Do yourself a favor and listen to this as an audiobook. Adjoa Andoh is an amazing narrator. She captures the vibe and characters in such a distinct way that I can't imagine the story without her voice. 

Translation State is a standalone in the Imperial Radch series, but you'll understand a lot more if you read the Ancillary series and Provenance first. While I recommend starting at the beginning, I could see myself still liking this book without the prior knowledge. 

The only other books I've found that are similar to this are the Wayfarers series by Becky Chambers or Murderbot by Martha Wells. However, the Radch has a more epic and intellectual quality that I appreciate. Intellectual isn't the right word, but the Radch is more imaginative and clever with its huge scale and mysterious plots. It also manages to address heavy subjects in a subtle way and not the direct preachyness other stories try to force on their readers. I like social commentary in my books, but I find it more enjoyable when it's worked into the plot and character development rather than laid out bare in the dialog or conflicts. 

I hope Leckie continues to write more novels in this universe because it's definitely becoming a favorite.