Related URLs:
http://www.ncbi.nlm.nih.gov/pubmed/19070310
Research Containing: Spaceflight
Summary – Bone in microgravity environments: "Houston, we have a problem"
With the recent change in leadership at NASA, a sea change in research priorities at the agency has occurred. Monies once dedicated to life science research have been dramatically reduced in order to provide resources for development of a new Crew Exploration Vehicle, designed to replace the aging shuttle vehicles. Bone loss during space flight, once considered a "show-stopper" when long duration exploration missions were more central to NASA planning,no longer commands center stage. The prevailing sentiment appears to be that changes in bone with short-term missions to the International Space Station (ISS) or to the lunar surface will be too small to impact on mission outcomes and will be successfully mitigated with current exercise countermeasures, perhaps in combination with bisphosphonate therapy. Strategies to minimize bone loss with long-term spaceflight (e.g.,2-3 years’ duration) may not be necessary 10 years from now some speculate, given projections of improved pharmacological treatments or even the integration of artificial gravity on board exploration vehicles. It behooves bone biologists to carefully define the specific challenges to bone integrity incurred during (or following) the shorter 3- to 6-month Lunar or ISS missions planned for the next 10 years. Data presented during this session illustrate well that, with reference to microgravity effects on bone integrity, there is too much of "we don’t know what we don’t know"
Related URLs:
http://ovidsp.ovid.com/ovidweb.cgi?T=JS&CSC=Y&NEWS=N&PAGE=fulltext&D=emed7&AN=2007033754
http://sfxhosted.exlibrisgroup.com/mayo?sid=OVID:embase&id=pmid:&id=doi:&issn=1108-7161&isbn=&volume=6&issue=4&spage=329&pages=329-330&date=2006&title=Journal+of+Musculoskeletal+Neuronal+Interactions&atitle=Summary+-+Bone+in+microgravity+environments%3A+%22Houston%2C+we+have+a+problem%22&aulast=Bloomfield&pid=%3Cauthor%3EBloomfield+S.A.%3C%2Fauthor%3E&%3CAN%3E2007033754%3C%2FAN%3E
International Space Station Medical Standards and Certification for Space Flight Participants
Introduction: The medical community of the International Space Station (ISS) has developed joint medical standards and evaluation requirements for Space Flight Participants (“space tourists”) which are used by the ISS medical certification board to determine medical eligibility of individuals other than professional astronauts (cosmonauts) for short-duration space flight to the ISS. These individuals are generally fare-paying passengers without operational responsibilities. Material and Context : By means of this publication, the medical standards and evaluation requirements for the ISS Space Flight Participants are offered to the aerospace medicine and commercial spaceflight communities for reference purposes. It is emphasized that the criteria applied to the ISS spaceflight participant candidates are substantially less stringent than those for professional astronauts and/or crewmembers of visiting and long-duration missions to the ISS. Conclusions: These medical standards are released by the government space agencies to facilitate the development of robust medical screening and medical risk assessment approaches in the context of the evolving commercial human spaceflight industry.
Related URLs:
http://www.ingentaconnect.com/content/asma/asem/2007/00000078/00000012/art00012
http://dx.doi.org/10.3357/ASEM.2175.2007
The Russian experience in medical care and health maintenance of the International Space Station crews
The main purpose of the medical support system aboard International Space Station (ISS) is crew health maintenance and high level of work capability assurance prior to during and after in space flights. In the present communication the Russian point of view dealing with the problems and achievements in this branch is presented. An overview on medical operations during flight and after finalization of the space missions based on Russian data of crew health and environment state monitoring, as well as data on the inflight countermeasures (prophylaxis) jointly with data on operational problems that are specific to ISS is presented. The report summarizes results of the medical examination of Russian members of the ISS and taxi crews during and after visits to the ISS.
