GOLDEN, Colo. — A hot topic for lunar researchers is whether water ice is a readily available resource at the moon’s south pole, as experts have long assumed. The search for usable water ice is a high priority for NASA’s Artemis agenda as the agency strives to ensure a sustainable human presence on the Moon.
Lunar water ice is thought to reside in permanently shadowed regions, or PSRs, contained within supercold cooling traps where gases can freeze into their solid form. But experts at the Space Resources Roundtable, held June 4-7 at the Colorado School of Mines campus, pointed out the lack of data supporting the prospect of using water ice on the moon. While there appears to be strong evidence that water is present, there remain a myriad of questions that remain unanswered and challenge the assumption that explorers will be able to tap into it.
Technical challenges
“The most ice is expected in old large craters with a permanent shadow, but no missions are going there because of the technical problems of landing in the dark and operating in extreme cold,” said Norbert Schörghofer, chief scientist of the Hawaii-based Planetary Science Institute. SpaceNews.
But hopes that water ice might be abundant on the moon’s surface have been dashed by data from the Korea Aerospace Research Institute’s Korea Pathfinder Lunar Orbiter, also known as Danuri. It entered lunar orbit in December 2022 and is now scheduled to continue its lunar observation mission until December 2025.
Danuri carries ShadowCam, a NASA-funded instrument built at Arizona State University to collect high-resolution PSR images of the Moon from lunar orbit to determine the distribution and availability of water ice and other volatiles. According to Schörghofer, ShadowCam did not find the water the researchers were hoping to see.
“Although ShadowCam found no evidence of ice in the lunar cold traps, there is still strong evidence of ice in the subsurface,” Schörghofer said. That ice may be present outside cold traps at shallow depths, a finding that could be verified with a single borehole, he said.
Schörghofer added that several orbital missions have found evidence of buried water on the moon, pointing to an instrument aboard NASA’s Lunar Prospector spacecraft, which orbited the moon from January 1998 to August 1999, and a Russian instrument on NASA’s Lunar Reconnaissance Orbiter, now orbiting the moon. Both lunar orbiters carried a neutron spectrometer that detected hydrogen, believed to be in the form of water.
“Physical confirmation of water ice could represent a significant boost for human and robotic exploration,” said Ben Bussey, chief scientist at Intuitive Machines.
Searching for water
While pointing to evidence from several sensors that ice may be abundant on the moon, Bussey said the unknowns are the location, amount and form of lunar water — and whether it can be harvested.
“Physical confirmation of water ice could represent a significant boost for human and robotic exploration,” Bussey said.
“There is a possibility that even if there are abundant reservoirs of water, they may be too difficult to access,” Bussey said. SpaceNews, such as water ice lurking inside the PSR. It is possible that the water is so widespread that mining the source would mean processing a large amount of lunar regolith, he said.
Bussey said another key piece of the puzzle will come from the Intuitive Machines hopper to fly to the lunar south pole as part of NASA’s Commercial Lunar Payload Services (CLPS) initiative, specifically targeting Shackleton Ridge, later in 2024. sunlight powering the lander on a roughly 10-day mission.
The lunar lander also carries the NASA-funded Polar Resources Ice-Mining Experiment-1 to assess the water content of the regolith and search for other volatiles in the polar lunar landing zone.
This area provides a clear line of sight to Earth for continuous communication and could serve as a potential target for subsequent human exploration.
If the robotic lander’s landing is successful, it will deploy the Micro Nova Hopper, a NASA-funded propulsion drone. The drone is designed to skim the lunar surface, Bussey said, and will carry a neutron spectrometer provided by Puli Space Technologies of Hungary to the permanently shadowed floor of Marston Crater.
“This will provide the first direct surface measurement of hydrogen, a key indicator of the presence of water,” Bussey said.