Ensign Jana Haines was a female Human Starfleet officer who lived during the mid-23rd century. She served in the command division aboard the USS Enterprise under Captain James T. Kirk, during a historic five-year mission that starship undertook. She served as one of the ship's relief navigators and science officer in 2268.
That year, she assumed both positions during Pavel Chekov's absence when a landing party to Gamma II went missing, captured by the Providers of Triskelion along with Captain Kirk and Lieutenant Uhura.
While the Enterprise crew was looking for any phenomenon that could help explain how and why the landing party went missing, Haines (working at the science station on the bridge) noticed and reported a barely detectable but consistent fluctuating energy reading in a distant hydrogen cloud. The Enterprise computers were able to identify the reading as an ionization trail, and Spock, acting as ship's captain in the absence of James T. Kirk, theorized that the trail might lead to the missing landing party. The Enterprise was able to follow the trail to Triskelion, with Haines acting as navigator. (TOS: "The Gamesters of Triskelion")