Several of the cyrogenic cells are empty, but there are no slime trails leading to them. With space at a premium it doesn't make sense to have empty cells, but the lack of slime trails means the Wirrn didn't take the bodies either. So where'd they go?
Why is the table screwed down to the floor? None of the other furniture is. Plus as the Doctor and Harry start to move the table there's no mounting in the floor where the screw was.
In the human-preservation chamber there are at least two levels of cells, but there are no ladders. How do the people get down when they wake up?
Given how readily the Doctor used his sonic screwdriver as a thermal lance in the previous episode, and how readily it went through reinforced metal, why doesn't he cut a quick hole here to get some air?
The space station noticeably "wobbles" as it orbits above Earth in the opening shot.
When they enter the cyrogenic chamber, the Doctor and Harry take forever to see the slime trail which is clearly visible to the audience from the start of the scene.
Not necessarily a goof, but you can see Sarah's knickers.
Look closely and you can see one of the cryogenically-frozen humans blinking, behind Harry as he is saying, "Doctor, are you serious? The entire human race?"
Sarah: Where are we?
The Doctor: I have no idea.
Sarah: A little trip to the Moon, you said, just to prove to Harry –
The Doctor: Well, I didn't expect him to start messing about with the helmic regulator!
The Doctor: Pity about the scarf. Madame Nostradamus made it for me. A witty little knitter.
Harry: Well, when you've seen one corpse, you've seen them all.
Doctor: There must be a remote control... You haven't touched anything, have you, Harry?
Doctor: Well, there are only two of us here and your name is "Harry."
The Doctor: You're improving, Harry.
Harry: Am I really?
The Doctor: Yes, your mind is beginning to work. It's entirely due to my influence, of course – you mustn't take any credit.
The Doctor: Homo sapiens. What an inventive, invincible species. It's only a few million years since they crawled up out of the mud and learned to walk. Puny, defenceless bipeds. They've survived flood, famine, and plague. They've survived cosmic wars and holocausts. And now, here they are, out among the stars, waiting to begin a new life. Ready to outsit eternity. They're indomitable… indomitable.
DVD: Doctor Who: The Ark in Space (BBCDVD 1097) released in April 2002. Released in U.S.A./Canada (Warner Home Video E1162) in August 2002.
Video: Doctor Who: The Ark in Space (BBCV 4244) (omnibus format) released in June 1989. Released in U.S.A./Canada (Warner Home Video E1162) in April 1991. Re-released in episodic format (BBCV 5218) in February 1994.
Novelisation: Doctor Who and the Ark in Space by Ian Marter (ISBN 0 426 11631 3) first published by Wyndham Publications in 1977.
This serial (and The Sontaran Experiment) were replacements for Space Station, a six-parter by Trevor Langley.
During the original broadcast the producer tinted the opening credits pink and green. The change was not well-received and they removed the tinting for subsequent repeats and syndication.
When this story was released on DVD in April 2002, it included new CGI footage to replace the model work of the station and the transport ship. The story can be watched with these new effects replacing the model shots, or as originally presented.
John Lucarotti does not receive an on-screen credit for his work. He submitted a script for the show that was deemed unacceptable and script editor Robert Holmes had to rewrite it.
This is the first episode to feature only the regular cast on-screen (ignoring voice-only actors) since Season 1's The Brink of Disaster.
The first in a series of linked stories that concludes with Terror of the Zygons.