Spearhead from Space: Episode 1

Because of a BBC strike, this story was shot entirely on location with no studio scenes. This made it the first Doctor Who (1963) serial to be made entirely on location and the only serial that was ever made entirely on film. The serial came close to the brink of being canceled after the first week of filming, but producer Derrick Sherwin persuaded the BBC to complete it on location. As a result, this serial was shot in about six weeks between September and November 1969 rather like a low-budget movie. Director Derek Martinus said Sherwin was "a very energetic and determined bloke. He had a tremendous fight to get the go-ahead, but he did and for a while, we all had this wonderful fantasy of doing Doctor Who all on film and selling it to America."

Liz Shaw states that most meteorites don't reach the Earth's surface. However, by definition, all "meteorites" reach the surface of the Earth. She should have said "meteors" instead. The Brigadier makes the same mistake, but she is supposed to have an advanced degree in physics.