Etienne Vascogne was a male Starfleet lieutenant, who served as chief of security aboard the USS Constellation in 2266. (TOS - The Brave and the Bold novella: The First Artifact)

Vascogne 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".

Constellation personnel
United Earth, Earth Starfleet	Constellation	Monique Duvall
Federation, Starfleet	USS Constellation (NCC-1017)	Alamanzar • R. Armstrong • M. Decker • Guthrie • G. Howard • Jazayerli • Lawford • H. Litwak • G. Masada • L. Rosenhaus • N. Shickele • Sontor • C. Soo • H. Takeshewada • E. Vascogne
	USS Constellation II	R. Cross • C. Ikeya • A. MacDougall • Raela hr'Sassish • I. Sasoaka • M. Walsh
mirror universe	ISS Constellation Terran Empire, Starfleet	Matthew Decker • Hiromi Takeshewada