- Ability over Appearance: Several of the main actors top 6 feet (183 cm) (Dennis Quaid and Scott Glenn in particular). However, none of the actual astronauts were over 5'11" (180 cm), as that was the maximum height allowed by the cramped Mercury capsu—er, spacecraft. Gus Grissom, who was 5'5" (165 cm) in real life, was portrayed by the 5'10" (178 cm) Fred Ward. The 5'10" Wally Schirra was, however, portrayed by the 5'10" Lance Henriksen.
- Acclaimed Flop: Despite being critically acclaimed and having been nominated for eight Oscars, the film failed to make back its budget.
- AFI's 100 Years... 100 Cheers: #19
- Box Office Bomb: Budget, estimated between $19 million to $27 million. Box office, $21,192,102. The triple-hit knockout of this film, Twice Upon a Time, and Once Upon a Time in America (the third of which became the unfortunate victim of Executive Meddling) led to the film's executive producer Alan Ladd, Jr. to shut down his production company and leave Warner Bros., and while he was appointed executive of MGM/UA just a year after the third aforementioned film's release, he would not return to his own and produce another film until Braveheart.
- California Doubling: Averted. Location managers are not likely to find a place more desolate than Edwards AFB, although the "Australia" in the film looked a lot like some of the more desolate places on the base...
- Cast the Runner-Up: Scott Glenn was initially considered for the role of Chuck Yeager, but he expressed that he would rather play Alan Shepard, and was cast in that part instead.
- Channel Hop: The film was originally picked up by United Artists, who outbid Universal Pictures for the rights to the book. They eventually put the film in turnaround and it was picked up by The Ladd Company.
- Creator Killer: Along with Twice Upon a Time and Once Upon a Time in America, this film's high-profile box office failure was credited for bringing down the company of famed Hollywood executive Alan Ladd, Jr.
- Disowned Adaptation: Tom Wolfe was unhappy with the film, because he felt it made too many changes to the book.
- Executive Meddling: The military insisted that swearing be removed from the movie so that it would get a lower rating, becuase they wanted teens to watch it and join the army.
- Fatal Method Acting: The stuntman portraying Chuck Yeager's bailout of the crashing F-104. His helmet filled with smoke, and he didn't get his parachute deployed. Yeager himself — a technical adviser for the film as well as giving his cameo — not only refused to re-enact the flight (he did most of the flying filmed), he had warned against stunt personnel doing so, warning that it would almost certainly be a fatal mistake. The scene is also a strange bit of Truth in Television, as Yeager actually collided with his seat after ejecting, and his helmet filled with liquid explosive materials, similarly filling his helmet with smoke and burning his face to a cinder. The aftermath is portrayed in the Out of the Inferno shot listed on the main page.
- Irony as She Is Cast: Sam Shepard, who played legendary pilot Chuck Yeager, was actually afraid of flying.
- Reality Subtext:
- Towards the end of the movie, Alan Shepard tells his wife Louise, in a "one of these days..." manner, "I'm going to the moon...". Shepard would be the only one of the Mercury Seven who would go to the moon, on Apollo 14 note .
- During the astronaut tryouts in the movie, Gordon Cooper gloats about breaking the record for holding one's breath, only to realize that John Glenn and Scott Carpenter are still going after he's done. In real life, Cooper did hold his breath the longest, since he was the only non-smoker in the Mercury Seven.
- At the movie's end, before Cooper lifts off on his mission, he's shown dozing off. Cooper was the first astronaut to sleep in outer space.
- The real John Glenn tried to use this for a presidential run in 1984. He didn't make it out of the Democratic primaries, finishing sixth with only two delegates.
- What Could Have Been:
- William Goldman was originally hired to write the script. This version focused on the astronauts, entirely ignoring Chuck Yeager.
- John Barry was the original composer, but left because he found it impossible to understand what Philip Kaufman wanted from the score, citing a meeting where Kaufman described his ideal score as "sounding like you're walking in the desert and you see a cactus, and you put your foot on it, but it just starts growing up through your foot."
Trivia / The Right Stuff