Star Trek had a spinoff idea in the works with Assignment: Earth, a spy-drama that centered around a mysterious agent that could’ve killed the brand.
There was an episode of Star Trek: The Original Series that saw the USS Enterprise go back in time to meet a man named Gary Seven, who was basically Superman but from the ’60s. Seven was a genetically enhanced human from an advanced alien planet that was sent to Earth to save humanity. He had a pretty secretary and a shape-shifting cat. The only difference between him and say, any other superhero of the 60s, is that Seven didn’t wear spandex. He was a spy.
The Trek episode was called Assignment: Earth and saw the crew of the Enterprise dealing with Seven and his motley companions. It was designed to be sold as its own series to spin out of the original Star Trek series. Had anyone picked it up as a show, it’s very likely that the Star Trek brand as we know it may have been damaged beyond repair.
The fans of Star Trek were fans of it for a given reason. It was a socio-political drama that featured fantastical aliens and even more fantastical ideas. It was the great escape of an era that was looking for something new to engage with. Assignment: Earth was simply another spy-drama that would’ve given fans something completely different from what they had grown to love.
Seeing as spy-dramas were in-vogue in the ’60s, it’s entirely possible that this, and not Star Trek, would’ve caught on, meaning that any late ’70s revival could’ve been about Assignment: Earth and not the adventures of James Kirk and his swashbuckling boys and girls. Which would have affected the renaissance of science fiction as well. Maybe instead of Star Trek: The Next Generation, it was Assignment: Earth: The new hairball.
It would’ve been awful. Though the idea of Patrick Stewart having to play a shape-shifting cat is rather hilarious.
The problem lies in Hollywood never really changing and not so much the gimmick of a time-traveling, alien-humans. Though that is a silly idea. Had the spin-off been a success, there’s every chance in the world that the Star Trek brand would’ve been buried to a point of non-existence. There was no way to buy the show or rent the show back in the ’60s. So the series survived in reruns through syndication. That may not have happened if Assignment: Earth was able to catch on with viewers.
This was also in an era where spy thrillers were massive. Jame Bond dominated the theaters, while The Avengers, Mission: Impossible, The Man from U.N.C.LE., Get Smart and other iconic spy=series were gaining mainstream appeal. Spinning off Trek into a spy-space thriller could’ve been the final nail in what would’ve been the two-season coffin for Star Trek.
Thankfully, it never came to pass. The third season of Star Trek was made, and eventually became a smash hit in syndication during the early ’70s, prompting the revisiting of the series in film form. Those films inspired The Next Generation, which in turn inspired Deep Space Nine, Voyager, Enterprise, and so on.
Who knows what science fiction as a whole would have looked like had Assignment: Earth ever gotten made into a series.