Radiological health risksThe crew of a manned Mars mission will be unavoidably exposed to galactic cosmic ray (GCR) flux. The Mars mission crew shielded by 2 g/sq cm Al could receive about 0.7 Sv in a 460-day mission at solar minimum. However, three-fourths of this dose-equivalent in free space is contributed by high LET heavy ions (Z 3 or greater) and target fragments with average Q of 10.3 and 20, respectively. Such high quality factors for these particles may be inappropriate. Moreover, in a 460-day mission, less than half of the nuclei in the body of an astronaut will have been traversed by a single heavy particle. The entire concept of absorbed dose/quality factors/dose-equivalents as applied to GCR must be reconsidered.
Document ID
19900040348
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Nachtwey, D. Stuart (NASA Johnson Space Center Houston, TX, United States)