Theory, why show was cancel.
Wow, when I first seen the TV show in the early 80's when I was a kid, I was so mesmerize if this could have been based on actual facts or incident that have occurred. This TV show was shortly played and aired on TV, it had me thinking why! I have the strangest feeling that why this show was made is maybe one day when the U.F.O. Phenomenon is finally revealed to the entire world (in other words, no doubts about the existence of extraterrestrial beings or intelligent civilizations that exist beyond the planet earth or our solar system) that officials will use this film and other U.F.O. related movies, TV shows, etc., to explain an event that had happen to the public, as a historical event. But anyway I think that the reason why this TV show was shortly cancel, is that some military official seen it on TV and realize it resemble closely to an incident that happen or something referencing to it. Then they (military officials) decided to yield their power or influences to the studio or executives to cancel the TV show (that's my theory). There will always be people who want to reveal the truth and there will be people as well to bury the truth.
If mankind is to head towards the stars, mankind should follow this African proverb: It takes a village to raise a child.