A small step for man, a big step for mankind: scientists have found a way to turn the Moon’s dusty surface into a reliable water source. Researchers in China developed a novel method for extracting significant amounts of water from lunar soil, potentially paving the way for a sustainable human presence on the Moon. This innovative process utilizes lunar regolith, the dusty surface material, and could yield over 50 kg of water from just one ton of lunar soil.

Unlocking Lunar Water Potential

Water is essential for sustaining life, making it a critical focus for future lunar missions. While previous missions like Apollo and Chang’e-5 confirmed the existence of water on the Moon’s surface, it’s not the water we’re familiar with — it’s usually in the form of hydroxyl (OH) compounds or ice mixed with regolith in permanently shadowed regions. Only 0.0001% to 0.02% of water by weight can be extracted from these compounds.

Now, a team led by Professor Junqiang Wang at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences has developed a novel approach. By reacting lunar regolith—a mixture of fine dust and broken rock on the Moon’s surface—with hydrogen, they discovered a method to produce water in larger quantities than previously possible.

The process involves heating lunar regolith to extremely high temperatures exceeding 1200 Kelvin (around 930°C or 1700°F) using concentrated sunlight. This triggers a chemical reaction between the regolith and the trapped hydrogen, releasing water vapor that can then be collected. The lunar soil was brought back to Earth in 2020 by the Chang’e-5 mission.

Around 51 to 71 milligrams of water can be extracted per gram of molten regolith. This process could yield over 50 kilograms of water per ton of lunar soil, sufficient to meet the daily drinking water needs of 50 people. The researchers found that lunar ilmenite (FeTiO3), a specific mineral in the regolith, contains the highest concentration of hydrogen due to its unique structure.

Implications for Lunar Settlements

Finding and making water is not just about quenching thirst. The water produced can also be used for growing plants, which are crucial for long-term space missions aiming for self-sustainability. Furthermore, water can be electrochemically split into hydrogen and oxygen. The oxygen could provide breathable air for astronauts, while the hydrogen could serve as an energy source or be used to produce rocket fuel.

The discovery comes at a crucial time, as both China and Roscosmos (Russia’s space agency) are planning to establish the International Lunar Research Station (ILRSP) in the Moon’s southern polar region by 2040. This new method of in-situ water production could significantly reduce the logistical challenges of transporting water from Earth, which is extremely costly and time-consuming. Unlike the International Space Station, which can be resupplied relatively quickly, lunar resupply missions would take several days, making on-site resource utilization essential.

While promising, there are still challenges to address. This method can only work during lunar days in the southern polar region due to sunlight availability. The lunar day lasts about two weeks. During the lunar night, another two weeks, there would be no sunlight to power the reaction. Researchers suggest that deploying a network of solar mirrors or satellites to direct sunlight to the processing facilities could mitigate this issue, but that all sounds extremely complicated.

Additionally, the process’s efficiency could vary depending on the lunar soil’s composition at different locations. Future missions, including China’s planned Chang’e-6 mission, will continue to collect samples from various parts of the Moon to test this method’s viability across different regions.

There are only a few sites suitable for a lunar settlement and these constraints would further thin our options. Additionally, further research is needed to optimize energy requirements and understand the long-term viability of this method.

Nevertheless, this is an exciting achievement. As space agencies worldwide look to establish permanent bases and research stations, the ability to produce water on-site will be a game-changer, reducing costs and making long-term lunar exploration more feasible.

The findings appeared in the journal The Innovation.