"Space Seed" co-writer and story creator Carey Wilber dreamt up the plot years earlier for Captain Video, a pioneering, low-budget sci-fi show from the early 1950s. There were some major differences, however, as the original narrative involved Ancient Greeks with mythological powers awakening from cryogenic suspension in outer space.

So, yeah, the "Khan" character was originally a Greek, and obviously not named "Khan." When Wilber pitched his old idea for Star Trek, he changed the antagonist to a Nordic named Harold or John Ericssen, who is later revealed to be a vicious Viking space pirate named Ragnar Thorwald. Roddenberry was apprehensive about using such outward criminals. Oddly, Lost in Space would air its episode "Space Vikings" (seen here) a week before "Space Seed."

Mexican actor Montalbán was hardly a good fit to play a Scandinavian, so the villain was tweaked. However, this being Hollywood in the 1960s, producers figured he could play a Sikh. (That being said, he must not be observant, as he does not wear a Dastar.) Roddenberry and writer Gene Coon changed the name to Sibahl Khan Noonien… until a fact-checking research company noted that "Singh" is a much more appropriate Sikh surname. They suggested the name "Govin Bahadur Singh." Coon and Roddenberry met them halfway and settled on the canonical Khan Noonien Singh.

In 1956, Roddenberry wrote one of his first pieces of TV sci-fi, "The Secret Weapon of 117," which appeared as an installment of the syndicated anthology series Chevron Hall of Stars. The episode featured Montalbán. In 1964, the actor again worked with Roddenberry on his earlier military series The Lieutenant.

Image: AP Photo

Another reason for constant script changes was the apprehension of producer Bob Justman, who felt the teleplay was too expensive to shoot. Despite scaling back the story to focus on core cast members and primary sets, special effects and model costs led to the episode going over budget.

At the beginning of Star Trek II: The Wrath of Khan, Chekov encounters a vengeful Khan, who puts that creepy bug in the Starfleet Commander's ear. Khan immediately recognizes Chekov from the events of "Space Seed." There is just one major problem: Chekov was not aboard the Enterprise for that first-season episode. In fact, Walter Koenig did not join the cast until season two. Tie-in novels have since tried to explain this plot hole, while Koenig jokes they met in the restroom. Sulu is also not in "Space Seed."

Image: Paramount / Giphy

Before he was Khan, Montalbán played a Native American named Matsou in "Day of Reckoning." The future Fantasy Island lead talked about his time on Bonanza with the Archive of American Television, explaining how the role forced him to lose his temper. Rhue, who portrayed Marla McGivers in "Space Seed," the Enterprise historian and lieutenant who fell for Khan, also played his love interest, Hatoya, in "Day of Reckoning."

Paramount had hoped to bring back Rhue and McGivers for The Wrath of Khan, however the actress had been diagnosed with multiple sclerosis in 1977 and was unable to appear in the role. They decided to write out the character rather than replace Rhue.

With "Space Seed" going over budget, Desilu Productions had to get its money back somehow. Khan's ship, Botany Bay, suspiciously popped up again a year later as the ore freighter Woden in "The Ultimate Computer." In digitally remastered versions of Star Trek, the Woden has been replaced with a unique CGI spaceship.

The original script called for the character of Yeoman Baker, who was to be played by Barbara Baldavin. The actress had appeared in two earlier episodes as Angela.

Wooden spaceships seem like a bad idea. READ MORE