Duration Space Missions Research Articles

Conserved plant transcriptional responses to microgravity from two consecutive spaceflight experiments.

Understanding how plants adapt to the space environment is essential, as plants will be a valuable component of long duration space missions. Several spaceflight experiments have focused on transcriptional profiling as a means of understanding plant adaptation to microgravity. However, there is limited overlap between results from different experiments. Differences in experimental conditions and hardware make it difficult to find a consistent response across experiments and to distinguish the primary effects of microgravity from other spaceflight effects. Plant Signaling (PS) and Plant RNA Regulation (PRR) were two separate spaceflight experiments conducted on the International Space Station utilizing the European Modular Cultivation System (EMCS). The EMCS provided a lighted environment for plant growth with centrifugal capabilities providing an onboard 1 g control. An RNA-Seq analysis of shoot samples from PS and PRR revealed a significant overlap of genes differentially expressed in microgravity between the two experiments. Relative to onboard 1 g controls, genes involved in transcriptional regulation, shoot development, and response to auxin and light were upregulated in microgravity in both experiments. Conversely, genes involved in defense response, abiotic stress, Ca++ signaling, and cell wall modification were commonly downregulated in both datasets. The downregulation of stress responses in microgravity in these two experiments is interesting as these pathways have been previously observed as upregulated in spaceflight compared to ground controls. Similarly, we have observed many stress response genes to be upregulated in the 1 g onboard control compared to ground reference controls; however these genes were specifically downregulated in microgravity. In addition, we analyzed the sRNA landscape of the 1 g and microgravity (μ g) shoot samples from PRR. We identified three miRNAs (miR319c, miR398b, and miR8683) which were upregulated in microgravity, while several of their corresponding target genes were found to be downregulated in microgravity. Interestingly, the downregulated target genes are enriched in those encoding chloroplast-localized enzymes and proteins. These results uncover microgravity unique transcriptional changes and highlight the validity and importance of an onboard 1 g control.

Electrochemical Peroxide Generation for in Situ Disinfection

Among the numerous technological advances sought in order to facilitate human exploration and habitation outside of earth’s atmosphere, solutions and innovations are needed for processing resources locally to support sustainable and long duration space missions. Such in-situ resource utilization (ISRU) is aimed at reducing the payload mass during launch and eliminate the need for ground support for long-term missions and ultimately space colonization. Disinfection needs is an area of particular need, which is currently accomplished through the use of pre-packaged, disposable, wetted disinfection wipes. These items represent an appreciable carry-along mass and disposal/replacement burden requiring ground support. Therefore, a system is desired that could utilize onboard utilities to create disinfecting solutions to eliminate storage/disposable problems of the wetted wipes and further reduce the astronaut’s dependence on earth-based supplies.Faraday Technology Inc. is addressing this challenge by demonstrating an in-situ approach, which utilizes on-board supplies of air and water for on demand electrochemical generation of hydrogen peroxide. Hydrogen peroxide is well-established disinfectant with non-toxic decomposition products (viz., O2 and H2O), that is safe enough for human contact to be sold commercially as a 1-5 w/w% solution, which makes it an ideal disinfecting solution for closed space environments. Faraday has continued to improve the TRL by scaling the electrochemical peroxide generation system from a sub-scale to alpha-scale process in order to deliver 1 L per day of ~2 w/w% hydrogen peroxide for disinfectant applications from DI water feed-stream with air as a feed source[1],[2],[3],[4]. These electrolytes were then sent to NASA for microbial control property characterization.This system eliminates the need to ferry disinfectant wipes to manned space capsules and is a critical enabling technology for future moon-based missions and beyond. Specifically, this talk will discuss the results of these advancements. Acknowledgements: Financial support of NASA Contracts NNX16CA43P, NNX17CJ12C, 80NSSC20C0070, and 80NSSC23CA036 is acknowledged.

Simulated galactic cosmic ray exposure activates dose-dependent DNA repair response and down regulates glucosinolate pathways in arabidopsis seedlings.

