across the galaxy. Therefore, it would be an example of soft science fiction. Star Trek could also be technical. In the episode "The Changeling," Nomad is an Earth space probe that becomes damaged, and then somehow merges with the alien probe Tan-Ru. Its programming somehow changes, and it now seeks out and destroys imperfect life-forms. Nomad destroys the Malurian System's four billion inhabitants, and then encounters the Enterprise. Kirk and his crew discover Nomad's past and its new programming, and have to stop it before it destroys any more races. This, of course, they do. This is a classic case of out-of-control technology. Without Nomad, the technological artifact, there could have been no story. Science is used to analyze Nomad, and to determine how to defeat it. Therefore, this episode is an example of hard science fiction. In this new form, Star Trek ran for three years until 1969, although it was never a huge ratings hit and stopped two years short of its planned five-year run. Only a fan campaign had prevented it from being canceled after the second season, but despite this apparent unpopularity, the show had a special quality to it that attracted a loyal fan base, and during syndication of the program in the early 1970s it proved to have an enduring popularity that would not go away. An animated series was commissioned, and eventually in the late 1970s a sequel series, Star Trek: Phase II was planned and work begun. However, after the success of Star Wars in the cinema, Paramount scrapped the idea of a new series and decided instead upon launching Star Trek as a film franchise. Star Trek would return to the small screen in a new form in due course, but not until 1987, some eighteen years after its original cancellation. Star Trek's propensity for social commentary, in an era when American viewers were more receptive of it, was a factor in the rise in popularity of science fiction in American culture in the late 1960s. Much of this rise came at the expense of the more traditionally-positioned TV western, which collapsed in popularity at the same time. 1970s Apart from repeats of Star Trek gathering popularity in syndication, the early 1970s proved to be at something of a low ebb for television science fiction in the US. Very few series of any great note or popularity were produced, and few