The test setup for the ESA/Azimut regolith. (Image Courtesy of ESA.)
Launching a rocket into space is an expensive affair. For every ounce of material shuttled away from Earth’s gravity, a tremendous amount of fuel must be spent. Therefore, it’s important for space mission planners to bring the bare minimum materials required for mission success.
In the case of building a lunar base, arguably the most resource-intensive mission ever attempted by humans, finding novel solutions for erecting such a base will be critical for mission success. And that’s just what the ESA has been after.
While the moon may be devoid of many of the Earth’s environmental luxuries (think water and an atmosphere), it does have an abundance of fine particulate rock strewn about its surface. Called regolith, this granular substance offers a readily available source of building material for future lunar explorers. But beyond its ability to form a barrier between explorers and the vacuum of space, regolith can also be used as a sink for storing solar energy.
In their study, ESA and Azimut engineers recreated lunar regolith by crushing terrestrial rock into a fine powder and compacted it into a brick. Once in brick form, the rock was then attached to a heat engine and exposed to a heat source.
“Any Moon-based technology would face incredibly tough conditions—long nights, temperatures ranging from -173°C to 127°C, and extremely low pressures,” explained Project Manager Luca Celotti from Azimut Space. “We mimicked these conditions as best as we could to create a ‘Moon-like’ environment for our brick.”
Upon testing the heat storage potential of their terrestrial regolith brick and examining the electrical potential generated by the attached heat engine, the engineers were encouraged by the results. That being said, the researchers acknowledged that process improvements would need to be implemented for regolith bricks to be a cornerstone of any sustainable lunar architecture plan.
“This is just the first step towards creating an innovative and sustainable method of heat storage and electricity generation that could make it possible for us to land on the Moon,” Celotti concluded.