].

PubMed

Afonin, B V

2013-01-01

The research excretory and incretory of activity of a stomach and pancreas is carried out at astronauts in the early period after completion of space flights of various duration. It is shown, that the increase of the contents of gastric and pancreatic enzymes and hormones (insulin and C-peptide) in blood reflects increased excretory and incretory activity of organs of gastroduodenal area which arises in weightlessness. The complex of countermeasures, which prevent ingress of subjects, infected by Helicobacter pylori in space flight crew, excluded participation of this microorganism in the mechanism of increase of secretory activity of a stomach. The absence of interrelation between increase of secretory activity of gastroduodenal area organs and space flights' duration has allowed to exclude the hypokinetic mechanism which determined by duration of stay in weightlessness. It was shown that after the end of space flights the increase ofbasal excretory activity of organs of gastroduodenal area occurs simultaneously with increase of a fasting insulin secretion. The changes in gastroduodenal area organs revealed after space flights were are compared to similar changes received in ground-based experiments, simulating hemodynamic reorganization in venous system of abdominal cavity, arising in weightlessness. The conclusion is made, that the basic mechanism of changes of a functional condition of digestive system in space flights, is determined by reorganization venous hemodynamic in abdominal cavity organs reproduced in ground experiments. Increase insulin and C-peptide after space flights are considered as hormonal component of this hemodynamic mechanism.
STS-60 Cosmonauts in Weightless Environment Training Facility (WETF) training

NASA Image and Video Library

1993-01-07

Russian Cosmonaut Vladimir Titov maneuvers a small life raft during bailout training at JSC's Weightless Environment Training Facility (WETF). Two SCUBA-equipped divers assisted Titov in the STS-60 training exercise.
Hydrogen and hydrocarbon diffusion flames in a weightless environment

NASA Technical Reports Server (NTRS)

Haggard, J. B., Jr.; Cochran, T. H.

1973-01-01

An experimental investigation was performed on laminar hydrogen-, ethylene-, and propylene-air diffusion burning in a weightless environment. The flames burned on nozzles with radii ranging from 0.051 to 0.186 cm with fuel Reynolds numbers at the nozzle exit from 9 to 410. Steady-state diffusion flames existed in a weightless environment for all the fuels tested. A correlation was obtained for their axial length as a function of Schmidt number, Reynolds numbers, and stoichiometric mole fraction. The maximum flame radii were correlated with the ratio of nozzle radius to average fuel velocity. The flames of ethylene and propylene on nozzles with radii 0.113 or larger appeared to be constantly changing color and/or length throughout the test. No extinguishment was observed for any of the gases tested within the 2.2 seconds of weightlessness.
Exercise during long term exposure to space: Value of exercise during space exploration

NASA Technical Reports Server (NTRS)

1990-01-01

There appear to be two general physiological reasons why exercise will be beneficial to space travelers who will experience a weightless and isolated environment for many months or a few years: (1) to alleviate or prevent tissue atrophy (principally bone and muscle), to maintain cardiovascular function, and to prevent deleterious changes in extracellular and cellular fluid volumes and plasma constituents, especially electrolytes; and (2) to maintain whole organism functional physical and physiological status with special reference to neuromuscular coordination (physical skill) and physical fitness (muscle strength and power, flexibility, and aerobic endurance). The latter reason also relates well to the ability of the crew members to resist both general and local fatigue and thus ensure consistent physical performance. Various forms of exercise, performed regularly, could help alleviate boredom and assist the travelers in coping with stress, anxiety, and depression. The type, frequency, duration and intensity of exercise and ways of ensuring that crew members engage in it are discussed.
Gravity Plant Physiology Facility (GPPF) Team in the Spacelab Payload Operations Control Center (SL

NASA Technical Reports Server (NTRS)

1992-01-01

The primary payload for Space Shuttle Mission STS-42, launched January 22, 1992, was the International Microgravity Laboratory-1 (IML-1), a pressurized manned Spacelab module. The goal of IML-1 was to explore in depth the complex effects of weightlessness of living organisms and materials processing. Around-the-clock research was performed on the human nervous system's adaptation to low gravity and effects of microgravity on other life forms such as shrimp eggs, lentil seedlings, fruit fly eggs, and bacteria. Materials processing experiments were also conducted, including crystal growth from a variety of substances such as enzymes, mercury iodide, and a virus. The Huntsville Operations Support Center (HOSC) Spacelab Payload Operations Control Center (SL POCC) at the Marshall Space Flight Center (MSFC) was the air/ground communication channel used between the astronauts and ground control teams during the Spacelab missions. Featured is the Gravity Plant Physiology Facility (GPPF) team in the SL POCC during the IML-1 mission.
U.S. view of human problems to be addressed for long duration space flights. [physiological and psychological effects

NASA Technical Reports Server (NTRS)

Berry, C. A.

1973-01-01

The Russian and American space programs have consisted of several thousands of hours of exposure of man to the space environment. In spite of numerous biological phenomena of adaptation observed, the space travellers have displayed, after their return, no enduring pathological effect. Although the usable data remain too limited to reflect fully the effects of space flight, it is possible to sketch the biological responses in the absence of gravity and to define the work bases for the future. Beyond its basic physiological effects, weightlessness has operational consequences in the daily life of the astronauts. These consequences will be still more evident during missions of long duration. The conclusions drawn in flight as well as on the ground are reviewed, and future requirements concerning prolonged flights are outlined. The gaps in actual knowledge are discussed and solutions are suggested. The problems of habitability are considered, particularly those which remain at present without satisfactory solutions: psychological responses to a confined life, cleaning, hygiene, and used material.
Human Research Program Human Health Countermeasures Element: Evidence Report - Artificial Gravity

NASA Technical Reports Server (NTRS)

Clement, Gilles

2015-01-01

The most serious risks of long-duration flight involve radiation, behavioral stresses, and physiological deconditioning. Artificial gravity (AG), by substituting for the missing gravitational cues and loading in space, has the potential to mitigate the last of these risks by preventing the adaptive responses from occurring. The rotation of a Mars-bound spacecraft or an embarked human centrifuge offers significant promise as an effective, efficient multi-system countermeasure against the physiological deconditioning associated with prolonged weightlessness. Virtually all of the identified risks associated with bone loss, muscle weakening, cardiovascular deconditioning, and sensorimotor disturbances might be alleviated by the appropriate application of AG. However, experience with AG in space has been limited and a human-rated centrifuge is currently not available on board the ISS. A complete R&D program aimed at determining the requirements for gravity level, gravity gradient, rotation rate, frequency, and duration of AG exposure is warranted before making a decision for implementing AG in a human spacecraft.
Anesthesia during and Immediately after Spaceflight

NASA Technical Reports Server (NTRS)

Seubert, Christoph N.; Price, Catherine; Janelle, Gregory M.

2006-01-01

The increasing presence of humans in space and long-duration manned missions to the Moon or Mars pose novel challenges to the delivery of medical care. Even now, cumulative person-days in space exceed 80 years and preparations for a return to the Moon are actively underway. Medical care after an emergent de-orbit or an accident during a non-nominal landing must not only address the specific disease or injuries but also the challenges posed by physiologic adaptations to microgravity. In the highly autonomous situation of a long-term space mission the situation is even more complex, because personnel, equipment, specific training, and clinical experience are by definition limited. To summarize our current knowledge specifically for anesthetic care during and immediately after spaceflight, we will review physiologic adaptations to microgravity with particular emphasis on the resulting anesthetic risks, discuss veterinary experiences with anesthesia in weightlessness or in animals adapted to microgravity, describe current research that pertains to anesthesia and spaceflight and point out unresolved questions for future investigation.
Space flight and bone formation.

PubMed

Doty, St B

2004-12-01

Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.
Space flight and bone formation

NASA Technical Reports Server (NTRS)

Doty, St B.

2004-01-01

Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.
Simulated spaceflight effects on mating and pregnancy of rats

NASA Technical Reports Server (NTRS)

Sabelman, E. E.; Chetirkin, P. V.; Howard, R. M.

1981-01-01

The mating of rats was studied to determine the effects of: simulated reentry stresses at known stages of pregnancy, and full flight simulation, consisting of sequential launch stresses, group housing, mating opportunity, diet, simulated reentry, and postreentry isolation of male and female rats. Uterine contents, adrenal mass and abdominal fat as a proportion of body mass, duration of pregnancy, and number and sex of offspring were studied. It is found that: (1) parturition following full flight simulation was delayed relative to that of controls; (2) litter size was reduced and resorptions increased compared with previous matings in the same group of animals; and (3) abdominal fat was highly elevated in animals that were fed the Soviet paste diet. It is suggested that the combined effects of diet, stress, spacecraft environment, and weightlessness decreased the probability of mating or of viable pregnancies in the Cosmos 1129 flight and control animals.
Midodrine prevents orthostatic intolerance associated with simulated spaceflight

NASA Technical Reports Server (NTRS)

Ramsdell, C. D.; Mullen, T. J.; Sundby, G. H.; Rostoft, S.; Sheynberg, N.; Aljuri, N.; Maa, M.; Mukkamala, R.; Sherman, D.; Toska, K.;

2001-01-01

Many astronauts after being weightless in space become hypotensive and presyncopal when they assume an upright position. This phenomenon, known as orthostatic intolerance, may interfere with astronaut function during reentry and after spaceflight and may limit the ability of an astronaut to exit a landed spacecraft unaided during an emergency. Orthostatic intolerance is more pronounced after long-term spaceflight and is a major concern with respect to the extended flights expected aboard the International Space Station and for interplanetary exploration class missions, such as a human mission to Mars. Fully effective countermeasures to this problem have not yet been developed. To test the hypothesis that alpha-adrenergic stimulation might provide an effective countermeasure, we conducted a 16-day head-down-tilt bed-rest study (an analog of weightlessness) using normal human volunteers and administered the alpha(1)-agonist drug midodrine at the end of the bed-rest period. Midodrine was found to significantly ameliorate excessive decreases in blood pressure and presyncope during a provocative tilt test. We conclude that midodrine may be an effective countermeasure for the prevention of orthostatic intolerance following spaceflight.

Midodrine prevents orthostatic intolerance associated with simulated spaceflight.

PubMed

Ramsdell, C D; Mullen, T J; Sundby, G H; Rostoft, S; Sheynberg, N; Aljuri, N; Maa, M; Mukkamala, R; Sherman, D; Toska, K; Yelle, J; Bloomfield, D; Williams, G H; Cohen, R J

2001-06-01

Many astronauts after being weightless in space become hypotensive and presyncopal when they assume an upright position. This phenomenon, known as orthostatic intolerance, may interfere with astronaut function during reentry and after spaceflight and may limit the ability of an astronaut to exit a landed spacecraft unaided during an emergency. Orthostatic intolerance is more pronounced after long-term spaceflight and is a major concern with respect to the extended flights expected aboard the International Space Station and for interplanetary exploration class missions, such as a human mission to Mars. Fully effective countermeasures to this problem have not yet been developed. To test the hypothesis that alpha-adrenergic stimulation might provide an effective countermeasure, we conducted a 16-day head-down-tilt bed-rest study (an analog of weightlessness) using normal human volunteers and administered the alpha(1)-agonist drug midodrine at the end of the bed-rest period. Midodrine was found to significantly ameliorate excessive decreases in blood pressure and presyncope during a provocative tilt test. We conclude that midodrine may be an effective countermeasure for the prevention of orthostatic intolerance following spaceflight.

