Radiation is the main source of biological stress in the low Earth orbit (LEO), which is the region encompassed by the Earth’s magnetosphere where all manned missions currently occur. In the upcoming missions to the moon and Mars, deep space radiation is a serious health risk. Low doses of radiation can cause dysfunction in the central nervous system, while larger doses of radiation cause pathological changes in neuronal cells. Moreover, radiation can not only directly cause damage to target organs, but also trigger side effects to affect non-target organs.