(written from a Production point of view)
The Making of Star Trek: The Motion Picture was a ten-minute documentary produced by Paramount Pictures in 1979. The featurette did not contain interviews but instead showcased behind-the-scenes footage of the production of Star Trek: The Motion Picture with an accompanying audio commentary.
Remarkable were the segments that showed the model makers at Magicam working on the various studio models at their company, the fitting of prosthetics to create various alien makeup, and the shaving of Persis Khambatta's head for her role as Ilia. Particularly noteworthy was the footage of the construction and destruction of D7-class breakaway models which was shot in the last quarter of 1978, while that particular scene was still slated to be featured in the movie, before it was re-imagined by Apogee, Inc. later on during the production. (See: K't'inga class model)
A rare and unique production, as it has to date never been included on any of the home media format, it was not seen for decades after the release of the movie nor was it ever included as a special feature on any of the home video releases. Recently, a version started to appear on the Internet on sites like YouTube but it is not clear if the featurette was ever broadcast on television as it lacks both opening and closing credits.
The featurette was therefore apparently conceived as a promotional tool produced by the studio intended to be shown in public places in the time period leading up to the release of the movie in December 1979, as later Star Trek production staffer Doug Drexler recalled, "I remember that Paramount was running this in the lobby of Pennsylvania Station in NYC. Friends and I made several trips to Penn Station just to watch it!"