Steven Spielberg wanted to make this movie. But the initial idea was to shoot it in outer space - extremely expensive and very risky, so he declined. Wonder how it would have turned out. [This seems farfetched. Source?] Corrected by JC Fernandez

When Swigert is being brought up to speed in the simulator (the re-entry simulation with the false indicator light), the Capcom announces loss of signal, but a few seconds later (right after the corridor light), the astronauts are talking to Houston again. (Note: this is far too soon for them to have come out of the blackout, since, according to the end of the movie, the blackout usually lasts around three minutes.) [Time compression. We could have watched them simulate the entire three minutes of blackout, but it wouldn't be particularly interesting and the film has better uses for those minutes at other points in the film. So they jump time a bit to keep the flow of the film. Absolutely standard practice.] Corrected by Tailkinker

When Marilyn has the nightmare about Jim's mission meeting disaster, the Capcom says, "We show S4B shutdown," and then a few seconds later says, "when you get in the LEM." This makes no sense, because S4B (Saturn 4B Booster) shutdown happens before the LEM is even docked (and days before anybody would actually get in the LEM). Granted, it's a dream, but Marilyn Lovell was actually fairly knowledgeable about the way lunar missions worked, and you'd think that if she could dream everything else correctly (the layout of the capsule, for instance), she (or the filmmakers) would get that detail correct. [It's a dream. These are not required to make factual sense, even if the dreamer in question is well acquainted with the subject matter. I'm pretty knowledgeable about cats, and am therefore reasonably sure that they can't fly, yet have, on occasion, had a dream that involved cats doing precisely that. Factually incorrect, but that's dreams for you.] Corrected by Tailkinker

When Jim Lovell is talking to his son about landing on the moon, he says his moon landing will be "Better than Neil Armstrong; way better than Pete Conrad." In fact, while Armstrong did make a less-than-stellar landing (hampered by low fuel and a problem with his targeting computer), Pete Conrad's Apollo 12 landing was nearly perfect. [So what? There's always a healthy level of rivalry among such people. If Lovell reckons that he can land better than his predecessors did, then it's not a mistake to say so; people are entitled to have opinions. Bear in mind that Lovell would consider Armstrong's landing, hampered by fuel and computer problems, to be a more impressive feat than Conrad's relatively mundane experience, so it's quite reasonable that he would rank them in that order.] Corrected by Tailkinker

During the launch countdown, the voice-over says "7.6.ignition sequence starts.3.2.1." The sequence is supposed to be in real time, but "6" and 3" are only about a second apart. [The difference in the '6' and '3' is two seconds. Try saying "ignition sequence starts" in one second. It takes closer to two seconds to say it. 'About a second apart' suggests that its more than a second. Such a small discrepancy is negligible.]

Mission Control in Houston calls up "B.P.C. clear", meaning that the 'Boost Protective Cover' has been safely jettisoned during ascent. However, the call comes on screen before it is shown being jettisoned. [This could mean mission command is giving the go-ahead by saying BPC clear, as in it is now safe to jettison the BPC.]

When the astronauts are preparing to dock with the Lunar Module, one of the people in Mission Control says, "If Swigert can't dock this thing, we don't have a mission." In fact, all three crew members were trained to peform the LEM docking, and had Swigert run into any trouble, Lovell or Haise could easily have done the procedure instead. This is confirmed in the DVD commentary. [Presumably Swigert is the best trained since this is his primary task, it's a reasonable, if not necessarily correct, remark to assume that if he can't do it then nobody can.] Corrected by tw_stuart

The scene showing the astronauts thrust towards the forward panels, and then violently back into their 'couches' is meant to show the massive thrust from the ascent and second stage engines. In fact, this sequence is inaccurate: The earlier Mercury and Gemini rockets did indeed create this massive 10 to 15-G load momentarily upon the astronauts, but the Saturn V did no such thing. The Saturn V never exceeded more than 2 Gs during any portion of lift off or ascent, and was in fact referred to as the "old man's rocket" by astronauts in reference to its relatively mild G-loads during flight. [This actually happened with the Apollo 13 mission. It wasn't supposed to, hence Swigert's sarcastic comment about "some little jolt", but a slight mistiming in the engine firing caused it.] Corrected by Tailkinker

During the ascent, the center engine light cuts off, indicating that one of the five ascent engines has stopped operating. Lovell grasps the 'abort' handle in anticipation of Capcom giving him the abort command. However, the escape tower on the top of the command module has already been jettisoned, making any kind of abort an impossibility. [While the abort issue is a genuine plot hole, the engine failure itself is real. The number 5 engine DID fail during Apollo 13's ascent to earth orbit.]

The Apollo 13 mission has a lot to do with the number 13. It's called Apollo 13, it took off at 13:13 Houston time from Pad 39 (which is 3 x 13), and the launch date was 11 April 1970 (4+1+1+7+0 = 13). [This is trivia about the mission itself, not the film. Nowhere in the film is this fact alluded to.]

