Infrastructure is going to be one of the biggest components of any permanent human settlement on the moon. NASA Artemis missions are focused directly on building up the facilities and processes necessary to support a moon base. ESA is also contributing both material and knowledge. Most recently, they made another step in their path to explore lava tubes and caves in the subterranean lunar world.
source https://phys.org/news/2021-03-esa-mission-explore-caves-moon.html
