The Constraint of Crewed Mars Missions Based on Current Radiation Dose Measurements

Abstract Crewed missions to Mars will be a milestone of future space exploration programs. However, the absence of Earth's magnetic field leaves astronauts directly exposed to unattenuated energetic particles in deep space, primarily galactic cosmic rays (GCRs), resulting in significantly higher radiation levels and enhanced health risks. Understanding and quantifying these radiation hazards is thus essential for evaluating the feasibility and safety of long‐duration Mars missions. Based on the dose data from the Trace Gas Orbiter mission and the Cosmic Ray Telescope for the Effects of Radiation (CRaTER), we perform correlation analyses between the measured dose rate and solar modulation conditions, parameterized as solar modulation potential, and develop empirical models that can be extrapolated to a broader range of solar activities. Using these models, the GCR‐cumulative dose for mission scenarios following three different transfer trajectories under varying solar modulation conditions during the past ∼60 years are calculated. Our results indicate that missions operated during solar maximum accumulate 30%–55% less GCR effective dose than those during solar minimum, with the specific percentage depending on their execution period and trajectory. Under similar shielding conditions of measurements used here, missions following the minimum energy trajectory and conducted during relatively active solar cycles can generally maintain the cumulative radiation effective dose below 1,000 mSv, but keeping it below the NASA's new limit of 600 mSv requires restricting the mission duration to the solar maximum. Nevertheless, faster transfer orbits can help satisfy this limit during solar minimum years.