Managing Lunar and Mars Mission Radiation Risks. Part 1; Cancer Risks, Uncertainties, and Shielding Effectiveness

By National Aeronautics and Space Administration

This document addresses calculations of probability distribution functions (PDFs) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPEs). PDFs are used to test the effectiveness of potential radiation shielding approaches. Monte-Carlo techniques are used to propagate uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments. Competing mortality risks and functional correlations in radiation quality factor uncertainties are treated in the calculations. The cancer risk uncertainty is about four-fold for lunar and Mars mission risk projections. For short-stay lunar missins (180 d) lunar or Mars missions, GCR risks may exceed radiation risk limits. While shielding materials are marginally effective in reducing GCR cancer risks because of the penetrating nature of GCR and secondary radiation produced in tissue by relativisitc particles, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding. Therefore, improving our knowledge of space radiobiology to narrow uncertainties that lead to wide PDFs is the best approach to ensure radiation protection goals are met for space exploration.Cucinotta, Francis A. and Kim, Myung-Hee Y. and Ren, LeiJohnson Space CenterBIOASTRONAUTICS; RADIOBIOLOGY; RADIATION DOSAGE; PROBABILITY DISTRIBUTION FUNCTIONS; CANCER; RADIATION HAZARDS; ASTRONAUTS; LUNAR EXPLORATION; MARS EXPLORATION; MANNED MARS MISSIONS; LONG DURATION SPACE FLIGHT; MANNED SPACE FLIGHT; RISK; RADIATION SHIELDING; MONTE CARLO METHOD

• Format: Paperback
• Language: English
• ISBN: 1723857912
• ISBN13: 9781723857911
• Release Date: January 1
• Publisher: Independently Published
• Length: 46 Pages
• Weight: 0.29 lbs.
• Dimensions: 0.1" x 8.5" x 11.0"