Researchers from China have developed a new technology which they say could produce water, oxygen and fuel from lunar soil. The equipment may allow for cheaper, more sustainable space exploration.

A single litre of water costs about $33,000 (roughly US$22,000) to ship by rocket to the Moon.

Finding ways of utilising lunar resources will be critical if humans are to return there and set up temporary or long-term habitats.

The new photothermal technology is described in a paper published in the journal Joule.

Lunar soil has stores of carbon dioxide and water, as well as other minerals which could be used by space mission crews. The problem is extracting these molecules in an energy efficient way on the Moon’s surface.

“We never fully imagined the ‘magic’ that the lunar soil possessed,” says co-author Lu Wang of the Chinese University of Hong Kong, Shenzhen.

Wang’s team previously used lunar soil samples returned to Earth by Chinese spacecraft Chang’e 5 to show that Moon dust has many useful compounds.

Their new research shows that it is possible to extract water from lunar soil, then use that water and CO2 exhaled by astronauts to produce hydrogen gas and carbon monoxide – products which can then be used to make fuel and breathable oxygen.

All that is required to power the process is a photothermal technology which converts sunlight to heat.

“The biggest surprise for us was the tangible success of this integrated approach. The one-step integration of lunar H2O extraction and photothermal CO2 catalysis could enhance energy utilisation efficiency and decrease the cost and complexity of infrastructure development.”

Illustration of lunar water extraction. Credit: Joule, Sun et al.

The lab experiments are a step forward, but the researchers are quick to bring us back down to Earth.

“The extreme environment of the Moon still poses unique challenges to the implementation of photothermal catalysis technology, including drastic temperature fluctuations, ultrahigh vacuum, intense solar radiation, and low gravity,” the authors write.

Lunar soil also does not have a uniform composition. Some areas may have more resources than others. The authors note that CO2 from astronauts’ exhalations may not be enough for all water, fuel and oxygen needs.

“Overcoming these technical hurdles and significant associated costs in development, deployment, and operation will be crucial to realising sustainable lunar water utilisation and space exploration,” they add.