They hired the mod creator (as an artist) and, from the Factorio Friday Facts blog posts[1], the expansion has some inspiration from the space mod but is not the same.
If you like Factorio and are at all interested in game design I can highly recommend every one of those blog posts.
It’s amazing how time and time again a they describe a feature and you’re like wow this is perfect and then later they’re like “here’s how to fix all the problems you don’t even notice”.