Technical and historical accuracy
In the film, Lovell tells his wife he was given command of Apollo 13 instead of 14 because the original commander, Alan Shepard's, "ear infection is flaring up again"; in fact, Shepard had no "ear infection", but had been grounded since 1963 by Ménière's disease. This was surgically corrected four years later, and he was returned to flight duty in May 1969, but Manned Spacecraft Center management felt he needed more training time for a lunar mission.
The film portrays the Saturn V launch vehicle being rolled out to the launch pad two days before launch. In reality, the launch vehicle was rolled out on the Mobile Launcher using the crawler-transporter two months before the launch date.
The film depicts the crew hearing a bang shortly after Swigert followed directions from mission control to stir the oxygen and hydrogen tanks. In reality, the crew heard the bang 95 seconds later.
The film depicts Sy Liebergot suggesting that the oxygen leak was in one or two of Odyssey's fuel cells, and the order to shut them down passed up to the crew, forcing abortion of the lunar landing mission. In reality, Mission Control did not order the shutdown; Haise found the cells were already dead, because of starvation due to the damage to the oxygen system.
The film depicts Swigert and Haise arguing about who was at fault. In the television show The Real Story: Apollo 13, broadcast on the Smithsonian Channel, Haise states that no such argument took place and that there was no way anyone could have foreseen that stirring the tank would cause problems. Similarly, on the BBC 13 Minutes to the Moon program, the backup lunar module pilot on the mission, Charles Duke, says the film portrayed Swigert as unprepared for the flight but that it was untrue, and that Swigert was very familiar with the Command Module, as he had been involved with its development during his time as an engineering test pilot at North American Aviation, prior to becoming an astronaut.
The dialogue between ground control and the astronauts was taken nearly verbatim from transcripts and recordings, with few exceptions. One of them is the tagline, "Houston, we have a problem". (This quote was voted #50 on the list "AFI's 100 Years... 100 Movie Quotes".) According to recorded audio of the air-to-ground communications, the actual words uttered by Swigert were "Okay, Houston, we've had a problem here." Ground control responded by saying, "This is Houston. Say again, please." Jim Lovell then repeated, "Houston, we've had a problem."
Another exception comes after the re-entry blackout. In the film, Lovell says, "Hello Houston... this is Odyssey... it's good to see you again." In the actual re-entry, the Command Module's transmission was finally received by a Sikorsky SH-3D Sea King recovery helicopter, which then relayed its communications to Mission Control. The CAPCOM astronaut Joe Kerwin (not Mattingly, who serves as CAPCOM in this scene in the film) then made a call to the spacecraft, saying, "Odyssey, Houston standing by. Over." Swigert, not Lovell, replied "Okay, Joe." Unlike in the film, this occurred well before the parachutes deployed, but it was visual confirmation of their deployment that triggered the celebrations depicted at Mission Control.
The tagline "Failure is not an option," said in the film by Gene Kranz, also became very popular but was not taken from the historical transcripts. The following story, from an e-mail by Apollo 13 Flight Dynamics Officer Jerry Bostick, relates the origin of the phrase:
As far as the expression "Failure is not an option," you are correct that Kranz never used that term. In preparation for the movie, the script writers, Al Reinart and Bill Broyles, came down to Clear Lake to interview me on "What are the people in Mission Control really like?" One of their questions was "Weren't there times when everybody, or at least a few people, just panicked?" My answer was "No, when bad things happened, we just calmly laid out all the options, and failure was not one of them. We never panicked, and we never gave up on finding a solution." I immediately sensed that Bill Broyles wanted to leave and assumed that he was bored with the interview. Only months later did I learn that when they got in their car to leave, he started screaming, "That's it! That's the tag line for the whole movie, Failure is not an option. Now we just have to figure out who to have say it." Of course, they gave it to the Kranz character, and the rest is history.
One of the film's most significant departures from history is its depiction of Flight Director Gene Kranz and his White Team as managing all of the essential parts of the flight, from liftoff to landing. Consequently, the actual role of the other flight directors and teams, especially Glynn Lunney and his Black Team, are neglected. In fact, it was Flight Director Lunney and his team who got Apollo 13 through its most critical period in the hours immediately after the explosion, including the mid-course correction that sent the mission on a "free return" trajectory around the Moon and back to the Earth. The astronaut Ken Mattingly, who was replaced as Apollo 13 Command Module Pilot at the last minute by Swigert, later said:
If there was a hero, Glynn Lunney was, by himself, a hero, because when he walked in the room, I guarantee you, nobody knew what the hell was going on. Glynn walked in, took over this mess, and he just brought calm to the situation. I've never seen such an extraordinary example of leadership in my entire career. Absolutely magnificent. No general or admiral in wartime could ever be more magnificent than Glynn was that night. He and he alone brought all of the scared people together. And you've got to remember that the flight controllers in those days were—they were kids in their thirties. They were good, but very few of them had ever run into these kinds of choices in life, and they weren't used to that. All of a sudden, their confidence had been shaken. They were faced with things that they didn't understand, and Glynn walked in there, and he just kind of took charge.
A DVD commentary track, recorded by Jim and Marilyn Lovell, included with the Signature Laserdisc, and later included on both DVD versions, mentions several more inaccuracies, all done for reasons of artistic license:
In the film, Mattingly plays a key role in solving a power consumption problem that Apollo 13 faced as it approached re-entry. Lovell points out in his commentary that there were several astronauts and engineers—including Charles Duke (whose rubella led to Mattingly's grounding)—who worked to solve that problem.
When Swigert is getting ready to dock with the Lunar Module, a concerned NASA technician says: "If Swigert can't dock this thing, we don't have a mission." Lovell and Haise also seem worried. In his DVD commentary, Jim Lovell says that if Swigert had been unable to dock with the module, he himself or Haise could have done it. He also says that Swigert was a well-trained Command Module Pilot and no one was really worried about whether he was up to the job but admits that the depicted uncertainty made a nice subplot for the film. What the astronauts were really worried about, Lovell says, was the planned expected rendezvous between the Lunar Module and the Command Module after Lovell and Haise left the surface of the Moon (which was aborted by the emergency).
A scene set the night before the launch, showing the astronauts' family members saying their goodbyes while separated by a road, to reduce the possibility of any last-minute transmission of disease, depicted a tradition that did not begin until the Space Shuttle program.
The film depicts Marilyn Lovell accidentally dropping her wedding ring down a shower drain. According to Jim Lovell, this did occur, but the drain trap caught the ring and his wife was able to retrieve it. Lovell has also confirmed that the scene in which his wife had a nightmare about him being "sucked through an open door of a spacecraft into outer space" did occur, though he believes it was prompted by a scene in Marooned, a 1969 film about astronauts trapped on an experimental space station, which they saw three months before Apollo 13 launched.
When the three astronauts are putting on their spacesuits, the NASA "worm" logo can be clearly seen on the glass behind Kevin Bacon, but that logo was not used until 1975.
