Helga Litwak was a female Human Starfleet ensign, who served as assistant chief of security aboard the USS Constellation in 2266. (TOS - The Brave and the Bold, Book One novella: The First Artifact) Litwak presumably perished with the rest of the Constellation crew in 2267 during the encounter with an ancient "planet killer" depicted in TOS episode: "The Doomsday Machine".