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NASA NTRS1990

Strategies for crew selection for long duration missions

Issues surrounding psychological reactions to long duration spaceflight are discussed with respect to the definition of criteria for selecting crewmembers for such expeditions. Two broad dimensions of personality and behavior are defined - Instrumentality including achievement orientation, leadership, and ability to perform under pressure and Expressivity encompassing interpersonal sensitivity and competence. A strategy for validating techniques to select in candidates with the optimum psychological profile to perform successfully on long duration missions is described.

Helmreich, Robert L.↗

NASA NTRSDate not supplied

Lessons Learned from Medical System Foundation Development for Long-Duration Lunar Orbit and Lunar Surface Missions

The Human Research Program (HRP) Exploration Medical Capability (ExMC) Element has been tasked with the development of Medical System Foundations for Level of Care IV for both short-duration lunar orbital missions and, subsequently, long-duration lunar orbital and surface operations missions. These Medical System Foundations serve as a framework to aid in early medical system design and mission planning. The content of both Foundation models is similar, consisting of a concept of operations, functional decomposition, clinical content (medical conditions, capabilities, and resources), technical requirements (interface, non-functional, and functional), and traces between these components and to the NASA standards documents and parent-level (Program- and Vehicle habitat system-level) requirements. Additionally, the development of both Foundations employed systems engineering principles and a model-based systems engineering (MBSE) approach. Throughout the development of these Foundations, ExMC has strived to improve the efficiency and robustness of its processes and to be more responsive to change (i.e., in design reference mission parameters and assumptions) and to stakeholders’ feedback. The most significant improvements made between the short- and long-duration Foundation models during this transformation process are the following: • Replacement of the traditional document-based ConOps with a model-based ConOps according to MBSE principles, which facilitated more efficient understanding of the material and the consolidation of all relevant information into a centralized location. • Utilization of an agile approach with tasks organized into sprints. This approach enabled solicitation of more frequent usability feedback from stakeholders, incorporation of more human factors reviews into the sprints, and more efficient tasking of team members. This presentation will discuss the journey of developing both Foundation models, as well as the lessons learned and resulting improvements made between the Short- and Long-Duration models.

M Kaetzer↗

NASA NTRS2023

Female Astronauts Exhibit Greater Reductions in Aerobic Peak Power Following Long-Duration Space Flight than Males

BACKGROUND: Long-duration exposure to microgravity during space flight causes cardiovascular deconditioning, ultimately reducing aerobic fitness. While sex-based differences play an integral role in health on Earth, there is a paucity of data to inform space flight-induced health and performance implications for female astronauts, which may be critical to ensure health, safety, and mission success. Therefore, this retrospective investigation characterized aerobic capacity in female and male astronauts to inform whether sex differences exist from pre to postflight. METHODS: A NASA historical database (n=47 crew; 11 female, 36 male) of International Space Station (ISS) crewmembers was used to characterize sex differences in aerobic capacity changes from pre to postflight to update the NASA Aerobic and Muscle Risk Evidence Report. Aerobic capacity (VO2pk; ml/kg/min) and peak power (W) were assessed using a graded cycling exercise protocol that included a 3-min warmup at 50 W, with stepwise increases in resistance (25 W/min) until volitional fatigue. Group differences in baseline demographics and the percent change in aerobic capacity from preflight (~90 days before launch) to postflight (~3 days after return) were compared using independent t-tests. Significance was set at P<0.05 (Mean ±SD). RESULTS: At preflight, females were younger (44.5±6.6 vs 48.6±5.6 yrs; p=0.041), weighed less (68.8±10.0 vs 81.0±8.8 kg; p< 0.001), with lower VO2pk (32.8±5.9 vs 37.8±6.0 ml/kg/min; p=0.021) and aerobic peak power (229±42 vs 299±52 W; p< 0.001) than males, but had similar heart rate at VO2pk (176.0±7.3 vs 173.0±10.8 beats/min; p=0.406). ISS flight durations (F: 205.0±58.3 vs M: 176.0±40.5 days; p=0.061) and reductions in VO2pk from pre to postflight were comparable between sexes (F: -11.8±10.7%; M: -8.8%±7.9%; p=0.32). However, females had a greater reduction in aerobic peak power than males (−13.3%±8.9% vs −4.9%±8.8%; p < 0.01). CONCLUSIONS: These data indicate that some indicators of fitness (i.e., aerobic peak power) are more impacted in female astronauts compared to males after long-duration space flight missions. Future investigations with larger sample sizes are necessary to identify the physiological basis of sex-based differences and develop effective countermeasure approaches for both sexes.

