USS Invincible (NCC-1861) was a Miranda-class starship in active Starfleet service during at least the 2270s and 2280s. Captain Philip Styles was Invincible's commanding officer in 2275. He had a reputation for being very "by-the-book" -- giving demotions where other commanders such as Clark Terrell would have given commendations. (Orion Press: "The Blue Rose")