PhD student at the space studies program, International Space University
The International Space Station is scheduled to conclude in 2024-- what shall we do with it after?
The International Space Station (ISS) is an inhabited artificial satellite which has been orbiting around Earth and supporting continuous research activities for over fifteen years. It is an international cooperative effort. Currently the project funding and efforts are scheduled until the year 2024. There are substantial tangible and intangible assets in the ISS which could be utilized for alternate applications in the case that the ISS is shut down at that time. Over $150 billion has been invested into the ISS and it is likely the most expensive single item constructed in human history. Consideration of its future purpose, whether continued as-is or repurposed, is important. A committee report on this topic will be presented at the 68th International Astronautical Congress, Sept. 25-29, 2017.
Abstract: To counteract microgravity (µG)-induced adaptation, European Space Agency (ESA) astronauts on long-duration missions (LDMs) to the International Space Station (ISS) perform a daily physical exercise countermeasure program. Since the first ESA crewmember completed an LDM in 2006, the ESA countermeasure program has strived to provide efficient protection against decreases in body mass, muscle strength, bone mass, and aerobic capacity within the operational constraints of the ISS environment and the changing availability of on-board exercise devices. The purpose of this paper is to provide a description of ESA's individualised approach to in-flight exercise countermeasures and an up-to-date picture of how exercise is used to counteract physiological changes resulting from µG-induced adaptation. Changes in the absolute workload for resistive exercise, treadmill running and cycle ergometry throughout ESA's eight LDMs are also presented, and aspects of pre-flight physical preparation and post-flight reconditioning outlined.With the introduction of the advanced resistive exercise device (ARED) in 2009, the relative contribution of resistance exercise to total in-flight exercise increased (33-46 %), whilst treadmill running (42-33 %) and cycle ergometry (26-20 %) decreased. All eight ESA crewmembers increased their in-flight absolute workload during their LDMs for resistance exercise and treadmill running (running speed and vertical loading through the harness), while cycle ergometer workload was unchanged across missions.Increased or unchanged absolute exercise workloads in-flight would appear contradictory to typical post-flight reductions in muscle mass and strength, and cardiovascular capacity following LDMs. However, increased absolute in-flight workloads are not directly linked to changes in exercise capacity as they likely also reflect the planned, conservative loading early in the mission to allow adaption to µG exercise, including personal comfort issues with novel exercise hardware (e.g. the treadmill harness). Inconsistency in hardware and individualised support concepts across time limit the comparability of results from different crewmembers, and questions regarding the difference between cycling and running in µG versus identical exercise here on Earth, and other factors that might influence in-flight exercise performance, still require further investigation.
Pub.: 05 Aug '16, Pinned: 29 Jun '17
Abstract: In recent years, NASA has renewed its focus on manned missions beyond low Earth orbit. These missions will take astronauts to asteroids, the moon, or to Mars. As mission designs become more concrete, it is clear that they will differ from current missions to the International Space Station (ISS) in many ways, including duration, real-time communication with ground, evacuation options, crew rotations, and distance from Earth. These differences will add new challenges to maintaining human health and performance on long-duration exploratory missions (LDEMs). Given the integral nature of teamwork to the success of space missions, differences from current ISS missions will also pose new risk factors to strong team performance over the course of the missions. Factors influencing team performance have previously been identified on past space missions and studies in analogous environments (e.g., submarines, Antarctic research stations). These existing risk factors that affect team performance may be exacerbated on longer space missions in closer quarters, and new risk factors are likely to emerge. Selecting astronauts with the “right stuff” for the new LDEM teams becomes an essential first step in promoting mission success.
Pub.: 06 Mar '17, Pinned: 29 Jun '17
Abstract: As NASA prepares for the first manned spaceflight to Mars, questions have surfaced concerning the potential for increased risks associated with exposure to the spectrum of highly energetic nuclei that comprise galactic cosmic rays. Animal models have revealed an unexpected sensitivity of mature neurons in the brain to charged particles found in space. Astronaut autonomy during long-term space travel is particularly critical as is the need to properly manage planned and unanticipated events, activities that could be compromised by accumulating particle traversals through the brain. Using mice subjected to space-relevant fluences of charged particles, we show significant cortical- and hippocampal-based performance decrements 6 weeks after acute exposure. Animals manifesting cognitive decrements exhibited marked and persistent radiation-induced reductions in dendritic complexity and spine density along medial prefrontal cortical neurons known to mediate neurotransmission specifically interrogated by our behavioral tasks. Significant increases in postsynaptic density protein 95 (PSD-95) revealed major radiation-induced alterations in synaptic integrity. Impaired behavioral performance of individual animals correlated significantly with reduced spine density and trended with increased synaptic puncta, thereby providing quantitative measures of risk for developing cognitive decrements. Our data indicate an unexpected and unique susceptibility of the central nervous system to space radiation exposure, and argue that the underlying radiation sensitivity of delicate neuronal structure may well predispose astronauts to unintended mission-critical performance decrements and/or longer-term neurocognitive sequelae.
Pub.: 17 Jul '15, Pinned: 29 Jun '17