The 1970 - 1971 television season was exciting for this then child: Gerry and Silvia Anderson's first live-action series, UFO, was the flagship.
The CTV (Canadian Television) network ran the series here in Canada, and the network's flagship station, CFTO, in Toronto, was where the dial turned to on our Zenith Colour television set. My parents watched, too. It was what we would now refer to as "appointment television".
UFO was what now would be considered to be very adult material for that time. For some reason the Brits were ahead of us in some departments on this side of the pond. They would not be afraid to address matters such as a death in the family, or family dysfunction (like a marriage falling apart). Wait a minute....it's called "UFO". There was the space stuff, of course, and the show's premise of a hostile alien force attacking us could be exciting, but the best episodes were not space-based -- believe it or not. "Sub-Smash", "A Question of Priorities", and "Confetti Check A-O.K." are standouts. (A few years ago I watched those three episodes, along with a few others, for the first time in decades, and was convinced.)
Unfortunately for the fans, UFO lasted just one season; totaling 26 stories.
Things went downhill after that for the Andersons as a husband and wife production team. Their later interstellar effort, Space: 1999 (1975 - 1977), was a big step down -- mainly in the characterization, acting, and scripting departments -- from what they had achieved with UFO.
I corrected the earlier version (from March 3rd of last year) where I stated: "Things went downhill after that for the Andersons; not only for their marriage, but their careers." While Gerry's own career did reach a low ebb after the let-down of Space: 1999, eventually he got back into the game. And Sylvia went on to work for HBO for three decades. The original posting gave the impression that their careers never recovered.