Giving astronauts a sense of purpose
When landing astronauts on planets and moons, let's have them actually build something.
Astronauts have an inventory in their rocket with building blocks, and can build bases, or anything else, similar to how building is done in minecraft.
How I vision bringing materials:
Building material could be brought on the rocket in the form of a new rocket part: Simply a compartment full of building materials that the astronauts can interact with.
Im sorry but this isnt happening, you'd have to redesign the terrain system entirely, not even mentioning the difficulties of implementing voxels on planet scale, even if you could manage it the performance would be necessairily way worse and probably wouldnt even really run on mobile.