It appeared sporadically from 1975 to 1979, a few episodes on Monday nights, then off for two months, then advertised in TV Guide on Tuesday but actually airing on Wednesday, so it was hard to see, or get any idea of what was going on.
I did like the intro, which featured a lot of British people in futuristic costumes looking solemn or scared and being thrown across rooms.
Apparently it was a sequel, of sorts, to the British sci-fi UFO, which was about fighting aliens from a base on the moon. On the far-future date of September 13, 1999, a massive thermonuclear explosion wrests the moon out of orbit and sends it careening into deep space, the 311 staff members of Moonbase Alpha with it. They then encounter lots of civilizations ruled by giant computers or aliens with godlike powers, a la Star Trek.
There were several attractive crew members, especially in the most revealing uniforms I have ever seen on tv, but the standout star was Nick Tate as chief pilot Alan Carter (top photo). Most scripts found some reason to get him out of his clothes.
I think this is Tony Anholt (Tony Veredichi), Chief of Security, who apparently got his clothes ripped off a lot, too.
Bodybuilder John Hamill had a guest spot in 1978, but kept his clothes on.
There wasn't a lot of hetero-romance, far less than on Star Trek, where Kirk kissed a different alien babe in a different semi-nude outfit every week. I didn't see enough episodes to notice any particular buddy-bonding, but gay fans point to a love-hate homoromance between Alan and John (Martin Landau, center).