Outside the protection of Earth's magnetic field, organisms are constantly exposed to space radiation consisting of energetic protons and other heavier charged particles. With the goal of crewed Mars exploration, the production of fresh food during long duration space missions is critical for meeting astronauts' nutritional and psychological needs. However, the biological effects of space radiation on plants have not been sufficiently investigated and characterized. To that end, 10-day-old Arabidopsis seedlings were exposed to simulated Galactic Cosmic Rays (GCR) and assessed for transcriptomic changes. The simulated GCR irradiation was carried out in the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Lab (BNL). The exposures were conducted acutely for two dose points at 40 cGy or 80 cGy, with sequential delivery of proton, helium, oxygen, silicon, and iron ions. Control and irradiated seedlings were then harvested and preserved in RNAlater at 3 hrs post irradiation. Total RNA was isolated for transcriptomic analyses using RNAseq. The data revealed that the transcriptomic responses were dose-dependent, with significant upregulation of DNA repair pathways and downregulation of glucosinolate biosynthetic pathways. Glucosinolates are important for plant pathogen defense and for the taste of a plant, which are both relevant to growing plants for spaceflight. These findings fill in knowledge gaps of how plants respond to radiation in beyond-Earth environments.

IAC-22-C3.3.8 Six years of spaceflight results from the AlSat-1N Thin-Film Solar Cell (TFSC) experiment

The increasing power demands of spacecraft payloads and the realistic prospect of space based solar power (SBSP) stations as a means of providing zero carbon electricity in the 2030s, means that there is an emerging requirement for large area, yet lightweight, solar photovoltaic (PV) arrays that will provide far greater power (kWpeak) than is currently available. To be practical, such arrays will need to use solar cells which have a much higher specific power (i.e., power per unit mass) and a much lower cost per watt than current space-rated solar PV technologies. To this end, the Centre for Solar Energy Research (CSER) at Swansea University have been working on a new solar cell technology, based on thin-film cadmium telluride (CdTe), deposited directly onto ultra-thin space qualified cover glass material. This offers a potentially high specific power and when adopting the conventional CdTe manufacturing process, a low-cost technology. The ultra-thin glass can produce a solar cell which is sufficiently flexible to allow “roll-out” deployment strategies. Four prototype cells were flown as part of the Thin-Film Solar Cell (TFSC) experimental payload, developed by CSER and the Surrey Space Centre (SSC), on the joint Algerian Space Agency (ASAL) – UK Space Agency AlSAT-1N Technology Demonstration CubeSat, launched into a 661 km × 700 km, 98.20° Sun Synchronous orbit, on September 26, 2016. The experiment has provided the first in-orbit current/voltage (I/V) measurements of this novel technology, and more than five years of flight results have now yielded new insights into its longer-term performance and inherent radiation hardness, which makes them particularly attractive for maintaining high end-of-life (EOL) performance for long duration space missions. The results help to strengthen the argument for further development of this technology for space application. The data, collected over ∼30,000 orbits, show no signs of cell delamination (a potential risk for such technologies), no deterioration in short circuit current or in series resistance. However, all four cell's fill factors were observed to decrease over the duration of the mission, caused primarily by a decrease in their shunt resistance. This has been attributed to the diffusion of gold atoms from the back electrical contacts. We conclude therefore that further development of this technology should utilize more stable back contacting methodologies more commonly employed for terrestrial CdTe modules. However, this flight has proven the basic soundness of the technology for use in space.

