Colony in Space is the fourth serial of the eighth season of the British science fiction television series Doctor Who, which was first broadcast in six weekly parts on BBC1 from 10 April to 15 May 1971.
Script editor Terrance Dicks has frequently stated that he disliked the original premise of the Doctor being trapped on Earth, and had meant to subvert this plan as soon as he felt he could get away with it.
He recalls in a DVD documentary interview (on the Inferno release) having had it pointed out to him by Malcolm Hulke that the format limited the stories to merely two types: alien invasion and mad scientist.
[1] However, she was replaced by Tony Caunter when the BBC's Head of Drama Serials made an intervention and decided the role was inappropriate for a woman to perform.
[2] The story, by former Communist Party of Great Britain member Malcolm Hulke, has been described as "unashamedly left wing", with the pioneering colonists and the greedy IMC.
[4] 16mm colour film trims of location sequences for the story still exist and short clips from this material was used in the BBC TV special Doctor Who: Thirty Years in the TARDIS (1993).
Paul Cornell, Martin Day, and Keith Topping gave the serial a mixed review in The Discontinuity Guide (1995), writing, "Well meaning, and much more interesting before the Master arrives, at which point it turns from a Hulke political parable into a typical runaround.
[4] In 2009, Radio Times reviewer Patrick Mulkern described the story as "richly detailed, fast-moving drama that rolls out eventfully over a six-week period", which made it "indigestible" to watch all at once.
[8] DVD Talk's John Sinnott rated Colony in Space three out of five stars, describing it as "a decent adventure" with minuses that outweighed the pluses.
He noted that the six-episode structure allowed for padding and repeated scenes, but it had "a lot of interesting aspects", such as the Time Lords sending the Doctor, the way the story was constructed, and Pertwee and Delgado's chemistry.
There is another extensive Malcolm Hulke prologue as an elderly Time Lord describes the Doctor-Master rivalry to his assistant and learns of the theft of the Doomsday Weapon files.