Related URLs:
http://www.sciencedirect.com/science/article/pii/S0094576506002931
Cultural Differences in Crewmembers and Mission Control Personnel During Two Space Station Programs
INTRODUCTION: Cultural differences among crewmembers and mission control personnel can affect long-duration space missions. We examine three cultural contrasts: national (American vs. Russian); occupational (crewmembers vs. mission control personnel); and organizational [Mir space station vs. International Space Station (ISS)]. METHODS: The Mir sample included 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel. The ISS sample included 8 astronauts, 9 cosmonauts, and 108 American and 20 Russian mission control personnel. Subjects responded to mood and group climate questions on a weekly basis. The ISS sample also completed a culture and language questionnaire. RESULTS: Crewmembers had higher scores on cultural sophistication than mission control personnel, especially American mission control. Cultural sophistication was not related to mood or social climate. Russian subjects reported greater language flexibility than Americans. Crewmembers reported better mood states than mission control, but both were in the healthy range. There were several Russian-American differences in social climate, with the most robust being higher work pressure among Americans. Russian-American social climate differences were also found in analyses of crew only. Analyses showed Mir-ISS differences in social climate among crew but not in the full sample. DISCUSSION: We found evidence for national, occupational, and organizational cultural differences. The findings from the Mir space station were essentially replicated on the ISS. Alterations to the ISS to make it a more user-friendly environment have still not resolved the issue of high levels of work pressure among the American crew.
Related URLs:
http://www.ingentaconnect.com/content/asma/asem/2009/00000080/00000006/art00004
http://dx.doi.org/10.3357/ASEM.2430.2009
Spaceflight-induced cardiovascular changes and recovery during NASA's Functional Task Test
Microgravity-induced physiologic changes could impair a crewmember's performance upon return to a gravity environment. The Functional Task Test aims to correlate these physiologic alterations with changes in performance during mission-critical tasks. In this study, we evaluated spaceflight-induced cardiovascular changes during 11 functional tasks in 7 Shuttle astronauts before spaceflight, on landing day, and 1, 6, and 30 days after landing. Mean heart rate was examined during each task and autonomic activity was approximated by heart rate variability during the Recovery from Fall/Stand Test, a 2-min prone rest followed by a 3-min stand. Heart rate was increased on landing day during all of the tasks, and remained elevated 6 days after landing during 6 of the 11 tasks. Parasympathetic modulation was diminished and sympathovagal balance was increased on landing day. Additionally, during the stand test 6 days after landing, parasympathetic modulation remained suppressed and heart rate remained elevated compared to preflight levels. Heart rate and autonomic activity were not different from preflight levels 30 days after landing. We detected changes in heart rate and autonomic activity during a 3-min stand and a variety of functional tasks, where cardiovascular deconditioning was still evident 6 days after returning from short-duration spaceflight. The delayed recovery times for heart rate and parasympathetic modulation indicate the necessity of assessing functional performance after long-duration spaceflight to ensure crew health and safety.
Related URLs:
http://www.sciencedirect.com/science/article/pii/S0094576512002147
Effects of mental stress on autonomic cardiac modulation during weightlessness
Sustained weightlessness affects all body functions, among these also cardiac autonomic control mechanisms. How this may influence neural response to central stimulation by a mental arithmetic task remains an open question. The hypothesis was tested that microgravity alters cardiovascular neural response to standardized cognitive load stimuli. Beat-to-beat heart rate, brachial blood pressure, and respiratory frequency were collected in five astronauts, taking part in three different short-duration (10 to 11 days) space missions to the International Space Station. Data recording was performed in supine position 1 mo before launch; at days 5 or 8 in space; and on days 1, 4, and 25 after landing. Heart rate variability (HRV) parameters were obtained in the frequency domain. Measurements were performed in the control condition for 10 min and during a 5-min mental arithmetic stress task, consisting of deducting 17 from a four-digit number, read by a colleague, and orally announcing the result. Our results show that over all sessions (pre-, in-, and postflight), mental stress induced an average increase in mean heart rate (Δ7 ± 1 beats/min; P = 0.03) and mean arterial pressure (Δ7 ± 1 mmHg; P = 0.006). A sympathetic excitation during mental stress was shown from HRV parameters: increase of low frequency expressed in normalized units (Δ8.3 ± 1.4; P = 0.004) and low frequency/high frequency (Δ1.6 ± 0.3; P = 0.001) and decrease of high frequency expressed in normalized units (Δ8.9 ± 1.4; P = 0.004). The total power was not influenced by mental stress. No effect of spaceflight was found on baseline heart rate, mean arterial pressure, and HRV parameters. No differences in response to mental stress were found between pre-, in-, and postflight. Our findings confirm that a mental arithmetic task in astronauts elicits sympathovagal shifts toward enhanced sympathetic modulation and reduced vagal modulation. However, these responses are not changed in space during microgravity or after spaceflight.
