Estimates of Galactic Cosmic Ray Shielding Requirements During Solar Minimum

Estimates of Galactic Cosmic Ray Shielding Requirements During Solar Minimum

Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-12-31

Total Pages: 34

ISBN-13: 9781792697661

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Estimates of radiation risk from galactic cosmic rays are presented for manned interplanetary missions. The calculations use the Naval Research Laboratory cosmic ray spectrum model as input into the Langley Research Center galactic cosmic ray transport code. This transport code, which transports both heavy ions and nucleons, can be used with any number of layers of target material, consisting of up to five different arbitrary constituents per layer. Calculated galactic cosmic ray fluxes, dose and dose equivalents behind various thicknesses of aluminum, water and liquid hydrogen shielding are presented for the solar minimum period. Estimates of risk to the skin and the blood-forming organs (BFO) are made using 0-cm and 5-cm depth dose/dose equivalent values, respectively, for water. These results indicate that at least 3.5 g/sq cm (3.5 cm) of water, or 6.5 g/sq cm (2.4 cm) of aluminum, or 1.0 g/sq cm (14 cm) of liquid hydrogen shielding is required to reduce the annual exposure below the currently recommended BFO limit of 0.5 Sv. Because of large uncertainties in fragmentation parameters and the input cosmic ray spectrum, these exposure estimates may be uncertain by as much as a factor of 2 or more. The effects of these potential exposure uncertainties or shield thickness requirements are analyzed. Townsend, Lawrence W. and Nealy, John E. and Wilson, John W. and Simonsen, Lisa C. Langley Research Center NASA-TM-4167, L-16715, NAS 1.15:4167 RTOP 199-04-16-11...


Biological Effects and Physics of Solar and Galactic Cosmic Radiation Part B

Biological Effects and Physics of Solar and Galactic Cosmic Radiation Part B

Author: Charles E. Swenberg

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 938

ISBN-13: 1461529166

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Space missions subject human beings or any other target of a spacecraft to a radiation environment of an intensity and composition not available on earth. Whereas for missions in low earth orbit (LEO), such as those using the Space Shuttle or Space Station scenario, radiation exposure guidelines have been developed and have been adopted by spacefaring agencies, for exploratory class missions that will take the space travellers outside the protective confines of the geomagnetic field sufficient guidelines for radiation protection are still outstanding. For a piloted Mars mission, the whole concept of radiation protection needs to be reconsidered. Since there is an increasing interest of many nations and space agencies in establishing a lunar base and lor exploring Mars by manned missions, it is both, timely and important to develop appropriate risk estimates and radiation protection guidelines which will have an influence on the design and structure of space vehicles and habitation areas of the extraterrestrial settlements. This book is the result of a multidisciplinary effort to assess the state of art in our knowledge on the radiation situation during deep space missions and on the impact of this complex radiation environment on the space traveller. It comprises the lectures by the faculty members as well as short contributions by the students given at the NATO Advanced Study Institute "Biological Effects and Physics of Solar and Galactic Cosmic Radiation" held in Armacao de Pera, Portugal, 12-23 October, 1991.


Shielding Strategies for Human Space Exploration

Shielding Strategies for Human Space Exploration

Author: John William Wilson

Publisher:

Published: 1997

Total Pages: 496

ISBN-13:

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The purpose of the workshop was to define requirements for the development and evaluation of high performance shield materials and designs and to develop ideas regarding approaches to radiation shielding.