'Star Trek' 50th: A Look Back at 5 Decades

— -- Fifty years ago today, a TV show boldly went where no program had gone before, launching a franchise that has endured for generations.

The original "Star Trek" series, created by Gene Roddenberry, premiered Sept. 8, 1966. Set somewhere around the year 2260, it followed the crew of the Starship Enterprise: William Shatner's Captain Kirk, Leonard Nimoy's Mr. Spock, George Takei's Sulu, DeForest Kelley's Dr. "Bones" McCoy, Nichelle Nichols' Uhura, James Doohan's Scotty, and, starting in the second season, Walter Koenig's Chekov.

The show was canceled after three seasons because of poor ratings, but became a huge hit in syndication.

It later spawned books, games, comics, an animated series and six movies with the original cast, beginning with 1979's "Star Trek: The Motion Picture" and continuing with classic sequels like "The Wrath of Khan" and "The Search for Spock."

Over the past three decades, additional "Star Trek" TV series aired, including "The Next Generation," "Deep Space Nine," "Voyager" and the upcoming series "Star Trek: Discovery," premiering in January.

The "Star Trek" franchise also continued on the big screen, starting with the 1994 film "Generations," which merged the cast of TV's "The Next Generation" with some of the original series cast members. Subsequent films included "First Contact." In 2009, J.J. Abrams rebooted the franchise; the third film in that new series, "Star Trek Beyond," was released this year.

Reflecting on "Star Trek's" legacy this summer at San Diego Comic-Con, Shatner called it "such a remarkable thing to be connected with," adding, "[I]n this 50 years, this mere television show and its various iterations have expanded to affect a great deal of our culture far beyond anything we know."

He added of the concept and lasting legacy, "It's a lot of fiction, but at the same time, science fiction is mythology and it tries to tackle those things that we can't explain. We, we've invented, through science fiction, a mythology, and ‘Star Trek’ is a huge part of that.”

It's certainly affected Adam Nimoy, the son of Leonard Nimoy, who died last year.

"I was excited as a young boy could be that my dad was going to be co-starring on a new, cool, out-of-this-world, out-of-this-universe TV series about a starship that went from planet to planet," he told ABC News. "I was so excited about that, and the fact is ... that excitement has never left me."

New stars like Zachary Quinto, who has taken on the mantle of Mr. Spock, have adapted the franchise as their own and couldn't be prouder.

"It means that I'm a part of an enduring legacy that is rooted in faith in humanity and optimism and a belief that there's strength and unity and inclusiveness and diversity and those are all ideas that I believe in strongly and am grateful to be a part of," he told ABC News.