Responses of blind fish to gravitational changes as achieved in parabolic flight

NASA Technical Reports Server (NTRS)

Vonbaumgarten, R. J.; Shillinger, G. L., Jr.; Baldright, G.

1972-01-01

Blind fish, during parabolic flight, display a measurable and consistent behavior. The most spectacular new behavioral response is the forward looping of blind fish in or near weightlessness. This response shows no measurable adaptation during the entire period of weightlessness of about 30 sec. During the entrance and exit of weightless parabolas (pushover and pullout) respectively, the fish assumes a forward tilted diving position. Parabolic flight with negative g in the range between 0g and -1g causes similar diving responses of the fish with the only difference being that the dive is directed toward the top of the fish tank. When the response to a g value less than 1g is compared to the response to increased g load on the ground (escape of darting response) an essential difference is seen: higher horizontal acceleration or jerk on the ground causes fish to swim, or even dart, against the direction of inertial force; fish during weightless parabolas move into the direction of the inertial or gravitational force. Since the vestibular system of fish is homologous to that of man, the observed behavior of fish in weightless flight could help to better understand human performance and sensations in comparable situations.
Analysis of human microcirculation in weightlessness: Study protocol and pre-study experiments.

PubMed

Bimpong-Buta, Nana-Yaw; Jirak, Peter; Wernly, Bernhard; Lichtenauer, Michael; Masyuk, Maryna; Muessig, Johanna Maria; Braun, Kristina; Kaya, Sema; Kelm, Malte; Jung, Christian

2018-04-14

In weightlessness, alterations in organ systems have been reported. The microcirculation consists of a network of blood vessels with diameters of a few μm. It is considered the largest part of the circulatory system of the human body and essential for exchange of gas, nutrients and waste products. An investigation of the microcirculation in weightlessness seems warranted but has not yet been performed. In this paper, we outline a study in which we will investigate the possible interrelations between weightlessness and microcirculation. We will induce weightlessness in the course of parabolic flight maneuvers, which will be conducted during a parabolic flight campaign. In this study protocol also an evaluation of a possible influence of parabolic flight premedication on microcirculation will be described. The microcirculation will be investigated by sublingual intravital measurements applying sidestream darkfield microscopy. Parameters of macrocirculation such as heart rate, blood pressure and blood oxygenation will also be investigated. In our pre-study experiments, neither dimenhydrinate nor scopolamine altered microcirculation. As the application of motion sickness therapy did not alter microcirculation, it will be applied during the parabolic flight maneuvers of the campaign. Our results might deepen the understanding of microcirculation on space missions and on earth.
Human Locomotion in Hypogravity: From Basic Research to Clinical Applications.

PubMed

Lacquaniti, Francesco; Ivanenko, Yury P; Sylos-Labini, Francesca; La Scaleia, Valentina; La Scaleia, Barbara; Willems, Patrick A; Zago, Myrka

2017-01-01

We have considerable knowledge about the mechanisms underlying compensation of Earth gravity during locomotion, a knowledge obtained from physiological, biomechanical, modeling, developmental, comparative, and paleoanthropological studies. By contrast, we know much less about locomotion and movement in general under sustained hypogravity. This lack of information poses a serious problem for human space exploration. In a near future humans will walk again on the Moon and for the first time on Mars. It would be important to predict how they will move around, since we know that locomotion and mobility in general may be jeopardized in hypogravity, especially when landing after a prolonged weightlessness of the space flight. The combination of muscle weakness, of wearing a cumbersome spacesuit, and of maladaptive patterns of locomotion in hypogravity significantly increase the risk of falls and injuries. Much of what we currently know about locomotion in hypogravity derives from the video archives of the Apollo missions on the Moon, the experiments performed with parabolic flight or with body weight support on Earth, and the theoretical models. These are the topics of our review, along with the issue of the application of simulated hypogravity in rehabilitation to help patients with deambulation problems. We consider several issues that are common to the field of space science and clinical rehabilitation: the general principles governing locomotion in hypogravity, the methods used to reduce gravity effects on locomotion, the extent to which the resulting behavior is comparable across different methods, the important non-linearities of several locomotor parameters as a function of the gravity reduction, the need to use multiple methods to obtain reliable results, and the need to tailor the methods individually based on the physiology and medical history of each person.
Human Locomotion in Hypogravity: From Basic Research to Clinical Applications

PubMed Central

Lacquaniti, Francesco; Ivanenko, Yury P.; Sylos-Labini, Francesca; La Scaleia, Valentina; La Scaleia, Barbara; Willems, Patrick A.; Zago, Myrka

2017-01-01

We have considerable knowledge about the mechanisms underlying compensation of Earth gravity during locomotion, a knowledge obtained from physiological, biomechanical, modeling, developmental, comparative, and paleoanthropological studies. By contrast, we know much less about locomotion and movement in general under sustained hypogravity. This lack of information poses a serious problem for human space exploration. In a near future humans will walk again on the Moon and for the first time on Mars. It would be important to predict how they will move around, since we know that locomotion and mobility in general may be jeopardized in hypogravity, especially when landing after a prolonged weightlessness of the space flight. The combination of muscle weakness, of wearing a cumbersome spacesuit, and of maladaptive patterns of locomotion in hypogravity significantly increase the risk of falls and injuries. Much of what we currently know about locomotion in hypogravity derives from the video archives of the Apollo missions on the Moon, the experiments performed with parabolic flight or with body weight support on Earth, and the theoretical models. These are the topics of our review, along with the issue of the application of simulated hypogravity in rehabilitation to help patients with deambulation problems. We consider several issues that are common to the field of space science and clinical rehabilitation: the general principles governing locomotion in hypogravity, the methods used to reduce gravity effects on locomotion, the extent to which the resulting behavior is comparable across different methods, the important non-linearities of several locomotor parameters as a function of the gravity reduction, the need to use multiple methods to obtain reliable results, and the need to tailor the methods individually based on the physiology and medical history of each person. PMID:29163225
Astronaut Sam Gemar, wearing EMU, prepares for training in WETF

NASA Image and Video Library

1987-03-01

S87-26630 (March 1987) --- Astronaut Charles D. (Sam) Gemar, wearing a training version of the Extravehicular Mobility Unit (EMU) space suit, prepares to be emersed in the 25-ft. deep waters of the Weightless Environment Training Facility (WET-F) at the Johnson Space Center (JSC). Once underwater, Gemar was able to achieve a neutrally buoyant state and to simulate the floating type activities of an astronaut in microgravity. Gemar began training as an astronaut candidate in the summer of 1985.
Application of EVA guidelines and design criteria. Volume 1: EVA selection/systems design considerations

NASA Technical Reports Server (NTRS)

Brown, N. E.

1973-01-01

Parameters that require consideration by the planners and designers when planning for man to perform functions outside the vehicle are presented in terms of the impact the extravehicular crewmen and major EV equipment items have on the mission, vehicle, and payload. Summary data on man's performance capabilities in the weightless space environment are also provided. The performance data are based on orbital and transearth EVA from previous space flight programs and earthbound simulations, such as water immersion and zero-g aircraft.
STS-45 backup Payload Specialist Chappell during water egress training at JSC

NASA Image and Video Library

1991-11-26

S91-52074 (26 Nov 1991) --- Charles R. (Rick) Chappell, alternate payload specialist, equipped with simulated parachute gear, descends into the water during bail-out training exercises in the Johnson Space Center's weightless environment training facility (WET-F). In this phase of the training program, Shuttle crewmembers learn the proper measures to take in the event of ejection and subsequent parachute landing into a body of water. A number of SCUBA-equipped swimmers who assisted in the training are pictured.
STS-42 crewmembers in LESs prepare for egress exercises in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1991-01-01

STS-42 Discovery, Orbiter Vehicle (OV) 103, crewmembers, (left to right) Commander Ronald J. Grabe, Payload Specialist Roberta L. Bondar, and Pilot Stephen S. Oswald, participate in launch emergency egress (bailout) exercises in JSC's Weightless Environment Training Facility (WETF) Bldg 29. The crewmembers are outfitted in their launch and entry suits (LESs) and launch and entry helmets (LEHs) as they prepare for the simulated water landing using the WETF's 25 ft deep pool as the ocean.
STS-52 Pilot Baker, in LES/LEH, during JSC WETF bailout exercises

NASA Technical Reports Server (NTRS)

1992-01-01

STS-52 Columbia, Orbiter Vehicle (OV) 102, Pilot Michael A. Baker smiles from under his launch and entry helmet (LEH) and from behind the communications carrier assembly (CCA) microphones as he adjusts his parachute harness. Baker, fully outfitted in a launch and entry suit (LES), prepares for emergency egress (bailout) training exercise in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. The WETF's 25-ft deep pool will be used in this simulation of a water landing.
STS-32 MS Dunbar wearing LES prepares for WETF water egress training

NASA Technical Reports Server (NTRS)

1989-01-01

STS-32 Mission Specialist (MS) Bonnie J. Dunbar, wearing a launch and entry suit (LES), orange parachute harness and life vest, is briefed on emergency egress procedures in JSC's Weightless Environment Training Facility (WETF) Bldg 29. During the exercises the crew practiced the procedures to follow in the event of an emergency aboard the Space Shuttle and familiarized themselves with post-Challenger pole system of emergency egress. The crewmembers will simulate parachuting into water by using the WETF's nearby 25 ft deep pool.
STS-45 MS Foale dons EMU with technicians' help in JSC's WETF Bldg 29

NASA Technical Reports Server (NTRS)

1991-01-01

STS-45 Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist (MS) C. Michael Foale stands on a platform as technicians help him don his extravehicular mobility unit (EMU). The technicians are preparing to connect the EMU upper and lower torsos at the waist ring. When fully suited, Foale will be lowered into a nearby 25 ft deep pool for an underwater simulation of contingency extravehicular activity (EVA) procedures. The pool is located in JSC's Weightless Environment Training Facility (WETF) Bldg 29.
STS-26 MS Hilmers floats in life raft during JSC WETF exercises

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) David C. Hilmers, wearing the newly designed launch and entry suit (LES), floats in single-occupant life raft in JSC Weightless Environment Training Facility (WETF) Bldg 29 pool. Hilmers pulls his legs into the inflating raft while he is assisted by two SCUBA-equipped divers. The simulation of the escape and rescue operations utilized the crew escape system (CES) pole method of egress from the Space Shuttle.
STS-26 Commander Hauck floats in life raft during JSC WETF exercises

