UFOs: Past, Present, and Future is was re-released in 1976 and 1979 under the title UFOs: It Has Begun to coincide with renewed interest in the subject due to the release of Steven Spielberg's Close Encounters of the Third Kind.
Speaking in the film Mirage Men, producer Robert Emenegger claims he was approached in 1971, by a purportedly official source, to create a documentary using only Department of Defence or NASA footage. He was allegedly promised footage of a 1964 landing at Holloman AFB. Supposedly, a few seconds of this film is featured in UFOs: Past, Present, and Future.