Krowed Kerbol is a modpack designded to add many more planet much closer and farther then stock as well as tech noliges to explore these places.
KSP Revolution, is a modpack that will change kerbal forever. Adds interactive buttons, switches, and screens in cockpits and pods. Adds surface detail to planets, and improves certain asspects of flight. Even adds new luanch pads and buildings. (Only adds 1 part mod, a warp drive)
Kerbol moons pack
Aims to add in at least one moon to each planet but is currently un finnished.