Goofs

In The Man Trap (1966), Spock says that the planet Vulcan has no moon. But while Spock is meditating on Vulcan in this film, two moons can be seen. (Fixed in the 2001 Director's Edition with an actual atmosphere and sky on Vulcan, eliminating the moon altogether.)

Spock's first scene shows him squinting into bright sunshine - preceded by a reverse shot showing a dark sky. (Fixed in the 2001 Director's Edition by removing the preceding dark sky shot, and also adding an aftershot with a new landscape and sky on Vulcan.)

Spock damages his console pretty badly when he bashes the V'ger probe's "hand". A few minutes later, the console is undamaged.

Early in the movie the crew is concerned about using warp drive while inside the solar system. At the end of the movie the Captain gives an order to go to warp 1 while the Enterprise is in Earth orbit but nobody seems concerned at all. This is an inconsistency throughout all of the Star Trek series as well.

Kirk's hairstyle changes in nearly every scene.

When flying past Jupiter, three consecutive shots of Jupiter and its moons are shown. The first and third are from the POV of the ship as it approaches and passes Jupiter, and show the sunshine on planet and several moons coming from the port aft. The second shot shows the opposite angle of the oncoming ship, and the sunshine on the planet and 4 moons is coming from a different direction on each body, none of them from the port aft.

When Kirk rescues Spock during the spacewalk outside of the entrance to V'ger, an unconscious Spock is floating towards Kirk who catches him. They remain stationary thereafter. This would not happen in the depicted environment. With nothing to keep Kirk in place, they should both move away, at reduced speed based on their relative masses, after Kirk catches Spock.

When the USS Enterprise is seen leaving spacedock bound for V'ger, the Earth is shown in the background as the sun slowly rises behind it. Since this appears to be a stationary camera facing towards the ship, it should not be possible that the sun can be seen 'rising up at dawn' from this position in outer space. Only an observer on Earth or a camera leaving Earth's gravity would see this view of the sunrise.

When the Enterprise is departing from Earth the Sun is seen to rise above the Earth. However sunrise is normally due to the rotation of the Earth, or in the case of the International Space Station the vehicle moving in a posigrade orbit round the Earth. In this case, the Enterprise is moving in the opposite direction, so if we were following it then the Sun would be seen to set if the Enterprise was in orbit. On the other hand, if the Enterprise was moving in an almost straight line, the Sun could come into view as the apparent size of the Earth diminished due to the Enterprise moving away from it. As the size of the Earth does not appear to change, the Sun can only appear to rise if the position of our viewpoint is moving in that same direction, but if that were so, we would be moving upwards, away from the Enterprise. This isn't happening either, so the scene might look nice but it is incorrect.

When Kirk first comes on board Enterprise he is called "Admiral," and then "Captain" a few seconds later. However, it is customary for the person in command of a ship to be addressed as "Captain," regardless of his military rank.

After V'ger destroys the Klingon ships, comm station Epsilon IX continues to receive a view of V'ger. This is because there are "sensor drones" placed throughout Federation space and bordering territories throughout the galaxy. It is the same reason the Enterprise continues to receive an image of the V'ger cloud AFTER Epsilon IX is destroyed by V'ger. It is well-known in the Star Trek universe that these drones are utilized to help transmit images back to Starfleet, if and when starships are unable to transmit the images on their own. The Enterprise attempts to use said drones to transmit images of the V'ger cloud back to Starfleet while inside the cloud. If the viewer pays attention to the dialogue in this film, they will hear at least two instances where the drones (and their functional purposes) are mentioned.

As Spock arrives on the Enterprise, he's met by Chekov and a security officer, and Spock immediately walks off, leaving Chekov behind. As he arrives on the bridge, Chekov is already there, ahead of him. Incorrectly regarded as goof: In every film version, after Spock is shown walking out of the lift onto the bridge and stopping in front of it, the next shot shows Chekov walking away from the lift and stopping a short distance to the side. Clearly, in the first scene, Chekov ran after Spock and joined him in the lift, for they arrived together at the bridge, and Spock got off first, with Chekov behind him.

When Spock is greeted by Dr. McCoy for the first time in years, he reacts with visible revulsion and does not reply. Beneath the rivalry between Spock and McCoy, there was mutual respect and even admiration for one another. Even if Spock had since changed his mind about McCoy, he would never have treated a fellow officer and former comrade in so many adventures in such a discourteous manner. However, Spock's unusual behavior in this instance is due to the after-effects of his failed attempt to achieve Kolinahr, the total suppression of all emotion.

V'ger is 3 days away from Earth so V'ger would need to traveling many, many times the speed of light to make it from the Klingon empire to Earth in 3 days. V'ger would need to be sub-light in order for the Klingons to engage in battle, fire torpedoes at V'ger (and vice-versa), and make evasive maneuvers. It is very possible V'ger detected the Klingons and slowed to sub-light to scan them and send the high frequency message (same that they sent to the Enterprise). But of course the Klingons did not notice they were contacted and obviously taken for hostile especially when they fired their torpedoes. Same thing for the Epsilon 9 encounter.

When Spock is doing his EVA into the interior of V'ger, the reflection we see in the visor of his spacesuit helmet should be the reverse of the image we see when looking over his shoulder, yet they are the same.

