I've wanted to do this for quite a while, as it's a frequently asked question: who in Star Trek fandom played the crew of the
USS Enterprise in "Star Trek: The Motion Picture" (1979)?
To thank the fans who'd supported the ongoing call, throughout the 70s, to put pressure on Paramount Pictures to make a Star Trek reunion movie, Gene Roddenberry - knowing that Hollywood couldn't possibly supply the number of Screen Extras Guild card-carrying bodies the scene in the Rec Deck needed - asked that a now legendary "cattle call" be organised by fan extraordinaire, Bjo Trimble. There were strict height and costume size restrictions, and the males had to forfeit any elaborate sideburns or moustaches, unless they were to be hidden inside a latex alien head.
Special white outfits were made for four guest extras who were too tiny to make the height restriction: including Susan Sackett (on the upper deck); Bjo Trimble herself; a Star Trek office secretary named Michelle; and Leonard Nimoy's then-fan club president, Louise Stange. Everyone else had to be aged between 20 and 40, men from 5'8" to 6'2", sizes 40-42, and women from 5'6" to 5'8', sizes 8-10.
Over the years, several books, including Bjo's own "On the Good Ship Enterprise" (Donning, 1982) and Walter Koenig's "Chekov's Enterprise" (Pocket, 1980) have mentioned partial lists of the fans who made up the successful group of about 170 (of over 350 hopefuls). An early article by Dennis Fischer (a regular "Cinefantastique" reviewer) was called "Part of the magic: the experience of being a Star Trek extra", which appeared in issue # 7 of "Enterprise Incidents" (Nov 1979, pp 4-8), the slick pro zine of the day. Dennis's article was written only days after the filming of the scene, and before any official publicity material about the TMP aliens had been released. It has the best list of participants, with a lot of information on who's who, and where to find some of them. Susan Sackett's "Starlog" column on the making of ST: TMP also featured the casting call (in issue #20, p 22).
Other fan extras have made themselves known in recent years via Internet sources. I've added a scale along the bottom of the photo to make it easier to point out certain humans and aliens. If you know anyone I missed, or can identify someone in the cast pic, please do let me know!

Extras and Star Trek fans play the crew of the USS Enterprise in ST:TMP.
James Doohan's twin sons,
Christopher Doohan and
Montgomery Doohan, appeared as extras, as did
Richard Arnold and
Bill Hickey (I think located in
third row at 6). Koenig's and Trimble's memoirs name "The Trouble With Tribbles" writer David Gerrold, Roddenberry's assistant, Susan Sackett,
Millicent Wise (director Robert Wise's wife,
front row at 7), TMP movie hairdresser
Barbara Minster, TMP makeup artist
Ve Neill, and fans JoAnn Christy,
Cedric Taporco (a handsome guy who ended up in a purple Saurian head), John Watts,
Rosanna Attias, Paula Crist,
Denise Tathwell (now Denise
Okuda!), Leigh Strother-Vien, Dennis Fischer, Kathleen Sky-Goldin,
Verne Dietsche,
Will Guest and
Eileen Salamas. Susan mentioned
Leah Livingston, daughter of TMP screenwriter Harold, as a participant in her 1980 book "The Making of Star Trek: The Motion Picture" (p. 38).
A summary of fan extras from Dennis Fischer's article:
Dennis Fischer himself - brown uniform, green epaulets, no rank, therefore considered himself an orderly or medical cadet. Placed at back of group because he was 6'4" (two inches taller than specified in the height restrictions!), and taller than the principal actors. He then describes several fans who were placed around him:
Leigh Strother-Vien, tall red-headed female of the Los Angeles Science Fiction Society (LASFS), placed next to Fischer.
Don Fanning - "big headed alien" with "methane mask with light-up eyes" covering his face and the "back of head looked like someone's posterior" (we now know to be a Zaranite), to the right of Strother-Vien.
Katherine Kurtz, tall blonde author of the "Deryni" series, placed on other side of Fischer to Strother-Vien, and to the left of Don Fanning's Zaranite.
