Juan's 'THAT' is a term used to refer to the Spanish language acronyms ESO and ESA. ESO stands for Estación Espacial de Observación, which translates to Space Observation Station in English. ESA stands for Estación de Servicio Automático, which translates to Automatic Service Station in English. These acronyms are commonly used in Spanish-speaking countries to refer to the two types of space stations THAT exist in the world.