After creating and producing a number of puppet shows for kids during the 60's, Gerry Anderson felt he was ready to branch out and try a live-action series. He'd produced one live-action film, "Journey to the Far Side of the Sun", also known as "Doppleganger", but in 1970, his first live-action series, aimed at adults, hit the air in England.
UFO was set in the then-future time of 1980, when it was feared aliens would invade the earth. Ed Bishop, who had worked on the puppet series, Captain Scarlet & the Mysterons, toplined as Straker, the leader of a government agency tasked to uncover the pending invasion.
The series, however, lasted 1 season, par for the course for ITC's dramas not named The Saint. In fact, you'd be hard pressed to find a British series other than Doctor Who, The Saint, or The Avengers that has had a long shelf life.
In 1972, ITC syndicated UFO in the US, and at first, were entertaining the idea of reviving the show, but as ratings here dipped near the end of the season, ITC changed its tune and the series was permanently dry-docked in cancellation. A couple of years later, Anderson reworked his pitch for the UFO revival into a new series that would last at least 2 years, and is more familiar to American audiences---Space: 1999.
Right now, let's scope the first part of the series premiere, "Identified":
Barry Gray, who composed the music for virtually all of Anderson's productions, was the musical director here, as well.