Bjo Trimble - white uniform, placed to Fisher's left behind two tall people. Many people expect to recognize Bjo on the Rec Deck but, as she explains in her book, she is quite short and was placed behind a hulking male Zaranite. Most assume that the petite woman in beige, in the
front row at 7 near
David Gerrold (
at 8.5), is Bjo - but no, that's Mrs Robert Wise!
Kathleen Sky - red-haired Bantam ST novelist, behind Fischer.
Ms Sky wrote "Vulcan!" and "Death's Angel", and was married to fellow Trek novelist Steven Goldin at the time.Jay Smith - red-haired male, next to Kathleen Sky.
Walt Doty - described as "handsome, young" African American student, a co-president of ASTRA SF club, who had to shave off his moustache to be a TMP extra; placed near other African American.
John Watts - Andorian
(third row at 15) - as mentioned in Trimble's book, "for three straight years" John played "one sort of blue-skinned character or other" at Equicon conventions. Coincidentally cast as an Andorian by Robert Wise, he walked bluely past Bjo saying, "How did they know?"
JoAnn Christy (now Nolan) - Vulcan female, in
front row at 6. The shy JoAnn is also mentioned in a cute anecdote in the Trimble book, and is named as T'Hesh in Christopher L. Bennett's novel, "Ex Machina".
(See more details below.) The article mistakenly calls her "Joanna" (sic). FANS ON BALCONY:
Vincent (no surname given) - in purple, Gorn-like "lizard outfit" (we now know as a Saurian).
(Fischer tells the same tongue-poking anecdote as Bjo did, so this may be Cedric Taporco.)James T Kirk, the 70s ST fan who had infamously changed his name by deed poll.
Marlene Willauer - almost chosen over JoAnn Christy to be the front row Vulcan, but ended up (
balcony at 7.5) "hobnobbing with Susan Sackett", to quote Fischer.
(Bjo's book misidentifies Marlene as Denise Tathwell - the future Mrs Michael Okuda - in the closeup group photograph. Denise can be seen in the rec deck scene at 17.5, four rows back, in front of a Rhaandarite.)Susan Sackett - white uniform (
balcony at 8).
Louise Stange - white uniform (
balcony at 5.5). Appeared in TMP by special request of Leonard Nimoy.
As often happened, Louise's surname appears as "Strange" (sic) in the article. Later known as Louise Stange-Wahl.Michelle - white uniform, a secretary from Roddenberry's office at Paramount. According to Fischer's article, Michelle supposedly "threatened to refile everything" in the Star Trek production office unless she got put into the film.
(I'm wondering if this is Michele Ameen Billy, who was secretary to Harold Livingston, the film's screenwriter? Ms Billy was cast as a speaking character on the Epsilon IX space station, filmed after the rest of principal photography - but this would mean that one Michele watched the other, identical, Michele die on the viewscreen! Today, Michele Ameen Billy is better known as Mrs Jon Povill.)Unclear if they "made it", but mentioned in the article:
Mike Hodel, radio announcer of "Hour 25" SF radio series (or was he just interviewing at the gate?)
Alan Frisbie - "an alternate" extra - Dennis Fischer reported that Frisbie only "has to kill 15 people" to get into the scene.
Other Starfleet alien descriptions, mentioned by Fischer's article, were "another purple alien that resembled the mutant from 'This Island Earth', but with a smaller cranium" (ie. Betelgeusian) and "bump-heads who resembled Frankenstein's monster with long, blond hair, and they looked like they were ready to do the 'Time Warp'" (we now know as being Rhaandarites, but they were Vegans on that day and "high-domed Vegans" in the shooting script.
Memory Alpha discloses that one "Vegan" was played by fan
Steven Lance, also known as
Steven L Hersh, who did a lot of screen extra work at the time and was a science fiction convention organiser.

