'Star Wars' opened on this day in 1977

— -- On May 25, 1977, fans were introduced to a galaxy far, far away.

While 20th Century Fox had little faith a movie called "Star Wars" would be a hit, the space opera from young filmmaker named George Lucas became a worldwide cultural phenomenon.

Forty years, and a handful of sequels, prequels, and follow-ups later, the multibillion-dollar franchise is a popular as ever.

After a successful re-launch with J.J. Abrams' "Star Wars: The Force Awakens" in 2015, fans also flocked to the first standalone "anthology" movie, 2016's "Star Wars: Rogue One." In December, we'll see the eighth chapter of the core franchise, "The Last Jedi."

Next year comes a film about the early days of Han Solo, scheduled for a May 25, 2018, release, followed by "Episode IX" on May 24, 2019. There's also at least one other rumored standalone film about the early adventures of another fan favorite character.

Mark Hamill, who plays Luke Skywalker in the franchise, thanked fans for their years of dedication at a panel at the Star Wars Celebration in Orlando last month.

"It's almost moving when you really think about how we've affected so many people, inspired so many people," he told fans. "[I]t's generational -- that it's handed down: the original fans are grown, with children of their own."

He added, "It's a gift, and something I will never take for granted."

Of course, any "Star Wars" anniversary reminds fans that Carrie Fisher, who played Princess Leia -- later General Leia -- is no longer with us. In the latest issue of Vanity Fair -- which features different "Star Wars" stars on four different covers -- Lucasfilm president Kathleen Kennedy says the late actress was determined to be the hero of "Episode IX," coming in 2019.

"The minute she finished [shooting 'Episode VIII'], she grabbed me and said, ‘I’d better be at the forefront of 'IX!'’ Because Harrison [Ford] was front and center on 'VII,' and Mark [Hamill] is front and center on 'VIII,'" says Kennedy. "She thought 'IX' would be her movie. And it would have been.”

As for Hamill, he tells Vanity Fair, "I can't say that phrase ... Carrie's name and then the 'd-word.' Because I think of her in the present tense. Maybe it’s a form of denial, but she’s so vibrant in my mind, and so vital a part of the family, that I can’t imagine it without her.”

Hamill also reveals that he and Fisher were "really attracted to each other" back in the day, and even had "makeout sessions," until they decided to pull back for fear of harming their relationship. In the "Star Wars" universe, of course, Luke and Leia were twins, but in that original film, they didn't know that.

"Star Wars: The Last Jedi" opens Dec. 15 from Disney, parent company of ABC News.