[Current status of the problem of radiation protection in space flight].

This review of radiation protection in space flight considers specific features of radiation effects (the composition of radiation, space-time changes of fluxes of charged particles, nonuniform radiation fields in spacecraft modules, formation of secondary radiations, etc) and the major sources of radiation hazards in space (Earth radiation belts, solar and galactic cosmic radiations). The paper presents estimates of the equivalent dose of protons and electrons of the Earth radiation belts at various orbits, as well as radiation characteristics of certain proton solar flares and galactic cosmic radiation. The paper also discusses the present-day criteria of radiation safety used in calculations of the shielding of manned spacecraft. The paper gives the standards of allowable radiation levels used in the USSR.