'Spy in Space' by Alan Fennell

When Fireball XL9 takes over patrol from XL5, it comes under attack and is forced to make a crash landing back at Space City. Steve agrees to resume the remainder of XL9’s patrol, and heads for a space station to refuel and take on supplies. However, he and the rest of the XL5 crew are unaware that they have fallen into the same trap as the commander of XL9, a devious plan concocted by the notorious Mr. and Mrs. Space Spy – who plan to seize control of Fireball XL5 by holding Venus hostage…

Paul Maxwell (Colonel Steve Zodiac / XL9 Pilot), Sylvia Anderson ( Doctor Venus / Griselda Space Spy), David Graham (Professor Matt Matic / Lieutenant 90 / Boris Space Spy), John Bluthal (Commander Zero), Gerry Anderson (Robert the Robot)

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

TX (UK - ITV):
1st April 1963

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