The USS Excelsior (NX-2000, later NCC-2000) was a Federation Excelsior-class explorer starship in service to Starfleet for many years from her commission in 2284. When newly commissioned, the Excelsior was the prototype for her class. She served as the test-bed for a failed transwarp drive in the 2280s decade, and protected the Khitomer conference which drafted the Khitomer Accords in 2293. Her most famous commander was Hikaru Sulu who commanded the Excelsior from 2290 to at least 2320. Other commanders included Rear Admiral James T. Kirk and Captain Lawrence Styles.