The USS Diana (NCC-589) was a Hermes-class scout in service in the mid to late 23rd century. (Star Fleet Technical Manual) In 2259 the Diana was destroyed during a routine servey mission. The USS Mars performed a rescue operation of the Diana, saving 40 of her crew. Then Lieutenant JG Julienne Cochrane, the Mars' transporter chief, participated in the rescue. (Tamerlane)