I've loved Star Trek since I was a little kid. I've seen every movie and episode of the TV series (including Enterprise) at least once if not many more times, and I happen to know more nerdy tech specs about each space station and ship on the show than a normal person should.
Some know that actor George Takei who played ensign Sulu in the original Star Trek series was a closeted gay man and today is a huge advocate for LGBT people's rights. Star Trek was historically a controversial show for its depiction of every gender, race, and even alien as equal members of society, many serving as professional officers in Starfleet.
In years of production, the show's original author Gene Roddenberry and his successors depicted various bizarre cultures, alien marriage structures, rituals, sexuality, foreign art and cultures all coming together in heroic adventures in the pursuit of scientific knowledge. Their mission was simple: "to seek out new lifeforms and new civilizations, to boldly go where no one has gone before."
Side note, the show's original slogan was changed from "boldly go where no MAN has gone before" to "boldly go where no ONE has gone before" by Gene Roddenberry out of respect for the diversity of the characters in gender and also the non-binary gender identities of some aliens.
In all of these episodes however, a human same-sex couple was never depicted. A single episode, "Rejoined" airing 1995, contained overarching themes of love between two biologically female aliens but otherwise LGBT people were not represented in the series.
It has been announced that one of the new Star Trek Movies releasing later in July 2016 will depict Hikaru Sulu - the ensign from the original series mentioned above - as an openly gay man with a husband and child. For the first time in Star Trek's history, a member of the LGBT community will be openly represented as a member of the diverse culture of Starfleet.
I've spent a lot of my childhood pretending I was one of the officers on one of those starships. Now, I can watch someone like me piloting the U.S.S. Enterprise herself. It's a great day to be a gay nerd!