Astronaut Performance Research Articles

The human body in different spaces

Space Medicine has revolutionized the way of understanding human physiology in extra-terrestrial environments, such as microgravity. Research in this field attempts to maintain synchrony between scientific and medical development, with the goal of improving the overall health and performance of astronauts. Engineering also plays a crucial role in the design of spacecraft and spacesuits to ensure the safety and health of astronauts on extended missions to the Moon and Mars. Radiation exposure in space poses health concerns, but strategies such as radiation control and shielding are being implemented to mitigate these risks. NASA is actively investigating how the human body reacts to long-duration spaceflight, with the goal of preparing for future extended space missions.

Augmented Reality in Extra-Vehicular Activities: Optimizing Alert Detection and Cognitive Workload

This study investigates the impact of augmented reality (AR) system complexity (active vs. passive) and lighting conditions (normal, dark, glare) on task performance, cognitive workload, and alert detection during simulated extravehicular activities (EVAs). Fifty-eight undergraduate students participated, using AR systems to complete tasks. Key metrics included task completion rate, completion time, alert detection, and cognitive workload assessed by the NASA Task Load Index (NASA-TLX). Results showed no significant differences in task performance or cognitive workload across lighting conditions and AR types. Notably, less than 15% of participants noticed any alerts, suggesting AR alerts may lack sufficient salience. The study’s lack of significant findings is attributed to the small sample size and potential insensitivity of measures. Future research should involve larger samples and refined methodologies to better understand AR’s impact on astronaut performance and safety during EVAs.

Alterations in Blood-Brain Barrier Integrity and Lateral Ventricle Differ in Rats Exposed to Space Radiation and Social Isolation.

The proposed Mars missions will expose astronauts to long durations of social isolation (SI) and space radiation (SR). These stressors have been shown to alter the brain's macrostructure and microenvironment, including the blood-brain barrier (BBB). Breakdown of the BBB is linked to impaired executive functions and physical deficits, including sensorimotor and neurocognitive impairments. However, the precise mechanisms mediating these effects remain unknown. Additionally, the synergistic effects of combined exposure to SI and SR on the structural integrity of the BBB and brain remain unknown. We assessed the BBB integrity and morphology in the brains of male rats exposed to ground-based analogs of SI and SR. The rats exposed to SR had enlarged lateral ventricles and increased BBB damage associated with a loss of astrocytes and an increased number of leaky vessels. Many deficits observed in SR-treated animals were attenuated by dual exposure to SI (DFS). SI alone did not show BBB damage but did show differences in astrocyte morphology compared to the Controls. Thus, determining how single and combined inflight stressors modulate CNS structural integrity is crucial to fully understand the multiple pathways that could impact astronaut performance and health, including the alterations to the CNS structures and cell viability observed in this study.

Twins And Telomeres-In Space!

As part of the NASA Twins Study, our investigations related to telomeres and DNA damage responses (genome stability) during long-duration spaceflight have important implications for the health and performance of astronauts participating in exploration missions, as well as for long-term aging and disease risk outcomes. Together with the other Twins Study investigations, results will guide future studies and development of personalized medicine approaches for evaluating health effects for individual astronauts as we make our way back to the moon and beyond. Particularly as the number and diversity of space travelers and even space tourists increases over the coming years, identifying individual differences in response to the extreme environment, experiences and chronic exposures associated with space travel, exploration, and eventual habitation of other planets, represents a critical next step for ensuring future astronaut performance and health during, and improving disease and aging courses following, such missions. Ad astra!

Investigating the psychological and physiological responses to isolation and confinement using the THOR space analog simulation

This research investigates astronaut performance under simulated space conditions, using THOR, an analog astronaut training protocol, during a week-long confinement in an Analog Astronaut Training Center in Poland. Materials and Five participants, including four military and one civilian, underwent a week of isolation. Tests were conducted to assess heart rate variability –HRV–, psychological health, and sleep patterns. Data collection and analysis were standardized, with an alpha level of p < 0.05 and power of 80%. The study found reductions in fat percentage and weight, while muscle mass and water content remained stable. HRV showed significant changes. Increased sleep and state anxiety levels were noted, along with decreased cognitive abilities. Personality traits exhibited heightened hostility and social anxiety, culminating in psychological discomfort. HRV values were normal with variations likely due to stress. A significant correlation was found between mental performance andHRV, indicating potential influence of sleep on cognitive function during isolation. The study highlights the need for more research on the psychological and physiological implications of long-duration space missions and similar high-demand environments.