Spinal column and midbrain integration for long duration space missions

Background: Deep space missions produce atrophied postural muscles and cognitive and proprioception losses. Lumbar and hip injury as well as limbic system dysregulation may result. In microgravity, the Neutral Body Position is the spinal baseline for the prone-position cycle, where the astronaut’s lumbar muscles and audio and visual-spatial centers can be informed through a virtual reality interface. Methods: The exercise can be reproduced as a low-fidelity space simulation in a epsom-salt float tank. MRI and ultrasound imaging of the spine at the start of the 4-week program can be compared to the imaged results upon program completion. Any contractile tightening would be evident in shortened IVD (intervertebral distances) in post-procedure MRI results. The terrestrial gravity cycling instrument establishes an effective baseline for determining anthropomorphic tolerances, the necessary workout duration and resistance levels in zero gravity. Results: An exercise regimen performed on an ergonomically-designed cycle can limit the stresses to demineralized postural bones thus reducing the risk of in-flight and post-flight fractures. The redistribution of spinal fluids is a specific focus of this exercise instrument. It's postulated that the secondary effect of reduced spinal fluid shifts are lower optic nerve and cranial pressures and the tertiary effect is the reduction of neuro-cognitive and cardio-vascular stresses brought on by weightlessness. Conclusions: The biomechanism of spinal fluid’s dynamic flow across a lower pressure gradient may be the cause of increased fluid volume in the spinal canal. This cycling exercise lessens the physical impact to areas of BMD depletion such as the hip socket. The exercise can maintain spinal flexibility, fluid stasis and posture. Human body systems affected by microgravity could be assisted with Virtual Reality (VR) inputs. The limbic system receives comprehensive, targeted sensory information that enables reorganization of neuronal networks that may serve to change dysregulated human immune, spatio-temporal, and cognitive systems.

Response of cardiac pulse parameters in humans at various inclinations via 360° rotating platform for simulated microgravity perspective

On the Earth, the human body is designed and adapted to function under uniform gravitational acceleration. However, exposure to microgravity or weightlessness as experienced by astronauts in space causes significant alterations in the functioning of the human cardiovascular system. Due to limitations in using real microgravity platforms, researchers opted for various ground-based microgravity analogs including head-down tilt (HDT) at fixed inclination. However, in the present study, an investigation of response of various cardiac parameters and their circulatory adaptation in 18 healthy male subjects was undertaken by using an indigenously developed 360° rotating platform. Cardiac pulse was recorded from 0° to 360° in steps of 30° inclination using piezoelectric pulse sensor (MLT1010) and associated cardiac parameters were analyzed. The results showed significant changes in the pulse shape while an interesting oscillating pattern was observed in associated cardiac parameters when rotated from 0° to 360°. The response of cardiac parameters became normal after returning to supine posture indicating the ability of the cardiovascular system to reversibly adapt to the postural changes. The observed changes in cardiac parameters at an inclination of 270°, in particular, were found to be comparable with spaceflight studies. Based on the obtained results and the proposed extended version of fluid redistribution mechanism, we herewith hypothesize that the rotation of a subject to head down tilt inclination (270°) along with other inclinations could represent a better microgravity analog for understanding the cumulative cardiac response of astronauts in space, particularly for short duration space missions.

Capturing Interaction Quality in Long Duration (Simulated) Space Missions With Wearables

Capturing Interaction Quality in Long Duration (Simulated) Space Missions With Wearables

Correlation between retinal vein pulse amplitude, estimated intracranial pressure, and postural change

Spaceflight associated neuro-ocular syndrome (SANS) is common amongst astronauts on long duration space missions and is associated with signs consistent with elevated cerebrospinal fluid (CSF) pressure. Additionally, CSF pressure has been found to be elevated in a significant proportion of astronauts in whom lumbar puncture was performed after successful mission completion. We have developed a retinal photoplethysmographic technique to measure retinal vein pulsation amplitudes. This technique has enabled the development of a non-invasive CSF pressure measurement apparatus. We tested the system on healthy volunteers in the sitting and supine posture to mimic the range of tilt table extremes and estimated the induced CSF pressure change using measurements from the CSF hydrostatic indifferent point. We found a significant relationship between pulsation amplitude change and estimated CSF pressure change (p < 0.0001) across a range from 2.7 to 7.1 mmHg. The increase in pulse amplitude was highest in the sitting posture with greater estimated CSF pressure increase (p < 0.0001), in keeping with physiologically predicted CSF pressure response. This technique may be useful for non-invasive measurement of CSF pressure fluctuations during long-term space voyages.

Rehabilitation assisted by Space technology-A SAHC approach in immobilized patients-A case of stroke.

