There has been considerable interest in images of medicine in popular science fiction and in representations of doctors in television fiction. Surprisingly little attention has been paid to doctors administering space medicine in science fiction. This article redresses this gap. We analyse the evolving figure of 'the doctor' in different popular science fiction television series. Building upon debates within Medical Sociology, Cultural Studies and Media Studies we argue that the figure of 'the doctor' is discursively deployed to act as the moral compass at the centre of the programme narrative. Our analysis highlights that the qualities, norms and ethics represented by doctors in space (ships) are intertwined with issues of gender equality, speciesism and posthuman ethics. We explore the signifying practices and political articulations that are played out through these cultural imaginaries. For example, the ways in which 'the simple country doctor' is deployed to help establish hegemonic formations concerning potentially destabilising technoscientific futures involving alternative sexualities, or military dystopia. Doctors mostly function to provide the ethical point of narrative stability within a world in flux, referencing a nostalgia for the traditional, attentive, humanistic family physician. The science fiction doctor facilitates the personalisation of technological change and thus becomes a useful conduit through which societal fears and anxieties concerning medicine, bioethics and morality in a 'post 9/11' world can be expressed and explored.