In the scene where Marilyn Lovell is in her backyard and she looks up at the jet flying over her house (presumably her husband), there is a contrail behind it. The jet is at too low of an altitude to produce a contrail. [Although this looks like a "contrail" behind the jet, it is actually condensation from wing-tip pressure. At lower altitudes, it is known as "ectoplasm." Ectoplasm is more commonly seen during high energy manouvers like those of a fighter jet, as the wings of a fighter jet cause a drop in air pressure in the vicinity of the wing. This causes a drop in temperature, which can cause water to condense out of the air, just like we see in the movie. (No special effects were used for this shot, it was a real jet, and the vapor trail you see is how it happened in real life.)] Corrected by Jazetopher

Many times in the movie, the Capcom refers to the CM and LM by their individual call signs, "Odyssey" and "Aquarius." In real life, those call signs would only be used when the LM had separated from the CM for a lunar landing. While the two ships were docked, as they were in this case for the entire mission, the single call sign "Apollo 13" would be used instead. [While this is true for a "routine" mission, Apollo 13 was not a mission anymore once it became "an emergency" situation. Remember that Lovell and his team had to use the Lunar Module as a "lifeboat" to survive the trip home. They don't refer to the Odyssey and the Aquarius separately until after the explosion. On a normal mission, the lunar module would not be attached to the SM or the CSM for the return trip. Using the call signs as opposed to similar sounding terms LM, SM, and CSM was also done to avoid confusion for the astronauts, as everything they had to do to get home was an unorthodox method that had never been attempted before, and the cold and lack of sleep was making it harder for them to concentrate.] Corrected by Jazetopher

When Deke tells Lovell that Mattingly will have to be removed from the flight, he says that if Lovell is unwilling to go with Swigert, the entire crew will be bumped to a later mission. Even if this really had been Lovell's decision to make (which it almost certainly wasn't in real life), there is no way that all three astronauts could have been bumped to a later mission. Even if the entire backup crew could have been brought up to speed in a week, they could not have flown Apollo 13, given that Charlie Duke (Fred Haise's backup as LEM pilot) had the measles. [It's never stated that the "backup crew" will be going if Lovell's team gets bumped to a later mission! Lovell's team was bumped up from Apollo 14 to Apollo 13 by NASA when one of the "original" Apollo 13 team members became ill. It would stand to reason that whatever team was now behind him for Apollo 14, which we know is still on the missions list, as Lovell was just a part of it a week earlier, would be bumped up by NASA to take the place of Lovell's team in the same manner that Lovell's team was bumped from Apollo 14 to Apollo 13.] Corrected by Jazetopher

In the shot where Jim is with Marilyn, outside of their house right after the Apollo 11 landing, he blocks out the moon with his thumb. In the final shot, where he puts his finger in front of his face to hide out the moon again, you can see the shadow below his chest. It should be on his eye. [This is one of the most frequently quoted "non-mistakes" of Apollo 13. It is valid only if the moon was the ONLY light source in the scene, and it is not. There are three or four strong porch light to screen right. Moonlight is pretty feeble and the lights cast the far stronger shadow.]

At the meeting in which Jim Lovell is informed that Ken Mattingly has been exposed to measles, and must be replaced by Command Module backup pilot Jack Swigert, Lovell complains about the last minute switch and says, "When's the last time he was in a simulator?" But Lovell eventually agrees, Swigert is put into service for Apollo 13, and he proceeds to intensify his training schedule. In one later scene he's shown in a simulator, being rather rusty and out of practice. But in an earlier scene, before the measles scene, the whole Apollo 13 backup crew, including Jack, were shown arriving at the simulator for practice. In reality, as a member of the backup crew, Swigert was in constant training and would not have even been considered were he unable to pilot the spacecraft. [I do not see where the mistake is in all this. Of course he would have not been considered if he wasn't up for it but the evidence you've provided is more opinion rather than fact. Lovell was extremely upset by Mattingly being replaced and what he said was more in the heat of the moment rather than being a true and accurate statement. Secondly the practice run Swigert went through wasn't evidence he was rusty, it was evident he didn't know how to handle that particular scenario. The technical staff afterwards discuss that even Mattingly didn't get that scenario the first time. Even so it was one mistake and we are only shown a few minutes of them training and not the hours upon hours they would have been training.] Corrected by Lummie

During liftoff, one of the five second stage engines fails. This is indicated by a shot of the control panel, and one of the five indicator lights is flashing with a buzzer going off loudly in time with the flashing light. In fact engine failures were indicated by having a light simply go out, and there was no buzzer. Director Ron Howard originally shot the scene accurately, having a light just turn off was visually uninteresting and did not convey the drama of an engine failure. After getting the OK from Astronaut and technical advisor Dave Scott, the more dramatic indication was used. [Artistic decision to convey the drama and assist the audience, not really a movie mistake. A typical embellishment which is quite permissible in movie world.] Corrected by tw_stuart

In the scene where Tom Hanks' wife is in the shower and drops her wedding ring down the drain, when she bends down to try and catch it, you can see the stick-on bra and light green underwear she is wearing for modesty purposes. Hard to catch it in full speed, but try frame by frame. Guess she (or director Ron Howard) didn't want to take any chances of nudity getting into the film. [As is stated in the rules of this site, if a mistake requires frame-by-frame to spot, it's not considered to be valid.] Corrected by Tailkinker

The real Jim Lovell is left handed and if you noticed Tom Hanks when he is writing down information is right Handed. Tom refused to attempt to write left handed. [He did not "refuse". He simply couldn't master the necessary skills in the time required. Nobody could - try it to see how long it takes.]

At the beginning, when they are discussing the Apollo 1 fire in January 1967, they state that 18 months after the fire Apollo 11 lands on the moon. In actuality, it is 30 months (2 1/2 years) after the fire that Apollo 11 lands on the moon. [Already submitted and corrected mistake. This was Walter Cronkite's real-life mistake on the air.] Corrected by Rlvlk

At one point on the return to Earth when they're about to make another burn, Lovell (Tom Hanks) looks out the window to his left at a stream of smoke or gas flowing by. At the left bottom corner a hand of the crew or someone outside of the ship is quickly noticeable, but even more so when you watch the scene in slow motion. The hand moves slightly, then quickly moves from the window as if the crew member realised what he was doing. [Watched this several times. What you see is Lovell's face reflected in the window not a crew member's hand.] Corrected by William Bergquist