Introduction: The idea behind the presentation of this case relates to utilizing space technology in earth applications with mutual benefit for both patients confined to bed and astronauts. Deconditioning and the progressiveness of skeletal muscle loss in the absence of adequate gravity stimulus have been of physiological concern. A robust countermeasure to muscle disuse is still a challenge for both immobilized patients and astronauts in long duration space missions. Researchers in the space medicine field concluded that artificial gravity (AG) produced by short-radius centrifugation on a passive movement therapy device, combined with exercise, has been a robust multi-system countermeasure as it re-introduces an acceleration field and gravity load. Methods: A short-arm human centrifuge (SAHC) alone or combined with exercise was evaluated as a novel, artificial gravity device for an effective rehabilitation strategy in the case of a stroke patient with disability. The results reveal valuable information on an individualized rehabilitation strategy against physiological deconditioning. A 73-year-old woman was suddenly unable to speak, follow directions or move her left arm and leg. She could not walk, and self-care tasks required maximal assistance. Her condition was getting worse over the years, also she was receiving conventional rehabilitation treatment. Intermittent short-arm human centrifuge individualized protocols were applied for 5 months, three times a week, 60 treatments in total. Results: It resulted in significant improvement in her gait, decreased atrophy with less spasticity on the left body side, and ability to walk at least 100 m with a cane. Balance and muscle strength were improved significantly. Cardiovascular parameters improved responding to adaptations to aerobic exercise. Electroencephalography (EEG) showed brain reorganization/plasticity evidenced through functional connectivity alterations and activation in the cortical regions, especially of the precentral and postcentral gyrus. Stroke immobility-related disability was also improved. Discussion: These alterations were attributed to the short-arm human centrifuge intervention. This case study provides novel evidence supporting the use of the short-arm human centrifuge as a promising therapeutic strategy in patients with restricted mobility, with application to astronauts with long-term muscle disuse in space.

Deep UV AlGaN LED reliability for long duration space missions

Space-based gravitational wave detection will be carried out by the laser interferometer space antenna (LISA), a joint European Space Agency and NASA collaboration. The configuration of this antenna will include three identical spacecraft in a triangular formation separated by 2.5×106km, flying in a drag-free formation around free-falling test masses. Charging of the test masses by cosmic ray fluxes and solar energetic particles must be compensated by photons that contain more energy than the effective work function of gold (4.3±0.4eV). The UV photons will be provided by AlGaN light emitting diodes, which must operate reliably for the duration of the mission. We have tested a large number (96 for dc and pulsed testing, more than 200 for all tests) of UV LEDs over a period of up to 600 days to characterize their performance over a wide range of operating conditions, assessing the lifetime performance under dc (1–80mA drive current) and pulsed conditions (500–100 000 pulses per second) and temperatures ranging from 20 to 80°C. Degradation of UV light output is faster at elevated temperatures and dc conditions. Preselection of LEDs based on initial spectral ratio of peak-to-midgap emission and ideality factor provides a positive correlation with subsequent reliability. The UV LEDs used for LISA will need to support 2 years of cruise and commissioning plus a 4-year baseline science mission.

Fragmentation Measurements in Particle Therapy: status and plans of the FOOT experiment

Due to the advantageous characteristics of the charged particle’s energy deposition in matter, protons or ion beams are used in hadrontherapy to treat deep-seated solid tumors. Using these beams, the maximum of the dose is released to the tumor tissues at the end of the beam range. In this process, nevertheless, fragmentation of both projectile and target nuclei can occur in the nuclear interactions of the beam with the patient tissues and, as showed in recent studies, needs to be carefully taken into account in the delivered dose calculation. Nuclear fragmentation is also extremely relevant for space radioprotection studies, when the exposition of sensors and human crews to solar and galactic particle flows have to be minimized. The goal of the FOOT (FragmentatiOn Of Target) experiment is to estimate target and beam fragmentation performing cross section measurements (with respect to the kinetic energy and direction) with a precision of the order of 5% in the energy range of interest for hadrontherapy (protons in the energy range of 70-230 MeV or ion beams with energy up to 400 MeV/u) and space radioprotection (ion beams with energy up to 800 MeV/u) in order to provide new data for medical physicists, radio-biologists and to improve not only the new generation of oncological Treatment Planning Systems but also the design of shielding elements for the future long duration space missions eventually with human crews. In this paper will be presented the project, the present status of the different detector sub-systems construction and the data-taking plans.