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck, wearing the newly designed launch and entry suit (LES), floats in single-occupant life raft in JSC Weightless Environment Training Facility (WETF) Bldg 29 pool. Removing water from his raft, Hauck awaits the assistance of SCUBA-equipped divers (one of whom is partially visible at bottom right). The simulation of the escape and rescue operations utilized the crew escape system (CES) pole method of egress from the Space Shuttle.
SKYLAB (SL) PRIME CREW - BLDG. 5 - JSC

NASA Image and Video Library

1973-03-20

S73-20759 (1 March 1973) --- Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, takes items from the M512 materials processing equipment storage assembly during Skylab training at Johnson Space Center. Conrad is standing in the Multiple Docking Adapter (MDA) trainer in the JSC Mission Simulation and Training Facility. The assembly holds equipment designed to explore space manufacturing capability in a weightless state. Conrad is holding one of the experiment parts in his left hand. Photo credit: NASA
CREW TRAINING (EXTRAVEHICULAR ACTIVITY [EVA]) - STS-41G - JSC

NASA Image and Video Library

1984-07-06

S84-36956 (1 July 1984) --- Astronaut Robert L. Crippen, 41-G crew commander, prepares his SCUBA mask prior to submerging into the weightless environment training facility's 25 ft. deep pool to observe a simulation exercise for two fellow 41-G crewmembers assigned to an extravehicular activity (EVA) in space. Not pictured are Astronauts Kathryn D. Sullivan and David C. Leestma, mission specialists who will perform the EVA during the eight-day mission scheduled for October of this year.
Astronauts Hoffman and Seddon demonstrate effect of weightlessness on slinky

NASA Image and Video Library

1985-04-14

51D-06-015 (12-19 April 1985) --- Astronaut Jeffrey A. Hoffman and Rhea Seddon mission specialists, demonstrate the effect of weightlessness on a slinky toy in the mid-deck of the Space Shuttle Discovery.
More Life-Science Experiments For Spacelab

NASA Technical Reports Server (NTRS)

Savage, P. D., Jr.; Dalton, B.; Hogan, R.; Leon, H.

1991-01-01

Report describes experiments done as part of Spacelab Life Sciences 2 mission (SLS-2). Research planned on cardiovascular, vestibular, metabolic, and thermal responses of animals in weightlessness. Expected to shed light on effects of prolonged weightlessness on humans.
BION-M 1: First continuous blood pressure monitoring in mice during a 30-day spaceflight.

PubMed

Andreev-Andrievskiy, Alexander; Popova, Anfisa; Lloret, Jean-Christophe; Aubry, Patrick; Borovik, Anatoliy; Tsvirkun, Daria; Vinogradova, Olga; Ilyin, Eugeniy; Gauquelin-Koch, Guillemette; Gharib, Claude; Custaud, Marc-Antoine

2017-05-01

Animals are an essential component of space exploration and have been used to demonstrate that weightlessness does not disrupt essential physiological functions. They can also contribute to space research as models of weightlessness-induced changes in humans. Animal research was an integral component of the 30-day automated Russian biosatellite Bion-M 1 space mission. The aim of the hemodynamic experiment was to estimate cardiovascular function in mice, a species roughly 3000 times smaller than humans, during prolonged spaceflight and post-flight recovery, particularly, to investigate if mice display signs of cardiovascular deconditioning. For the first time, heart rate (HR) and blood pressure (BP) were continuously monitored using implantable telemetry during spaceflight and recovery. Decreased HR and unchanged BP were observed during launch, whereas both HR and BP dropped dramatically during descent. During spaceflight, BP did not change from pre-flight values. However, HR increased, particularly during periods of activity. HR remained elevated after spaceflight and was accompanied by increased levels of exercise-induced tachycardia. Loss of three of the five mice during the flight as a result of the hardware malfunction (unrelated to the telemetry system) and thus the limited sample number constitute the major limitation of the study. For the first time BP and HR were continuously monitored in mice during the 30-day spaceflight and 7-days of post-flight recovery. Cardiovascular deconditioning in these tiny quadruped mammals was reminiscent of that in humans. Therefore, the loss of hydrostatic pressure in space, which is thought to be the initiating event for human cardiovascular adaptation in microgravity, might be of less importance than other physiological mechanisms. Further experiments with larger number of mice are needed to confirm these findings. Copyright © 2017 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.
Effect of weightlessness conditions on the somatic embryogenesis in the culture of carrot cells

NASA Technical Reports Server (NTRS)

Butenko, R. G.; Dmitriyeva, N. N.; Ongko, V.; Basyrova, L. V.

1977-01-01

A carrot cell culture seeded in Petri dishes in the United States and transported to the USSR was subjected to weightlessness for 20 days during the flight of Kosmos 782. The controls were cultures placed on a centrifuge (1 g) inside the satellite and cultures left on ground in the U.S.S.R. and the United States. A count of structures in the dishes after the flight showed that the number of developing embryonic structures and the extent of their differentiation in weightlessness did not reliably differ from the number and extent of differentiation in structures developed on the ground. Structures with long roots developed in weightlessness. Analysis of the root zones showed that these roots differed by the increased size of the zone of differentiated cells. The increased size of the zones of differentiated cells can indicate earlier development of embryonic structures.
Whole-Body Movements in Long-Term Weightlessness: Hierarchies of the Controlled Variables Are Gravity-Dependent.

PubMed

Casellato, Claudia; Pedrocchi, Alessandra; Ferrigno, Giancarlo

2017-01-01

Switching between contexts affects the mechanisms underlying motion planning, in particular it may entail reranking the variables to be controlled in defining the motor solutions. Three astronauts performed multiple sessions of whole-body pointing, in normogravity before launch, in prolonged weightlessness onboard the International Space Station, and after return. The effect of gravity context on kinematic and dynamic components was evaluated. Hand trajectory was gravity independent; center-of-mass excursion was highly variable within and between subjects. The body-environment effort exchange, expressed as inertial ankle momentum, was systematically lower in weightlessness than in normogravity. After return on Earth, the system underwent a rapid 1-week readaptation. The study indicates that minimizing the control effort is given greater weight when optimizing the motor plan in weightlessness compared to normogravity: the hierarchies of the controlled variables are gravity dependent.

Regulation of Bone Formation During Disuse by miRNA

NASA Technical Reports Server (NTRS)

Thomas, Nicholas; Choi, Catherine Y.; Alwood, Joshua S.

2016-01-01

Astronauts lose bone structure during long-duration spaceflight. These changes are due, in part, to insufficient bone formation by the osteoblast cells. Little is known about the role that small (approximately 22 nucleotide), non-coding micro-RNAs (miRNAs) play in the osteoblast response to microgravity. We hypothesize that osteoblast-lineage cells alter their miRNA status during microgravity exposure, contributing to impaired bone formation during weightlessness. To simulate weightlessness, female mice (C57BL/6, Charles River, 10 weeks of age, n = 6) were hindlimb unloaded for 12 days. Age-matched and normally ambulating mice served as controls (n=6). To assess the expression of miRNAs in skeletal tissue, the right and left tibia of the mice were collected ex vivo and cleaned of soft-tissue and marrow. Total RNA was collected from tibial bone and relative abundance was measured for miRNAs of interest using quantitative real time PCR array looking at 372 unique and well-characterized mature miRNAs using the delta-delta Ct method. Transcripts of interest were normalized to an average of 6 reference RNAs. Preliminary results show that hindlimb unloading decreased the expression of 14 miRNAs to less than 1.4-2.9X control levels and increased the expression of 5 miRNAs relative to the control mice greater than 1-2-1.5X (p less than 0.05, respectively). Using the miRSystem we assessed overlapping target genes predicted to be regulated by multiple members of the 19 differentially expressed miRNAs as well as in silico predicted targets of our individual miRNAs. Our miRSystem results indicated that a number of our differentially expressed miRNAs were regulators of genes related to the Wnt-Beta Catenin pathway-a known regulator of bone health-and, interestingly, the estrogen-mediated cell-cycle regulation pathway, which may indicate that simulated weightlessness induced systemic hormonal changes that contributed to bone loss. We plan to follow up these findings by measuring gene expression of miRNA-regulated genes within these two pathways with the aim of furthering our understanding of the function of miRNAs in the skeletal response to spaceflight.
Mechanisms of Orthostatic Intolerance During Real and Simulated Microgravity

NASA Technical Reports Server (NTRS)

1997-01-01

Session MP1 includes short reports on: (1) Orthostatic Tests after 42 Days of Simulated Weightlessness; (2) Effects of 12 Days Exposure to Simulated Microgravity on Central Circulatory Hemodynamics in the Rhesus Monkey; (3) Increased Sensitivity and Resetting of Baroflex Control of Exercise Heart Rate After Prolonged Bed-Rest; (4) Complex Cardiovascular Dynamics and Deconditioning During Head-down Bed Rest; (5) The Cardiovascular Effects of 6 Hours of Head-down Tilt Upon Athletes and Non-athletes; (6) Individual Susceptibility to Post-spaceflight Orthostatic Intolerance: Contributions of Gender-related and Microgravity-related Factors; (7) Cassiopee Mission 1996: Comparison of Cardiovascular Alteration after Short and Long-term Spaceflights; (8) Cerebral and Femoral Flow Response to LBNP during 6 Month MIR Spaceflights (93-95); and (9) Cerebrovascular Changes due to Spaceflight and Postflight Presyncope.
Effects of Simulated Weightlessness on Mammalian Development. Part 2: Meiotic Maturation of Mouse Oocytes During Clinostat Rotation

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Grills, G. S.

1985-01-01

In order to understand the role of gravity in basic cellular processes that are important during development, the effects of a simulated microgravity environment on mammalian gametes and early embryos cultured in vitro are examined. A microgravity environment is simulated by use of a clinostat, which essentially reorients cells relative to the gravity vector. Initial studies have focused on assessing the effects of clinostat rotation on the meiotic progression of mouse oocytes. Modifications centered on providing the unique in vitro culture of the clinostat requirements of mammalian oocytes and embryos: 37 C temperature, constant humidity, and a 5% CO2 in air environment. The oocytes are observed under the dissecting microscope for polar body formation and gross morphological appearance. They are then processed for cytogenetic analysis.
Simulating certain aspects of hypogravity: Effects on the mandibular incisors of suspended rats (PULEH model)

NASA Technical Reports Server (NTRS)

Simmons, D. J.; Winter, F.; Morey-Holton, E. R.