When the V'ger probe first comes onto the bridge, the portion of the set around the probe appears to "shrink". For example, the view screen is not as wide in one shot, and the dome in the bridge ceiling disappears and reappears as the probe passes in front of the helm and navigation console. This was due to a distortion effect, done to "hide" the electrician holding the light source used in this sequence. (Fixed in the 2001 Director's Edition.)

When V'ger's energy probe is on the Enterprise's bridge, there is a mismatch between the sides of the screen on each side of the probe e.g. the handrail near view screen does not match up - the left hand side of the rail is higher than the right hand side. (Fixed in the 2001 Director's Edition.)

When Spock's shuttle is seen docking with the Enterprise from the observation deck, the star field moves in front of, rather than behind, the warp nacelles. (Fixed in the 2001 Director's Edition.)

When Spock puts the nerve pinch on the man in charge of the suit lockers, the thruster suits in the lockers are those intended to be worn for the original Memory Wall sequence that would have followed this scene originally. The suits worn by Spock and Captain Kirk later on in the movie are of a very different design and have a larger helmet.

At 23:46 just before Kirk enters Engineering, a voice over incorrectly announces "Engineering, show me your readings on photon capacitators" instead of capacitors, which is correctly displayed in the subtitles.

When the Enterprise reaches Warp 7, the screen shows the "coming out of warp" effect. The Enterprise is actually remaining in warp, and should not show the "coming out of warp" effect until they slow down when they get to the vicinity of V'ger.

Edna Glover's scene as the Vulcan Kolinahr Master was filmed with her speaking English. Only later were Vulcan words (invented by UCLA linguist Hartmut Scharfe) recorded over the original dialogue. The phonetics of the Vulcan words were chosen to closely follow the original English script so that her lips would seem to move correctly, and English subtitles were inserted with the phrasing reworded so the change would not be obvious. For example, when the subtitles say, "Our ancestors cast out their animal passions on these very sands" her lips are clearly saying "Spock, on these sands our ancestors cast out their animal passions." Other examples are "Your thoughts... give them to me" [subtitle] versus "Spock... give me your thoughts" [actual] and "Your human blood is touched by it, Spock" [subtitle] versus "It stirs your human half, Spock" [actual].

When the ship is leaving space dock, multiple, large dirt marks are present on the camera lens. (Fixed in the 2001 Director's Edition by restoration/remastering.)

As Kirk exits the shuttle at Starfleet Headquarters, immediately before he first sees Commander Sonak, a male crew member with regular 20th-century clothes is very quickly visible near the back of the shuttle next to a blonde female extra before both are obscured by Sonak's entry doorway (the extra begins her own walk-through in the background once Kirk and Sonak begin speaking). The crew member may be taken to represent a 23rd-century person dressed eccentrically.

William Shatner wore a girdle (corset) during the production as he had gained weight in the years since the TV show ended. The lines of the girdle were often visible through his uniform. For example, at about 31 mins in, when he steps off the turbolift and Uhura announces Lt. Ilia has boarded the Enterprise and is en route to the bridge, the line of the girdle is quite noticeable just beneath his chest area as he goes to sit in his chair.

When the Enterprise moves out of the spacedock, the bracing used to hold the model can be seen silhouetted against the spacedock on the Starboard side of the ship. (Fixed in the 2001 Director's Edition.)

Set rigging when Kirk makes the EVA to rescue Spock. (1983 TV/VHS Special Longer Version only. Fixed in the 2022 4K release of the Special Longer Version.)

In the message from Epsilon 9, it is stated that the V'ger cloud measures 82 AU in diameter. 1 AU (astronomical unit) is the distance between the Earth and the sun (approx 93 million miles), so a cloud measuring 82 times this would completely cover the solar system. (This is fixed in the 2001 Director's Edition by removing the "eighty" in the audio thus altering the size to 2 AU, but even that would be ridiculously huge.)

Near the beginning of the movie Kirk tells Scotty "...an alien object of unbelievable destructive power is less than three days away from this planet (Earth). The only starship in interception range is the Enterprise." While this is of course important for the whole plot of the movie and the reason why the Enterprise should intercept V'ger, it is highly unlikely that in generally and also especially in a time with war conditions with for example the Klingon Empire there is no protective fleet (not one ship apparently) inside the Solar System or within a 3-days-journey of it.

Immediately before Spock walks out of the shuttle onto the Enterprise, there is an announcement which states; "Identity: Starfleet, inactive". Yet when on the Bridge, Spock tells Kirk that he has been monitoring their communications with Starfleet and is aware of their warp drive problems. Surely communications between the Enterprise and Starfleet would be secured, especially during a major mission, and no person who did not have a current active position in Starfleet should be able to listen in.

Shortly after two crew members are killed in the transporter, a comical moment comes along when McCoy refuses to step onto the transporter pads, making a remark that he first wanted to see how it scrambled everyone else's molecules first (Extended and director's cut).

In Star Trek lore, each star ship has one Captain and one Commander who is usually the first officer. However for some unexplained reason, the Enterprise is manned with three commanders, being Scott, Spock, and Decker (once he is temporarily demoted from captain). This would cause a problem in the ship's command structure as any of these three could offer alternatives to their captain causing much frustration.

On the other hand, no explanation is given as to why Decker is demoted when later on, Spock kept his rank of captain when serving with Kirk, both being the same rank.