Dr. Mark Piper was a male Human Starfleet officer who lived during the mid-23rd century. He served in the sciences division aboard the USS Enterprise under Captain James T. Kirk, during his historic five-year mission. In 2265, Piper served as both the ship's chief medical officer and life sciences department head. Along with the rest of the landing party, Piper was knocked unconscious by Mitchell as he escaped with Dehner. After regaining consciousness, he revived Captain Kirk, who ordered the doctor not to revive Spock until after he had departed after Mitchell.