1984-01-01

The effect of a hypogravity simulating model on the rate of mandibular incisor formation, dentinogenesis and, amelogenesis in laboratory rats was studied. The model is the partial unloading by elevating the hindquarters. In this system, rat hindquarters are elevated 30 to 40 deg from the cage floors to completely unload the hindlimbs, but the animals are free to move about using their forelimbs. This model replicates the fluid sift changes which occur during the weightlessness of spaceflight and produces an osteopenia in the weight bearing skeletons. The histogenesis and/or mineralization rates of the mandibular incisor during the first 19d of PULEH in young growing rats are recorded.
Development and testing of a mouse simulated space flight model

NASA Technical Reports Server (NTRS)

Sonnenfeld, Gerald

1987-01-01

The development and testing of a mouse model for simulating some aspects of weightlessness that occurs during space flight, and the carrying out of immunological experiments on animals undergoing space flight is examined. The mouse model developed was an antiorthostatic, hypokinetic, hypodynamic suspension model similar to one used with rats. The study was divided into two parts. The first involved determination of which immunological parameters should be observed on animals flown during space flight or studied in the suspension model. The second involved suspending mice and determining which of those immunological parameters were altered by the suspension. Rats that were actually flown in Space Shuttle SL-3 were used to test the hypotheses.
Comparison between the weightlessness syndrome and aging

NASA Technical Reports Server (NTRS)

Miquel, J.

1982-01-01

The similarity of detrimental effects of normal aging and of exposure to space weightlessness is discussed. The effects include: the reduction in cardiac output, increase in blood pressure, decrease in respiratory vital capacity, decrease in lean body weight and muscle mass, collagen and fat infiltration of muscle, bone demineralization, and a decrease in urinary excretion of total 17-hydroxicorticosteroids. It is also noted that dispite the accelerated aging of organisms, if animals or human subjects were to spend their entire lives in weightlessness, their lifespans might be significantly increased because of a reduction in metabolic rate. Experimental results are cited.
Design and testing of a unique randomized gravity, continuous flow bioreactor

NASA Technical Reports Server (NTRS)

Lassiter, Carroll B.

1993-01-01

A rotating, null gravity simulator, or Couette bioreactor was successfully used for the culture of mammalian cells in a simulated microgravity environment. Two limited studies using Lipomyces starkeyi and Streptomyces clavuligerus were also conducted under conditions of simulated weightlessness. Although these studies with microorganisms showed promising preliminary results, oxygen limitations presented significant limitations in studying the biochemical and cultural characteristics of these cell types. Microbial cell systems such as bacteria and yeast promise significant potential as investigative models to study the effects of microgravity on membrane transport, as well as substrate induction of inactive enzyme systems. Additionally, the smaller size of the microorganisms should further reduce the gravity induced oscillatory particle motion and thereby improve the microgravity simulation on earth. Focus is on the unique conceptual design, and subsequent development of a rotating bioreactor that is compatible with the culture and investigation of microgravity effects on microbial systems. The new reactor design will allow testing of highly aerobic cell types under simulated microgravity conditions. The described reactor affords a mechanism for investigating the long term effects of reduced gravity on cellular respiration, membrane transfer, ion exchange, and substrate conversions. It offers the capability of dynamically altering nutrients, oxygenation, pH, carbon dioxide, and substrate concentration without disturbing the microgravity simulation, or Couette flow, of the reactor. All progeny of the original cell inoculum may be acclimated to the simulated microgravity in the absence of a substrate or nutrient. The reactor has the promise of allowing scientists to probe the long term effects of weightlessness on cell interactions in plants, bacteria, yeast, and fungi. The reactor is designed to have a flow field growth chamber with uniform shear stress, yet transfer high concentrations of oxygen into the culture medium. The system described allows for continuous, on line sampling for production of product without disturbing fluid and particle dynamics in the reaction chamber. It provides for the introduction of substrate, or control substances after cell adaptation to simulated microgravity has been accomplished. The reactor system provides for the nondisruptive, continuous flow replacement of nutrient and removal of product. On line monitoring and control of growth conditions such as pH and nutrient status are provided. A rotating distribution valve allows cessation of growth chamber rotation, thereby preserving the simulated microgravity conditions over longer periods of time.
Ames Research Center life sciences payload - Overview of results of a spaceflight of 24 rats and 2 monkeys

NASA Technical Reports Server (NTRS)

Callahan, P. X.; Schatte, C.; Grindeland, R. E.; Bowman, G.; Lencki, W. A.

1985-01-01

Engineering and biological data gathered with the research animal holding facilities (RAHFs) used on the Spacelab 3 mission are summarized. The animals totaled 24 rats and two squirrel monkeys. The RAHFs included biotelemetry, cameras and environmental monitoring equipment. The primary mission goal was engineering evaluation of the RAHFs and ancillary equipment. Tightly-fitted seals were found to be a necessity for keeping waste and food particles from contaminating the Spacelab equipment. All the rats returned with little muscle tone and suppressed immune systems. The monkeys displayed highly individual responses to spaceflight. Both species exhibited reduced abilities to maintain meticulously clean furs in weightlessness. Details of several physiological changes detected during post-flight autopsies are provided.
Man in space - A time for perspective. [crew performance on Space Shuttle-Spacelab program

NASA Technical Reports Server (NTRS)

Winter, D. L.

1975-01-01

Factors affecting crew performances in long-term space flights are examined with emphasis on the Space Shuttle-Spacelab program. Biomedical investigations carried out during four Skylab missions indicate that initially rapid changes in certain physiological parameters, notably in cardiovascular response and red-blood-cell levels, lead to an adapted condition. Calcium loss remains a potential problem. Space Shuttle environmental control and life-support systems are described together with technology facilitating performance of mission objectives in a weightless environment. It is concluded that crew requirements are within the physical and psychological capability of astronauts, but the extent to which nonastronaut personnel will be able to participate without extensive training and pre-conditioning remains to be determined.
Proposed application of lower body negative pressure to cardiology

NASA Technical Reports Server (NTRS)

Schmidt, E. V.; Debusk, R. F.; Popp, R. L.

1975-01-01

Potential medical applications are presented of lower body negative pressure to the evaluation and treatment of cardiac patients. The essential features of an LBNP unit and the basic cardiovascular physiology of lower body negative pressure (LBNP) testing are described. Some of the results of previous spaceflight experiences and bedrest studies are summarized. The deconditioning effects of weightlessness experienced by orbiting astronauts are compared with the effects of bedrest restrictions prescribed for convalescing cardiac patients. The potential of LBNP for evaluating both pharmacological and physical activity regimens was examined, particularly in relation to post-myocardial infarction and coronary artery bypass patients. Applications of LBNP to the cardiac catheterization laboratory and the out-patient follow-up of cardiac patients are proposed.
Ultrastructure of meristem and root cap of pea seedlings under spaceflight conditions

NASA Technical Reports Server (NTRS)

Sytnyk, K. M.; Kordyum, E. L.; Bilyavska, N. O.; Tarasenko, V. O.

1983-01-01

Data of electron microscopic analysis of meristem and root cap of pea seedlings grown aboard the Salyut-6 orbital research station in the Oazis apparatus and in the laboratory are presented. The main morphological and anatomical characteristics of the test and control plants are shown to be similar. At the same time, some differences are found in the structural and functional organization of the experimental cells as compared to the controls. They concern first of all the plastic apparatus, mitochondria and Golgi apparatus. It is assumed that cell function for certain periods of weightlessness on the whole ensures execution of the cytodifferentiation programs genetically determined on the Earth. Biochemical and physiological processes vary rather markedly due to lack of initially rigorous determination.
Physiological Targets of Artificial Gravity: The Sensory-Motor System. Chapter 4

NASA Technical Reports Server (NTRS)

Paloski, William; Groen, Eric; Clarke, Andrew; Bles, Willem; Wuyts, Floris; Paloski, William; Clement, Gilles

2006-01-01

This chapter describes the pros and cons of artificial gravity applications in relation to human sensory-motor functioning in space. Spaceflight creates a challenge for sensory-motor functions that depend on gravity, which include postural balance, locomotion, eye-hand coordination, and spatial orientation. The sensory systems, and in particular the vestibular system, must adapt to weightlessness on entering orbit, and again to normal gravity upon return to Earth. During this period of adaptation, which persists beyond the actual gravity-level transition itself the sensory-motor systems are disturbed. Although artificial gravity may prove to be beneficial for the musculoskeletal and cardiovascular systems, it may well have negative side effects for the neurovestibular system, such as spatial disorientation, malcoordination, and nausea.
View of human problems to be addressed for long-duration space flights

NASA Technical Reports Server (NTRS)

Berry, C. A.

1973-01-01

Review of the principal physiological changes seen in space flight, and discussion of various countermeasures which may prove to be useful in combating these changes in long-term space flight. A number of transient changes seen in Apollo astronauts following space flights are discussed, including cardiovascular and hemodynamic responses to weightlessness, musculoskeletal changes, changes in fluid and electrolyte balance, microbiological changes, and vestibular effects. A number of countermeasures to the effects of space flight on man are cited, including exercise, medication, diet, lower-body negative pressure, gradient positive pressure, venous occlusion cuffs, and others. A detailed review is then made of a number of psychological factors bearing on the ability of the human organism to withstand the rigors of long space flights.
Human Health and Performance Aspects of the Mars Design Reference Mission

NASA Technical Reports Server (NTRS)

Charles, John B.

2000-01-01

This paper will describe the current planning for exploration-class missions, emphasizing the medical, and human factors aspects of such expeditions. The details of mission architecture are still under study, but a typical Mars design reference mission comprises a six-month transit from Earth to Mar, eighteen months in residence on Mars, and a six-month transit back to Earth. Physiological stressors will include environmental factors such as prolonged exposure to radiation, weightlessness in transit, and hypogravity and a toxic atmosphere while on Mars. Psychological stressors will include remoteness from Earth, confinement, and potential interpersonal conflicts, all complicated by circadian alterations. Medical risks including trauma must also be considered. Results of planning for assuring human health and performance will be presented.
Medical results of the Skylab program

NASA Technical Reports Server (NTRS)

Johnston, R. S.; Dietlein, L. F.

1974-01-01

The Skylab food system, waste management system, operational bioinstrumentation, personal hygiene provisions, in-flight medical support system, and the cardiovascular counterpressure garment worn during reentry are described. The medical experiments program provided scientific data and also served as the basis for real-time decisions on flight duration. Premission support, in-flight operational support, and postflight medical activities are surveyed. Measures devised to deal with possible food spoilage, medical instrument damage, and toxic atmosphere caused by the initial failures on the Orbital Workshop (OWS) are discussed. The major medical experiments performed in flight allowed the study of physiological changes as a function of exposure to weightless flight. The experiments included studies of the cardiovascular system, musculoskeletal and fluid/electrolyte balance, sleep, blood, vestibular system, and time and motion studies.
Current Concepts and Future Directions of CELSS

NASA Technical Reports Server (NTRS)

Macelroy, R. D.; Bredt, J.