Related URLs:
http://ajpheart.physiology.org/ajpheart/298/1/H202.full.pdf
Status of the International Space Station (ISS) Trace Contaminant Control System
A habitable atmosphere is a fundamental requirement for human spaceflight. To meet this requirement, the cabin atmosphere must be constantly scrubbed to maintain human life and system functionality. The primary system for atmospheric scrubbing of the US on-orbit segment (USOS) of the International Space Station (ISS) is the Trace Contaminant Control System (TCCS). As part of the Environmental Control and Life Support Systems' (ECLSS) atmosphere revitalization rack in the US Lab, the TCCS operates continuously, scrubbing trace contaminants generated primarily by two sources: the metabolic off-gassing of crew members and the off-gassing of equipment in the ISS. It has been online for approximately 95% of the time since activated in February 2001. The TCCS is comprised of a charcoal bed, a catalytic oxidizer, and a lithium hydroxide post-sorbent bed, all of which are designed to be replaced on-orbit when necessary. In 2006, all three beds were replaced following an observed increase in the system resistance that occurred over a period several months. The beds were returned to ground and subjected to a test, teardown and evaluation (TT&E) to investigate the root cause(s) of the decrease in flow rate through the system. In addition, various chemical and physical analyses of the bed materials were performed to determine contaminant loading and any changes in performance. This paper will mainly focus on the results of these analyses and how this correlates with what has been observed from archival sampling and on-orbit events. This has provided insight into the future performance of the TCCS and rate of change for orbital replacement units in the TCCS.
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Study of the autonomic regulation of blood circulation during a long-term space flight
The five-year experience of experimentation in the autonomic regulation of blood circulation on board the International Space Station is presented. The heart rate variability (HRV) analysis was the basic methodical approach in these investigations. The probabilistic approach to the estimation of the risk of pathology under long-term spaceflight conditions based on HRV analysis is described. The individual type of autonomic regulation was taken into account in the analysis of the results of the investigations. The type of regulation inherent in every cosmonaut under the conditions of weightlessness has been shown to be retained during subsequent flights. New scientific data on the relationship between the character of the adaptive response of the body to spaceflight factors and the individual type of autonomic response have been obtained. Staying in weightlessness has been shown to be connected with the readjustment of regulatory systems and with transition to the zone of prenosological states. Adaptation responses in weightlessness are characterized by the increased tension of the regulatory systems and the preservation of sufficient functional reserves. The mobilization of additional resources is required after returning to earth, due to which the functional reserve of the mechanisms of regulation decreases. Cosmonauts with the vagotonic and normosympathotonic types of autonomic regulation appear to be the most resistant. The knowledge of the type of autonomic regulation allows us to judge the potential response of the cosmonaut to spaceflight factors. The likelihood estimates were calculated, and the risk categories were determined by the results of HRV analysis in the last months of the flight. Three pathology risk groups were identified. In conclusion, the theoretical and applied significance of the experiments was considered.
Related URLs:
http://dx.doi.org/10.1134/S0362119713050046
Current problems of space cardiology
The development of space cardiology is considered, from the first flights of animals and humans to the studies conducted on board International Space Station (ISS). The material is recounted in four sections in accordance with the theoretical statements presented in the book “Space Cardiology” (1967). The first section is analysis of rearrangement of blood circulation under the conditions of microgravity. Long-term microgravity has been demonstrated to require mobilization of additional functional reserves of the body. During the first six months of the flight, the cardiovascular homeostasis is supported by the regulatory mechanisms of the blood circulation system, whereas in the case of a more prolonged impact of microgravity, intersystem control is actively involved (suprasegmental divisions of autonomic regulation). In the second section dealing with the roles of the right and left divisions of the heart in adaptation to microgravity of the cardiovascular system, the important role of the right heart at the initial stage of a space flight (SF) is emphasized. The third section addresses the problem of reducing the orthostatic stability; this study has been initiated as early as the first manned space flights. The results obtained on board ISS testify to the importance of evaluating the functional reserves of the blood circulation system. The fourth section presents data on the new methods of myocardial examination that are to be soon introduced into SF medical provision. In conclusion, some new projects in space cardiology are discussed.
Related URLs:
http://dx.doi.org/10.1134/S0362119710070042