Analysis of Probable Radiation Exposure to Cosmonauts in a Short-Term Lunar Mission

Probable radiation exposure to cosmonauts during a short-term lunar mission, including transit and surface operations, were estimated using experimental data and model calculations. The radiation dose received during a 21-day mission with a 14-day stay on the lunar surface under solar minimum conditions is approximately 130 mSv. During solar maximum, and in the event of a solar particle event, radiation doses may reach 9–12 Sv, compared to a maximum permissible dose of 250 mSv per month. Increasing the mass thickness of radiation shielding in the command module from 10 to 20 g/cm2 (aluminum equivalent), as well as that of the EVA spacesuit from 0.2 to 0.5–1.0 g/cm2 (aluminum equivalent), can reduce the total radiation dose to cosmonauts by a factor of 1.4 under solar minimum conditions. Minimizing crew radiation exposure requires consideration of solar activity forecasts to identify launch windows when the flux of high-energy electrons in Earth’s outer radiation belt is minimal, as well as favorable space weather conditions along the Earth–Moon trajectory.