1985-01-01

Bioregenerative life support systems for use in space were studied. Concepts of such systems include the use of higher plants and/or microalgae as sources of food, potable water and oxygen, and as sinks for carbon dioxide and metabolic wastes. Recycling of materials within the system will require processing of food organism and crew wastes using microbiological and/or physical chemical techniques. The dynamics of material flow within the system will require monitoring, control, stabilization and maintenance imposed by computers. Studies included higher plant and algal physiology, environmental responses, and control; flight experiments for testing responses of organisms to weightlessness and increased radiation levels; and development of ground based facilities for the study of recycling within a bioregenerative life support system.
Spacelab mission 4 - The first dedicated life sciences mission

NASA Technical Reports Server (NTRS)

Perry, T. W.; Reid, D. H.

1983-01-01

Plans for the first Spacelab-4 mission dedicated entirely to the life sciences, are reviewed. The thrust of the scientific mission scheduled for late 1985 will be to study the acute effects of weightlessness on living systems, particularly humans. The payload of the Spacelab compartment will contain 24 experiments of which approximately half will involve humans. Among the major areas of interest are cardiovascular and pulmonary function, vestibular function, renal and endocrine physiology, hematology, nitrogen balance, immunological function, the gravitational biology of plants, inflight fertilization of frogs' eggs and the effects of zero gravity on monkeys and rats. In selecting the array of experiments an effort was made to combine investigations with complementary scientific objectives to develop animal models of human biological problems.
Hydromechanics and heat and mass exchange in weightlessness (Russian book): Table of contents

NASA Technical Reports Server (NTRS)

Avduyevskiy, V. S.; Poleshayev, V. I.

1983-01-01

The table of contents is given for a book on hydromechanics and heat and mass exchange in weightlessness. The book covers such subjects as hydromechanics, convection and heat and mass exchange, and technological experiments and complicated systems.
GEMINI-TITAN (GT)-8 - TRAINING - PILOT IN WEIGHTLESSNESS USING EXPERIMENT TOOL - FL

NASA Image and Video Library

1966-02-18

S66-24410 (18 Feb. 1966) --- Astronaut David R. Scott performs a maintenance and repair experiment with a battery-powered tool during a state of weightlessness while in extravehicular activity (EVA) training on a KC-135. Photo credit: NASA
Effects of Zoledronate and Mechanical Loading during Simulated Weightlessness on Bone Structure and Mechanical Properties

NASA Technical Reports Server (NTRS)

Scott, R. T.; Nalavadi, M. O.; Shirazi-Fard, Y.; Castillo, A. B.; Alwood, J. S.

2016-01-01

Space flight modulates bone remodeling to favor bone resorption. Current countermeasures include an anti-resorptive drug class, bisphosphonates (BP), and high-force loading regimens. Does the combination of anti-resorptives and high-force exercise during weightlessness have negative effects on the mechanical and structural properties of bone? In this study, we implemented an integrated model to mimic mechanical strain of exercise via cyclical loading (CL) in mice treated with the BP Zoledronate (ZOL) combined with hindlimb unloading (HU). Our working hypothesis is that CL combined with ZOL in the HU model induces additive structural and mechanical changes. Thirty-two C57BL6 mice (male,16 weeks old, n8group) were exposed to 3 weeks of either HU or normal ambulation (NA). Cohorts of mice received one subcutaneous injection of ZOL (45gkg), or saline vehicle, prior to experiment. The right tibia was axially loaded in vivo, 60xday to 9N in compression, repeated 3xweek during HU. During the application of compression, secant stiffness (SEC), a linear estimate of slope of the force displacement curve from rest (0.5N) to max load (9.0N), was calculated for each cycle once per week. Ex vivo CT was conducted on all subjects. For ex vivo mechanical properties, non-CL left femurs underwent 3-point bending. In the proximal tibial metaphysis, HU decreased, CL increased, and ZOL increased the cancellous bone volume to total volume ratio by -26, +21, and +33, respectively. Similar trends held for trabecular thickness and number. Ex vivo left femur mechanical properties revealed HU decreased stiffness (-37),and ZOL mitigated the HU stiffness losses (+78). Data on the ex vivo Ultimate Force followed similar trends. After 3 weeks, HU decreased in vivo SEC (-16). The combination of CL+HU appeared additive in bone structure and mechanical properties. However, when HU + CL + ZOL were combined, ZOL had no additional effect (p0.05) on in vivo SEC. Structural data followed this trend with ZOL not modulating trabecular thickness in CL + NAHU mice. In summary, our integrated model simulates the combination of weightlessness, exercise-induced mechanical strain, and anti-resorptive treatment that astronauts experience during space missions. Based on these results, we conclude that, at the structural and stiffness level, zoledronate treatment during simulated spaceflight does not impede the skeletal response to axial compression. In contrast to our hypothesis, our data show that zoledronate confers no additional mechanical or structural benefit beyond those gained from cyclical loading.

Comparative studies on the influence of "simulated weigthlessness" on fish otolith growth

NASA Astrophysics Data System (ADS)

Brungs, Sonja; Hendrik Anken, Ralf; Li, Xiao-Yan; Hauslage, Jens; Wang, Gaohong; Liu, Yongding; Hilbig, Reinhard; Hemmersbach, Ruth

Stimulus dependence is a general feature of all developing sensory systems. Concerning the vestibular organ of fish, it has been shown earlier that the growth of inner ear otoliths of developing Cichlid fish (Oreochromis mossambicus) and Zebrafish (Danio rerio) is slowed down by increased gravity (hypergravity) as an adaptation. Several studies proposed that otolith growth actively is adjusted via a feedback mechanism to produce a test mass of the appropriate physical capacity. Applying diminished gravity such as microgravity during spaceflight yielded an opposite effect, i.e., larger than normal otoliths in swordtails Xiphophorus helleri. Since there are no data on spaceflown early larval stages of the Cichlid fish and the Zebrafish available, these model organisms were subjected to simulated weightlessness using a submersed clinostat with one axis of rotation (O. mossambicus) and rotating-wall vessels (RWVs; O. mossambicus was maintained within a submersed RWV, which was recently developed at DLR, whereas D. rerio was kept within a modified RWV, developed by NASA). Developmental stages were subjected to clinorotation (60 rpm) and wall vessel rotation (Cichlid fish: 44 rpm; Zebrafish: 12.5 rpm; at these speeds, the larvae did neither sediment nor were they centrifuged away from the center of the RWVs) at a point of time when inner ear otolith mineralisation began. The experimental runs were discontinued when the animals hatched (O. mossambicus, stage 12, reached after 2-3 days at 22° C) or when they began to actively move within the devices (D. rerio, after 6 days at 28° C). After clinostat exposure, both utricular and saccular otoliths (Lapilli and Sagittae, respectively) of the Cichlids were significantly larger as compared to otoliths from the 1g controls. A similar result was obtained after wall vessel rotation for 3 and 6 days of the Zebrafish. These results support the idea that a feedback mechanism correlates the gravity level with the physical capacity of an otolithic test mass during early development and after calcification of otoliths has begun. Interestingly, wall vessel rotation had no effects on Cichlid fish otolith growth. In contrast to D. rerio, O. mossambicus is a mouth-breeding species: the mother animal turns around the larvae in her mouth for supply with fresh (aerated) water. Possibly, wall vessel rotation (rather than clinorotation) mimics this passive, natural movement, which likely will not be perceived as "weightlessness" by the offspring. In the course of further studies, Zebrafish should be subjected to clinorotation and experiments using further devices to simulate weightlessness (e.g., Levitron) should be carried out.
Effect of spaceflight on the maximal shortening velocity, morphology, and enzyme profile of fast- and slow-twitch skeletal muscle fibers in rhesus monkeys

NASA Technical Reports Server (NTRS)

Fitts, R. H.; Romatowski, J. G.; De La Cruz, L.; Widrick, J. J.; Desplanches, D.

2000-01-01

Weightlessness has been shown to cause limb muscle wasting and a reduced peak force and power in the antigravity soleus muscle. Despite a reduced peak power, Caiozzo et al. observed an increased maximal shortening velocity in the rat soleus muscle following a 14-day space flight. The major purpose of the present investigation was to determine if weightlessness induced an elevated velocity in the antigravity slow type I fibers of the rhesus monkey (Macaca mulatta), as well as to establish a cellular mechanism for the effect. Spaceflight or models of weightlessness have been shown to increase glucose uptake, elevate muscle glycogen content, and increase fatigability of the soleus muscle. The latter appears to be in part caused by a reduced ability of the slow oxidative fibers to oxidize fats. A second goal of this study was to establish the extent to which weightlessness altered the substrate profile and glycolytic and oxidative enzyme capacity of individual slow- and fast-twitch fibers.
The role of weightlessness in the genetic damage from preflight gamma-irradiation of organisms in experiments aboard the Salyut 6 orbital station

NASA Astrophysics Data System (ADS)

Vaulina, E. N.; Anikeeva, I. D.; Kostina, L. N.; Kogan, I. G.; Palmbakh, L. R.; Mashinsky, A. L.

The effect of weightlessness on chromosomal aberration frequency in preflight irradiated Crepis capillaris seeds, on the viability, fertility and mutation frequency in Arabidopsis thaliana, and on the frequency of nondisjunction and loss of X chromosomes in preflight irradiated Drosophila melanogaster gametes was studied aboard the Salyut 6 orbital station. The following effects were observed: a flight-time dependent amplification of the effects of preflight ?-irradiation in A. thaliana with respect to all the parameters studied; unequal effects in seeds and seedlings of Crepis capillaris; and a significant increase in the frequency of nondisjunction and loss of chromosomes during meiosis in Drosophila females. These observations are discussed in terms of the data of ground-based model experiments and flight experiments with a different time of exposure of objects to weightlessness. An attempt is made to elucidate the role of weightlessness in the modification of ionizing radiation effects.
Surgical Instrument Restraint in Weightlessness

NASA Technical Reports Server (NTRS)

Campbell, Mark R.; Dawson, David L.; Melton, Shannon; Hooker, Dona; Cantu, Hilda

2000-01-01

Performing a surgical procedure during spaceflight will become more likely with longer duration missions in the near future. Minimal surgical capability has been present on previous missions as the definitive medical care time was short and the likelihood of surgical events too low to justify surgical hardware availability. Early demonstrations of surgical procedures in the weightlessness of parabolic flight indicated the need for careful logistical planning and restraint of surgical hardware. The consideration of human ergonomics also has more impact in weightlessness than in the conventionall-g environment. Three methods of surgical instrument restraint - a Minor Surgical Kit (MSK), a Surgical Restraint Scrub Suit (SRSS), and a Surgical Tray (ST) were evaluated in parabolic flight surgical procedures. The Minor Surgical Kit was easily stored, easily deployed, and demonstrated the best ability to facilitate a surgical procedure in weightlessness. Important factors in this surgical restraint system include excellent organization of supplies, ability to maintain sterility, accessibility while providing secure restraint, ability to dispose of sharp items and biological trash, and ergonomical efficiency.
Effect of weightlessness and centrifugation on red cell survival in rats subjected to space flight

NASA Technical Reports Server (NTRS)

Leon, H. A.; Serova, L. V.; Landaw, S. A.

