Alternate versions

A number of syndicated and video-released TV movies were created by editing together assorted episodes. These are: Alien Attack (1976), _Destination Moonbase Alpha (1976) (TV)_,Journey Through the Black Sun (1982) and Cosmic Princess (1982).

In 1999, a special 7-minute film called "Message From Moonbase Alpha" was created for showing at a Space: 1999 convention held on Sept. 13, 1999 -- the day the moon was blasted out of earth orbit. Original series actress Zienia Merton appears as her character Sandra in this short, written by series writer Johnny Byrne. The film takes place 20 years after the time of the series, and has Sandra recording a final message as the crew of Moonbase Alpha prepares to abandon the moon once and for all.

Three episodes were edited together into the movie Spazio: 1999 (1975) for release in Italy. This film, which has been released to video in Italy, features new music by Ennio Morricone.

The first episode of season two, "The Metamorph," was first broadcast in the US in a slightly different edit than that shown in Britain and later syndication. During the original run, many American stations cut key scenes from the episodes in order to fit time slots. The Sci-Fi Channel reruns of "Space: 1999" were reportedly heavily edited. When the first two episodes were edited into the TV-movie, Alien Attack (1976), several additional scenes were filmed using non-regulars.

The North American DVD release includes footage not included in original US broadcasts.

In Germany for unknown reasons only 30 episodes were dubbed by the ZDF (Zweites Deutsches Fernsehen), the other 18 have never been broadcast. Many of the shown episodes were cut by up to 10 minutes. The main theme by Barry Gray (season 1)/Derek Wadsworth (season 2) was deleted from all episodes, instead "Oxygene Part 2" by Jean-Michel Jarre was used. The introductions which came before the main titles were also deleted.

At the MainMission:2000 convention in New York City, Eric Bernard presented three re-mastered episodes with enhanced special effects: "Breakaway," "Another Time, Another Place" and "The Testament of Arkadia."