Engineers pave the way for building lunar roads with Moon dust

Researchers in Germany's proof-of-concept study shows solar energy could be harnessed to turn lunar dust into paving for landing pads and roads.

The engineers conducted experiments using a substitute for regolith and powerful carbon dioxide lasers to melt the compound into a more solid form capable of supporting structures.

In a paper published in Nature Scientific Reports today, the authors gave a detailed breakdown of the concept. "The next steps for the expansion of the human presence in the solar system will be taken on the Moon. However, due to the low lunar gravity, the suspended dust generated when lunar rovers move across the lunar soil is a significant risk for lunar missions as it can affect the systems of the exploration vehicles. One solution to mitigate this problem is the construction of roads and landing pads on the Moon."

The researchers then point out that to sustain Moon habitability, we can assume it might be difficult to bring road-building materials from Earth. Therefore, engineers must use what they find around them, so-called in situ resource utilization (ISRU) techniques.

The team led by Juan-Carlos Ginés-Palomares, Miranda Fateri – both researchers at Germany's Aalen University – and Jens Günster of the Federal Institute of Materials Research and Testing in Berlin proposed that solar light could be focused into high energy beams on the surface of the Moon.

To simulate the process, the engineers used a carbon dioxide laser to show how an earthbound substitute for lunar dust could be melted into a solid substance. After experimenting with laser strengths of up to 12 kilowatts and a diameter of 100 mm (3.93 inches) across, they found that criss-crossing or overlapping the laser beam path led to cracking. They hit upon an approach using a 45 mm (1.77 inch) diameter laser beam to produce triangular shapes of about 250 mm (9.84 inches) in size.

"At the end of the study, large samples (approximately 250 × 250 mm) with interlocking capabilities were fabricated by melting the lunar simulant with the laser directly on the powder bed," the paper said.

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Taking the process to the Moon might employ a Fresnel lens – a composite, flat or compact lens – of about 2.37 m² to produce the required effect.

The researchers concluded: "Large areas of lunar soil can be covered with these samples and serve as roads and landing pads, decreasing the propagation of lunar dust. These manufactured samples were analyzed regarding their mineralogical composition, internal structure and mechanical properties."

However, the study conceded that more work would be required to refine the process before putting it into practice.

US space agency NASA has plans to return to the Moon and build a permanent base there. It plans to employ robots, "conduct more science than ever before," and explore the prospects for mining. Plans were included in the 2020 budget that suggest Artemis would shoot for a Moon base by 2028, although more reports say it might be 2030.

The soil on the Moon or Mars is called regolith. Researchers have a number of suggestions about how it might be used as a structural material. Earlier this year, a team at Manchester University showed how potato starch can be used to create a concrete-like material they have chosen to call "StarCrete." ®