Ranking every 'Star Trek' movie and TV series from first to worst

We get the science fiction we need at the time we need it. When "Star Trek" premiered on Sept. 8, 1966, the United States was escalating its involvement in the Vietnam War while also reckoning with the civil rights movement -- not to mention waging a cold war with the Soviet Union that seemed always on the verge of heating up. Right along with that tumult was the beacon of scientific hope that was NASA's space program, which in turn stoked the passion of an America obsessed with tomorrow. World's fairs were in the business of showing us the cars, kitchens and cities of tomorrow. Writer-producer Gene Roddenberry channeled those twin poles of the human condition -- strife and hope -- into "Star Trek," the show he pitched to NBC as " 'Wagon Train' to the stars."