The lunar night lasts approximately 14 days, during which temperatures as low as -150 ºC have been recorded. This complicates a rover’s movement and equipment functioning on the lunar surface, requiring heavy batteries from earth or the use of nuclear energy.
A team of researchers from the Polytechnic University of Catalonia, along with collaborators from the US, have studied two options for storing energy on the Moon during the day for use at night.
The first system consists of modifying fragments of regolith, or lunar soil, incorporating elements such as aluminium, for example, such that it becomes a thermal mass.
“When the sun’s rays hit the surface, a system of mirrors reflects the light to heat the thermal mass, which later can transmit heat during the night to rovers,” said Ricard Gonzalez-Cinca, co-author of the study.
The second system has a more sophisticated series of mirrors and a heat engine. The heat generated converts the liquid into a gas, which in turn heats the thermal mass.
Afterwards, during the long lunar night, the heat is transferred to a Stirling engine to produce electricity.
“This system is better equipped than the previous model for lunar projects with greater energy needs, such as a manned mission spending the night on the moon,” added Gonzalez-Cinca.
The findings of the study were published in the journal Acta Astronautica.