The following research project contains the translation into Spanish of the short story “Cosmic Yo-yo” by Ross Rocklynne, and the corresponding annotations, which consist of an analysis of all the informed decisions that were made when rendering this particular story. This specific analysis was performed through research regarding various translation techniques and approaches. The decision to work on this project was based on two different reasons: the first one is to improve skills as translators of science fiction by providing a translation that contains language and terminology that is imbedded in this particular literary genre; and the second one is to provide a rendering into Spanish of a work that has not been translated for the Spanish-speaking audience yet. The aforementioned analysis was done by developing one chart containing linguistic characteristics and extracts from the original and the translated versions in order to establish parallels and divergence between the two texts. Regarding the translated version, a description of what translation techniques and approaches were used has been added in order to provide recommendations for future translators interested in developing texts of this nature.