Problems of radiation norms development for manned Mars mission

A carrier limit and limit for an annual flight for near-Earth orbits are restricted by an effective dose of 1.0 and 0.5 Sv, respectively. But for this category of flights it is possible to restrict the cosmonauts' irradiation after such a massive annual exposure during a long period of time (some years). Such tactics of dose rate restriction corresponds to the established by the ground Radiation Safety Norms NRB-99 regulation of planned exposure to man during radiation accidents elimination. According to Radiation Safety Norms NRB-99 an annual exposure of 200 mSv is considered to be hazardous and can result in deterioration of crewmembers' health and performance impairment. The same requirements can perhaps be addressed to a case of crewmembers' exposure to a dose exceeding 200 mSv per flight with duration of one year. Consequently, it is necessary to develop tactics of dose rate restriction during the flight for minimizing the above-mentioned negative consequences of exposure. The report contains peculiarities of developing a dose limit system for a Mars mission and outlines the ways of the problem's solution.