Space: 1999 
The crew of Moonbase Alpha must struggle to survive when a massive explosion throws the Moon from orbit into deep space.
Space: 1999: Death's Other Dominion Rewatch Season 1, Episode 14
Back after another long break, and given the lack of any inter-episode continuity within most of Season One I'm jumping ahead to 'Death's Other Dominion', featuring BRIAN BLESSED. (Also, lots and lots of Shakespearean thesping, and one of the series' more memorable denouements.) [more inside]
Space: 1999: Missing Link Rewatch Season 1, Episode 7
Injured in an Eagle crash, Koenig lies in medlab, unresponsive to Dr Russell's efforts to revive him. At the same time he finds himself on an alien world, subjected to illusions created by alien scientist Raan (Peter Cushing) as part of an anthropological experiment upon him - an experiment that treats him as a 'missing link' to the early history of Raan's race. [more inside]
Space: 1999: Another Time, Another Place Rewatch Season 1, Episode 6
The Moon encounters another negative space wedgie; as well as transporting it a vast distance, it causes the Alphans to briefly perceive doubles of themselves. Main Mission operative Regina Kesslann is far more seriously affected though; when she awakes in the medlab she seems convinced that she is living on a planet colonised by the Alphans, that she was married to Alan Carter - and that Carter and Commander Koenig are long dead. [more inside]
Space: 1999: Earthbound Rewatch Season 1, Episode 5
Tiresome bureaucrat Commissioner Simmonds was stranded on Moonbase Alpha along with the rest of its personnel at the end of 'Breakaway'. The arrival of an Earthbound alien spacecraft – captained by Christopher Lee, the first of many big-name guest stars on Space: 1999 – offers an opportunity for someone to return home, and Simmonds isn't inclined to leave it to the Main Computer to decide who. [more inside]
Space: 1999: Ring Around the Moon Rewatch Season 1, Episode 4
A mysterious sphere of energy appears near the Moon, taking over an Alpha technician and using him as a conduit to access the Main Computer. The strain kills him - but the alien force has another Alphan lined up to take his place - Dr Helena Russell. [more inside]
Space: 1999: Black Sun Rewatch Season 1, Episode 3
The Moon is approaching a giant gravitational vortex. Professor Bergman's modification of Moonbase Alpha's gravity generator system to provide a shield may provide a slim hope of survival, but Cdr Koenig has a plan to give some of the Alphans an alternative, if equally risky, escape plan. [more inside]
Space: 1999: Matter of Life and Death Rewatch Season 1, Episode 2
(Note: I'm going by the production order of episodes, which is also the order on currently available DVD or Blu-ray, rather than the rather random order in which they were first shown.)
The Moon approaches an apparently habitable planet. Have the crew of Moonbase Alpha found a home? But when the first reconnaissance Eagle lands the crew are unconscious - and although only two of them went out, there is now a third person aboard. A person very familiar to one of Alpha's senior staff... [more inside]
Space: 1999: Breakaway Rewatch Season 1, Episode 1
September 13th, 1999. John Koenig, just appointed as Commander of Moonbase Alpha, is having a bad day. If it wasn't bad enough dealing with a mysterious illness spreading through his flight crew and an annoying boss who's flown from Earth to micro-manage him, the nuclear waste dump is starting to misbehave... [more inside]