"On the Good Ship Enterprise" devotes a chapter to the cattle call and the big day of filming. A black and white casual, group photo in the book shows some fans in uniform surrounding Grace Lee Whitney. ("Enterprise Incidents" has a differently-cropped version of the same photo accompanying its Fischer article, which unfortunately leaves off the alien, Worene, on Bjo's right).
There's a whole chapter, in "On the Good Ship Enterprise", about
Worene, the wolfish alien created for TMP by actress/stuntwoman
Paula Crist (who later played Baby the brontosaurus in Disney's "Baby: Secret of the Lost Legend"). Ms Crist met Gene Roddenberry at several conventions in Los Angeles. Once she was dressed as Thorwor, a feral-looking male alien. Roddenberry invited her to test for Bridge Alien, doing her own makeup, which she modified as female, but the role was won by fellow pro actor
Billy Van Zandt (
front row at 2, who scored Fred Phillip's Rhaandarite makeup, and one line of dialogue that wasn't restored until the ABC TV premiere). Because Paula Crist (now know as Paula Crist-Pickett) was a Screen Actors Guild member, she did score herself a screen credit for playing Worene on the Rec Deck.
Paula Crist told Dennis Fischer on the day of filming that she called Worene's makeup a
Czintii. He assumes she did not intend any connection to Larry Niven's felinoid
kzinti (of "Star Trek: The Animated Series" and Niven's "Known Space" science fiction universe). Fischer thought that Worene resembled a female Tellarite (TOS).
By the way, Worene's species is given as
Aulacri in the more recent Star Trek novel, "Ex Machina" (2005), a sequel to TMP. (P-
aula cri-st, get it?) The novel's author, Christopher L Bennett, has some great
closeups of the Rec Deck characters, to whom he's given identities and personalities, in that novel. David Gerrold's character is named
Gerry Auberson. Billy Van Zandt's is
Vaylin Zaand. And one of the Rec Deck's Andorians is actually named for
me in "Ex Machina":
Shantherin th'Clane! Incredibly, this was the same Andorian played by fan John Watts; when I visited Bjo Trimble in January 1984, she thought John and I had lots in common, even beyond the blue skin and antennae.
(John and I finally did get in touch via Facebook!)The tall male Vulcan, whom Christopher Bennett calls
Spanla, is easily recognisable in TMP:
Scott Dweck, or perhaps spelt "Dwek", (
three rows back at 9, in the above colour photo) is the son of Grace Lee Whitney. Scott and his brother had appeared uncredited in the episode "Miri" (TOS) as young children. Ms Whitney used to sell pics of her Vulcan son at conventions. If I recall correctly, Scott is the one who became the commercial pilot. His most exciting duty used to be to take actor Christopher Reeve for his annual pilot renewal test. In the 80s, Grace Lee Whitney used to boast that her son gave Superman his license to fly!

This pic joins together the two b/w photos mentioned above.
Front row, from left: Marlene Willauer, Scott Dweck (as a Vulcan), Paula Crist (as Worene), Bjo Trimble, Grace Lee Whitney (as Janice Rand), Susan Sackett and Louise Stange.
Next row, from left: Kathleen Sky, Leigh Strother-Vien and the very tall Dennis Fischer. David Gerrold is behind Grace Lee Whitney.
Captain's Log: Supplemental. The 2009 DVD release of TMP features a reunion between fan extras
Fred Bronson (writer of "The Counter-clock Incident", TAS), Bjo Trimble, Christopher Doohan, David Gerrold and Jo Ann Nolan, chatting on the same soundstage used for the rec deck scene.
In August 2010, I was contacted by fan extra
Don J Long, who explained that he could be seen "in the center at 8.5". His friend,
Gordon Cardoza, "is on my right" (ie. to the left in the photo). Don's head is clearly visible in front of a African American man in a white costume (who is standing by the column in the center of the picture). Another fan extra known to Don was
Randall Larson, from the Federation Outpost Star Trek store. Thanks Don!
More updates welcomed any time!