Dry eye disease in astronauts: a narrative review.

Long-duration spaceflight can have adverse effects on human health. One of the most common ocular conditions experienced by astronauts is dry eye disease (DED). Symptoms of DED include feelings of eye irritation, eye strain, foreign body sensation and blurred vision. Over 30% of International Space Station expedition crew members reported irritation and foreign body sensation. We reviewed the current literature on the prevalence and mechanisms of DED in astronauts and its potential implications for long-duration spaceflight, including the influence of environmental factors, such as microgravity and fluid shift on tear film physiology in space. DED has negative effects on astronaut performance, which is why there is a need for further research into the pathophysiology and countermeasures. As an in-flight countermeasure, neurostimulation seems to be among the most promising options.

Circuits and Biomarkers of the Central Nervous System Relating to Astronaut Performance: Summary Report for a NASA-Sponsored Technical Interchange Meeting.

Biomarkers, ranging from molecules to behavior, can be used to identify thresholds beyond which performance of mission tasks may be compromised and could potentially trigger the activation of countermeasures. Identification of homologous brain regions and/or neural circuits related to operational performance may allow for translational studies between species. Three discussion groups were directed to use operationally relevant performance tasks as a driver when identifying biomarkers and brain regions or circuits for selected constructs. Here we summarize small-group discussions in tables of circuits and biomarkers categorized by (a) sensorimotor, (b) behavioral medicine and (c) integrated approaches (e.g., physiological responses). In total, hundreds of biomarkers have been identified and are summarized herein by the respective group leads. We hope the meeting proceedings become a rich resource for NASA's Human Research Program (HRP) and the community of researchers.

Carie - The Space Pet

Robotics is the fusion of science, engineering, and technology that creates robots, or machines, that mimic or take the place of human beings in performing tasks. Multiple sorts of robotics are possible. It is also possible to use robotics for space research. Physically and mentally challenging situations might arise for humans during space travel. The use of technology can help us to some extent get past the mental challenges as the physical challenges are unavoidable. We employ robotics in order to get over mental obstacles. To reach the objective of promoting astronaut wellness in space, we combine robotics with a number of other technologies. This project is aimed at developing an autonomous robot companion for astronauts during space missions. The objective is to provide real time monitoring, forecasting capability and navigation assistance in order to ensure the safety, efficiency and well-being of astronauts. The robot companion is capable of monitoring astronaut's health conditions and detecting potential problems at an early stage by integrating high resolution sensors and sophisticated algorithms. The robot aims to improve the overall experience and performance of astronauts in space by applying predictive analytical tools and advanced navigation systems.

Communication quality affects performance of astronauts and support teams through increased workload: Insights from the AMADEE-20 analog Mars mission

Astronaut crews and ground control support teams are highly interdependent teams that need to communicate effectively to achieve a safe mission - despite being separated by large distances. Team communication quality with its facets clarity of objectives and information flow, is a key coordination process to achieve high team performance and task satisfaction. Especially in interdependent teams working in extreme environments with time-delayed communications, the team's success is threatened if communication is ineffective. In this study, we hypothesized that communication quality affects two key team outcomes, performance and task satisfaction, and that these effects can be explained by increases in workload (effort and frustration). Hypotheses were tested during the AMADEE-20 analog Mars mission hosted by the Austrian Space Forum. The analog astronauts (AA) were supported by an On-Site-Support (OSS) team and a remote Mission-Support-Centre (MSC) team. The MSC was the only contact line for both AA and OSS, and the communication between them had a one-way time delay of 10 min. Our study consisted of three runs in which members across the three different multiteam systems had to exchange information to solve an interdependent task. We measured communication quality, effort and frustration, task satisfaction, and team performance. Results show that clarity of objectives and information flow positively impacted multiteam system performance. Furthermore, clarity of objectives reduced experienced effort and this in turn enhances team performance. High levels of information flow reduced experienced frustration, which in turn enhanced task satisfaction. Our findings show that these facets of communication quality are essential for multiteam systems that work separated from each other by a distance. We stress that specific (team) communication training for astronauts and support personnel will be key to effective teamwork during future Mars missions, and thus to overall mission success.

