'Space Immigrants' by Anthony Marriott

Venus and an engineer named Jock are aboard the Mayflower III en route to Earth II, a planet about to be terraformed; until Earth II can be made suitable for colonisation, everyone visiting it must take oxygen pills to survive in its thin atmosphere. 332 light years away from Earth, two small, evil Lillispatians named Minodor and Minotran capture the pilot of Fireball XL7, Ken Ross, who is assessing Earth II; the aliens then send a message to Robert instructing him to destroy all supplies of oxygen pills. When Jock falls ill from appendicitis and needs an urgent operation, Venus and the others are unaware that their robot friend has destroyed all the drugs in the medicine cabinet. Meanwhile, Minodor and Minotran plan a deadly reception for them on Earth II…

Paul Maxwell (Colonel Steve Zodiac), Sylvia Anderson (Doctor Venus), David Graham (Professor Matt Matic / Lieutenant 90 / Zoony the Lazoon / Minodor), John Bluthal (Commander Zero / Jock Campbell / Minotran / Captain Ross), Gerry Anderson (Robert the Robot)

Directed by Alan Pattillo
Produced by Gerry Anderson
Associate Producer Reg Hill

TX (UK - ITV):
15th April 1963

Notes:
*Featuring Colonel Steve Zodiac, Venus, Professor Matt Matic, Commander Zero, Lieutenant 90 and Robert the Robot