Astronomer's Visual Pack
Must have the following dependencies before installing:
Optionally, there's also support for/recommended to play with:
To install KSPRC side by side with AVP, first download and install Kopernicus, download the latest KSPRC release, drag and drop the KSPRC folder in the archive into your GameData, and remove all files and folders inside except Terrain and PluginData, i.e. you only have a KSPRC folder with Terrain and PluginData left in your GameData.