A Matter of Balance

Space: 1999, a British science-fiction television series, ran for 48 episodes broadcast between 1975-77. The first series (or season, often referred to as Year One) of 24 episodes began transmission in 1975, though production of the first episode began in 1973. In addition, a number of compilation films have been produced using material from multiple episodes, some containing additional footage. A brief, semi-official series denouement was filmed for exhibition at the Breakaway 1999 fan convention, held in Los Angeles, California in September 1999.

Individual episodes are intended to be broadcast in a progressive order so that, for Year One, "Breakaway" should be broadcast first, with "Black Sun" and "Earthbound" being broadcast at an early stage to present the Moon entering a new and different part of space and the Alphans encountering their first aliens. However, many stations in the United States aired "Dragon's Domain" (production number 23) as the second installment after "Breakaway" in September 1975. In the United Kingdom, "Force of Life" (production number 9) was the follow-up to "Breakaway". The other guidelines are that the episodes should progress to show John Koenig's and Helena Russell's relationship develop and blossom. "The Metamorph" should be the first episode of Year Two, followed by the remaining episodes (there is a two-part episode in Year Two) in the order that the days on Russell's status report (which commences each episode) dictates. Regional and national stations aired the series in a wide range of orders. In some cases, this included mixing Year One and Year Two episodes at random.

Original episode air dates below reflect the order of Space: 1999 as broadcast first, in Australia and the UK. The transmission dates given below are those for the UK.

Four films were assembled from various episodes of Space: 1999 in the 1970s and 1980s. One aim was to provide content for new American and European cable and satellite TV stations (and for theatrical release, which occurred in a number of European countries). The fifth film, Spazio 1999, was created specifically for theatrical release in Italy. With the exception of Spazio 1999, the films were released on home video years before individual episodes.

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