Nicole C Strock↗

NASA NTRSDate not supplied

In-Space Manufacturing and Planetary Surface Construction: A "Make It, Don't Take It" Approach to Long Duration Human Exploration

This presentation will focus on technology development efforts at NASA Marshall Space Flight Center (MSFC) related to the long term sustainability of human spaceflight operations. NASA’s in-space manufacturing (ISM) project is developing approaches for on-demand manufacturing of metals, printed electronics, and recycling. These technologies will be demonstrated onboard the International Space Station (ISS) before transitioning to more logistically remote platforms such as Gateway or a foundational lunar surface habitat. Based on quantitative analyses, the operations and logistics approach used for ISS (which relies on storage of a large volume of spares and frequent cargo resupply), will not be transferrable to long duration, long endurance missions beyond low earth orbit. The deployment of manufacturing and recycling technologies on crewed platforms will enable on-demand manufacturing of spares at the point of use and conversion of nuisance materials to manufacturing feedstock, reducing both launch mass and waste material. This talk will also include information on NASA’s 3D Printed Habitat Centennial Challenge, which concluded in 2019 and served to advance the state of the art for large scale 3D printing with indigenous materials similar to those which would be available on a planetary surface. MSFC also recently began work on the Moon-to-Mars Planetary Autonomous Construction Technologies (MMPACT) project, which seeks to demonstrate capabilities for the creation of infrastructure on the lunar surface via construction of landing pads and habitats with lunar regolith based materials.

materials↗

NASA NTRS2014

Focal Gray Matter Plasticity as a Function of Long Duration Head-down Tilt Bed Rest

Long duration spaceflight (i.e., > or = 22 days) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether these sensorimotor changes may be related to structural and functional brain changes is yet unknown. However, experimental studies revealed changes in the gray matter (GM) of the brain after simulated microgravity. Thus, it is possible that spaceflight may affect brain structure and thereby cognitive functioning and motor behavior. Long duration head-down tilt bed rest has been suggested as an exclusionary analog to study microgravity effects on the sensorimotor system. Bed rest mimics microgravity in body unloading and bodily fluid shifts. In consideration of the health and performance of crewmembers both in- and post-flight, we are conducting a prospective longitudinal 70-day bed rest study as an analog to investigate the effects of microgravity on the brain. VBM analysis revealed a progressive decrease from pre- to in- bed rest in GM volume in bilateral areas including the frontal medial cortex, the insular cortex and the caudate. Over the same time period, there was a progressive increase in GM volume in the cerebellum, occipital-, and parietal cortex, including the precuneus. The majority of these changes did not fully recover during the post-bed rest period. Analysis of lobular GM volumes obtained with BRAINS showed significantly increased volume from pre-bed rest to in-bed rest in GM of the parietal lobe and the third ventricle. Temporal GM volume at 70 days in bed rest was smaller than that at the first pre-bed rest measurement. Trend analysis showed significant positive linear and negative quadratic relationships between parietal GM and time, a positive linear relationship between third ventricle volume and time, and a negative linear relationship between cerebellar GM volume and time. FM performance improved from pre-bed rest session 1 to session 2. From the second pre-bed rest measure to the last-day-in-bed rest, there was a significant decrease in performance that only partially recovered post-bed rest. No significant association was observed between changes in brain volume and changes in functional mobility. Extended bed rest, which is an analog for microgravity, can result in local volumetric GM increase and decrease and adversely affect functional mobility. These changes in brain structure and performance were not related in this sample. Whether the effects of bed rest dissipate at longer times post-bed rest, and if they are associated with behavior are important questions that warrant further research including more subjects and longer follow-up times.

