Piper was present on the bridge when the Enterprise crew embarked on an exploratory expedition outside of the Milky Way Galaxy. After the ship's encounter with an exotic energy field at the galaxy's edge, Piper tended to Lieutenant Gary Mitchell and Doctor Elizabeth Dehner, who were mysteriously affected by the barrier. Later, Piper accompanied Captain Kirk and a landing party to the surface of Delta Vega, where the crew was attempting to adapt the power packs of an automated lithium cracking station to regenerate the ship's warp engines. While there, Piper observed Lieutenant Mitchell, who had begun to manifest extremely powerful psychokinetic abilities as a result of his exposure to the energy barrier. 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 departed after Mitchell, but not before imparting orders to Piper that the entire planet be subjected to a lethal dose of neutron radiation, should Kirk not report back within twelve hours. (TOS: "Where No Man Has Gone Before")
|Chief medical officers of the starships Enterprise|
|USS Enterprise:||April • Boyce • Piper • McCoy • Chapel|
|USS Enterprise-D:||Crusher • Pulaski • Ogawa|
|ISS Enterprise NX-01:||Phlox|
|ISS Enterprise (NCC-1701):||McCoy|
|USS Enterprise (alternate reality):||Puri • McCoy|
After the departure of John Hoyt (Philip Boyce in "The Cage"), Mark Piper was temporarily intended to fill the vacancy of Star Trek's regular doctor character. Due to a casting recommendation from director James Goldstone to Gene Roddenberry, Piper was played by Paul Fix. (Inside Star Trek: The Real Story, p. 75) The fact that Roddenberry, Goldstone and casting director Joseph D'Agosta discussed the regular doctor as being an old country doctor was a deciding factor in the casting of Paul Fix. (The Star Trek Interview Book, p. 118)
Ultimately, Gene Roddenberry was unsatisfied with the way Paul Fix portrayed the character, however, and believed that something was missing from the role. (Inside Star Trek: The Real Story, p. 84) D.C. Fontana explained, "Gene wanted a somewhat younger, more active doctor. He didn't want an aging Solon, he wanted definitely a younger, more vigorous doctor." (Starfleet Access for "Where No Man Has Gone Before", TOS Season 1 Blu-ray special features)
Writer Samuel A. Peeples was also unhappy about how Paul Fix played the doctor, later remarking, "In my opinion he was a little too old for the part [...] I just felt he wasn't right for the part." This was despite the fact that Peeples found Fix to have done "a good job" of playing the old country doctor that Piper was meant to be. In other words, Peeples felt the problem was more in how the character had been conceived. He went on to say, "The physical element, I thought, required every crewman of the USS Enterprise to be active. He had to be not only mentally alert, but the traditional images of a country doctor would hardly have fit the images of a man who would say, 'We've got an unknown disease, and there's a cure on this planet. Our only choice is to try it. It might kill you,' and I don't think Paul Fix's interpretation of the character would have been able to do that." In conclusion, Peeples agreed with interviewer Allan Asherman's assessment that Fix, in the role, was "distinctly twentieth century." (The Star Trek Interview Book, p. 118)
Due to Gene Roddenberry's dissatisfaction with the part, the character of Mark Piper was replaced, as the series' regular doctor, by Leonard McCoy (played by DeForest Kelley, who Roddenberry had been wanting to cast in the position since working on "The Cage"). (Inside Star Trek: The Real Story, pp. 75 & 84)
- Chief Medical Officer Dr. Piper is the oldest and most experienced space traveler aboard the Enterprise. As head of the ship's Medical Department, Piper is responsible for the mental and physical health of the crew. His evaluation of the reaction of the men to the pressures of the intergalactic space travel and the strange flora and fauna encountered on the planets visited will have a vital bearing on the conduct of each mission.
The character of Dr. Mark Piper also appears in the novels Captain's Peril by William Shatner, et al. and Star Trek: Vanguard: Harbinger by David Mack. Captain's Peril mentioned that as an infant, Piper was "bounced on the knee" of Jack Archer, presumably a relative of Former Captain Jonathan Archer.
In the novel Enterprise: The First Adventure, as Kirk assumes command of the ship for the first time from Captain Pike, Piper has been replaced by McCoy. However, McCoy is late reporting in from leave and Kirk tries to contact Piper to fill in, but can't reach him, either. McCoy finally reaches a location with communications and reports in.
In the subsequent novel Strangers from the Sky, McCoy goes on leave to deal with "personal matters" (his divorce), and Piper fills in temporarily, pending his retirement from Starfleet. Thus, Piper is aboard when the Enterprise explores the edge of the galaxy. In the novel Traitor Winds (set sometime between TOS and Star Trek: The Motion Picture), Piper is killed by traitors within Starfleet.