Ensign Harper was a male Human Starfleet officer who lived during the mid-23rd century. He served in the operations division aboard the USS Enterprise under Captain James T. Kirk, working as an engineer directly under Lieutenant Commander Montgomery Scott during the 2260s.
In 2268, Harper was unfortunately killed when he was ordered by Kirk and Scott to cut off the power supply of the malfunctioning M-5 multitronic unit. A power beam intensified, at M-5's command, and vaporized Harper, to the Captain's shock and outrage. (TOS: "The Ultimate Computer")