A Multi-View Vision System for Astronaut Postural Reconstruction with Self-Calibration

Space exploration missions involve significant participation from astronauts. Therefore, it is of great practical importance to assess the astronauts’ performance via various parameters in the cramped and weightless space station. In this paper, we proposed a calibration-free multi-view vision system for astronaut performance capture, including two modules: (1) an alternating iterative optimization of the camera pose and human pose is implemented to calibrate the extrinsic camera parameters with detected 2D keypoints. (2) Scale factors are restricted by the limb length to recover the real-world scale and the shape parameters are refined for subsequent postural reconstruction. These two modules can provide effective and efficient motion capture in a weightless space station. Extensive experiments using public datasets and the ground verification test data demonstrated the accuracy of the estimated camera pose and the effectiveness of the reconstructed human pose.

Repetitive transcranial magnetic stimulation rescues simulated space complex environment-induced emotional and social impairments by enhancing neuronal excitability in the medial prefrontal cortex.

Studies have shown that spaceflight affects the emotional and social performance of astronauts. Identifying the neural mechanisms underlying the emotional and social effects of spacefaring-specific environments is essential to specify targeted treatment and prevention interventions. Repetitive transcranial magnetic stimulation (rTMS) has been shown to improve the neuronal excitability and is used to treat psychiatric disorders such as depression. To study the changes of excitatory neuron activity in medial prefrontal cortex (mPFC) in simulated space complex environment (SSCE), and to explore the role of rTMS in behavioral disorders caused by SSCE and the neural mechanism. We found that rTMS effectively ameliorated the emotional and social impairments of mice in SSCE, and acute rTMS could instantaneously enhance the excitability of mPFC neurons. During depression-like and social novelty behaviors, chronic rTMS enhanced the mPFC excitatory neuronal activity that was inhibited by SSCE. Above results suggested that rTMS can completely reverse the SSCE-induced mood and social impairment by enhancing the suppressed mPFC excitatory neuronal activity. It was further found that rTMS suppressed the SSCE-induced excessive dopamine D2 receptor expression, which may be the cellular mechanism by which rTMS potentiates the SSCE-evoked hypoactive mPFC excitatory neurons. Our current results raise the possibility of rTMS being applied as a novel neuromodulation for mental health protection in spaceflight.

Dynamic visual acuity as a biometric for astronaut performance and safety

Astronauts are exposed to an austere and constantly changing environment during space travel. To respond to these rapid environmental changes, high levels of dynamic visual acuity (DVA) are required. DVA is the ability to visualize objects that are in motion, or with head movement and has previously been shown to decrease significantly following spaceflight. Decreased DVA can potentially impact astronauts while performing mission critical tasks and drive space motion sickness. In this paper, we suggest that DVA assessment during spaceflight and during G-transitions should be considered to help further understand the vestibulo-ocular impacts of interplanetary spaceflight and ensure mission performance including potential manned missions to Mars.

Minified Augmented Reality as a Terrestrial Analog for G-Transitions Effects in Lunar and Interplanetary Spaceflight

Brief periods of extreme gravitational transition are anticipated during interplanetary spaceflight, including transitions between microgravity, hypogravity, and hypergravity. Rapid sensorimotor adaptation will occur following these G-transitions which may affect astronaut performance including gaze control and dynamic visual acuity. Significant decrements in dynamic visual acuity could lead to mission compromise or failure (e.g., impairing mission critical tasks or spacecraft maneuvering). It is crucial to provide astronauts with the training necessary to overcome these physiological barriers they are bound to encounter during spaceflight missions. Minifying lenses in augmented reality may serve as an easily applicable, low-cost, method to simulate vestibulo-ocular dysfunction that occurs during gravitational transitions. In this paper, we review the effects of G-transitions on the vestibulo-ocular system and report on the novel development of minified augmented reality as a potential simulator and training tool for future spaceflight. We also report the results from an early validation study with a mean decrease in DVA (0.370 LogMAR) with 80% minifying effect, as well as a mean increase of DVA post-minifying (0.030 LogMAR). These early results suggest that minified augmented reality may serve as an accessible terrestrial analog for G-transitions, thus having potential for pre-mission training, particularly for lunar and interplanetary spaceflight.