Koppelmans, V.↗

NASA NTRS1992

Results of the TTF-TCNQ and the calcium carbonate crystallization on the Long Duration Exposure Facility

Experiment A0139A on the Long Duration Exposure Facility (LDEF) carried four large containers into orbit five years with crystal growth solutions for lead sulfide, calcium carbonate, and TTF-TCNQ. Although temperature data was lost, the experimental program had been working since the valves in all containers had been opened. All four experiments produced crystals of varying quality. The calcium carbonate crystals had the best appearance. The TTF-TCNQ crystals were packed together near the valve openings of the container. When taken apart, the single crystals showed some unusual morphological properties. X ray investigations as well as conductivity measurements on long duration space grown TTF-TCNQ crystals will be presented. Comparisons will be made with our previous space solution growth experiments. The TTF-TCNQ crystals are no longer of the highest interest, so this activity has been terminated in favor of calcium carbonate and calcium phosphate crystallizations.

Nielsen, Kjeld Flemming↗

NASA NTRS2014

Focal Gray Matter Plasticity as a Function of Long Duration Head-down Tilt Bed Rest

Koppelmans, Vincent↗

NASA NTRS1994

Evolution of the NASA long-duration balloon program

The development of long-duration ballooning techniques to support flights of 1-2 ton payloads for periods up to 2 weeks, possibly even longer, offers a near-space scientific mission capability with an order of magnitude improvement over traditional balloon flights. This revolution in scientific research ballooning began with the solution of the manufacturing difficulties that plagued the program in the first half of the 1980's, and it has culminated in the early 1990's with three successive circumnavigations of the Antarctic continent in 9 to 14 day flights. A complementary capablity in the Northern hemisphere, which would approximately double the number of flights that could be supported each year, is needed to accommodate the trend for conventional payloads to be modified, or developed, for long-duration flights. Plans are already underway to employ the order-of-magnitude increased flight time for support of multi-flight research programs that will produce results comparable to some space missions. An overview of the current status and near-term plans for ballooning will be presented, along with a discussion of some major science initiatives that have been enabled.

Jones, W. Vernon↗

NASA NTRS2011

Defining the Relationship Between Biomarkers of Oxidative and Inflammatory Stress and the Risk for Atherosclerosis in Astronauts During and After Long-Duration Spaceflight

Future human space travel will primarily consist of long-duration missions aboard the International Space Station (ISS) or exploration class missions to Mars, its moons, or nearby asteroids. These missions will expose astronauts to increased risk of oxidative and inflammatory damage primarily from radiation, but also from psychological stress, reduced physical activity, diminished nutritional status, and, in the case of extravehicular activity, hyperoxic exposure. There is evidence that increased oxidative damage and inflammation can accelerate the development of atherosclerosis. PURPOSE The purpose of this proposal is to identify biomarkers of oxidative and inflammatory stress and to correlate them to indices of atherosclerosis risk before, during, and after long-duration spaceflight. METHODS To meet the objectives of the study, we will study astronauts before, during, and up to 5 years after long-duration missions aboard ISS. Biomarkers of oxidative and inflammatory stress, some of which we have previously shown to be elevated with spaceflight, will be measured before, during, and after spaceflight. Arterial structure will be monitored using ultrasound to measure carotid intima-medial thickness before, during, and after weightlessness. Carotid intima-medial thickness has been shown to be a better indicator than Framingham Risk scores for prediction of atherosclerosis. Arterial function will be monitored using brachial flow-mediated dilation before flight and after landing. Brachial flow-mediated dilation is a good index of endothelium-dependent vasodilation, which is a sensitive predictor of atherosclerotic risk. This is the first study to propose assessing atherosclerotic risk using biochemical, structural, and functional measures before, during, and immediately after spaceflight and structural functional measures for up to 5 years after landing. EXPECTED RESULTS We hypothesize that these biomarkers of oxidative and inflammatory stress will be increased with spaceflight and will correlate with increased carotid intima-medial thickness in- and postflight and with decreased flow-mediated dilation after the mission. Furthermore, we hypothesize that measures of oxidative stress will return to baseline after flight, but that biomarkers of inflammatory stress and vascular indices of atherosclerosis risk will remain elevated.

