This dissertation investigates the relationship between American mass-media soundscapes and everyday experiences of scientific meaning and truth-value during the Space Race. Agitated by seismic social and political shifts, the years between 1957 and 1975 provide fertile ground for investigating slippages between environment, aesthetics, and social practice. I look at objects that seem imbued with the shifting spatial-temporalities of a nation whose self-ascribed spiritual calling to protect and revere nature met the rapid capitalist-technological innovations of the Space Age. Amidst technological acceleration, social revolutions, and science fiction lore from Roswell to Area 51, media sounds and stories came to embody an inability to reconcile the known and the unknown, the visible and the invisible, the present and the future. By tracing an emerging sonic vocabulary through various genres and media products, my dissertation illustrates how sound worlds inscribed the political fantasies of an unstable society craving the presumed stability of knowledge. My methodology incorporates approaches from anthropology and affect theory, which seek to draw out naturalized social patterns that have faded into the invisible background of everyday life. Seeking to understand how sound worlds—understood as both the sounds of the world and as composer-created “worlds of sound”—contribute to “worlding,” or the creation of the world through both creative and “rational” processes of community consensus. I take stock of a range of cultural products in order to look across different types of boundaries. My case studies follow narrative threads through the following research themes and topics: (1) satellite radio transmissions and sonically mediated scientific discourse; (2) sound and music as aids to empirical “truth” in acoustics pedagogy and popular science recordings; (3) the standardization of new electronic sounds popularized by radio drama, science fiction film, and space lounge music; and (4) musical representations of nature, the natural sciences, and technological development in oceanographic documentaries. In this way, a comparative study of media and bodies of scholarship are brought into conversation, through analysis of disparate genres. The inherently interdisciplinary nature of my project bears application to musicology, sound studies, cultural studies, film studies, and philosophies of science. Above all, I am interested in exploring how these products reflect and transform philosophies of what it means to be human during an era that has been described as the Anthropocene on one hand, and posthuman on the other. Following Donna Haraway’s cyborgian call to explore “transgressed boundaries, potent fusions, and dangerous possibilities,” I ask how dynamics of consensus formation in mid- to late-twentieth century American soundscapes have informed social perspectives in ways that prime listeners to mix science fiction and social reality. Like lieux de memoire, the audio media I analyze are at once archive and cultural memory—archive of a technological-aesthetic moment and memory that harbors the public continuities of history and the private discontinuities of recollection. In such a way does sound slip between being an index of lived reality and a signifier of imagined places, scientific possibilities, and utopia. By pursuing the subtle mystery of that slippage, I argue that the sonic explorations and experiences particular to this time and place imbricate the Romantic uncanny of the unknown with the certainty promised by positivism. Ultimately, I describe lineages of sound and music that serve various political agendas, asking how we can seek out, accumulate, and carry with us alternative epistemologies.