Air-breathing electric propulsion: mission characterization and design analysis

AbstractAir breathing electric propulsion (atmosphere-breathing electric propulsion) (ABEP) has attracted significant interest as an enabling technology for long duration space missions in very low Earth orbit (VLEO) altitudes below about 300 km. The ABEP spacecraft and mission analysis model developed allows parametric characterization of key spacecraft geometry and thruster performance parameters such as spacecraft length-to-diameter, the ratio of solar array span to spacecraft diameter, thrust-to-power, effective exhaust velocity, and inlet efficiency. For the missions analyzed ABEP generally outperforms conventional electric propulsion (EP) below 250 km altitude. Using a 6U spacecraft architecture the model shows that below 220 km ABEP is the only viable propulsion option for desirable mission lifetimes. Parametric evaluations of key spacecraft and ABEP characteristics show that the most significant technological improvements to ABEP spacecraft performance and range of applicability for VLEO missions will come from advancements in inlet efficiency, low drag materials, solar array efficiency, and thrust-to-power.

Meta-analysis of health research data from greater than three months International Space Station missions

Despite extensive research, the understanding of human health changes that result from long-duration spaceflight remains limited, in part due to the wide range of study types and designs, lack of independent experiment replication and data dispersal in many articles. We have compiled a database from 37 health studies that reported data for 517 parameters from missions of longer than 3-month duration on the International Space Station. We found an abundance of physiological and biochemical parameters and limited psychological/behavioral in-flight data. When we compared in-flight to pre-flight data, 14 out of 40 studied measurement type categories changed significantly, whereas only 3 categories changed significantly post-flight. Collagen breakdown biomarkers in urine showed the greatest effect, a 2-fold increase in-flight, but no data in this category was reported post-flight. Eye movements related to the vestibular system function had the greatest in-flight effect that was sustained post-flight, with a decrease of 81% in-flight and a 32% decrease remained post-flight. Analysis of the in-flight compared to post-flight biochemical and physiological changes revealed overall low correlations (R2 = 0.03 & R2 = 0.23, respectively), as parameters tend to return to baseline post-flight. As we look to longer duration space missions, this review provides an opportunity to identify and highlight salient results that have been reported to date for long duration spaceflight, to enhance our understanding of space health and to develop effective countermeasures. We believe that the compiled data could be explored for medical interpretation of the observed changes, in-flight timeline of changes for natural history studies, correlation analysis for parameters across different body systems, and comparison of in-flight responses to ground-based studies.

The impact of stance during heel raises on the hybrid ultimate lifting kit (HULK) device: A future microgravity exercise machine.

Extended missions in microgravity, such as those on the International Space Station (ISS) or future missions to Mars, can result in the physiological deconditioning of astronauts. Current mitigation strategies include a regimented diet in addition to resistance training paired with aerobic exercise. With the increased effort toward long duration space missions, there is room to optimize the cost, required time of use, and mass of exercise equipment. This research effort focuses on understanding the biomechanics of Heel Raise (HR) exercises while using the Hybrid Ultimate Lifting Kit (HULK) device, an exercise device designed to optimize volume and functionality. Using the biomechanics tool OpenSim, the effect of HR foot stance (15° inward, 15° outward, and straight) was assessed by analyzing kinematic and kinetic data. In particular, we analyzed peak joint angles, range of motion, joint moments, and angular impulses of a single subject. Preliminary results indicated no significant differences in terms of ankle/metatarsophalangeal/subtalar joint angles, range of motion, joint moments, and angular impulses between foot stances. In addition, loaded HR exercises were compared to body weight HR exercises without the HULK device. Finally, recommendations are made towards an optimal HR routine for long-duration space missions. The impact to health and rehabilitation on Earth is also discussed.

