(written from a Production point of view)
Mark Andren Stetson (born 27 March 1952; age 69), a 1978 graduate from the Art Center College of Design in Pasadena, California (as was his fellow Magicam co-worker Chris Ross, and which also counts William Ware Theiss and classmate Andrew Probert among their alumni), was a modelmaker who worked from May 1978 through November 1979 on Star Trek: The Motion Picture.
In his first professional employment after graduating, he has worked among others on the workbee model, the eight-foot refit-Enterprise studio model and has constructed the small refit-Constitution-class shuttlebay maquette.
During his tenure on the movie, he was employed by three consecutive companies: Magicam, Inc., Astra Image Corporation and Entertainment Effects Group (EEG), as he, aside from constructing, detailing and finishing the models, was also retained for handling and maintaining the various miniatures while the models were in use for filming , or as he himself had put it, "I just followed the models along. I worked for almost all the production companies except Apogee. I worked first for Magicam, then for Astra, and then, when Trumbull took over the picture, I came down to the Maxella facility and worked over there until the close of the picture." (Return to Tomorrow - The Filming of Star Trek: The Motion Picture, p. 384)
Career outside Star Trek
After his tenure at Magicam, Stetson continued his career as visual effects staffer in the motion picture business, having worked for a variety of companies, firstly at EEG, as model maker and model shop supervisor on productions like Blade Runner (1982, with Ross, supervised by Douglas Trumbull and Richard Yuricich, and for which he was recommended by Gregory Jein), Brainstorm (1983, again with Douglas Trumbull), Ghost Busters (1984), The Adventures of Buckaroo Banzai Across the 8th Dimension (1984 with several other Trek alumni including Gregory Jein, Denise Okuda, Christopher Lloyd, and Robert Ito, among others), Total Recall (1990), True Lies (1994) and The Fifth Element (1997, and in the latter two cases reuniting him with The Motion Picture co-worker Ron Gress). During this period Stetson worked as an independent contractor, operating his own company which was in existence from January 1980 through February 1995, first as Stetson Visual Services, and from January 1989 onward as Stetson Visual Services, Inc.
After 1997, he has worked for several studios, mostly as visual effects supervisor and has been the recipient of various award nominations, among others three Academy Award nominations in the Visual Effects category for 2010 (1984), The Lord of the Rings: The Fellowship of the Ring (2001), and Superman Returns (2006); the second one he won, sharing it with, among others, Jim Rygiel. In his acceptance speech, Stetson acknowledged Magicam's Jim Dow, mentioning The Motion Picture for giving him his first professional job, as well as acknowledging Jein and Trumbull. 
In 2010, Stetson was hired as Creative Director/Visual Effects Supervisor - Feature Films at ZOIC Studios, a position he, as of 2012 still holds. Stetson was prominently featured in the 2011 documentary Sense of Scale (mentioning his involvement with The Motion Picture), in which several fellow model makers discussed their craft, also featuring Ron Gress, Greg Jein, Pat McClung, Bruce MacRae, and Gene Rizzardi.
Star Trek interviews
- "The Making Of The Visual Effects Of Star Trek:TMP, Part 3: Filming The Effects", Dennis Fischer, Enterprise Incidents, issue 17, May 1984, pp. 42-51
- Star Trek: Creating the Enterprise, December 2012
- Return to Tomorrow - The Filming of Star Trek: The Motion Picture, December 2014