The Global Race to Water at the Moon’s South Pole
Why landing in this lunar region—as India has done—is so challenging
India became the first country to land at the moon’s south pole—a logistically challenging achievement expected to kick off a new era of space exploration. It joins the U.S., China and Russia in successfully pulling off an uncrewed lunar landing.
The presence of water ice has made the moon’s south pole an area of intense interest for space scientists and engineers, but the difficulty of landing on this part of the moon has made it an elusive goal until now.
Water there potentially could be used for drinking, cooling equipment and producing oxygen at future lunar bases. The water also could be refined into rocket fuel to one day power missions to other parts of the solar system like Mars, according to the National Aeronautics and Space Administration.
The Indian Space Research Organization landed a research device as part of its Chandrayaan-3 mission near the lunar south pole on Aug. 23, equipped with monitors for studying seismic activity and carrying out other research. A rover with two different sensors was stored inside the lander.
The U.S. company Intuitive Machines, with its IM-1 mission, also plans to land a device near the region. IM-1 could start in mid-November with a rocket launch.
India's mission was designed to test its ability to softly land a device at the lunar south pole and deploy scientific instruments for research. An upcoming mission from a U.S. company has similar goals.
Russia’s Luna-25 mission would have been the first to touch down at the moon’s south pole, but Russian officials said the vehicle crashed on Aug. 20.
Uncrewed lunar landings are no easy feat. The moon’s almost nonexistent atmosphere makes it harder to slow a descending spacecraft as it approaches the lunar surface. Landers use onboard engines that allow them to lower their altitudes and softly touch down. That is what India pulled off at the south pole, going from a “rough braking” period during the descent to “fine braking” before the landing.
Such an operation—and any necessary maneuvers on the way down—requires fuel, which can run out. A private Japanese moon-landing mission failed earlier this year after the craft ran out of fuel.
Landing on the lunar south pole is tougher than on other parts of the moon. There, the sun always sits close to the horizon, its light shining on the surface at an oblique angle.
Towering terrain and deep craters create a shadowy environment that can make it harder to distinguish surface features when attempting a landing. The director of Roscosmos, Russia’s space agency, had put the likelihood of a successful Luna-25 landing at the south pole at 70%.
Some of the water on the moon has been found embedded in microscopic glass beads, according to a March paper published in the journal Nature Geoscience.
The beads—which range in size from a few tens of micrometers to a few millimeters—could hold up to 71 trillion gallons of water, the study’s authors estimate.