Star Trek has been around in one form or another for over 30 years. The creator, Gene Roddenbery, had a hard time pitching it to the networks, and then had a hard time keeping it on the air. The original series lasted only three seasons and was severely under-budgeted. If you catch any of these shows, you get to see real ingenuity in doing special effects on a shoestring -- which is about all that some of the alien women got to wear.
When Star Trek (which is now sometimes called Star Trek: The Original Series or TOS, for short) was canceled due to low ratings by NBC, a letter-writing campaign which had been started to help the show slowly but surely turned into a Star Trek fan movement. The term "Trekkie" was coined. TOS began to make its money only in syndicated reruns, and in merchandising.
In the seventies, there was a very short-lived animated series with the real actor's voices.
Twenty years after TOS ran on TV, the whole cast was brought back together for a series of films, which cemented the casts' cult popularity, and introduced them to a new generation of fans. Around this time, some fans preferred to be known as "Trekkers."
The movies proved to be so successful that Roddenbery was able to get Star Trek: The Next Generation on the air. Avoiding networks this time, he sold the show directly into syndication and made a lot of money. Deep Space Nine (DS9) was the first offshoot from The Next Generation, and ran from 1993 - 1999. Voyager, currently the only active series, began in 1995 but will be ending this season. Although popular, DS9 and Voyager have failed to captivate the public's interest as TOS and The Next Generation (TNG) did. However, reruns of all the series can currently be seen on various networks. There are also unconfirmed rumours of yet another TV series...