Long-Term Microgravity Effects on Isometric Handgrip and Precision Pinch Force with Visual and Proprioceptive Feedback

The study and analysis of human physiology during short- and long-duration space flights are the most valuable approach in order to evaluate the effect of microgravity on the human body and to develop possible countermeasures in prevision of future exploratory missions and Mars expeditions. Hand performances such as force output and manipulation capacity are fundamental for astronauts’ intra- and extravehicular activities. Previous studies on upper limb conducted on astronauts during short-term missions (10 days) indicated a temporary partial reduction in the handgrip maximum voluntary contraction (MVC) followed by a prompt recovery and adaptation to weightlessness during the last days of the mission. In the present study, we report on the “Crew’s Health: Investigation on Reduced Operability” (CHIRO) protocol, developed for handgrip and pinch force investigations, performed during the six months increment 7 and increment 8 (2003-2004) onboard International Space Station (ISS). We found that handgrip and pinch force performance are reduced during long-term increments in space and are not followed by adaptation during the mission, as conversely reported during short-term increment experiments. The application of protocols developed in space will be eligible to astronauts during long-term space missions and to patients affected by muscle atrophy diseases or nervous system injury on Earth

Cerium Oxide Nanoparticle Administration to Skeletal Muscle Cells under Different Gravity and Radiation Conditions

For their remarkable biomimetic properties implying strong modulation of the intracellular and extracellular redox state, cerium oxide nanoparticles (also termed "nanoceria") were hypothesized to exert a protective role against oxidative stress associated with the harsh environmental conditions of spaceflight, characterized by microgravity and highly energetic radiations. Nanoparticles were supplied to proliferating C2C12 mouse skeletal muscle cells under different gravity and radiation levels. Biological responses were thus investigated at a transcriptional level by RNA next-generation sequencing. Lists of differentially expressed genes (DEGs) were generated and intersected by taking into consideration relevant comparisons, which led to the observation of prevailing effects of the space environment over those induced by nanoceria. In space, upregulation of transcription was slightly preponderant over downregulation, implying involvement of intracellular compartments, with the majority of DEGs consistently over- or under-expressed whenever present. Cosmic radiations regulated a higher number of DEGs than microgravity and seemed to promote increased cellular catabolism. By taking into consideration space physical stressors alone, microgravity and cosmic radiations appeared to have opposite effects at transcriptional levels despite partial sharing of molecular pathways. Interestingly, gene ontology denoted some enrichment in terms related to vision, when only effects of radiations were assessed. The transcriptional regulation of mitochondrial uncoupling protein 2 in space-relevant samples suggests perturbation of the intracellular redox homeostasis, and leaves open opportunities for antioxidant treatment for oxidative stress reduction in harsh environments

No Effect of Microgravity and Simulated Mars Gravity on Final Bacterial Cell Concentrations on the International Space Station: Applications to Space Bioproduction

Microorganisms perform countless tasks on Earth and they are expected to be essential for human space exploration. Despite the interest in the responses of bacteria to space conditions, the findings on the effects of microgravity have been contradictory, while the effects of Martian gravity are nearly unknown. We performed the ESA BioRock experiment on the International Space Station to study microbe-mineral interactions in microgravity, simulated Mars gravity and simulated Earth gravity, as well as in ground gravity controls, with three bacterial species: Sphingomonas desiccabilis, Bacillus subtilis, and Cupriavidus metallidurans. To our knowledge, this was the first experiment to study simulated Martian gravity on bacteria using a space platform. Here, we tested the hypothesis that different gravity regimens can influence the final cell concentrations achieved after a multi-week period in space. Despite the different sedimentation rates predicted, we found no significant differences in final cell counts and optical densities between the three gravity regimens on the ISS. This suggests that possible gravityrelated effects on bacterial growth were overcome by the end of the experiment. The results indicate that microbial-supported bioproduction and life support systems can be effectively performed in space (e.g., Mars), as on Earth

The instrument control unit of the PLATO payload: design consolidation following the preliminary design review by ESA

