Lissa Hart was a 23rd century Human woman. She was an engineering technician who served in Starfleet aboard the Federation starship USS Enterprise and reported to Commander Montgomery Scott in the late 2260s.
When the Enterprise crashed into an inter-dimensional contact point with another universe, creating a jagged hull breach in engineering, she monitored an unusual power drain and tracked life support readings. She joined Kirk, Dubois, Scott, Spock, and Leonard McCoy in the briefing room to discuss options. When Dubois volunteered to enter the other universe long enough to retrieve a power coupling essential to saving the ship, she was concerned, but got him a safety harness, rig and safety line from ship's stores. Unfortunately, his mind could not cope with what he perceived in the other universe, and it destroyed his mind. Hart was grief stricken by the loss. (TOS - The New Voyages short story: "Intersection Point")