8 Crazy Behind-The-Scenes Secrets From Classic Sci-Fi Movies

Keir Dullea in 2001: A Space Odyssey

Ever since I first caught part of The Terminator as a young kid on cable, I have been obsessed with the sci-fi genre. That obsession has only grown over the years, and whenever I upgrade my home theater experience, I always test out the new tech with some of my favorite movies (Terminator 2: Judgment Day was my first Blu-ray; 2001: A Space Odyssey my first 4K Blu-ray). Along with the upgraded visuals and dynamic sound, I also like to dig through the bonus features to learn all the sci-fi movie secrets to find out how all those iconic scenes came together.

So, it's easy to imagine how excited I was when I was tasked with coming up with a list of behind-the-scenes secrets from classic sci-fi movies. To share my love of the classics, how they came together, and the genre as a whole, I’ve put together eight crazy facts about the making of everything from The Day the Earth Stood Still to RoboCop and everything in between.

Heather Downham in 2001: A Space Odyssey

The Floating Pen In 2001: A Space Odyssey Was Pulled Off With Double-Sided Tape And A Pane Of Glass

Stanley Kubrick’s 2001: A Space Odyssey is not only one of the best sci-fi movies of all time, it also has a permanent spot in the annals of cinema. From the “Dawn of Man” opening segment to the terrifying presence of HAL 9000 later on, there’s an endless list of reasons why the movie is still held in such high esteem. One of the biggest reasons is the impressive work from the special effects crew, especially the plan they drew up to replicate a zero-gravity shuttle scene. In the Making a Myth documentary, special effects artist Brian Johnson revealed that he and his crew used double-sided tape to attach a pen to a circular sheet of glass that was surrounded by a steel frame and bearings that allowed them make it as if it was floating.

The Alien cast

The Alien Cast Didn’t Know The Full Extent Of The Famous Chestburster Scene Until They Started Filming

There are few moments in Ridley Scott’s Alien that are more terrifying than the chestburster scene. But as traumatizing as it was for the millions who watched the movie in theaters and countless others who have watched in horror over the years, nothing will quite compare to the reactions of the cast on set.

In a 2015 BBC Breakfast interview, Sigourney Weaver, who portrayed the badass Ellen Ripley in Alien, explained that the cast knew about the scene before going into shooting, but the script did not prepare them for what came next. The first shot called for John Hurt’s reaction to the Xenomorph preparing to pop through his chest and was so realistic Weaver thought her co-star was dying. The next shot, however, featured the actual puppet popping through the fake chest with blood squirting around the set. Weaver revealed that the actors’ reactions seen in the movie are genuine.

The T-800 in The Terminator

The Idea Behind The Terminator Came To James Cameron In A Fever Dream

Like a lot of artists, the idea behind The Terminator came to James Cameron when the film’s writer and director least expected. In the the documentary The Making of The Terminator, the visionary and award-winning director revealed that the concept of his landmark film came to him in the state of a fever dream while in Rome promoting Piranha II: The Spawning, revealing:

I was just sitting around in my hotel room. I was in fact sick at the time, I had a real high fever. I was just lying on the bed thinking, and came up with all this bizarre imagery. I think, also, the idea that because I was in a foreign city by myself and I felt very dissociated from humanity in general, it was very easy to project myself into these two characters from the future who were out of sync, out of time, out of place.

James Cameron would go on to explain that he had always wanted to make the definitive robot movie and so he took the idea that came to him in the fever dream and turned into The Terminator as we know it today.

Arnold Schwarzenegger, Linda Hamilton and Leslie Hamilton in Terminator 2: Judgment Day

Linda Hamilton’s Twin Sister Helped Pull Off The Sarah Connor Mirror Trick In Terminator 2: Judgment Day

Terminator 2: Judgment Day is arguably the greatest summer blockbuster of all time and is filled with one iconic special effects shot after another. And while there are a ton of state-of-the-art visual effects pulled off with advanced computer technology one of the movie’s biggest tricks — the reflection of Sarah Connor (Linda Hamilton) — was pulled off in a more practical but equally clever way: Hamilton’s twin sister, Leslie.

