Overview
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 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 airdates below reflect the non-uniform order of Space: 1999 as broadcast worldwide. Space: 1999 premiered on 23 July 1975 in Australia and 4 September 1975 in the UK. The Year Two opener "The Metamorph" was first broadcast on American television in August 1976, several weeks before its British debut on 4 September.
One preferred order is to use the original production order, to account for subtle changes in sets and cast. For Year Two episodes, the number of days since the Moon left Earth orbit is often mentioned in the dialogue, although this number does not always progress consistently. DVD releases have followed this order as well. Another order is suggested by Andrew Kearley on a site that he created as a tribute to and analysis of the series.
Read more about this topic: List Of Space: 1999 Episodes