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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

Assessment of Nutritional Intake During Space Flight and Space Flight Analogs

Background: Maintaining adequate nutrient intake in microgravity is important not only to meet health maintenance needs of astronauts but also to help counteract the negative effects of space flight. Beyond this, food provides psychosocial benefits throughout a mission. Objective: The purpose of this presentation is to discuss dietary intake data from multiple space programs, including Space Shuttle and the International Space Station. Description: These data arise from medical monitoring of both dietary intake and crew health, as well as research protocols designed to assess the role of diet in counteracting bone loss and other health concerns. Ground-based studies are conducted to better understand some of the negative issues related to space flight. Examples of these analog studies are extended bed rest studies, vitamin D supplementation studies in Antarctica, and saturation diving missions on the floor of the ocean. Methods and findings will be presented describing the use of weighed records, diet diaries, and food frequency questionnaires in these various environments. Provision of food and nutrients in spaceflight is important for many body systems including cardiovascular, musculoskeletal, endocrine, immune, and others. Some key areas of concern are loss of body mass, bone and muscle loss, radiation exposure, nutrient intakes during spacewalks, depletion of nutrient stores, and inadequate dietary intake. Initial experimental research studies using food and nutrition as a countermeasure to aid in mitigating these concerns are underway. Conclusion: Beyond their importance for the few individuals leaving the planet, these studies have significant implications for those remaining on Earth.

Rice, Barbara L.↗
NASA NTRS1998

Immune responses in space flight

Space flight has been shown to have profound effects on immunological parameters of humans, monkeys and rodents. These studies have been carried out by a number of different laboratories. Among the parameters affected are leukocyte blastogenesis, natural killer cell activity, leukocyte subset distribution, cytokine production - including interferons and interleukins, and macrophage maturation and activity. These changes start to occur only after a few days space flight, and some changes continue throughout long-term space flight. Antibody responses have received only very limited study, and total antibody levels have been shown to be increased after long-term space flight. Several factors could be involved in inducing these changes. These factors could include microgravity, lack of load-bearing, stress, acceleration forces, and radiation. The mechanism(s) for space flight-induced changes in immune responses remain(s) to be established. Certainly, there can be direct effects of microgravity, or other factors, on cells that play a fundamental role in immune responses. However, it is now clear that there are interactions between the immune system and other physiological systems that could play a major role. For example, changes occurring in calcium use in the musculoskeletal system induced by microgravity or lack of use could have great impact on the immune system. Most of the changes in immune responses have been observed using samples taken immediately after return from space flight. However, there have been two recent studies that have used in-flight testing. Delayed-type hypersensitivity responses to common recall antigens of astronauts and cosmonauts have been shown to be decreased when tested during space flights. Additionally, natural killer cell and blastogenic activities are inhibited in samples taken from rats during space flight. Therefore, it is now clear that events occurring during space flight itself can affect immune responses. The biological significance of space flight-induced changes in immune parameters remains to be established; however, as duration of flights increases, the potential for difficulties due to impaired immune responses also increases.

manned↗
NASA NTRS1999

Renal Stone Risk During Space Flight

Space flight produces a number of metabolic and physiological changes in the crewmembers exposed to microgravity. Following launch, body fluid volumes, electrolyte levels, and bone and muscle undergo changes as the human body adapts to the weightless environment. Changes in the urinary chemical composition may lead to the potentially serious consequences of renal stone formation. Previous data collected immediately after space flight indicate changes in the urine chemistry favoring an increased risk of calcium oxalate and uric acid stone formation (n = 323). During short term Shuttle space flights, the changes observed include increased urinary calcium and decreased urine volume, pH and citrate resulting in a greater risk for calcium oxalate and brushite stone formation (n = 6). Results from long duration Shuttle/Mir missions (n = 9) followed a similar trend and demonstrated decreased fluid intake and urine volume and increased urinary calcium resulting in a urinary environment saturated with the calcium stone-forming salts. The increased risk occurs rapidly upon exposure to microgravity, continues throughout the space flight and following landing. Dietary factors, especially fluid intake, or pharmacologic intervention can significantly influence the urinary chemical composition. Increasing fluid intake to produce a daily urine output of 2 liters/day may allow the excess salts in the urine to remain in solution, crystals formation will not occur and a renal stone will not develop. Results from long duration crewmembers (n = 2) who had urine volumes greater than 2.5 L/day minimized their risk of renal stone formation. Also, comparisons of stone-forming risk in short duration crewmembers clearly identified greater risk in those who produced less than 2 liters of urine/day. However, hydration and increased urine output does not correct the underlying calcium excretion due to bone loss and only treats the symptoms and not the cause of the increased urinary salts. Dietary modification and promising pharmacologic treatments may also be used to reduce the potential risk for renal stone formation. Potassium citrate is being used clinically to increase the urinary inhibitor levels to minimize the development of crystals and the growth of renal stones. Bisphosphonates are a class of drugs recently shown to help in patients with osteoporosis by inhibiting the loss of bones in elderly patients. This drug could potentially prevent the bone loss observed in astronauts and thereby minimize the increase in urinary calcium and reduce the risk for renal stone development. Results of NASA's renal stone risk assessment program clearly indicate that exposure to microgravity changes the urinary chemical environment such that there is an increased risk for supersaturation of stone-forming salts, including calcium oxalaie and brushite. These studies have indicated specific avenues for development of countermeasures for the increased renal stone risk observed during and following space flight. Increased hydration and implementation of pharmacologic countermeasures should largely mitigate the in-flight risk of renal stones.