Is frying possible in space?

Dietary nutrition and uptake of earth-like foods are extremely important aspects for the health and performance of astronauts, especially during future planned long-term space missions. Despite the major progress in studying and designing systems for crop cultivation in microgravity conditions in the last years, there hasn’t been equal interest in food preparation processes and cooking. There are several reasons for this but it is chiefly because at present astronauts stay in space for a few months at most, so there is no serious nutritional or psychological need for earth-like food habits. This, however, will change drastically in long-term missions, e.g., to Moon and Mars. French fries are a very popular food commodity across many cultural backgrounds on earth and as such they may be appreciated by long-term space travelers of different origin. The process of frying in hot oil is associated with complex heat and mass transfer along with the growth and detachment of water vapor bubbles. These phenomena are strongly affected by buoyancy and gravitational acceleration making the study of frying at space conditions a challenging task. The present work examines potato frying in hot oil during the short duration low gravity conditions achieved in a Parabolic Flight Campaign organized by the European Space Agency. An innovative device has been constructed, allowing the simultaneous observation of bubbles dynamics above the potato surface and the thermal behavior inside the potato flesh. It is seen that even in the absence of buoyancy i.e., during parabolas, vapor bubbles still detach and depart from the surface of potato permitting hot oil to maintain contact with the potato surface and leading eventually to a fried product. Instantaneous overpressure inside potato pores due to vapor formation upon boiling of potato water is suggested as the mechanism generating the force for bubbles detachment and departure. Moreover, the amount of produced vapor is comparable among the examined values of gravitational acceleration, including the low gravity conditions during parabolas. All in all, the results of the present study provide primary experimental evidence that frying can occur in space.

Head-Mounted Dynamic Visual Acuity for G-Transition Effects During Interplanetary Spaceflight: Technology Development and Results from an Early Validation Study.

INTRODUCTION: Dynamic visual acuity (DVA) refers to the ability of the eye to discern detail in a moving object and plays an important role whenever rapid physical responses to environmental changes are required, such as while performing tasks onboard a space shuttle. A significant decrease in DVA has previously been noted after astronauts returned from long-duration spaceflight (0.75 eye chart lines, 24 h after returning from space). As part of a NASA-funded, head-mounted multimodal visual assessment system for monitoring vision changes in spaceflight, we elaborate upon the technical development and engineering of dynamic visual acuity assessments with virtual reality (VR) technology as the first step in assessing astronaut performance when undergoing G-transitional effects. We also report results from an early validation study comparing VR DVA assessment with traditional computer based DVA assessment.METHODS: Various VR/AR headsets have been utilized to implement DVA tests. These headsets include HTC Vive Pro Eye system. Epic's game engine UnrealEngine 4 Version 4.24 was used to build the framework and SteamVR was used to experience virtual reality content. Eye tracking technology was used to maintain fixation of the participant. An early validation study with five participants was conducted comparing this technology versus traditional DVA with a laptop.RESULTS: The head-mounted technology developed for assessing DVA changes during G-transitions is fully functional. The results from the early validation study demonstrated that the two DVA tests (laptop-based and VR) indicated a strong association between both methods (Pearson correlation coefficient of 0.91). A Bland-Altman plot was employed to assess levels of agreement, with all data points falling within the limits of agreement.DISCUSSION: The results from this early validation study indicate that head-mounted DVA assessment performs similarly to traditional laptop-based methods and is a promising method for assessing DVA during spaceflight, particularly in G-transitions. Future studies are required for further assessment of validation and reliability of this technology. With its ease of use, accessibility, and portable design, VR DVA has the potential in the near-future to replace conventional methods of assessing DVA. The technology will likely be an important aspect to help monitor functionality and safety during interplanetary missions where astronauts are exposed to G-transitions.Waisberg E, Ong J, Zaman N, Kamran Sa, Lee AG, Tavakkoli A. Head-mounted dynamic visual acuity for G-transition effects during interplanetary spaceflight: technology development and results from an early validation study. Aerosp Med Hum Perform. 2022; 93(11):800-805.

