Star Trek was coming back to TV until they decided to make it into a film.
Star Wars success influenced the movie decision. But the TV decision was made before the premiere of Star Wars in theaters in May 1977.
I think I would have much preferred a new TV series with Kirk then then the movies. Oh well.
Many of the first scripts were recycled for TNG.
Trek was coming back in some form, regardless of a movie called Star Wars.
It HAD already come back in the Animated Series in 1973 when you really think about it.
Star Trek: Phase II (also known as Star Trek II) was planned to be the first live-action spin-off series of Star Trek: The Original Series.
In 1977, Paramount Pictures began working on the idea of launching a new television network. Following the rapid growth of Trek fandom, and a general growing interest in science fiction programming, Paramount drew up plans to launch a new Star Trek series as the network's flagship programme, covering a second five-year mission. The Enterprise was to be refit, and new characters were to be introduced. By July, construction on the sets began, and the writers' and directors' guide was published in August, with the premiere expected in spring of 1978.
The original cast returned to reprise their roles (with the notable exception of Leonard Nimoy as Spock), alongside several new characters: Xon (replacing Spock as science officer), navigator Ilia and first officer Willard "Will" Decker.
However, as preproduction finished, and work was scheduled to begin on the feature-length pilot, "In Thy Image", the network deal fell through, and, influenced by the success of Star Wars and Close Encounters of the Third Kind, Paramount chose to turn the pilot into a full feature, Star Trek: The Motion Picture, so as to recoup the costs already underwritten.
Several scripts already completed were later used as episodes of Star Trek: The Next Generation. In fact, many of the series concepts from Phase II would become the basis of TNG, such as the "lost love" relationship between new first officer Decker and Ilia would lead to similar scenes in TNG Season 1.