HUMANS IN SPACE: THE RADIATION ISSUE

Abstract:


At present there are two known issues that have to be solved if humans are to spend long periods in space, or to be more precise, away from the friendly confines of the near-surface of our planet. Those issues are radiation and de-calcification in low-gravity. This talk will present a brief introduction to the problems associated with exposure to the space radiation environment. Exposure to radiation, as will be demonstrated during the talk, is ubiquitous even in our everyday environment. The risks from radiation exposure are also fairly well known, even if the detailed causes are not well understood. There are two regimes of exposure that we normally consider, acute and chronic. Acute (high-rate, short-duration) exposures cause predictable deterministic detrimental effects and must be prevented at all costs in space flight situations. Chronic (low-rate, long duration) exposures case stochastic effects like cancer. Acceptable limits for chronic exposures are arbitrary and based on current statutory requirements. The space radiation environment will be discussed along with the estimates for exposures from some of the baseline long-duration missions being considered at the present time. Measurement of this environment and dosimetry will play an important role in the future of manned (and unmanned) spaceflight, and the new Medipix-based technology is currently one of the most promising hardware candidates for such devices (and it will be employed on the upcoming LUCID project). A brief introduction to this new CERN-inspired pixel-based hardware technology will be presented along with a demonstration of the capabilities of a prototype version.