Effects of human thermophysiology and psychology in exposure to simulated microgravity

BackgroundAffected by the microgravity, astronauts will experience physiological discomfort in spaceflight, leading to an impaired ability of thermoregulation and deteriorating the mentality and operational performance of astronauts. It is significant to research on the thermophysiological and psychological phenomena in microgravity for the improvement of the astronauts' long-term comfort in orbit and out of the cabin. ObjectiveThis study aims to explore the effects of microgravity on human thermophysiology and psychology, as well as the correlation between the two indexes, so as to provide a theoretical basis for the thermal control system and mental health protection in space suits and space stations. MethodsThe sublingual temperature, local skin temperatures and anxiety-depression psychological indexes of 12 subjects in a stable thermal environment were monitored. The experimental period was 29 days, in which the first 7 days were for the adaptation and basic data collection, the following 15 days were for −6° head down bed rest (HDBR), and the last 7 days after getting up were for the recovery and physical examination. The thermophysiological and psychological indexes were measured on the 4th day before HDBR, the 1st, 5th, 9th, 13th day during HDBR and the 2nd day after HDBR. The temperatures were measured three times one day (morning, noon and evening). ResultsThe duration of HDBR had significant effects on the sublingual temperature (p = 0.017) and the weighted average skin temperature (p = 0.014), while the effect on anxiety is marginally significant (p = 0.065). Anxiety and depression scale scores are significantly correlated in simulated microgravity (p = 0.016), while no significant correlation is found between the sublingual temperature and anxiety-depression scale scores (p > 0.05), nor the weighted average skin temperature and anxiety-depression scale scores (p > 0.05). The back skin temperature and the anxiety score are significantly correlated in simulated microgravity (p = 0.012). ConclusionsThe peak of anxiety and depression in the early stage of HDBR appeared on the 5th day. Thermophysiological and psychological adaptation occurred in the middle period, with values recovering to the initial levels in the later stage and after HDBR. This study could support the improvement of the thermal control system in space suits and space stations, and the protection of astronauts' mental health. A larger set of subjects and a longer experimental period could be considered in the future research, exploring more precise and complete principles of human thermophysiological and psychological changes in simulated microgravity.

Small tissue chips with big opportunities for space medicine

The spaceflight environment, including microgravity and radiation, may have considerable effects on the health and performance of astronauts, especially for long-duration and Martian missions. Conventional on-ground and in-space experimental approaches have been employed to investigate the comprehensive biological effects of the spaceflight environment. As a class of recently emerging bioengineered in vitro models, tissue chips are characterized by a small footprint, potential automation, and the recapitulation of tissue-level physiology, thus promising to help provide molecular and cellular insights into space medicine. Here, we briefly review the technical advantages of tissue chips and discuss specific on-chip physiological recapitulations. Several tissue chips have been launched into space, and more are poised to come through multi-agency collaborations, implying an increasingly important role of tissue chips in space medicine.

Simulated Space Radiation Exposure Effects on Switch Task Performance in Rats.

BACKGROUND: Astronauts on the mission to Mars will be subjected to galactic cosmic radiation (GCR) exposures. While ground-based studies suggest that simulated GCR (GCRsim) exposure impairs performance in multiple cognitive tasks, the impact of such exposures on task switching performance (an important skill for all aviators) has not yet been determined.METHODS: Male Wistar rats previously exposed to 10 cGy of ⁴He ions or GCRsim and their sham littermates were trained to perform a touchscreen-based switch task designed to mimic warning light response tests used to evaluate pilots' response times.RESULTS: Irradiated rats failed to complete a high cognitive task load training task threefold more frequently than shams. There were 18 (4 Sham, 7 He-, and 7 GCR-exposed) rats that successfully completed initial training and underwent switch task testing. Relative to the sham rats in the switch task, the GCRsim-exposed rats had significantly slower response times in switch but not repeat trials. The GCRsim-exposed rats had significantly (P < 0.01) higher switch response ratios (switch/repeat trial response time) and absolute switch costs (switch minus repeat trial response time) than either the sham or He-exposed rats.DISCUSSION: Rats exposed to GCRsim have significantly impaired performance in the switch task manifested as an absolute switch cost of ∼700 ms. The operational significance of such an increase requires further investigation, but a 1000-ms switch cost results in a twofold increase in cockpit error rates in pilots. If exposure to GCR in space results in similar effects in humans, the operational performance of astronauts on the Mars mission may be suboptimal.Stephenson S, Britten R. Simulated space radiation exposure effects on switch task performance in rats. Aerosp Med Hum Perform. 2022; 93(9):673-680.

