Ouma was meant to be a regular character, but people disliked working with Lon Satton (allegedly hitting on female cast members), so he was fired from the series after this episode.
Consideration had been made to produce the series in Hollywood, but it was decided Britain would be more cost-effective. Pre-production and rehearsals began in late August 1973 at EMI-MGM Elstree Studios (where Gerry Anderson's series The Protectors (1972) had wrapped up early that year), but three weeks later MGM vacated the premises, placing the studio under threat of closure. Under the cover of darkness, Space:1999's entire production moved to Pinewood Studios one weekend, where all of the sets had to be rebuilt. As a result of this "moonlight flight", they were blacklisted by the unions. As soon as that had been sorted out, the British government imposed a "three-day work week" (which was in progress by the time this episode was finished filming), which lasted three months, to try and deal with the oil crisis (and coal-mining strike) at the time. Getting the series off the ground wasn't a slam-dunk.
Originally conceived as a new season of UFO (1970). The plot would have had the aliens from that series trying to destroy SHADO's moon-base by knocking the moon out of orbit. Retooled to a new series - going through various tentative titles including "Menace in Space" (referring to the Alphans) - the show was planned with 26 half-hour episodes taking place in 1999. The pilot episode titled "Zero G", written by Gerry Anderson and Sylvia Anderson, retained the concept of having aliens knocking the moon out of orbit, but with the Earth being destroyed in the process. However, ITC's Abe Mandell (who would prove to be a thorn in the side of the entire production of the series) demanded format changes, believing American viewers wouldn't feel comfortable with the thought of the Earth being destroyed. The show ended up being reworked further, including adopting the new title Space:1999, with a new 90-minute pilot script titled "The Void Ahead", written by George Bellak (hand-picked by the Andersons as the show's Script Editor, as ITC insisted on an American in that role), who abandoned the alien concept. Bellak became instrumental in outlining the series' concepts and characters, but being side-tracked with other writing projects caused friction between he and Gerry Anderson, causing him to resign. "The Void Ahead" was re-written by Christopher Penfold (who had originally been hired as Gerry Anderson's assistant in developing UFO's second season and had been assisting Bellak in the development of this new series) into a 60-minute pilot retitled "The Turning Point", but Penfold gave Bellak the sole writing credit. Obviously, it would be retitled one last time. Penfold was then given the role of Story Consultant for the series (and being charged with bringing in new writers), while American writer Edward Di Lorenzo alternated with Irish writer/poet Johnny Byrne as script editor for the series until half-way through the production when di Lorenzo departed, leaving Byrne to take on the role full-time (always uncredited) for the remainder of the season.
The screen from a Panasonic TR-001 television (released in 1970) was used to make the handheld video communicators ('Commlocks').
This episode takes place from September 9 to September 13, 1999.