1980-01-01

Rats were flown aboard the Soviet biosatellite Cosmos 936 for 18.5 d during August, 1977. Five rats were subjected to near-weightless space flight, as with Cosmos 782, and five rats were subjected to a 1-G force via an on-board centrifuge. These rats and three control groups were injected with 2-(C-14) glycine 19 d preflight. The flight rats were recovered from orbit after 18.5 d of space flight. Erythrocyte hemolysis and lifespan were evaluated in the five groups of rats by quantitation of radioactive carbon monoxide exhaled in the breath which arises from the breakdown of the previously labeled hemoglobin. The results support the previous findings wherein hemolysis was found to increase as a result of weightless space flight. A comparison to the centrifuged animals indicates that artificial gravity attenuates the effect of weightlessness on hemolysis and appears to normalize the hemolytic rate in the early postflight period.
Mass discrimination during weightlessness

NASA Technical Reports Server (NTRS)

Ross, H.

1981-01-01

An experiment concerned with the ability of astronauts to discriminate between the mass of objects when both the objects and the astronauts are in weightless states is described. The main object of the experiment is to compare the threshold for weight-discrimination on Earth with that for mass-discrimination in orbit. Tests will be conducted premission and postmission and early and late during the mission while the crew is experiencing weightlessness. A comparison of early and late tests inflight and postflight will reveal the rate of adaptation to zero-gravity and 1-g. The mass discrimination box holds 24 balls which the astronaut will compare to one another in a random routine.
Germination of pine seed in weightlessness (investigation in Kosmos 782)

NASA Technical Reports Server (NTRS)

Platonova, R. N.; Parfenov, G. P.; Olkhovenko, V. P.; Karpova, N. I.; Pichugov, M. Y.

1978-01-01

An investigation was made of the orientation of aboveground and underground organs of pine plants grown from seed in weightlessness. Orientation was found to be caused by the position of the seeds relative to the substrate surface. Normal growth was manifest only for the plants grown from seed oriented with embryo toward the substrate. Differences were noted between experiment and control as to the quantitative content of nucleoli in the meristematic cells of the rootlets and the shape of cells in the cotyledonous leaflets. No complete agreement was found between data obtained in weightlessness and when gravity was compensated (clinostat treatment with horizontal rotation).
Pine seed germination under weightlessness (a study of the Kosmos 782 satellite)

NASA Technical Reports Server (NTRS)

Platonova, R. N.; Parfenov, G. P.; Olkhovenko, V. P.; Karpova, N. I.; Pichugov, M. Y.

1977-01-01

Orientation of the above and underground organs of pine plants, grown from seeds under weightlessness, was found to be determined by seed position on the substrate. Normal plant growth was observed only if the seed embryos were oriented toward the substrate. Some differences were noted between the experimental and control plants concerning the amount of nucleoli in the root meristematic cells and the cell shape in cotyledonous leaves. No complete similarity was found in experimental results obtained with plants under weightlessness and under compensated gravity. The seeds were obtained from Pinus silvestris, considered to be particularly suitable for this experiment.
Man and machine design for space flight

NASA Technical Reports Server (NTRS)

Louviere, A. J.

1979-01-01

The factors involved in creating effective designs for living and working in a weightless environment are discussed. Among the areas covered are special provisions for eating and drinking, a special shower nozzle to remove soap, electric shavers designed for vacuum containment of the clippings, and the need for restraint systems at the crew's workstations. Attention is given to the fact that the crewmen assume a neutral body posture in weightlessness which is an important consideration in designing displays, controls, and windows. It is concluded that the incorporation of the change in body posture and the requirement for restraint into future designs will greatly facilitate the crewman's task in the weightless environment.
Perception of time under conditions of brief weightlessness

NASA Technical Reports Server (NTRS)

Lebedev, V. I.; Chekidra, I. F.; Kolosov, I. A.

1975-01-01

Results of experiments under conditions of brief weightlessness confirmed the theoretical concepts of the dependence of time perception on the emotional state of a man. The time test, together with other methods, can be used to precisely define the emotional state of subjects in stress situations.
Effects of orbital spaceflight on human osteoblastic cell physiology and gene expression

NASA Technical Reports Server (NTRS)

Harris, S. A.; Zhang, M.; Kidder, L. S.; Evans, G. L.; Spelsberg, T. C.; Turner, R. T.

2000-01-01

During long-term spaceflight, astronauts lose bone, in part due to a reduction in bone formation. It is not clear, however, whether the force imparted by gravity has direct effects on bone cells. To examine the response of bone forming cells to weightlessness, human fetal osteoblastic (hFOB) cells were cultured during the 17 day STS-80 space shuttle mission. Fractions of conditioned media were collected during flight and shortly after landing for analyses of glucose utilization and accumulation of type I collagen and prostaglandin E(2) (PGE(2)). Total cellular RNA was isolated from flight and ground control cultures after landing. Measurement of glucose levels in conditioned media indicated that glucose utilization occurred at a similar rate in flight and ground control cultures. Furthermore, the levels of type I collagen and PGE(2) accumulation in the flight and control conditioned media were indistinguishable. The steady-state levels of osteonectin, alkaline phosphatase, and osteocalcin messenger RNA (mRNA) were not significantly changed following spaceflight. Gene-specific reductions in mRNA levels for cytokines and skeletal growth factors were detected in the flight cultures using RNase protection assays. Steady-state mRNA levels for interleukin (IL)-1alpha and IL-6 were decreased 8 h following the flight and returned to control levels at 24 h postflight. Also, transforming growth factor (TGF)-beta(2) and TGF-beta(1) message levels were modestly reduced at 8 h and 24 h postflight, although the change was not statistically significant at 8 h. These data suggest that spaceflight did not significantly affect hFOB cell proliferation, expression of type I collagen, or PGE(2) production, further suggesting that the removal of osteoblastic cells from the context of the bone tissue results in a reduced ability to respond to weightlessness. However, spaceflight followed by return to earth significantly impacted the expression of cytokines and skeletal growth factors, which have been implicated as mediators of the bone remodeling cycle. It is not yet clear whether these latter changes were due to weightlessness or to the transient increase in loading resulting from reentry.
Spacelab

NASA Image and Video Library

1992-09-01

The Spacelab-J (SL-J) mission was a joint venture between NASA and the National Space Development Agency of Japan (NASDA) utilizing a marned Spacelab module. Materials science investigations covered such fields as biotechnology, electronic materials, fluid dynamics and transport phenomena, glasses and ceramics, metals and alloys, and acceleration measurements. Life sciences included experiments on human health, cell separation and biology, developmental biology, animal and human physiology and behavior, space radiation, and biological rhythms. Before long-term space ventures are attempted, numerous questions must be answered: how will gravity play in the early development of an organism, and how will new generations of a species be conceived and develop normally in microgravity. The Effects of Weightlessness on the Development of Amphibian Eggs Fertilized in Space experiment aboard SL-J examined aspects of these questions. To investigate the effect of microgravity on amphibian development, female frogs carried aboard SL-J were induced to ovulate and shed eggs. These eggs were then fertilized in the microgravity environment. Half were incubated in microgravity, while the other half were incubated in a centrifuge that spins to simulate normal gravity. This photograph shows an astronaut working with one of the adult female frogs inside the incubator. The mission also examined the swimming behavior of tadpoles grown in the absence of gravity. The Spacelab-J was launched aboard the Space Shuttle Orbiter Endeavour on September 12, 1992.
Spacelab

NASA Image and Video Library

1992-09-01

The Spacelab-J (SL-J) mission was a joint venture between NASA and the National Space Development Agency of Japan (NASDA) utilizing a marned Spacelab module. Materials science investigations covered such fields as biotechnology, electronic materials, fluid dynamics and transport phenomena, glasses and ceramics, metals and alloys, and acceleration measurements. Life sciences included experiments on human health, cell separation and biology, developmental biology, animal and human physiology and behavior, space radiation, and biological rhythms. Before long-term space ventures are attempted, numerous questions must be answered: how will gravity play in the early development of an organism, and how will new generations of a species be conceived and develop normally in microgravity. The Effects of Weightlessness on the Development of Amphibian Eggs Fertilized in Space experiment aboard SL-J examined aspects of these questions. To investigate the effect of microgravity on amphibian development, female frogs carried aboard SL-J were induced to ovulate and shed eggs. These eggs were then fertilized in the microgravity environment. Half were incubated in microgravity, while the other half were incubated in a centrifuge that spins to simulate normal gravity. This photograph shows astronaut Mark Lee working with one of the adult female frogs inside the incubator. The mission also examined the swimming behavior of tadpoles grown in the absence of gravity. The Spacelab-J was launched aboard the Space Shuttle Orbiter Endeavour on September 12, 1992.
STS-47 Spacelab-J, Onboard Photograph

NASA Technical Reports Server (NTRS)

1992-01-01

The Spacelab-J (SL-J) mission was a joint venture between NASA and the National Space Development Agency of Japan (NASDA) utilizing a marned Spacelab module. Materials science investigations covered such fields as biotechnology, electronic materials, fluid dynamics and transport phenomena, glasses and ceramics, metals and alloys, and acceleration measurements. Life sciences included experiments on human health, cell separation and biology, developmental biology, animal and human physiology and behavior, space radiation, and biological rhythms. Before long-term space ventures are attempted, numerous questions must be answered: how will gravity play in the early development of an organism, and how will new generations of a species be conceived and develop normally in microgravity. The Effects of Weightlessness on the Development of Amphibian Eggs Fertilized in Space experiment aboard SL-J examined aspects of these questions. To investigate the effect of microgravity on amphibian development, female frogs carried aboard SL-J were induced to ovulate and shed eggs. These eggs were then fertilized in the microgravity environment. Half were incubated in microgravity, while the other half were incubated in a centrifuge that spins to simulate normal gravity. This photograph shows an astronaut working with one of the adult female frogs inside the incubator. The mission also examined the swimming behavior of tadpoles grown in the absence of gravity. The Spacelab-J was launched aboard the Space Shuttle Orbiter Endeavour on September 12, 1992.
STS-47 Spacelab-J Onboard Photograph

NASA Technical Reports Server (NTRS)

1992-01-01

The Spacelab-J (SL-J) mission was a joint venture between NASA and the National Space Development Agency of Japan (NASDA) utilizing a marned Spacelab module. Materials science investigations covered such fields as biotechnology, electronic materials, fluid dynamics and transport phenomena, glasses and ceramics, metals and alloys, and acceleration measurements. Life sciences included experiments on human health, cell separation and biology, developmental biology, animal and human physiology and behavior, space radiation, and biological rhythms. Before long-term space ventures are attempted, numerous questions must be answered: how will gravity play in the early development of an organism, and how will new generations of a species be conceived and develop normally in microgravity. The Effects of Weightlessness on the Development of Amphibian Eggs Fertilized in Space experiment aboard SL-J examined aspects of these questions. To investigate the effect of microgravity on amphibian development, female frogs carried aboard SL-J were induced to ovulate and shed eggs. These eggs were then fertilized in the microgravity environment. Half were incubated in microgravity, while the other half were incubated in a centrifuge that spins to simulate normal gravity. This photograph shows astronaut Mark Lee working with one of the adult female frogs inside the incubator. The mission also examined the swimming behavior of tadpoles grown in the absence of gravity. The Spacelab-J was launched aboard the Space Shuttle Orbiter Endeavour on September 12, 1992.
Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight.

