Correct modeling results are needed to inform mission planning and shield design

Publication date: Available online 16 November 2019Source: Life Sciences in Space ResearchAuthor(s): Tony C. Slaba, Robert C. SingleterryAbstractThere are a large number of modeling results in the literature focused on astronaut protection from solar particle events (SPE) over a broad range of mission architectures. These studies form the basis for shield design and mission planning strategies currently used by NASA. To optimize SPE protection or affect decision making criteria for these missions, one must have an accurate assessment of exposure levels at one or more locations within a vehicle or habitat concept. Such assessments require some definition for the SPE being considered, a description of the mass shielding for the vehicle or habitat, and a radiation transport model to describe how the radiation field is modified as it propagates through shielding. It is well known that in these circumstances, astronaut exposure estimates are highly sensitive to the choice of SPE and shielding geometry. A recent study by El-Jaby et al. analyzed historical SPE with spherical aluminum shielding and two radiation transport codes (MCNPX and OLTARIS). Surprisingly large differences between the MCNPX and OLTARIS results were reported and generally attributed to differing transport methodologies, nuclear physics models, boundary condition setup, and detector regions. In this commentary, we show that the discrepancy between the MCNPX and OLTARIS results is attributable to the use of a volu...
Source: Life Sciences in Space Research - Category: Biology Source Type: research