“The Bomb”, Exterior Landscape, Refusis

On these albums

Doctor Who: The ArkPaul Erickson and Lesley Scott starring William Hartnell, Jackie Lane & Peter Purves · 2006Soundtrack

Doctor Who: The TV Episodes - Collection SixVarious Artists · 2013

Source: MusicBrainz recording a9785a43-c100-4afd-974e-ad10cbf8326c (CC0).