In the early 1960s, international astronomy was about to take off in Chile. This essay examines Jürgen Stock’s expedition, which led the first site testings to develop the United States’ plan of building an astronomical observatory in the Southern Hemisphere. By addressing the experience of technological settling in Latin America, specifically in a semidesert area in northern Chile, it is possible to observe the convergence of high technology, animals, scientists, and local actors. In this way, stars, mules, and interferometers represent a multifactor history of technology and its intersections with environmental history.