Lee, Stuart M. C.↗

NASA NTRS1998

Psychological and Behavioral Health Issues of Long-Duration Space Missions

It will be the responsibility of the long-duration space flight crew to take the actions necessary to maintain their health and well-being and to cope with medical emergencies without direct assistance from support personnel, including maintaining mental health and managing physiological and psychological changes that may impair decision making and performance. The Behavior and Performance Integrated Product Team at Johnson Space Center, working, within the Space Medicine, Monitoring, and Countermeasures Program, has identified critical questions pertaining to long-duration space crew behavioral health, psychological adaptation, human factors and habitability, and sleep and circadian rhythms. Among the projects addressing these questions are: the development of tools to assess cognitive functions during space missions; the development of a model of psychological adaptation in isolated and confined environments; tools and methods for selecting individuals and teams well-suited for long-duration missions; identification of mission-critical tasks and performance evaluation; and measures of sleep quality and correlation to mission performance.

Eksuzian, Daniel J.↗

NASA NTRS2014

Defining the Relationship between Biomarkers of Oxidative and Inflammatory Stress and the Risk for Atherosclerosis in Astronauts during and after Long-duration Spaceflight

Future human space travel will consist primarily of long-duration missions onboard the International Space Station (ISS) or exploration-class missions to Mars, its moons, or nearby asteroids. These missions will expose astronauts to increased risk of oxidative and inflammatory damage from a variety of sources, including radiation, psychological stress, reduced physical activity, diminished nutritional status, and hyperoxic exposure during extravehicular activity. Evidence exists that increased oxidative damage and inflammation can accelerate the development of atherosclerosis. PURPOSE The purpose of this investigation is to determine whether biomarkers of oxidative and inflammatory stress are elevated during and after long-duration spaceflight and investigate if a relation exists between levels of these biomarkers and structural and functional indices of atherosclerotic risk measured in the carotid and brachial arteries. This is the first study to propose assessing atherosclerotic risk using biochemical, structural, and functional measures before, during, and immediately after spaceflight, and structural and functional measures for up to 5 years after landing. METHODS We will study 12 astronauts before, during, and up to 5 years after long-duration ISS missions. A panel of biomarkers of oxidative and inflammatory stress will be measured twice before flight, early (flight days 15 and 60) and late (2 weeks before landing) during the mission, and early in the postflight recovery phase (approx 3 days after landing). Arterial structure and vascular compliance will be measured at the same times and also at 1, 3, and 5 years after landing (surveillance). Arterial function will be measured using the same preflight, postflight, and surveillance schedule as arterial structure and vascular compliance measures, but will not be measured inflight. Biomarkers, some of which we have previously shown to be elevated with spaceflight, will be measured in venous blood samples and 24-h (in-flight) and 48-h (pre- and post-flight) urine pools. Arterial structure will be assessed from measures of carotid intima-media thickness, which have been shown to be better indicators of atherosclerotic than the Framingham Risk Score. Arterial function will be assessed using brachial flow-mediated dilation, a well-validated measure used to assess endothelium-dependent vasodilation and is a sensitive predictor of atherosclerotic risk. Arterial pulse pressure measured in the brachial artery and stroke volume measured from cardiac ultrasound will be used to assess hemodynamic status, cardiac function, and systemic vascular compliance. Three astronauts are actively participating in the preflight data collection and training activities. One astronaut has completed all preflight activities and will participate in the first in-flight data collection sessions by the end of 2013. The first post-flight data collection sessions will occur in the spring of 2014. EXPECTED RESULTS We hypothesize that biomarkers of oxidative and inflammatory stress will increased with spaceflight and will correlate with increased carotid intima-media thickness during and after flight and with decreased flow-mediated dilation after the mission. Furthermore, we hypothesize that measures of oxidative stress will return to baseline after flight, but biomarkers of inflammatory stress and vascular indices of atherosclerotic risk will remain elevated.

