Happy Star Wars Day! Since 1978, May the fourth has been recognized as the unofficial Star Wars holiday, and we're celebrating by looking back at some of the things you might not have known about the saga that's almost 40 years old.
Is the force strong with you? Test your knowledge with the behind-the-scenes trivia below.
Harrison Ford, despite working with Lucas before in American Graffiti, was never considered for the role of Han Solo. He was hired to read against the actors auditioning for A New Hope, but Lucas was so impressed with his reading, he chose to give him the role.
David Prowse, the actor who played Darth Vader in his suit, was initially considered for the role of Chewbacca.
Casting the supporting actors, from the documentary Empire of Dreams
Peter Cushing (Grand Moff Tarkin) said his costume's boots were too small and uncomfortable, and so he wore a pair of fuzzy slippers in all shots that didn't show his feet.
A New Hope, released in 1977, remains the highest domestic grossing Star Wars film when adjusted for ticket price inflation, at $1.2 billion. Second place is The Empire Strikes Back at $845 million adjusted dollars.
The design on the Millennium Falcon is said to be based on a burger with an olive attached to its side with a toothpick. Reportedly, it earned the nickname "Porkburger" by the crew.
The sound of the lightsabers were created by sound designer Ben Burtt by waving the microphone across two humming old movie projectors. He later incorporated the buzzing sound after recording a tube television buzz with a broken tape recorder.
The Birth of the Lightsaber featurette
While filming the special effects for A New Hope, Industrial Light & Magic spent half of its budget on only four effect shots that Lucas would later deem unusable. Lucas then edited together scenes of WWII aerial dogfights to show ILM how he planned to pace the action scenes.
How Lucas helped ILM overcome the challenge, from Empire of Dreams
Before the film's release, George Lucas showed an early cut of A New Hope to director friends Brian De Palma, John Milius and Steven Spielberg. All of them, including Lucas, felt the film was a disappointment with the exception of Spielberg, who thought it was bound to be a hit.
A New Hope is the only Star Wars film ever to be nominated for Best Picture.
In each Star Wars film, the line "I have a bad feeling about this" is spoken by one of the characters.
Most of the Stormtroopers are left-handed because their blaster, based on a real weapon, had its magazine on the left side. To prevent the magazine from bumping themselves in the chest, many of the right-handed actors switched the gun to their left hand.
Anthony Daniels (C-3PO) was never intended to also voice his character until post-production. Originally, 3PO was meant to sound like a "used-car salesman," but Lucas grew to like the "snooty British butler" voice Daniels had created.
During the filming of Star Wars: A New Hope, Peter Mayhew (Chewbacca) was working as an orderly in a London hospital when not donning the hairy suit.
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When Luke is trapped inside the wampa's cave and uses the force to retrieve his lightsaber, the effect was achieved by having Mark Hamill toss the lightsaber away until it stuck in snow. Afterward, the film was reversed.
The extremely tall AT-AT Imperial walkers, first seen in the Hoth battle, were inspired by the walking machines described in H.G. Wells's "War of the Worlds." The way they walk is based on elephants.
Iconic bounty hunter Boba Fett took a lot of his costume design from early concepts of Darth Vader, who at one point was conceived to look more like a mercenary than a dark knight.
Initial 1978 Boba Fett costume screentest
Part of the inspiration behind freezing Han Solo in carbonite came because nobody was sure if Harrison Ford would come back for Return of the Jedi. Some executives suggested the character be killed off at this point in the series, but Lucas decided he still had more in store for Solo.
The role of Yoda was originally offered to puppeteer Jim Henson, famous at the time for his role of Kermit the Frog, who turned it down. Henson recommended Frank Oz, famous for playing Kermit's wife Miss Piggy, who got the part.
Because secrets about the plot were so closely guarded, not even actor David Prowse (Darth Vader) knew his character was claiming to be Luke's father. Prowse was told the line was "Obi-Wan killed your father," which was later dubbed as "I am your father" by voice actor James Earl Jones.
Steven Spielberg was Lucas' first choice to direct Return of the Jedi, but he declined because he was still a member for the Director's Guild, which Lucas had previously left to due disagreements over The Empire Strikes Back. As a result, Lucas chose non-union director Richard Marquand.
After Darth Vader claimed to be Luke's father in The Empire Strikes Back, many moviegoers (as well as the voice of Vader, James Earl Jones) thought Vader was lying. In order to cement the truth, Lucas rewrote the script to have Yoda -- who was not to appear in the film at all -- confirm Luke's heritage early on in Return of the Jedi.
Jabba's interrogator droid EV-9D9, who assigns C-3PO and R2-D2 their new jobs, was voiced by the film's director Richard Marquand.
The sound of Jabba's slimy slithering was created by sound designer Ben Burtt running his hands through cheese casserole.
The growls and snarls of Jabba's pet Rancor were actually voiced by a dachshund.
While filming Jabba's sail barge scenes in Arizona, the set was often interrupted by dune buggy enthusiasts. In order to preserve the film's secrecy, producers told passersby that they were making a horror film called "Blue Harvest" with the tagline "Horror beyond imagination." They even had caps and T-shirts made up for the crew. Producers continued to use this faux title throughout production.
Emperor Palpatine's name was originally meant to be Palantine, after a character in Martin Scorsese's Taxi Driver (1976). The name was changed to avoid legal problems.
Ian McDiarmid talks about creating The Emperor's voice
The Walt Disney Company is the parent company of both Lucasfilm and this station.
Got any more Star Wars trivia you'd like to share? Let us know in the comments below.