Planetariums disseminate astrophysics, space technology and planetary science to the public. These subject areas are often perceived as being ‘hard science’ and thus symbolically associated with the masculine. To what extent is this gendering also present within planetarium exhibitions? We address this question with a three-fold conceptual framework combining theories on the implied visitor, gender, and science exhibitions, respectively. We analyse to what extent gendered structures are embodied within the exhibition Space Mission. We find that the dominant discourse within the exhibition is one that presents science as technical, fact-based, and individualist, organised through competitive and game-like activities. We argue that these characteristics are associated with masculinity, thereby reproducing the discourse of astrophysics as being within the masculine domain and potentially excluding a large diversity of visitors. We offer some hypotheses about the origin of this gendering and discuss its implications.