Health, hygiene, and microbial monitoring during long-duration space simulations

The significance of the human-microbe relationship is amplified in long duration space exploration (LDSE), where isolated and confined microbial environments degenerate space habitat integrity, compromise planetary protection goals, and have largely unknown and potentially deleterious effects on astronaut health. While environmental surveillance is assumed to be a key component of future deep space missions, the optimal modality, frequency, and location of such surveillance is not yet defined. In order to investigate strategies of microbial surveillance, a series of experiments, conducted at a long-duration, isolated and confined (ICE) Mars simulation, furthered our understanding of the microbiome sampling challenges presented by food, environment, and crewmembers. Descriptive analyses revealed key considerations for microbial monitoring in future long duration space missions, including special considerations for surface sanitation, previously undocumented potential sources of food-borne toxicity, and a novel outlook on the dynamic human microbiome in isolation.

Countermeasure Analysis for Galactic Cosmic Radiation Induced Damage

Galactic cosmic radiation (GCR) exposure is increased to space flight crews as travel moves beyond low Earth orbit. GCR includes high energy protons and heavy ionizing ions such as 56Fe, 28Si, and 16O and there are distinct differences in the biological response compared to low‐energy transfer events (x‐rays). Although the exposure rate is relatively low, the cumulative radiation dose is likely to have deleterious effects for long duration flight crews. The underlying mechanisms for these elevated risks are thought to include direct DNA damage as well as chronically elevated oxidant stress, and inflammation.Given the relatively low fluence rate of GCR exposure during flight operations it might be possible to manage these deleterious effects using small molecules currently available. To that end we have utilized a FDA approved drug library to perform a high throughput screen of cultured cells following exposure to GCR. H9c2 cells were exposed to a single 75 cGy dose using the 5‐ion GCRsim protocol developed by NSRL. Following GCRsim exposure, cells were treated using 10 µM for each drug. At harvest, cells were tested for protein content, oxidant stress, cellular senescence, and mitochondrial function.Of 725 drugs, more than 500 were ineffective in managing GCR exposure. Within the top 160 drugs, 33 were primarily designated as anti‐inflammatory. Significant variations within drug classes were observed. Only 10 of 46 drugs that interacted with histamine receptors were found useful and most were 5‐HT3 specific. The COX inhibitors deemed useful were all COX2 specific. Surprisingly, some anti‐diabetic medications observed to be useful including metformin.The bias of mitochondrial degradation as a central readout comes from several “omics” analyses that identified mitochondrial dysfunction as a consequence of GCR exposure. Mitochondrial dysfunction is also an antecedent event in the transformation leading to carcinogenesis. And the potential for carcinogenesis is a significant risk for long duration space missions. Separate from examining mitochondrial and cellular dysfunction as readouts, we have developed a Afp‐tdTomato expressing cell line that is responsive to different carcinogenic reagents including GCR. We have observed that some of the lead candidates will at least partially rescue the cells from GCR induced Afp driven expression. Additionally adapting cell doubling time protocols we observed that GCR exposure significantly increased cell doubling time; a finding indicative of mitotic dysfunction. We also observed that this increase was partially ameliorated by some of the lead candidates. That no one class of drug dominated the response to radiation exposure speaks to the complexity of managing GCR exposure.

Phenotypic and transcriptional changes in Escherichia coli K12 in response to simulated microgravity on the EagleStat, a new 2D microgravity analog for bacterial studies.

