The mono graph contains 8 chapters, and their contents cover all principal aspects of the problem: 1. Introduction and brief his tory of the radiation problem and background information ofradiation hazard in the near-Earth and interplanetary space. 2. General description of radiation conditions and main sources of charged partic1es in the Earth's environment and interplanetary space, effects of space environment on spacecraft. 3. Basic information about physical conditions in space and main sources of charged particles in the Earth's environment and interplanetary space, in the context of "Space W eather" monitoring and prediction. 4. Trapped radiation belts of the Earth (ERB): theory of their origin, spatial and temporal dynamics, and experimental and statistical models. 5. Galactic cosmic rays (GCR): variations of energetic, temporal and spatial characteristics, long-term modulation, and anomalous cosmic ray (ACR) component, modeling of their dynamics. 6. Production of energetic particles (SEPs) at/ne ar the Sun: available databases, acceleration, propagation, and prediction of individual SEP event, statistical models of solar cosmic rays (SCR). 7. Existing empirical techniques of estimating, prediction and modeling of radiation hazard, methodical approaches and constraints, some questions of changes in the Earth's radiation environment due to changes of the solar activity level. 8. Unresolved problems of radiation hazard prediction and spacecraft protection, radiation experiments on board the spacecraft, estimating of radiation conditions during interplanetary missions. Space does not allow us to explain every time the solar-terrestrial and radiation physics nomencIature used in current English-language literature.