I saw these two images on Tumblr yesterday, and both put me in mind of Princesses In SPACE!!! (not the actual title). The first seems like an actual possible location from the book, so I'll keep this in mind:
This one doesn't fit anything specific from the book(s) at all, but it does convey, to me at least, a bit of the sense of adventure that I'm trying to partly capture with these stories.
The first image is sourced on Tumblr to here, and the second, to here.