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, during a historic five-year mission that starship undertook. He served as one of Lieutenant Commander Montgomery Scott's engineers in 2268.
That year, 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")