GALACTIC COSMIC RAY RADIATION LEVELS IN SPACECRAFT ON INTERPLANETARY MISSIONS

Using the Langley Research Center galactic osmic ray (GCR) transport computer code (HZETRN) and the computerized anatomical man (CAM) model, crew radiation levels inside manned space-craft on interplanetary missions are estimated. These radiation-level stimates include particle fluxes, LET (linear energy transfer) spectra, absorbed ose, and dose equivalent within various organs of interest in GCR protection studies. Changes in these radiation levels resulting from the use of various different ypes of shield materials are presented. ~TRODUCTION Manned interplanetary space travel will involve long periods away from the protective cover of the Earth's magnetosphere to the regions where there exists the possibility of serious biological injury from galactic cosmic rays (GCR) and energetic solar particle events (SPE). For an SPE, the major concerns are acute effects arising from sudden exposure to very large radiation doses of solar protons. The severeness of these effects can be reduced when protective shieldings uch as storm shelters are adequately provided /1, 2/. On the other hand, the cumulative xposure to the low level, high-LET (linear energy transfer) components of GCR poses a challenge to th