Lee, Stuart M. C.↗

NASA NTRSDate not supplied

Status of Long-Duration Lander Capabilities Developed Under the LLISSE Project

- Long-duration Insitu measurements on Venus are necessary - The latest planetary decadal notes science needs for Insitu temporal measurements at the surface - LLISSE development is to: - Answer science questions - Mature technology for future missions - Key enabler is to address the life and durability impacting factors for landers (primarily surface temperature and reactive atmosphere) Approach to addressing challenges - Develop ability to operate at Venus temperatures for long durations- Use of only materials inert to reactive Venus surface atmosphere - Innovative concept of operations to enable temporal surface science and lander-to-orbiter communications for life of lander

Venus↗

NASA NTRS2016

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31% decrease in bone volume ratio, a 14% decrease in trabecular thickness, and a 20% decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1.This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration persists during long-duration spaceflight. Furthermore, spaceflight femurs from BionM1 indicate onset of an accelerated aging-like phenotype with signs of osteoarthritic disease shown by disruption of the epiphyseal boundary and endochondral ossification. These effects are likely caused by a failure of stem cells to regenerate degraded tissues and may have significant implications for bone and cartilage health following extensive periods of mechanical unloading during long-duration spaceflight.

microgravity↗

NASA NTRS2016

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31 decrease in bone volume ratio, a 14 decrease in trabecular thickness, and a 20 decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1. This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration persists during long-duration spaceflight. Furthermore, spaceflight femurs from BionM1 indicate onset of an accelerated aging-like phenotype with signs of osteoarthritic disease shown by disruption of the epiphyseal boundary and endochondral ossification. These effects are likely caused by a failure of stem cells to regenerate degraded tissues and may have significant implications for bone and cartilage health following extensive periods of mechanical unloading during long-duration spaceflight.

stem cells↗

NASA NTRS1995

Space Station as a Long Duration Exposure Facility

There is need for a space platform for experiments investigating long duration exposure to space. This platform should be maintainable in the event of a malfunction, and experiments should be easily recoverable for analysis on Earth. The International Space Station provides such a platform. The current Space Station configuration has six external experiment attachment sites, providing utilities and data support distributed along the external truss. There are also other sites that could potentially support long duration exposure experiments. This paper describes the resources provided to payloads at these sites, and cites examples of integration of proposed long duration exposure experiments on these sites. The environments to which external attached payloads will be exposed are summarized.

Folley, Adrienne↗

NASA NTRS2014

Focal Gray Matter Plasticity as a Function of Long Duration Head Down Tilted Bed Rest: Preliminary Results

Long duration spaceflight (i.e., 22 days or longer) has been associated with changes in sensorimotor systems, resulting in difficulties that astronauts experience with posture control, locomotion, and manual control. The microgravity environment is an important causal factor for spaceflight induced sensorimotor changes. Whether these sensorimotor changes are solely related to peripheral changes from reduced vestibular stimulation, body unloading, body fluid shifts or that they may be related to structural and functional brain changes is yet unknown. However, a recent study reported associations between microgravity and flattening of the posterior eye globe and protrusion of the optic nerve [1] possibly as the result of increased intracranial pressure due to microgravity induced bodily fluid shifts [3]. Moreover, elevated intracranial pressure has been related to white matter microstructural damage [2]. Thus, it is possible that spaceflight may affect brain structure and thereby cognitive functioning. Long duration head down tilt bed rest has been suggested as an exclusionary analog to study microgravity effects on the sensorimotor system [4]. Bed rest mimics microgravity in body unloading and bodily fluid shifts. In consideration of the health and performance of crewmembers both in- and post-flight, we are conducting a prospective longitudinal 70-day bed rest study as an analog to investigate the effects of microgravity on brain structure [5]. Here we present results of the first six subjects. Six subjects were assessed at 12 and 7 days before-, at 7, 30, and ~70 days in-, and at 8 and 12 days post 70 days of bed rest at the NASA bed rest facility in UTMB, Galveston, TX, USA. At each time point structural MRI scans (i.e., high resolution T1-weighted imaging and Diffusion Tensor Imaging (DTI)) were obtained using a 3T Siemens scanner. Focal changes over time in gray matter density were assessed using the voxel based morphometry 8 (VBM8) toolbox under SPM. Longitudinal processing in VBM8 includes linear registration of each scan to the mean of the subject and subsequently transforming all scans in to MNI space by applying the warp from the mean subject to MNI to the individual gray matter segmentations. Modulation was applied so that all images represented the volume of the original structure in native space. Voxel wise analysis was carried out on the gray matter images after smoothing, using a flexible factorial design with family wise error correction. Focal changes in white matter microstructural integrity were assessed using tract based spatial statistics (TBSS) as part of FMRIB software library (FSL). TBSS registers all DTI scans to standard space. It subsequently creates a study specific white matter skeleton of the major white matter tracts. For each subject, for each DTI metric (i.e. fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD)), the maximum value in a line perpendicular to the skeleton tract is projected to the skeleton. Non-parametric permutation based t-tests and ANOVA's were used for voxel-wise comparison of the skeletons. For both VBM and TBSS, comparison of pre bed rest measurements did not show significant differences. VBM analysis revealed decreased gray matter density in bilateral areas including the frontal medial cortex, the insular cortex and the caudate (see Figure) from 'pre to in bed rest'. Over the same time period, there was an increase in gray matter density in the cerebellum, occipital-, and parietal cortex, including the precuneus (see Figure). The majority of these changes did not recover from 'during to post bed rest'. TBSS analysis did not reveal significant changes in white matter microstructural integrity after correction for multiple comparisons. Uncorrected analyses (p<.015) revealed an increase in RD in the cerebellum and brainstem from pre bed rest to the first week in bed rest that did not recover post bed rest. Extended bed rest, which is an analog for microgravity, can result in gray matter changes and potentially in microstructural white matter changes in areas that are important for neuro motor behavior and cognition. These changes did not recover at two weeks post bed rest. Whether the effects of bed rest wear off at longer times post bed rest, and if they are associated with behavior are important questions that warrant further research.