Towards a flexible and generalizable computational model-based framework for mitigation of spatial disorientation in sensory-deprived environments

PurposeSpatial disorientation (SD), an incorrect perception of one's orientation, position or motion, jeopardizes the safety and performance of aviators, astronauts, and professionals in other domains such as SCUBA and firefighting. Active countermeasures can assist navigators in real-time with maintaining orientation – and may mitigate the deleterious impacts of SD. A necessary component of such a system, however, is a method by which to estimate possible SD being experienced, and detect when intervention is warranted. Computational tools utilizing models of human spatial orientation perception provides an unobtrusive means to estimate the spatial awareness of the navigator. Previously proposed computational detection methods, however, have been designed to capture specific SD events that are commonly experienced by fixed-wing aircraft pilots. We propose a generalizable computational framework that can be adapted to different environments, vehicles (e.g., spacecraft) and operating theatres. ProposalWe leverage the state-of-the-art Observer model to compute spatial orientation perception in sequence with an integrative algorithm to capture the severity of orientation misperception over time. A Bayesian likelihood model is used for system and parameter identification of the proposed algorithm candidates we have developed. A novel two-part experimental methodology is proposed to first gather necessary data for informing likelihood estimators (e.g., estimates of SD), and then assess the potential system benefits (e.g., safety, control performance) while using a well-tuned computational detection tool in real-time. ImplementationSimulated motion stimuli were used in the development of algorithm candidates and optimization techniques. Our simulation results and application of the generalized framework to various navigation environments demonstrate the utility of capturing all state parameters related to orientation perception (e.g., acceleration, angular velocity, zenith etc.) which enables the system to capture the continuum of SD involving a variety of different stimuli. As a proof-of-concept effort, we have developed an experimental paradigm representing a helicopter piloting scenario in the presence of mission-related distractions. ConclusionThe proposed computational tool, when appropriately fitted for the environment of relevance, may be used to trigger real-time countermeasure interventions for the goal of mitigating adverse impacts of SD events in operational environments. SD can manifest in drastically different ways given the sensory environment, such as an absence of a tonic loading of gravity during spaceflight. The integrative and generalizable nature of this framework may facilitate translatable progress in SD mitigation research across the many domains which it plagues.

Microfluidic chip-based long-term preservation and culture of engineering bacteria for DNA damage evaluation.

Understanding the effects of long-term exposure to space environment is paramount to maintaining the safety, health of astronauts. The physical dosimeters currently used on the space station cannot be used to assess the physiological effects of radiation. Moreover, some developed biological methods are time-consuming and passive and cannot be used for active and real-time detection of the physiological effects of radiation in space environment. Here, the SOS promoter: recA-eGFP genetic engineering bacteria was constructed and characterized, and DNA damage effects of some chemical reagents and radiation were evaluated. The results indicated the constructed engineering bacteria can distinguish DNA damage reagents from non-damage reagents and have a good dose-fluorescence effect against Co-60 radiation with the detection limit of 0.64Gy; in order to overcome the restriction of long-term preservation of bacteria in space environment, the bacteria were freeze-dried, and the protectants were optimized, the storage time of bacteria under dry conditions was explored by accelerated storage experiment. Finally, a microfluidic chip was designed and fabricated for freeze-drying genetic engineering bacteria recovery, culture, and analysis in space environment. This study can provide support for the establishment of on-orbit radiation damage risk monitoring and early warning and can provide basic data for maintaining the health and performance of astronauts on long-term space flight missions. Moreover, the technique developed herein has a great potential to be used as a powerful tool for efficiently screening various radioactive substance, toxic chemicals, drugs, etc. KEY POINTS: • The SOS promoter: recA-eGFP genetic engineering bacteria was successfully constructed, which can distinguish DNA damage reagents from non-damage reagents and possess a good dose-effect relationship against Co-60 radiation. • The bacteria were freeze-dried to overcome the restriction of long-term preservation of bacteria in space environment, and protectants were optimized, and the survival rate of freeze-dried engineering bacteria can be predicted based on the results of accelerated storage experiment. • Microfluidic chip-based culture platform was successfully designed, fabricated, and used for freeze-drying genetic engineering bacteria recovery, culture, and analysis.