Abstract: Although space colonization appears to belong to the world of science fiction, private corporations owned by Silicon Valley billionaires—and supported by the US state—have spent billions making it a reality. Analyses of space colonialism have sometimes viewed these projects as distinct from earthly histories of colonialism, instead locating them within traditions of libertarianism, neoliberalism or techno-utopianism. By reconstructing technology elites’ political visions for celestial settlements within literature on colonial-era corporations and property, this essay argues that the idea of outer space as an empty frontier relies on the same logic of territorialization which was used to justify terrestrial colonialism and indigenous dispossession. It further traces how the idea of “engineering territory” has inspired wider Silicon Valley political exit projects such as cyberspace, sea-steading and network states which, rather than creating spaces of anarchical freedom, are attempting to recreate the territorial state in new spaces.