Space: 1999 - Full Series Information, Trailer & IMDb Reviews
Watch Space: 1999 Season 2 Episode 22 online — it may be available on legal streaming platforms such as YouTube, Netflix, Prime Video, Hulu, Disney+, and others.
Space: 1999: Koenig explores a planet that was devastated by some sort of weapon that killed all the inhabitants but did not affect the plants or destroy any buildings. He discovers that there is life on one of the moons and when he goes to investigate, he crash lands, and realizes that the moon is a prison and the inmates don't know they have no one to go home to.