Whitson, Peggy A.↗
NASA NTRS1980

Changes in erythropoietin levels during space flight or space flight simulation

Two hundred and seventy samples from 24 subjects involved in 3 bedrest studies and from 3 subjects involved in Spacelab Mission Development Test 3 were assayed for erythropoietin (Ep), in an in vitro fetal mouse liver cell assay, and for ferritin using a commercially available immunoradiometric assay kit. No trends or significant changes in serum Ep were observed. Serum ferritin concentrations tended to increases slightly during the 'missions', reflecting a redirection of iron from the suppressed erythron into iron stores.

Dunn, C. D. R.↗
NASA NTRS2000

Integrated Testing Regimen: Assessment of Countermeasures for Long Duration Space Flight

Space flight has been shown to induce changes in the physiology of crewmembers which can adversely affect their performance. The objectives of Countermeasures Evaluation and Validation Project (CEVP) are to develop and validate potential countermeasures to the deleterious effects of space flight for operational implementation and use. In order to accomplish this objective, a group of standardized tests, the Integrated Testing Regimen or ITR, will be utilized for the evaluation of candidate countermeasures. Additionally, the ITR will illuminate intersystem effects of the potential countermeasures and provide normative values for the physiological responses. Due to the small number of crewmembers available as test subjects, statistically rigorous validation of countermeasures presents a challenging problem. Strategies for reliable evaluation of small N clinical studies will be utilized for these activities. These approaches will permit effective analysis of promising countermeasure to support human space flights of increasing duration.

Sams, Clarence F.↗
NASA NTRS2002

Red blood cell and iron metabolism during space flight

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.

STS Shuttle Project↗
NASA NTRS1998

Nutrition, endocrinology, and body composition during space flight

Space flight induces endocrine changes that perturb metabolism. This altered metabolism affects both the astronauts' body composition and the nutritional requirements necessary to maintain their health. During the last 25 years, a combination of studies conducted on Skylab (the first U.S. space laboratory), U.S. Shuttle flights, and Soviet and Russian flights provides a range of data from which general conclusions about energy and protein requirements can be drawn. We have reviewed the endocrine data from those studies and related it to changes in body composition. From these data it appears that protein and energy intake of astronauts are similar to those on Earth. However, a combination of measures, including exercise, appropriate diet, and, potentially, drugs, is required to provide the muscle health needed for long duration space flight.

Flight Experiment↗
NASA NTRS1993

Nutrition and human physiological adaptations to space flight

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.

Review↗
NASA NTRS1996

Destruction of newly released red blood cells in space flight

Space flight results in a rapid change in total blood volume, plasma volume, and red blood cell mass because the space to contain blood is decreased. The plasma volume and total blood volume decreases during the first hours in space and remain at a decreased level for the remainder of the flight. During the first several hours following return to earth, plasma volume and total blood volume increase to preflight levels. During the first few days in space recently produced red blood cells disappear from the blood resulting in a decrease in red blood cell mass of 10-15%. Red cells 12 d old or older survive normally and production of new cells continues at near preflight levels. After the first few days in space, the red cell mass is stable at the decreased level. Following return to earth the hemoglobin and red blood cell mass concentrations decrease reflecting the increase in plasma volume. The erythropoietin levels increase responding to "postflight anemia"; red cell production increases, and the red cell mass is restored to preflight levels after several weeks.

