Radiation protection during space flight

The problem of ensuring space flight safety arises from conditions inherent to space flights and outer space and from the existing weight limitations of spacecraft. In estimating radiation hazard during space flights, three natural sources are considered: the Earth's radiation belt, solar radiation, and galactic radiation. This survey first describes the major sources of radiation hazard in outer space with emphasis on those source parameters directly related to shielding manned spacecraft. Then, the current status of the safety criteria used in the shielding calculations is discussed. The rest of the survey is devoted to the rationale for spacecraft radiation shielding calculations. The recently completed long-term space flights indicate the reliability of the radiation safety measures used for the near-Earth space exploration. While planning long-term interplanetary flights, it is necessary to solve a number of complicated technological problems related to the radiation protection of the crew.