Abstract：
Long duration space missions present unique radiation protection challenges due to the complexity of the space radiation environment, which includes high charge and energy particles and other highly ionizing radiation such as neutrons. Based on a recommendation by the National Council on Radiation Protection and Measurements, a 3% lifetime risk of exposure-induced death for cancer has been used as a basis for risk limitation by the National Aeronautics and Space Administration (NASA) for low-Earth orbit missions. NASA has developed a risk-based approach to radiation exposure limits that accounts for individual factors (age, gender, and smoking history) and assesses the uncertainties in risk estimates. New radiation quality factors with associated probability distribution functions to represent the quality factor\'s uncertainty have been developed based on track structure models and recent radiobiology data for high charge and energy particles. The current radiation dose limits are reviewed for spaceflight and the various qualitative and quantitative uncertainties that impact the risk of exposure-induced death estimates using the NASA Space Cancer Risk (NSCR) model. NSCR estimates of the number of \"safe days\" in deep space to be within exposure limits and risk estimates for a Mars exploration mission are described.
摘要：
由于空间辐射环境的复杂性，长时间的太空任务提出了独特的辐射防护挑战，其中包括高电荷和能量粒子以及其他高电离辐射，如中子。根据国家辐射防护和测量委员会的建议，3％的终生暴露导致癌症死亡的风险已被国家航空航天局（NASA）用作低地球轨道任务风险限制的基础。NASA开发了一种基于风险的辐射暴露限制方法，该方法考虑了个人因素（年龄，性别,和吸烟史)，并评估风险估计的不确定性。根据轨道结构模型和最近的高电荷和能量粒子的放射生物学数据，开发了具有相关概率分布函数的新辐射质量因子，以表示质量因子的不确定性。使用NASA太空癌症风险（NSCR）模型，对当前的辐射剂量限值进行了审查，并对影响暴露引起的死亡风险的各种定性和定量不确定性进行了评估。描述了NSCR对深空“安全日”在暴露范围内的数量的估计以及火星探测任务的风险估计。