In an August 2020 EW article announcing Leslie Hamilton’s death, it was revealed the twin sister of the franchise’s star’s only film credit came when she appeared as the T-1000 impersonating Sarah Connor as well as in the scene in which the the hero is seen in a mirror working on the T-800.

Linda and Leslie Hamilton weren’t the only twins to appear in the 1991 blockbuster, as Dan and Don Stanton were used to pull off the scene in which T-1000 (Robert Patrick) replicates one of the orderlies in the mental hospital scene.

The Dog-Thing in The Thing

Special Effects Icon Stan Winston Created The Dog-Thing Puppet In The Thing But Didn’t Ask For Credit

The majority of the special effects in John Carpenter’s 1982 sci-fi horror flick The Thing were handled by the legendary Rob Bottin. But when his team was stretched thin throughout the film’s production, Bottin called on the services of the late Stan Winston and his team came up with a rather simple approach to creating one of the film’s most iconic moments: the nightmarish Dog-Thing seen in the epic dog kennel scene.

With little time, Stan Winston and his team worked around the clock to get something in working order. After everything was completed, however, Winston asked that he not be credited for his work so that he wouldn’t take anything away from Rob Bottin and the impressive work he did on the rest of the movie, per the Stan Winston School of Character Arts.

Jeff Bridges and Cindy Morgan in Tron

Tron Was Shot In Black-And-White With The Color Added In During Post-Production

To make Jeff Bridges and the rest of the Tron cast look like they were digitized characters, the production team came up with an ingenious method that didn’t require hours and hours of computer work like other aspects of the movie. In a 2017 Variety retrospective released on the 35th anniversary of Tron’s release, it was revealed that the actors were dressed in white clothing and were shot in black-and-white. After that, backlit animation would be added to give them that iconic wavy coloring that we all know today.

Kurtwood Smith and Peter Weller in RoboCop

Peter Weller, Training For The New York City Marathon While Filming RoboCop, Hung Out With The ‘Bad Guys’ Because They Were ‘Health Freaks’

Detroit police officer Alex Murphy goes to Hell and back in Paul Verhoeven’s over-the-top sci-fi action flick RoboCop, and the same thing can be said about the Peter Weller, the actor who played the slain officer-turned-cyborg created to wipe the streets clean of crime in a dystopian Detroit.

In an SFX retrospective on the making of the 1987 cult-classic, Weller explained that in addition to having to sit through hours of costuming before shooting each day, he was also in the process of training for the New York City Marathon. But he didn’t turn to any of his on-screen allies for help and support during all this. Instead, he ended up hanging around with all the “bad guys” like Kurtwood Smith, Ray Wise, Calvin Jung, and Paul McCrane, who were all “health freaks.” See, RoboCop’s Boddicker gang isn’t all that bad after all.

The Actor Who Played Gort In The Day The Earth Stood Still Was First Spotted Working At Grauman’s Chinese Theatre

The giant robot, Gort, featured in the 1951 version of The Day the Earth Stood Still wasn’t brought to life with crafty camera tricks or special effects but instead through the actions of the 7-foot-7 Lock Martin. In a 2011 breakdown of the sci-fi classic’s iconic final scene by the Independent, it is revealed that when the film’s producers were trying to come up with the right actor to take on the role of the silent robot, someone remembered seeing Martin, a tall doorman at Grauman’s Chinese Theatre in Hollywood.

Lock Martin would later pass away in 1959 following a series of appearances in various film productions, with his final appearance being an uncredited performance as the Yeti in The Abominable Snowman of the Himalayas.

These are just a few of the crazy behind-the-scenes secrets from some of cinema’s great sci-fi classics. And while some are more impressive than others, each of these secrets will surely make you want to go back and watch them again and see if there is anything you can spot. In the event you’ve seen all of these classics and already know all these facts, go ahead and check out CinemaBlend’s list of 2021 new movie releases to see when the next great sci-fi movie will come your way.

Philip Sledge
Content Writer

Philip grew up in Louisiana (not New Orleans) before moving to St. Louis after graduating from Louisiana State University-Shreveport. When he's not writing about movies or television, Philip can be found being chased by his three kids, telling his dogs to stop barking at the mailman, or yelling about professional wrestling to his wife. If the stars properly align, he will talk about For Love Of The Game being the best baseball movie of all time.