PubMed

Mukai, C N; Lathers, C M; Charles, J B; Bennett, B S

1994-05-01

Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.
Cardiovascular responses to repetitive exposure to hyper- and hypogravity states produced by parabolic flight

NASA Technical Reports Server (NTRS)

Mukai, C. N.; Lathers, C. M.; Charles, J. B.; Bennett, B. S.

1994-01-01

Physiologic changes to repetitive hyper- and hypogravity stresses occurring during eight to ten parabolas on NASA's KC-135 aircraft were studied. Hemodynamic responses in 11 subjects in 4 different postures (supine, standing, sitting, and semisupine Space Shuttle launch position) were determined using noninvasive impedance cardiography. Five seconds of heart rate, cardiac index, thoracic fluid index, stroke index, ejection velocity index, and ventricular ejection time data were averaged during four different gravity (g) states: 1.3g (before parabola onset); 1.9g (parabola entry); 0g (parabola peak); and 1.7g (parabola exit) for each subject. The standing position was associated with the largest changes in the cardiovascular response to hypo- and hypergravity. The thoracic fluid index did not indicate a headward redistribution during transition from a simulated launch position to weightlessness. Analysis of the eight to ten parabolas revealed that, in general, values obtained at 1.8g differed from 1.6g, 0g differed from 1.6 and 1.3g, and 1.6g differed from 1.3g. The factors of gravity, thoracic fluid index, and cardiac index exhibited significant differences that were most likely to occur between parabola 1 versus parabolas 6, 7, and 8, and parabola 2 versus parabolas 4 through 8. Only the parameter of thoracic fluid index exhibited significance for parabolas 3 versus parabolas 6 and 7.
Analysis of head-down tilt as an analog of weightlessness using a methematical simulation model

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1984-01-01

Antiorthostasis or head down tilt of a moderate degree was used as a ground based analog of weightless space flight to study headward fluid shifts, decreased plasma volume, orthostatic intolerance and muscular skeletal degradation. A mathematical model was used to help interpret these observations. The model proved most valuable for these studies was originally developed as a description of the major circulatory, fluid and electrolyte control systems. Two different experimental studies are employed to validate the model. The first is a 24 hour head down tilt study and the second is a 7 day head down bed rest study. The major issues addressed include the reduction in plasma volume, the dynamic changes of venous pressure and cardiac output, the extent of central hypervolemia during long term zero g exposure, the existence of an early diuresis, the mechanisms which alter the renal regulating hormones during the short term and long term periods, the significance of potassium loss on other zero g responses, and the role of transcapillary filtration in adjusting fluid shifts. The use of mathematical models as an interpretive and analysis technique for experimental research for space life science is illustrated.
Postnatal development under conditions of simulated weightlessness and space flight

NASA Technical Reports Server (NTRS)

Walton, K.

1998-01-01

The adaptability of the developing nervous system to environmental influences and the mechanisms underlying this plasticity has recently become a subject of interest in space neuroscience. Ground studies on neonatal rats using the tail suspension model of weightlessness have shown that the force of gravity clearly influences the events underlying the postnatal development of motor function. These effects depend on the age of the animal, duration of the perturbation and the motor function studied. A nine-day flight study has shown that a dam and neonates can develop under conditions of space flight. The motor function of the flight animals after landing was consistent with that seen in the tail suspension studies, being marked by limb joint extension. However, there were expected differences due to: (1) the unloading of the vestibular system in flight, which did not occur in the ground-based experiments; (2) differences between flight and suspension durations; and (3) the inability to evaluate motor function during the flight. The next step is to conduct experiments in space with the flexibility and rigor that is now limited to ground studies: an opportunity offered by the International Space Station. Copyright 1998 Published by Elsevier Science B.V.
Abbreviated closure for remote damage control laparotomy in extreme environments: A randomized trial of sutures versus wound clamps comparing terrestrial and weightless conditions.

PubMed

Kirkpatrick, Andrew W; McKee, Jessica Lynn; Tien, Colonel Homer; LaPorta, Anthony J; Lavell, Kit; Leslie, Tim; McBeth, Paul B; Roberts, Derek J; Ball, Chad G

2017-05-01

Far-Forward Damage Control Laparotomies (DCLs) might provide direct-compression of visceral hemorrhage, however, suturing is a limiting factor, especially for non-physicians. We thus compared abbreviated skin closures comparing skin-suture (SS) versus wound-clamp (WC), on-board a research aircraft in weightlessness (0g) and normal gravity (1g). Surgeons conducted DCLs on a surgical-simulator; onboard the hangered-aircraft (1g), or during parabolic flight (0g), randomized to either WC or SS. Ten surgeons participated. Two (40%) surgeons randomized to suture in 0g were incapacitated with motion-sickness, and none were able to close in either 1 or 0g. With WC, two completely closed in 1g as did three in 0g, despite having longer incisions (p = 0.016). Overall skin-closure with WC was significantly greater in both 1g (p = 0.016) and 0g (p = 0.008). WC was more effective in 1g and particularly 0g. Future studies should address the utility of abbreviated WC abdominal closure to facilitate potential Far-Forward DCL. ID ISRCTN/77929274. Copyright © 2017 Elsevier Inc. All rights reserved.

Astronaut health monitoring

NASA Astrophysics Data System (ADS)

Inscore, Frank; Shende, Chetan; Gift, Alan; Maksymiuk, Paul; Farquharson, Stuart

2006-10-01

Extended weightlessness causes numerous deleterious changes in human physiology, including space motion sickness, cephalad fluid shifts, reduced immune response, and breakdown of muscle tissue with subsequent loss of bone mass and formation of renal stones. Furthermore, these physiological changes also influence the metabolism of drugs used by astronauts to minimize these deleterious effects. Unfortunately, the changes in human physiology in space are also reflected in drug metabolism, and current pre-flight analyses designed to set dosage are inadequate. Furthermore, current earth-based analytical laboratory methods that employ liquid or gas chromatography for separation and fluorescence or mass spectrometry for trace detection are labor intensive, slow, massive, and not cost-effective for operation in space. In an effort to overcome these instrument limitations we have been developing a sampling device to both separate these drugs and metabolites from urine, and generate surface-enhanced Raman (SER) spectra. The detailed molecular vibrational information afforded by Raman scattering allows chemical identification, while the surface-enhancement increases sensitivity by six or more orders of magnitude and allows detection of nanogram per milliliter concentrations. Generally no more than 1 milliliter of sample is required and complete analysis can be performed in 5 minutes using a portable, light-weight Raman spectrometer. Here we present the SER analysis of several drugs used by astronauts measured in synthetic urine and reconstituted urine.
STS-53 MS Voss, in EMU, in lowered into JSC's WETF pool for EVA simulation

NASA Image and Video Library

1992-08-07

S92-43335 (28 July 1992) --- STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist James S. Voss, wearing extravehicular mobility unit (EMU), is lowered into JSC?s Weightless Environment Training Facility (WETF) Bldg. 29 pool. Voss waves to his daughter standing on the poolside as the platform he is positioned in is submerged in the pool. Technicians on the poolside and scuba equipped divers in the water monitor activities. Once underwater, Voss will participate in contingency extravehicular activity (EVA) procedures.
Hydroelectrolytic and hormonal modifications related to prolonged bedrest in antiorthostatic position

NASA Astrophysics Data System (ADS)

Güell, A.; Dupui, Ph.; Fanjaud, G.; Bes, A.; Moatti, J. P.; Gharrib, Cl.

The effects of prolonged bedrest in antiorthostatic position (-4° head down) on electrolyte balance were studied in 4 young volunteers. An increase was noted in sodium excretion during the first 4 days. Plasma renin activity and plasma aldosterone varied in parallel manner during the same period. Potassium balance and creatinine clearance were not significantly modified. In light of these data we feel that prolonged bedrest in antiorthostatic position constitutes an effective way to simulate on earth metabolic and hormonal modifications occurring in man under weightlessness conditions.
Engineer pedals STS-37 CETA electrical cart along track in JSC MAIL Bldg 9A

NASA Technical Reports Server (NTRS)

1990-01-01

McDonnell Douglas engineer Gary Peters operates crew and equipment translation aid (CETA) electrical hand pedal cart in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Peters, wearing extravehicular mobility unit (EMU) boots and positioned in portable foot restraint (PFR), is suspended above CETA cart and track via harness to simulate weightlessness. The electrical cart is moved by electricity generated from turning hand pedals. CETA will be tested in orbit in the payload bay of Atlantis, Orbiter Vehicle (OV) 104, during STS-37.
STS-45 MS Foale in EMU is lowered into JSC's WETF pool for underwater test

NASA Image and Video Library

1991-02-26

S91-30197 (1 March 1991) --- A wider shot of astronaut C. Michael Foale, mission specialist, standing on a platform which is part of a system that will lower him into a 25-ft. deep pool. Foale used the pool in the weightless environment training facility (WET-F) to rehearse a contingency extravehicular activity (EVA). Two SCUBA-equipped swimmers assist. Astronauts wear pressurized spacesuits configured for achieving a neutrally buoyant condition in the water to simulate both planned and contingency EVAs.
CREW TRAINING (EXTRAVEHICULAR ACTIVITY [EVA]) - STS-13 - JSC

NASA Image and Video Library

1983-11-01

S83-42893 (19 Oct 1983) ---- Astronauts George D. Nelson and James D. van Hoften, two of three STS-41C mission specialists, share an extravehicular activity (EVA) task in this simulation of a Solar Maximum Satellite (SMS) repair visit. The two are making use of the Johnson Space Center's (JSC) weightless environment training facility (WET-F). Dr. Nelson is equipped with the manned maneuvering unit (MMU) trainer and he handles the trunion pin attachment device (TPAD), a major tool to be used on the mission. The photograph was taken by Otis Imboden.
Crippen, pilot for STS-1, during a training session

NASA Image and Video Library

1978-03-22

S79-25014 (13 Dec. 1978) --- Astronaut Robert L. Crippen, pilot of the first space shuttle orbital flight test (STS-1), eases into a water immersion facility (WIF) during a training session in the Johnson Space Center?s training and test facility (Bldg. 260). The WIF affords one of two ways to simulate the feeling of weightlessness experienced during space extravehicular activity (EVA), the other being inside aircraft flying a parabolic curve. Crippen will be joined by astronaut John W. Young, commander for the STS-1 flight. Photo credit: NASA
Behavioral, psychiatric, and sociological problems of long-duration space missions

NASA Technical Reports Server (NTRS)

Kanas, N. A.; Fedderson, W. E.

