I’m the writer of a book and manga called Equilibrium, where I use a plot with a post-apocalyptic Earth, moon and an artificial satellite called Empire. Despite of my Manga, something I used there is about Spaceships called by "Ark". If you wanna know more about it, just search for my profile on Deviantart (Telles0808).
So, what about having a DLC expanding the universe of Fallout 4 to the moon and using something similar to it?
Okay, so here we go:
While the Nuclear War started, a new Government started the development of a base on the Moon. On the Earth, the teleporter machine starts to malfunction after a radiative storm and as result of it teleported the lone wanderer to the moon.
On the moon, you discover strange things, like Spaceships called by "Ark" where Government stored all type of seeds, human technology, DNAs and the Spaceships have the power of creating life, mutating it as needed, terraforming the environment and its drones are a good and heavy defense for it.
The Arks are powerful machines, capable of recover the Earth to its original status, but it’s nailed at the Moon crust.
It digs its tunnel in the crust turning the rock into lava and expelling it behind the spaceship, closing the hole.
Inside the moon crust have tunnels, mainly because of the water stored there while in its formation and evaporated along the millennium. Government used the caves to start a new civilization, waiting the Earth become more habitable.
Well, as English is not my main language, I don’t feel confidence to talk polite enough and make it a wall of text, but if you get the point, please, support the idea =]
Also, Equilibrium will be released in 2020, after I finish at least 5 season and finish the write of my first book.