Researchers want to build roads on the moon

“Fly me to the moon,” sang Frank Sinatra in 1964 – and like the numerous moon missions (in addition to the US, India, Japan, Russia and China are also attempting this), the fascination with exploring the Earth’s satellite has by no means disappeared . means reduced.

In the future, there should be a lot of traffic on the moon with various rovers. Such missions could benefit greatly from paved paths, as the international research team, made up of Austrian scientists, explained in “Scientific Reports.”

First attempts on Earth
The experiments with the proof-of-concept study (which was intended to test the feasibility of the idea), on which the Viennese space architecture platform Liquifer around Barbara Imhof, René Waclavicek and Waltraut Hoheneder worked, took place – using a system developed by the European Space Agency ESA has developed a fine-grained lunar dust simulation material, called “EAC-1A”, on Earth.

The technology used could in principle also be implemented on the moon, it was said. “But there is still a lot of development work to be done before the approach to the moon can be made,” Imhof and Waclavicek told the APA. The lower gravity on the moon must also be taken into account better.

Dust on the moon poses a major risk
The lunar regolith is a fine loose material. The rapidly swirling dust due to the relatively low gravity poses a major risk to the lunar vehicles and the functionality of the sensitive instruments; Paved roads and rocket landing pads would make missions safer. However, the implementation of such infrastructure projects would only be cost-effective if solar energy were used as an energy source and the materials were used on site.

Laser melts motionless stones
In the current study, a CO2 laser replaced sunlight to melt the material. The mobility of the laser allowed the sintering to take shape. The interlocking, triangular-looking paving stones could be produced in one layer of 250 by 250 millimeters each – with a height of 15 millimeters.

“We tried to find a shape that has good entanglement properties, so that the stones do not shift under heavy loads from the vehicles or the rocket landing,” explains Liquifer director Waclavicek.

Laser beam, “like a thick felt-tip pen”
In addition, a “thick laser beam” was used with a circular laser point with a diameter of up to 10 centimeters, “which allows you to draw in almost the same way as with a thick felt-tip pen – that is why we only have rounded corners.” A challenge with lasering has been the thermal stresses “that arise between the very hot and cold areas during printing or cooling,” which could lead to brittleness and cracking of the material.

“In the end you have a very robust material,” says the expert. To print the components, the laser was aimed at a mobile structure using mirrors.

By layering multiple layers on top of each other – as with 3D printing – you can also ‘go higher’, says Imhof, the architect and co-founder of Liquifer. Multi-layer stones could be printed in this way, for example as building blocks for habitable habitats on the moon.

Material in abundance
“The laser printer that is to be transported to the moon must then be built in such a way that it can withstand the extreme environmental conditions there, i.e. both the vacuum and the extreme temperature fluctuations from minus 250 to plus 150 degrees Celsius – depending on the sunny or shady spot.” Paving stones too. The stones would then have to be laid with a large group of robots, the architect explains.

“Consideration is being given to building a permanent base at the moon’s south pole, where there is also constant sunlight,” the experts said. “You could then print the building blocks with two things that are abundant on the moon: sunlight, which is much more intense due to the lack of an atmosphere, and lunar sand.”