Gerry and Sylvia Anderson were famous for Brit Sci/Fi puppet stories in the 1960s. Many of these were known as Stingray, Thunderbirds, Captain Scarlet and Joe 90. Between 1969 and 1970, they broke the mold and decided to use real people. This started with a new tv show called UFO. It was very exciting at the time and although dated now; the cheesy and sexy way the program was presented still entertains today.
The lead actor was an American called Ed Bishop. He plays the Commander of operations and his character name is Ed Straker. The actor, Ed Bishop, also did the voice for Captain Blue in the puppet Sci/Fi, Captain Scarlet.
There are a host of other regular actors too, including George Sewell as Colonel Freeman, Paul Billington as Foster, Gabrella Drake as the Moon base operative and Peter Gordeno as the Sky craft pilot - the vessel that is launched out of water from a submarine.
This 1970's series is set in the future of 1980. Therefore, the viewer is looking at the show from a retro 1969/1970 perspective. The Earth is being raided by humanoid alien beings intent on stealing body organ parts because the wretched visitors from space are in the advance stages of sterility. They are desperately trying to stay alive by harvesting new body parts.
The world has set up an organisation to secretly defend mankind against such raids. This secret army is called SHADO: Security Headquarters Alien Defence Organisation.
Unbeknown to the rest of the world, and to avoid mass panic, SHADO fights a secret war against the alien raiders each week, as a UFO tries to penetrate Earth's defence force and go plundering for reluctant and unsuspecting organ donors.
It was all good clean fun with aliens that still retained a scary anonymity, despite us knowing they are humanoid. Every time SHADO managed to catch one, the off worlder was usually dead or just short of it. Much of the knowledge acquired on the aliens came from autopsy. They breath green oxygenated liquid because of faster then light space travel and when exposed to Earth air, they would rapidly age and die. Also their skin complexion has a green stain from the liquid they have been immersed in.