Regarding the film's premise, Ben Affleck asked director Michael Bay, "Wouldn't it be easier for NASA to train astronauts how to drill rather than training drillers to be astronauts?" Bay told Affleck to shut up.
Bruce Willis came to the film after he decided a comedy he was filming called "Broadway Brawler" could not be salvaged and sought a way to exit the project. Disney's then-head Joe Roth worked out a deal where Willis would star in Armageddon and two future films for the studio, and in exchange Disney would absorb the failed project's costs as an advance against his initial salary. The two films Willis later made under this deal were The Sixth Sense (1999) and Unbreakable (2000).
The film crew was also allowed to shoot sequences at the top of a real launch pad with an actual space shuttle docked to it. The only condition was that they not step into the shuttle itself. Ben Affleck admitted to stepping inside the orbiter for a brief moment before NASA technicians ordered him out of the spacecraft.
Michael Bay thinks Armageddon is his worst film. "I will apologize for Armageddon, because we had to do the whole movie in 16 weeks," he told The Miami Herald in 2013. "It was a massive undertaking. That was not fair to the movie. I would redo the entire third act if I could."
Rockhound's line about sitting on a million pounds of fuel in a rocket built by the lowest bidder is a variation of an actual radio transmission by Mercury astronaut Alan Shepard, just prior to lift-off.
Because of the patriotic nature of the script and the success of using Top Gun (1986) as recruitment material, the producers persuaded NASA to allow director Michael Bay and company to shoot in the normally restricted space agency. This included the neutral buoyancy lab, a 65-million-gallon, 40-foot-deep pool used to train astronauts for weightlessness and the use of two $10-million space suits. The crew was also allowed to shoot in the historic launch pad that went out of service after the Apollo 1 disaster, and parts of the movie were filmed at Edwards Air Force Base in California.
There is a scene where the meteors are raining down on New York with a short cut to the World Trade Center with a fiery hole punched through the center of one tower and a chunk missing at the top of the other tower. This looks very much like the real images from the terrorist plane strike on the WTC on 9/11/01, 3 years after the film was made. Statistically speaking, this is the most likely distribution of two strikes on a pair of towers (by meteors, planes, or otherwise).
According to the Criterion Collection commentary, many of the errors found in the film were acknowledged by the director and known even during filming/production and were left in deliberately (such as fire in space). Michael Bay said, "It's a movie and not many people know about it", so they were kept in for entertainment value.
The shuttle launches were filmed for real. Disney (Touchstone Pictures) were allowed to put cameras (about 16 of them) all over the place. The camera on the launch pad was shook so hard (25G) that all the screws fell out of the lens and it had to be returned to Panavision in a box of pieces, which they put back together).
During the training of the mission team, an Aerosmith song ("Sweet Emotion") is playing in the background with vocals by Liv Tyler's father, Steven Tyler, who also sings the theme song "I Don't Want to Miss a Thing." The two Tylers appear in the Armageddon music video.
The famous rock in the logo of Touchstone Pictures (one of the production companies) has the same shape as the asteroid that hits the Earth in the first scene, causes global destruction 65 million years ago.
The convenient existence of a fault plane passing right through the asteroid is not unrealistic. Several asteroids are now believed to be "contact binaries", each apparently consisting of two separate lumps of rock that are just sitting on each other.
The astronaut training occurs at NASA's Houston facility. Several scenes indicate that the home headquarters for Harry Stamper Oil is also nearby. On the night the boys are allowed out, Rockhound visits his loan shark, Chick visits ex-wife and son and, in a deleted scene available on the extended version, Harry pays a visit to his father. Since they were only out for 1 night and couldn't travel long distances, by inference, they must be in familiar territory in the greater Houston area.
The original script did not include the romantic subplot between AJ and Grace, and instead had more emphasis on Truman. It was added after the success of Titanic (1997) with teenage girls. Most of the romantic scenes were written by Scott Rosenberg and were filmed late in production.
Director Michael Bay said in a magazine interview that the solution in the movie for dealing with the asteroid was very clever but not realistic, but that one idea for countering the threat was in line with actual NASA research (anti-gravity systems). He also said that a problem with a film like this was that it would make Americans erroneously think that if a situation like the movie actually occurred then there was anything that could be done about it.
On the Criterion Collection DVD, then Disney Chairman Michael Eisner makes a surprise appearance on the space shuttle set to jokingly tell Bruce Willis that he has been fired and replaced with Kevin Costner.
Footage from this film (namely the destruction of the Atlantis space shuttle) was utilized in a hoax which purportedly featured actual satellite photographs of the February 1st, 2003 destruction of Space Shuttle Columbia.
The trivia items below may give away important plot points.
When the Thunderbirds fly over in the final scenes, the formation they are supposed to be flying in is known as the "Missing Man" formation. However, the missing man formation is flown with only four jets, and the #3 jet pulls straight up without using afterburner while the rest of the formation flies in their original positions. This was obviously done for Stamper. It is an extraordinary honor to have this formation flown during a funeral or, in this case, after a mission, equivalent to the riderless horse. The Thunderbirds later flew this maneuver in air shows out of respect for US military personnel lost in the "War on Terror".
Ben Affleck came up with the idea for scenes of AJ and Grace's wedding to be filmed on Super 8. His personal Super 8 camera was used for the shoot, and he held and operated it for all the shots he wasn't acting in. The cake fight was improvised, and the cast threw most of it at Michael Bay.