Cryogenic Lunar Sample Return

The discovery of lunar water-ice volatiles in shadowed regions of the Moon potentially offers abundant scientific information about lunar history and resources for future lunar missions. These volatiles must be preserved at cryogenic temperatures to retain their scientific integrity. Current lunar sample return plans include a stop at the Lunar Gateway space station and transport the samples within crew vehicles. This method prolongs the samples’ transit time and imposes crew-safe handling restrictions which complicates the cryogenic storage requirement. A direct, uncrewed lunar sample return would bypass both constraints and ultimately allow for a potentially simpler mission architecture. This study conceptually analyzes a mission to directly return surface volatiles from the Lunar South Pole focusing on the launch and return trajectory, Earth reentry, and payload design. It utilizes a derivative of the Mars Ascent Vehicle for launch from the Moon and a mechanically deployable heat shield for reentry. A passive cryogenics system utilizing liquid nitrogen or neon is used for cooling. It was found that such a mission could return to Earth up to 6 kg of samples frozen at 77 K.