Understanding the impacts of microgravity on bacteria is vital for successful long duration space missions. In this environment, bacteria have been shown to become more virulent, more resistant to antibiotics and to regulate biofilm formation. Since the study of these phenomena under true microgravity is cost- and time challenging, the use of ground-based analogs might allow researchers to test hypotheses before planning and executing experiments in the space environment. We designed and developed a 2D clinostat with capabilities robust enough for bacterial studies to allow for multiple simultaneous replicates of treatment and control conditions, thus permitting the generation of growth curves, in a single run. We used computational fluid dynamics (CFD), biofilm growth measurement and differential gene expression analysis on Escherichia coli cultures grown to late exponential phase (24 h) to validate the system's ability to simulate microgravity conditions. The CFD model with a rotational speed of 8 rpm projected cells growing homogeneously distributed along the tube, while the static condition showed the accumulation of the cells at the bottom of the container. These results were empirically validated with cultures on nutrient broth. Additionally, crystal violet assays showed that higher biofilm biomass grew on the internal walls of the gravity control tubes, compared to the simulated microgravity treatment. In contrast, when cells from both treatments were grown under standard conditions, those exposed to simulated microgravity formed significantly more biofilms than their gravity counterparts. Consistent with this result, transcriptome analysis showed the upregulation of several gene families related to biofilm formation and development such as cells adhesion, aggregation and regulation of cell motility, which provides a potential transcriptional explanation for the differential phenotype observed. Our results show that when operated under parameters for simulated microgravity, our 2D clinostat creates conditions that maintain a proportion of the cells in a constant free-falling state, consistent with the effect of microgravity. Also, the high-throughput nature of our instrument facilitates, significantly, bacterial experiments that require multiple sampling timepoints and small working volumes, making this new instrument extremely efficient.

The Role of Different Afferent Systems in the Modulation of the Otolith-Ocular Reflex After Long-Term Space Flights.

BackgroundThe vestibular (otolith) function is highly suppressed during space flight (SF) and the study of these changes is very important for the safety of the space crew during SF missions. The vestibular function (particularly, otolith-ocular reflex–OOcR) in clinical and space medicine is studied using different methodologies. However, different methods and methodologies can influence the outcome results.ObjectiveThe current study addresses the question of whether the OOcR results obtained by different methods are different, and what the role is of the different afferent systems in the modulation of the OOcR.MethodsA total of 25 Russian cosmonauts voluntarily took part in our study. They are crewmembers of long duration space missions on the International Space Station (ISS). Cosmonauts were examined in pre- and post-flight “Sensory Adaptation” and “Gaze Spin” experiments, twice before (preflight) and three times after SF (post-flight). We used two different video oculography (VOG) systems for the recording of the OOcR obtained in each experiment.ResultsComparison of the two VOG systems didn’t result into significant and systematic differences in the OOcR measurements. Analysis of the static torsion otolith–ocular reflex (OOR), static torsion otolith–cervical–ocular reflex (OCOR) and static torsion otolith–ocular reflex during eccentric centrifugation (OOREC) shows that the OOREC results in a lower OOcR response compared to the OOR and OCOR (before flight and late post-flight). However, all OOcRs were significantly decreased in all cosmonauts early post-flight.ConclusionAnalysis of the results of ocular counter rolling (OCR) obtained by different methods (OOR, OCOR, and OOREC) showed that different afferent systems (tactile-proprioception, neck-cervical, visual and vestibular afferent input) have an impact on the OOcR.

Dark Food: Feeding People in Space Without Photosynthesis

Production of food in space via photosynthetic crops similar to the ones we use on Earth requires profligate use of resources that will be in short supply in early long duration space missions. We demonstrate that production of bulk calories via chemotrophic single-cell organisms is 2–3 orders of magnitude less expensive in terms of energy, volume, and water usage than via photosynthetic crops. In addition, we survey the history and current state of the art in production of food from nonphotosynthetic single-cell organisms.

Spaceflight Associated Neuro-Ocular Syndrome: New Technologies to Advance Research in a Fast Moving Field

Spaceflight is expected to boom in the next several decades. This will likely include an increase in deep space exploration and long-duration missions. It is well established that spaceflight has potentially hazardous effects on human health. One of the concerning conditions experienced by astronauts on long duration space missions is spaceflight associated neuro-ocular syndrome (SANS), which includes symptoms such as swelling around the optic disk, changes in ocular anatomy, and visual refractory errors. Multiple theories have been proposed to explain the pathophysiology of this syndrome. However, there are unique challenges faced with studying this syndrome and a clear etiology is not currently known. As more individuals venture into space for longer periods of time, it is important to assess the value new technologies could add to learning more about syndromes such as SANS and improving human health in space overall. New complex human in vitro models and other technological devices may allow researchers to investigate these issues and give greater insight into the pathophysiology of SANS, potentially leading to improved countermeasures and therapeutics.