scholarly journals Utilisation of Moon Regolith for Radiation Protection and Thermal Insulation in Permanent Lunar Habitats

2021 ◽  
Vol 11 (9) ◽  
pp. 3853
Author(s):  
Yulia Akisheva ◽  
Yves Gourinat

In the context of a sustainable long-term human presence on the Moon, solutions for habitat radiation and thermal protection with regolith are investigated. Regolith compression is studied to choose the optimal density-thickness combination in terms of radiation shielding and thermal insulation. The applied strategy is to protect the whole habitat from the hazards of galactic cosmic rays and design a dedicated shelter area for protection during solar particle events, which eventually may be a lava tube. Simulations using NASA’s OLTARIS tool show that the effective dose equivalent decreases significantly when a multilayer structure mainly constituted of regolith and other available materials is used instead of pure regolith. The computerised anatomical female model is considered here because future missions will be mixed crews, and, generally, more sex-specific data are required in the field of radiation protection and human spaceflight. This study shows that if reasonably achievable radioprotection conditions are met, mixed crews can stay safely on the lunar surface. Compressed regolith demonstrates a significant efficiency in thermal insulation, requiring little energy management to keep a comfortable temperature inside the habitat. For a more complete picture of the outpost, the radiation protection of lunar rovers and extravehicular mobility units is considered.

2020 ◽  
Vol 3 (4) ◽  
pp. 503-514
Author(s):  
Mu-Tai Liu ◽  
Russel J Reiter

During a deep space mission, the central nervous system (CNS) and other organs are exposed to galactic cosmic rays and solar particle events. Health risks associated with various organs and systems are important issues in a long-term spaceflight. Potential CNS damage during a space mission could alter cognitive functions which might impact performance and individual’s health. The neuronal injury originating from exposure to 56Fe particle irradiation involves the elevated oxidative stress which can be inhibited by melatonin pretreatment. Melatonin exerts potent neuroprotective effects against carbon ion-induced mitochondrial dysfunction and apoptosis in the mouse brain. A significant increase in the count of immature neurons and proliferating cells was detected in the mice under 56Fe particle irradiation cotreated with the melatonin metabolite, AFMK. Melatonin treatment also significantly reduced the carbon ion-induced apoptotic cells and elevated oxidative stress in the mouse testis. The results suggest that melatonin treatment is a potential strategy to protect against space radiation hazards. Spaceflight-induced molecular, cellular, and physiologic changes lead to alterations across many organs and systems. Epigenetic, gene expression, inflammatory, and metabolic responses to spaceflight should be examined and means to safe-guard against these changes in upcoming missions. Precision medicine will be crucial for assessing and augmenting efficacy of melatonin or other medications in astronauts. In addition, enhancing radio-resistance of humans is a novel strategy for a long-term space mission. Further investigations with a combination of melatonin and other novel technologies are warranted to better alleviate HZE particle irradiation-induced damage to astronauts on long-term space exploration missions. 


2021 ◽  
Author(s):  
Yulia Akisheva ◽  
Yves Gourinat ◽  
Nicolas Foray ◽  
Aidan Cowley

This chapter discusses regolith utilization in habitat construction mainly from the point of view of radiation protection of humans on missions of long duration. It also considers other key properties such as structural robustness, thermal insulation, and micrometeoroid protection that all have to be considered in parallel when proposing regolith-based solutions. The biological hazards of radiation exposure on the Moon are presented and put in the context of lunar exploration-type missions and current astronaut career dose limits. These factors guide the research in radiation protection done with lunar regolith simulants, which are used in research and development activities on Earth due to the reduced accessibility of returned lunar samples. The ways in which regolith can be used in construction influence its protective properties. Areal density, which plays a key role in the radiation shielding capacity of a given material, can be optimized through different regolith processing techniques. At the same time, density will also affect other important properties of the construction, e.g. thermal insulation. A comprehensive picture of regolith utilization in habitat walls is drawn for the reader to understand the main aspects that are considered in habitat design and construction while maintaining the main focus on radiation protection.


2021 ◽  
pp. 79-86
Author(s):  
V.G. Babashov ◽  
◽  
N.M. Varrik ◽  

Based on the analysis of recent publications of scientific and technical literature, data on the production of zirconium oxide fibers used for the manufacture of high-temperature thermal insulation materials are presented. Information is provided on various methods of obtaining zirconium oxide fibers (methods of impregnation of the template and molding of the mixture, sol-gel method of spinning a fiber-forming precursor solution), as well as on the technique of fiber molding (manual pulling, dry and wet spinning, blowing and electrospinning). The use of such fibers for the production of thermal insulation materials (felts, cords and blocks) instead of currently existing materials made of aluminum oxide-based fibers can significantly increase the operating temperatures of the thermal protection systems.


2021 ◽  
pp. 20210477
Author(s):  
Jenia Vassileva ◽  
Ola Holmberg

This review summarises the current knowledge about recurrent radiological imaging and associated cumulative doses to patients. The recent conservative estimates are for around 0.9 million patients globally who cumulate radiation doses above 100 mSv, where evidence exists for cancer risk elevation. Around one in five is estimated to be under the age of 50. Recurrent imaging is used for managing various health conditions and chronic diseases such as malignancies, trauma, end-stage kidney disease, cardiovascular diseases, Crohn’s disease, urolithiasis, cystic pulmonary disease. More studies are needed from different parts of the world to understand the magnitude and appropriateness. The analysis identified areas of future work to improve radiation protection of individuals who are submitted to frequent imaging. These include access to dose saving imaging technologies; improved imaging strategies and appropriateness process; specific optimisation tailored to the clinical condition and patient habitus; wider utilisation of the automatic exposure monitoring systems with an integrated option for individual exposure tracking in standardised patient-specific risk metrics; improved training and communication. The integration of the clinical and exposure history data will support improved knowledge about radiation risks from low doses and individual radiosensitivity. The radiation protection framework will need to respond to the challenge of recurrent imaging and high individual doses. The radiation protection perspective complements the clinical perspective, and the risk to benefit analysis must account holistically for all incidental and long-term benefits and risks for patients, their clinical history and specific needs. This is a step toward the patient-centric health care.


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