Acting for Two: Dick Tufeld provided the voice of the robot as well as the opening narration "Last week, as you may recall.."
Beam Me Up, Scotty!: Despite the popularity of the phrase, Robot B-9's infamous supposed catchphrase "Danger, Will Robinson!" is said exactly once in the original show, in the episode "The Deadliest of the Species". The phrases "Warning" and "Danger" would be would used throughout the series, however.
The Cast Show Off: Billy Mumy, a talented guitar player and singer, got to perform "Green Sleeves" in one episode and "Sloop John B" in another. Also, Guy Williams, who played Zorro, got to show off his fencing skills more than once.
Corpsing: The whole cast, but especially Billy Mumy and Angela Cartwright, have trouble holding in their laughter when Jonathan Harris starts Chewing the Scenery. And as noted above, the ridiculous villain in "The Great Vegetable Rebellion" provoked this reaction in more than one cast-member.
Creator's Favorite: Bill Mumy has said in interviews this was his favorite role of all time and would jump at the chance to play it again.
Dueling Shows: The great contemporary rival of Star Trek, which CBS passed over for this series. (Ironically enough, after several mergers and acquisitions, CBS now ownsStar Trek.)
Fake American: Both daughters are played by non-American actresses (Marta Kristen, who played Judy, is originally from Norway; while Penny's actress, Angela Cartwright, is British).
Angela Cartwright is actually British-American, born in Great Britain but having moved to the US several years before Lost In Space originally aired, hence her convincing American accent in the series.
Friendship on the Set: Between Bill Mumy and Jonathan Harris, also an example of Intergenerational Friendship. Mumy and Harris remained friends after production ended and for decades afterwards, with Mumy even asked to give the eulogy at Harris's funeral.
A sea monster outfit that had been featured on Voyage to the Bottom of the Sea might get a spray paint job for its, while space monster costumes were reused on Voyage as sea monsters. The clear round plastic pen holder used as a control surface in the episode "The Derelict" turned up regularly throughout the show's entire run both as primary controls to activate alien machinery (or open doors or cages), and as background set dressing; some primary controls were seen used in episodes such as Season 1's "The Keeper (Parts 1 and 2)", "His Majesty Smith", and Season 3's "A Day At The Zoo", and "The Promised Planet".
Spacecraft models were also routinely re-used. The foreboding derelict ship from season 1 was redressed to become the Vera Castle in season 3. The Fuel Barge from season 2 became a Space Lighthouse in season 3. The derelict ship was used again in season 3, with a simple color change. Likewise the alien pursuer's ship in "The Sky Pirate", was lifted from the 1958 film War of the Satellites, and was re-used in the episode "Deadliest of the Species".
The Jupiter 2 set from the 2004 pilot (see below) was reused by Battlestar Galactica (2003) as the bridge of the Pegasus.
Young Sheldon: In "A Pink Cadillac and a Glorious Tribal Dance", Mr. Givens is dressed as Doctor Smith for the comic con. He and Star Trek fan Nathan get in an argument over which is the better show.
Throw It In!: When the episode guest-starring Al Lewis came in a couple minutes short, Lewis suggested they fill it with a routine he'd used in his vaudeville days, with Dr. Smith repeatedly turning around on his way into the spaceship to mention something he'd forgotten, to Lewis' increasing frustration.
Wag the Director: Jonathan Harris was given an extremely rare level of creative control for an actor, often completely rewriting all his lines (every single insult toward the Robot came straight from him).
Working Title: The series was originally titled Space Family Robinson, but was changed as CBS was concerned that the title was too close to the title of Swiss Family Robinson. Also, Gold Key comics had been publishing a comic book called Space Family Robinson with a different Robinson family who were lost in space some time before the TV series began. Interestingly, after this occurred, the comic book added the words "Lost in Space" to its title although its characters remained the same, suggesting that the TV show producers may have allowed this tie-in with their show by the comic book in order to avoid a possible plagarism suit.
The film
Box Office Bomb: Budget, $80 million. Box office, $69,117,629 (domestic), $136,159,423 (worldwide). It ended Titanic (1997)'s historic 15-week reign at the top of the box office, but declined soon after.
I pretty much disavow Lost in Space because, for whatever fucking reason, they decided to dub half my performance with some other person and watching it is an abomination. You think, how drunk were they when they decided that the audience wouldn't notice it's two completely different people even with one line.
Cut Song: British band Lighthouse Family recorded the song "Lost in Space" for this film, but the producers decided not to use it. It wasn't released for two months after the film's US release.
Dawson Casting: Heather Graham was twenty seven, making her only 14 years younger than her mother and 12 years older than her oldest sibling.
After escaping the planet, "Older Blawp" appears on the ship again after "baby blawp" hops onto Penny's shoulders. The older alien was removed in the final cut.
More dialogue between John and Don before they get attacked by "future robot".
The inside of the "time bubble" was originally sunny and orange, but was changed to cold and blue in final version.
More dialogue between Smith, Don, John, and Judy in the "Hydroponics" garden on the "Proteus" after finding Blawp.
Several scenes in the time bubble were cut including: scenes showing different time portals including "THUNDER PORTAL" and "SNOW PORTAL"
Fake American: In the movie the Bad Future version of Will Robinson is played by English actor Jared Harris. Though most of his dialogue was dubbed over by an American actor, Lex Langnote Who, like Harris, seems to see this as an Old Shame, as his website once listed his looping for Gary Oldman and William Hurt only.
Kids' Meal Toy: Which is also the only time Long John Silver's did such a tie-in.
The Merch: Trendmasters contributed an impressive toyline, and even gave the classic B-9 robot a lot of love. Unfortunately, the failure of the movie to spawn a franchise might have killed Trendmasters' presence.
The Other Marty: Sean Patrick Flanery was originally cast as Don West, but he was let go while the project was still in rehearsal because it was thought that he too closely resembled William Hurt.
So My Kids Can Watch: Gary Oldman was the first member of the cast to sign on, jumping at the chance to appear in a family film.
Star-Derailing Role: Riding high on the peak of his Friends heat, this was Matt LeBlanc's big attempt to jump from the small to the big screen. The film proceeded to completely tank, and his performance was thoroughly dragged by fans and critics. He returned to TV and has not made another huge big screen attempt since.
Stillborn Franchise: The cast had signed three-film contracts. The movie was only mediocre at the box office so no sequels came. The DVD Commentary track even has screenwriter Akiva Goldsman saying what he planned for follow-ups. The sequel would have been about the Robinson family making it to Alpha Prime. However, they'd discover that Alpha Prime is already populated with humans because they previously went through a wormhole in the first movie that sends them into the future. There would also have been a sub-plot with Judy Robinson creating a cure for Dr. Smith to prevent the spider infection from turning him into Spider Smith and Penny ending up receiving the same color-changing abilities as Blarp has.
Ironically, Bill Mumy and Jonathan Harris, the two actors most supportive of the idea of a new movie (as well as the two most popular characters on the show), did not appear. Mumy wanted to play the older Will Robinson but the director thought it would be too distracting from the plot to have the original Will play the older Will. Harris was to have played the man who hired, then betrayed, Dr. Smith. In an interview for TV Guide prior to the film's release, it was mentioned that Harris bluntly stated, "I will have you know I have never done a walk-on or bit part in my life! And I do not intend to start." He announced that if he could not play his own role in the movie, he wanted nothing to do with it - famously being quoted as saying "Either I play Doctor Smith, or I do not play."
. Understandably, and fortunately, wiser heads prevailed.