Fenn wrote:
The series was revamped as "Space 1999" which was sort of a sequel. Entire episodes are on youtube. Wikipedia says - "UFO is a 1970 British science fiction television series about the ongoing covert efforts of a government defense organization to prevent an alien invasion of Earth. It was created by Gerry Anderson and Sylvia Anderson with Reg Hill, and produced by the Andersons and Lew Grade's Century 21 for Grade's ITC Entertainment company."
Yes I remember Space 1999
The concept has actually been around since the rather improvised cover-up at Roswell in 1947. Accounts of covert handling alien bodies gave rise to the conspiracy that the US government met with aliens etc...
But on the topic of NASA. For many years since the inception of the space race, NASA have been accused of covering up UFOs captured on their cameras. They have been strangely quiet on the subject until the last couple of years when this entry for UAPs suddenly (and weirdly) popped up on their FAQs.