PLATO is an M-class mission (M3) of the European Space Agency (ESA) whose launch is scheduled in 2026. The main aim of the mission is the detection and characterization of terrestrial exoplanets orbiting around bright solar-type star. The payload consists of 26 small telescopes: 24 "normal" cameras and 2 "fast" cameras. The huge amount of data produced by the PLATO telescopes is acquired and processed on-board by the Data Processing System (DPS) made up by various processing electronic units. The DPS of the PLATO instrument comprises the Normal and Fast DPUs (Data Processing Units) and a single ICU (Instrument Control Unit), are data routed through a SpaceWire network. The topic of this paper is the description of the architecture of the ICU and its role within the DPS, the status of the Avionic Validation Model (AVM) testing at the end of the Unit Preliminary Design Review (UPDR) performed by ESA and the results of the test of the first engineering model

Subjective visual vertical in erect/supine subjects and under microgravity: effects of lower body negative pressure

Perception of the subjective visual vertical (SVV) is mainly based on the contributions from the visual, vestibular, and proprioceptive systems, and participates to the process of spatial orientation in relation to the surrounding environment and to the gravito-inertial force. The SVV can be significantly influenced by the presence of a displaced visual field, as in the case of the rod and frame test (RFT). A series of studies showed the effects of haematic mass shifts to and from the lower limbs on SVV, due to visceral mechanoreceptors (VM) located at the level of the kidneys and of the thorax. These sensors may be artificially activated with a lower body negative pressure (LBNP) device. In this study, the role of visual and VM cues to orientation perception have been evaluated using the RFT and the LBNP devices under a microgravity environment. A preliminary investigation was conducted in a sample of military pilots to develop a RFT protocol to be used in microgravity environments. This protocol was adopted to evaluate the contribution of VM to the SVV in a cosmonaut before, during and after a 10 day space flight, with and without concurrent activation of LBNP. The same test sequence, including LBNP exposure, was repeated a few months later on Earth on the same subject. As expected, the influence of the frame on rod positioning was statistically significant in all test conditions. During the in-flight experimental step, a substantial lack of significant changes compared to the pre-flight condition was observed. Moreover, substantially no effects due to LBNP were observed. A mild rod displacement from the body axis was detected under microgravity compared to the pre-flight recording. Such a finding was in part reduced during LBNP. The same findings were observed during the post-flight repetition of the experiment. Our results showed an absence in this subject of significant effects on the RFT due to microgravity. In conclusion, no effects from his VM on the RFT and minor changes in the SVV could be detected

Electro-active polymers for actuation and sensing in space applications

Electro Active Polymers (EAPs) respond to an applied electrical potential with displacement. This permits their use for electrically-driven actuation mechanisms and in reverse as strain sensors. EAPs are currently the most promising class of materials for 'artificial muscles', as they are light-weight with high compliance, have high active strains and/or stresses depending on the kind of material (sometimes in excess of natural muscles), fast response (electronic type EAPs only), good controllability and low cost. This paper focuses on the potential of EAPs to provide solutions to integrating actuation and sensing functions required by future space systems. Performance indicators are covered, covering force levels, density, stiffness, displacement, power, and dynamic response. Their limitations are discussed in the context of environmental aspects, such as temperature, pressure, radiation, gravity, and in relation to robustness (degradation, fatigue). Dielectric elastomers are concluded to be the most promising class of EAP for application in a wide variety of space actuation tasks, and some of the possible applications of EAPs in space are Investigated. The paper concludes with a short case study on the use of a novel EAP device for a jumping mechanism in a Martian tumbleweed rover is presented as a novel example application

Robot assisted surgery in space: Pros and Cons. A review from the surgeon’s point of view.

The target of human flight in space has changed from permanence on the International Space Station to missions beyond low earth orbit and the Lunar Gateway for deep space exploration and Missions to Mars. Several conditions affecting space missions had to be considered: for example the effect of weightlessness and radiations on the human body, behavioral health decrements or communication latency, and consumable resupply. Telemedicine and telerobotic applications, robot-assisted surgery with some hints on experimental surgical procedures carried out in previous missions, had to be considered as well. The need for greater crew autonomy in health issues is related to the increasing severity of medical and surgical interventions that could occur in these missions, and the presence of a highly trained surgeon on board would be recommended. A surgical robot could be a valuable aid but only inasfar as it is provided with multiple functions, including the capability to perform certain procedures autonomously. Space missions in deep space or on other planets present new challenges for crew health. Providing a multi-function surgical robot is the new frontier. Research in this field shall be paving the way for the development of new structured plans for human health in space, as well as providing new suggestions for clinical applications on Earth