1971-01-01

A literature search was conducted in an effort to isolate the problems that might be expected on long-duration space missions. Primary sources of the search include short-term space flights, submarine tours, Antarctic expeditions, isolation-chamber tests, space-flight simulators, and hypodynamia studies. Various stressors are discussed including weightlessness and low sensory input; circadian rhythms (including sleep); confinement, isolation, and monotony; and purely psychiatric and sociological considerations. Important aspects of crew selection are also mentioned. An attempt is made to discuss these factors with regard to a prototype mission to Mars.
Studies of acid-base homeostasis during simulated weightlessness: Application of the water immersion model to man

NASA Technical Reports Server (NTRS)

Epstein, M.

1975-01-01

The effects of water immersion on acid-base homeostasis were investigated under carefully controlled conditions. Studies of renal acidification were carried out on seven healthy male subjects, each consuming a diet containing 150 meq sodium and 100 meq potassium. Control and immersion studies were carried out on each subject on the fourth and sixth days, respectively, of dietary equilibration, by which time all subjects had achieved sodium balance. The experimental protocols on study days were similar (except for the amount of water administered).
STS-55 Payload Specialist Schlegel with technicians during JSC WETF bailout

NASA Technical Reports Server (NTRS)

1992-01-01

STS-55 Columbia, Orbiter Vehicle (OV) 102, Payload Specialist 2 Hans Schlegel, wearing launch and entry suit (LES), launch and entry helmet (LEH), and parachute, discusses procedures with technicians Karen Porter and Todd Bailey prior to launch emergency egress (bailout) exercises. The session, held in JSC's Weightless Environment Training Facility (WETF) Bldg 29, used the facility's 25-foot deep pool to simulate the ocean as Schlegel and other crewmembers practiced water bailout procedures. Schlegel represents the DLR for the upcoming Spacelab Deutsche 2 (SL-D2) mission.
STS-55 backup Payload Specialist Thiele with technician in JSC's WETF

NASA Technical Reports Server (NTRS)

1992-01-01

STS-55 Columbia, Orbiter Vehicle (OV) 102, backup German Payload Specialist Dr. P. Gerhard Thiele, wearing launch and entry suit (LES), launch and entry helmet (LEH), and parachute, seated on the poolside waits his turn to participate in launch emergency egress (bailout) exercises. The session, held in JSC's Weightless Environment Training Facility (WETF) Bldg 29, used the facility's 25-foot deep pool to simulate the ocean as Thiele and other crewmembers practiced water bailout procedures. Thiele represents the DLR for the upcoming Spacelab Deutsche 2 (SL-D2) mission.
The effect of simulated weightlessness on performance and mood

NASA Technical Reports Server (NTRS)

Rosenberg, Bonnie

1988-01-01

The performance results of the bedrest study at Ames were not what were expected. The Air Combat Maneuvering performance test was tested to assure its reliability. However, the results from this study show a continued increase in performance. One would assume that scores would become constant if not decrease by the first days of bedrest because an inverted position would affect performance. It is also interesting to observe that while the subject's moods deteriorated, their performance improved. Although the performance results were surprising, the mood results were as expected.
Teaching Science. A Weighty Gravity Lesson.

ERIC Educational Resources Information Center

Leyden, Michael B.

1996-01-01

Describes an activity that uses a candle, a scale, and an elevator to demonstrate the concept of weightlessness in space, showing that astronauts are not truly weightless. Activity includes an exploration phase, a concept introduction phase, and a concept application phase. Provides guidelines and safety measures for conducting the activity. (JW)
NASA Facts, Weightlessness.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

Weightlessness and how it can be artificially produced is described in this pamphlet written for junior high school students. The pamphlet is one of the NASA Facts Science Series (each of which consists of four pages) and is designed to fit in the standard size three-ring notebook. Review questions, suggested activities, and references are…
Fluid and electrolyte homeostasis during spaceflight: Elucidation of mechanisms in a primate

NASA Technical Reports Server (NTRS)

Churchill, Susanne

1990-01-01

Although it is now well accepted that exposure to the hypogravic environment of space induces a shift of fluid from the lower extremities toward the upper body, the actual physiological responses to this central volume expansion have not been well characterized. Because it is likely that the fluid and electrolyte response to hypogravity plays a critical role in the development of Cardiovascular Deconditioning, elucidation of these mechanisms is of critical importance. The goal of flight experiment 223, scheduled to fly on SLS-2, is the definition of the basic renal, fluid and electrolyte response to spaceflight in four instrumented squirrel monkeys. The studies were those required to support the development of flight hardware and optimal inflight procedures, and to evaluate a ground-based model for weightlessness, lower body positive pressure (LBPP).
U.S. biological experiments in space

NASA Technical Reports Server (NTRS)

Klein, H. P.

1981-01-01

The history of biologic experimentation in space is traced. Early balloon and rocket borne animals showed no abnormalities on the macroscale, and biosatellite launches with bacteria and amoebae revealed no microscopic dysfunctions. Adult Drosophila flies on board Cosmos spacecraft died with a shortened lifespan, while their offspring lived full lifespans. Green pepper plants grown in weightlessness showed a different orientation, but no physiological disturbances. Normal bone growth in rats has been found to almost cease after 11 days in space, and the mean life span of red blood cells decreases by four days. A series of experiments designed by U.S. scientists will be performed on primates provided and flown by the U.S.S.R. Finally, experiments on board Spacelab will involve determination of the persistence of circadian rhythms in bacteria and humans.
STS-78 Post Flight Presentation

NASA Technical Reports Server (NTRS)

1996-01-01

The flight crew of the STS-78 mission, Cmdr. Terence T. Henricks, Pilot Kevin R. Kregel, Payload Cmdr. Susan J. Helms, Mission Specialists Richard M. Linnehan, Charles E. Brady, Jr., and Payload Specialists Jean-Jacques Favier, Ph.D. and Robert B. Thirsk, M.D., back from their seventeen day mission, offer a video and still photo presentation of their journey. Included in the presentation are pre-launch, launch, and post-launch activities; experiments performed in the Spacelab; and re-entry; and the landing at KSC. Each of the STS-78 crew members discuss particular aspects of the mission including the 22 LMS life science and microgravity experiments. The experiments address human physiology, metallic alloys and protein crystal growth, and the study of the behavior of fluids and materials processing in the near-weightless environment of space.
Causes and consequences of reduced blood volume in space flight - A multi-discipline modeling study

NASA Technical Reports Server (NTRS)

Leonard, J. I.

1983-01-01

A group of mathematical models of various physiological systems have been developed and applied to studying problems associated with adaptation to weightlessness. One biomedical issue which could be addressed by at least three of these models from varying perspectives was the reduction in blood volume that universally occurs in astronauts. Accordingly, models of fluid-electrolyte, erythropoiesis, and cardiovascular regulation were employed to study the causes and consequences of blood volume loss during space flight. This analysis confirms the notion that alterations of blood volume are central to an understanding of adaptation to prolonged space flight. More importantly, the modeling studies resulted in specific hypotheses accounting for plasma volume and red cell mass losses and testable predictions concerning the behavior of the circulatory system.
GEMINI-TITAN (GT)-3 - WEIGHTLESSNESS EXPERIMENT - AMES RESEARCH CENTER (ARC), CA

NASA Image and Video Library

1965-03-01

S65-18762 (March 1965) --- Effects of the weightless environment on cell division, the basic growth process for living tissue, will be studied during the Gemini-Titan 3 flight scheduled for March 23, 1965. A spiny black sea urchin (upper left) is stimulated by mild electric shock or potassium chloride. As a result it sheds many thousands of eggs. When fertilized, these eggs become actively dividing cells very similar in basic processes to cells of other animals, including humans. These pictures show stages of cell division. At upper right is a single cell; at lower right cell divisions have produced many cells. Cell photos are magnified about 700 times, and all cells shown are too small to be seen by the naked eye. (Photos at upper right and lower left are of sea urchin eggs. Group of cells at lower right are from a sand dollar, which like the sea urchin, is an Echinoderm. Its eggs are virtually identical and are used interchangeably with those of the sea urchin in NASA Ames Center weightlessness experiments.) The Gemini experiment will involve cell division like that shown here. This will take place during several hours of weightlessness aboard the Gemini spacecraft. The experiment will be flown back to laboratories at Cape Kennedy after spacecraft recovery. It has been designed so that any abnormal cell division found by postflight analysis should suggest that the weightless environment has effects on individual cells. This might mean hazards for prolonged periods of manned spaceflight.
International Space Station as Analog of Interplanetary Transit Vehicle For Biomedical Research

NASA Technical Reports Server (NTRS)

Charles, John B.

2012-01-01

Astronaut missions lasting up to six months aboard the International Space Station (ISS) have much in common with interplanetary flights, especially the outbound, Earth-to-Mars transit portion of a Mars mission. Utilization of ISS and other appropriate platforms to prepare for crewed expeditions to planetary destinations including Mars has been the work of NASA's Human Research Program (HRP) since 2005. HRP is charged specifically to understand and reduced the risks to astronaut health and performance in space exploration missions: everything HRP does and has done is directly related to that responsibility. Two major categories of human research have capitalized on ISS capabilities. The first category centers on the biomedical aspects of long-duration exposure to spaceflight factors, including prolonged weightlessness, radiation exposure, isolation and confinement, and actual risk to life and limb. These studies contribute to astronaut safety, health and efficiency on any long-duration missions, whether in low Earth orbit (LEO) or beyond. Qualitatively, weightlessness is weightlessness, whether in LEO or en route to Mars. The HRP sponsors investigations into losses in muscle and bone integrity, cardiovascular function, sensory-motor capability, immune capacity and psychosocial health, and development and demonstration of appropriate treatments and preventative measures. The second category includes studies that are focused on planetary expeditions beyond LEO. For these, ISS offers a high fidelity analog to investigate the combined effects of spaceflight factors (described above) plus the isolation and autonomy associated with simulated increasing distance from Earth. Investigations address crew cohesion, performance and workload, and mission control performance. The behavioral health and performance and space human factors aspects of planetary missions dominate this category. Work has already begun on a new investigation in this category which will examine the effects of a simulated lag in communications (mimicking that expected in transit to Mars) on astronaut performance aboard ISS. Extension of the current ISS increment duration from six months to nine or even twelve months would provide opportunities for expanded research relevant to long duration missions, albeit at the cost of fewer astronauts as subjects for those investigations. Given the possible limited access to ISS after 2020, if ISS is intended to facilitate future exploration missions, then the in-flight human investigations should focus on those that clearly enable future exploration missions.

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