[2]

OVERVIEW OF NASA'S RADIATION HEALTH PROGRAM.  W. Schimmerling.  NASA HQ, Code UB, Washington.

   The goal of radiation protection in space is to eventually enable a permanent human presence without incurring unacceptable health risks due to the unavoidable exposure to ionizing space radiation.  The components of this radiation that are of concern are high-energy, charged particles, especially the components of galactic cosmic rays consisting of high-energy (high-E) nuclei of heavier (high atomic number Z) elements ("HZE particles").  Predictions about the nature and magnitude of these risks are limited by current scientific knowledge and are subject to large uncertainties.  Prudent use of worst-case scenarios may impose unacceptable constraints on shielding mass for spacecraft or habitats, and on the radius and duration of sorties on planetary surfaces.   NASA is developing the knowledge required to accurately predict and to efficiently manage radiation risk in space.  The strategy employed has three components: (1) ground-based simulation of space radiation components to develop a science-based understanding of radiation risk; (2) space-based measurements of the radiation environment on planetary surfaces and interplanetary space, as well as use of space platforms to validate predictions; and, (3) implementation of countermeasures to mitigate risk.  NASA intends to significantly expand its support of radiation research in line with completion of the Booster Applications Facility (BAF) at Brookhaven National Laboratory, expected in summer of 2003. A joint research solicitation with the Department of Energy is under way and other interagency collaborations are being considered. In addition, a Space Radiation Initiative has been submitted by the Administration to Congress that would provide answers to most questions related to the International Space Station within the next 10 years. The current aspects and status of this program will be discussed.