STS-58 Shuttle Project↗
NASA NTRS1999

Functional Assessment of NK and LAK Cells Following Space Flight

Space flight associated stress alters some aspects of the human immune response. In this study, we determined the effects of 10 days aboard the Space Shuttle on the cytotoxic activity of NK and LAK cells. PBMCs were collected from 10-ml blood specimens from 5 astronauts 10 days before launch, immediately after landing, and again at 3 days after landing and stored at -80 C. All PBMCs were thawed simultaneously, and the cytotoxic activities of NK and LAK cells were measured by a 4 hour Cr-51 release assay. K562 cells were used to assess NK cell cytotoxicity. Following 4 days of IL-2 activation, the LAK cell cytotoxic activity was determined using K562 cells and Daudi cells as the target cells. NK cell cytotoxicity decreased at landing (p<.05) in 3/5 astronauts, and recovered to preflight levels by 3 days following landing; NK cell cytotoxicity was increased (p=0.1) in the remaining 2 astronauts at landing. In 4/5 astronauts, LAK cytotoxic activity was decreased at landing against K562 cells (p = 0.13) and Daudi cells (p = 0.08). Phenotyping of PBMC's and LAK cells showed alterations in some surface markers and adhesion molecules (CD11b, CD11c, CD11a, CD16, L-selectin, and CD3).

Kaur, Indreshpal↗
NASA NTRS2008

Actions Needed to Ensure Scientific and Technical Information is Adequately Reviewed at Goddard Space Flight Center, Johnson Space Center, Langley Research Center, and Marshall Space Flight Center

This audit was initiated in response to a hotline complaint regarding the review, approval, and release of scientific and technical information (STI) at Johnson Space Center. The complainant alleged that Johnson personnel conducting export control reviews of STI were not fully qualified to conduct those reviews and that the reviews often did not occur until after the STI had been publicly released. NASA guidance requires that STI, defined as the results of basic and applied scientific, technical, and related engineering research and development, undergo certain reviews prior to being released outside of NASA or to audiences that include foreign nationals. The process includes technical, national security, export control, copyright, and trade secret (e.g., proprietary data) reviews. The review process was designed to preclude the inappropriate dissemination of sensitive information while ensuring that NASA complies with a requirement of the National Aeronautics and Space Act of 1958 (the Space Act)1 to provide for the widest practicable and appropriate dissemination of information resulting from NASA research activities. We focused our audit on evaluating the STI review process: specifically, determining whether the roles and responsibilities for the review, approval, and release of STI were adequately defined and documented in NASA and Center-level guidance and whether that guidance was effectively implemented at Goddard Space Flight Center, Johnson Space Center, Langley Research Center, and Marshall Space Flight Center. Johnson was included in the review because it was the source of the initial complaint, and Goddard, Langley, and Marshall were included because those Centers consistently produce significant amounts of STI.

Information management↗
NASA NTRS1999

Assurance of COTS Boards for Space Flight

Space Flight hardware and software designers are increasingly turning to Commercial-Off-the-Shelf (COTS) products in hopes of meeting the demands imposed on them by projects with short development cycle times. The Technology Validation Assurance (TVA) team at NASA GSFC has embarked on applying a method for inserting COTS hardware into the Spartan 251 spacecraft. This method includes Procurement, Characterization, Ruggedization/Remediation and Verification Testing process steps which are intended to increase the user's confidence in the hardware's ability to function in the intended application for the required duration. As this method is refined with use, it has the potential for becoming a benchmark for industry-wide use of COTS in high reliability systems.

Plante Jeannette↗
NASA NTRS1998

Assurance of COTS Boards for Space Flight

Space Flight hardware and software designers are increasingly turning to Commercial-Off-the-Shelf (COTS) products in hopes of meeting the demands imposed on them by projects with short development cycle times. The Technology Validation Assurance (TVA) team at NASA GSFC has embarked on applying a method for inserting COTS hardware into the Spartan 251 spacecraft. This method includes Procurement, Characterization, Ruggedization/Remediation and Verification Testing process steps which are intended to increase the uses confidence in the hardware's ability to function in the intended application for the required duration. As this method is refined with use, it has the potential for becoming a benchmark for industry-wide use of COTS in high reliability systems.

Plante, Jeannette↗
NASA NTRS2003

The biomedical challenges of space flight

Space medicine has evolved considerably through past U.S. missions. It has been proven that humans can live and work in space for long durations and that humans are integral to mission success. The space medicine program of the National Aeronautics and Space Administration (NASA) looks toward future long-duration missions. Its goal is to overcome the biomedical challenges associated with maintaining the safety, health, and optimum performance of astronauts and cosmonauts. This program investigates the health effects of adaptation to microgravity: the nature of their pathologies, the effects of microgravity on pathophysiology, and the alterations in pharmacodynamics and treatment. A critical capability in performing research is the monitoring of the health of all astronauts and of the spacecraft environment. These data support the evidence-based approach to space medicine, incorporating past studies of microgravity-related conditions and their terrestrial counterparts. This comprehensive approach will enable safe and effective exploration beyond low Earth orbit.

Mir Project↗