Koppelmans, V.↗

NASA NTRS1994

Overview of the space environmental effects observed on the retrieved Long Duration Exposure Facility (LDEF)

The Long Duration Exposure Facility (LDEF), which encompassed 57 experiments with more than 10,000 test specimens, spent 69 months in Low Earth Orbit (LEO) before it was retrieved by the Space Shuttle in January 1990. Hundreds of LDEF investigators, after studying for over two years these retrieved test specimens and the onboard recorded data and systems hardware, have generated a unique first-hand view of the long-term synergistic effects that the LEO environment can have on spacecraft. These studies have also contributed significantly toward more accurate models of the LEO radiation, meteoroid, manmade debris and atomic oxygen environments. This paper provides an overview of some of the many LDEF observations and the implications these can have on future spacecraft such as Space Station Freedom.

Kinard, W.↗

NASA NTRS2017

The Effects of Long-Duration Spaceflight on Training Retention and Transfer

Training our crew members for long duration, exploration-class missions will have to maximize long-term retention and transfer of the trained skills. The expected duration of the missions, our inability to predict all the possible tasks the crew will be called upon to perform, and the low training-to-mission time ratio require that the training be maximally effective such that the skills acquired during training will be retained and will be transferrable across a wide range of specific tasks that are different from the particular tasks used during training. However, to be able to design training that can achieve these ambitious goals, we must first understand the ways in which long-duration spaceflight affects training retention and transfer. Current theories of training retention and transfer are largely based on experimental studies conducted at university laboratories using undergraduate students as participants. Furthermore, all such studies have been conducted on Earth. We do not know how well the results of these studies predict the performance of crew members. More specifically, we do not know how well the results of these studies predict the performance of crew members in space and especially during long-duration missions. To address this gap in our knowledge, the current on-going study seeks to test the null hypothesis that performance of university undergraduate students on Earth on training retention and transfer tests do in fact predict accurately the performance of crew members during long-duration spaceflights. To test this hypothesis, the study employs a single 16-month long experimental protocol with 3 different participant groups: undergraduate university students, crew members on the ground, and crew members in space. Results from this study will be presented upon its completion. This poster presents results of study trials of the two tasks used in this study: a data entry task and a mapping task. By researching established training principles, by examining future needs, and by using current practices in spaceflight training as test beds, this research project is mitigating program risks and generating templates and requirements to meet future training needs.

ISS↗