Extraterrestrial photosynthesis: China's plan to produce oxygen on the Moon

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How to photosynthesize on the Moon

Just as plants do on Earth, on our satellite it could be possible to to produce oxygen and fuel from solar radiation, CO2 emitted by astronauts and compounds in the lunar soil. This is the opinion of Chinese scientists after analyzing the samples brought back by the Chang'e 5 spacecraft.

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Chang'e 5

He oxygen that we breathe comes from plants and other photosynthetic organisms, such as cyanobacteria, and they produce it as they convert carbon dioxide (CO2) and the sunlight into energetic sugars. Now, Chinese researchers are proposing to perform a similar photosynthesis process on the Moon, according to a study published this week in the journal Joule.

After analyzing the lunar soil brought by Chinese spacecraft Chang'e 5the authors discovered that the sample contains some compounds - such as iron- and titanium-rich substances - that could function as catalysts to produce oxygen and fuel from solar radiation and COthat future astronauts will exhale.

How to perform photosynthesis on the Moon
Photovoltaic-driven water electrolysis catalyzed by lunar soil / Yingfang Yao

Extraterrestrial photosynthesis

The team, led by scientists Yingfang Yao and Zhigang Zou of Nanjing University, proposes a strategy of '.extraterrestrial photosynthesis' that could be used to facilitate human exploration on the Moon and beyond.

With the aid of solar radiation, the system uses the lunar soil to electrolyze the waterwhich could be extracted from the Moon itself and dehydrating the gases exhaled by the astronauts, generating two products: oxygen and hydrogen.

The carbon dioxide emitted by the future inhabitants of the Moon can also be stored and combined with this hydrogen through a hydrogenation process catalyzed by the lunar soil. This generates hydrocarbons such as methanewhich could be used as fuel.

The study uses lunar sample returned by China s Chang e 5 spacecraft. CREDIT Yingfang Yao
Sample of lunar soil brought back by the Chinese spacecraft Chang'e 5. / Yingfang Yao

This strategy does not use external powerThe team is already looking for an opportunity to test this system in space, probably with only sunlight, to produce a number of products of interest (such as water, oxygen and fuel) that could support life on a lunar base, according to the researchers. The team is already looking for an opportunity to test this system in space, most likely with the future manned lunar missions China.

Lunar soil can work as a catalyst for extraterrestrial photosynthesis to make oxygen and fuels needed for long term survival on the moon. CREDIT Y
Diagram showing how lunar soil can function as a catalyst for extraterrestrial photosynthesis to make the oxygen and fuels needed to survive on the Moon / Yingfang Yao

This strategy does not use external powerThe team is already looking for an opportunity to test this system in space, probably with only sunlight, to produce a number of products of interest (such as water, oxygen and fuel) that could support life on a lunar base, according to the researchers. The team is already looking for an opportunity to test this system in space, most likely with the future manned lunar missions China.

 

Use what is available and do not wear it

"We use environmental resources on site to minimize rocket payloads, offering a strategy for a sustainable and affordable extraterrestrial living environment scenario," Yao says.

We use in-situ resources to minimize rocket payloads, providing a strategy for a sustainable and affordable extraterrestrial living environment.
Yingfang Yao (Nanjing University).
 
Although the catalytic efficiency of the lunar soil is lower than that of catalysts available on Earth, Yao says the team is testing different approaches to improve its design, such as melt the lunar soil into a "high entropy nanostructured material", which is a better catalyst.

The authors recall that many options for extraterrestrial survival have been proposed, but most require Earth energy sources. For example, the rover Perseverance NASA has an instrument that can use CO2 of Mars' atmosphere to manufacture oxygen, but it is powered by a nuclear battery.

As Yao comments, "In the near future, we will see the manned spaceflight industry develop rapidly. Just like the 'Age of Sail' in the 17th century, when hundreds of ships took to the sea, we are now entering an 'Age of Spaceflight'," says Yao.Space Age'.

But, he continues, "if we want to carry out large-scale exploration of worlds beyond our own, we will have to think of ways of reduce payloadthat is, to rely on as few supplies as possible from Earth and to use extraterrestrial resources instead". 

The team at Nanjing University is holding the lunar soil sample. CREDIT Yingfang Yao
Nanjing University research team with the lunar soil sample./ Yingfang Yao

Reference:

Yingfang Yao et al. "Extraterrestrial Photosynthesis by Chang'E-5 Lunar Soil". Joule, 2022.

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