I had written about their concept to lay a SpaceX Starship flat on the moon to start a moonbase. I did not know the source of the graphic until now.

There is a well-established and researched idea of utilizing the large volume and properties of empty fuel tanks to create robust space habitats. This was applied on Skylab, and has been proposed for various rocket stages such as the external tanks on the Space Shuttle. While this is applicable to any sufficiently large rocket body, after surveying the current state-of-the-art launchers and what bodies can be delivered to the lunar surface, the most mature concept was using the SpaceX Starship Human Landing System (HLS) as a structural basis for the lunar settlement, (see above). The reported capabilities, low cost, massive volume, and high mass capacity means that a larger and more capable habitat can be delivered and constructed on the lunar surface, more so than any other concept achievable within the next decade. The concept is to decommission a Starship HLS and transform it into a permanent base while using its entire internal volume, including the fuel tanks, as a habitat.

The additional volume provided by the conversion of the fuel tanks means there is great potential for renting out this space to other entities to generate revenue and promote sustainability and growth. This plan relies mostly on existing technologies and limited modifications to the vehicle, including using a series of rovers, MOdular RObotic Construction Autonomous System (MOROCAS), for the purpose of setting up equipment to horizontalize the lander on its side. Additionally, they will aid in setting up surface infrastructure and stacking regolith on top of the base for crew protection. This makes the Rosas Base solutions incredibly viable for the construction of a lunar base in the near future.