While some people claim museum theatre is a powerful tool that can affect visitors’ attitudes and inspire learning, others continue to question if its role is education, entertainment, or some combination of the two. In light of these mixed perceptions of museum theatre, there is ongoing demand for evidence that these shows promote meaningful learning. One method for measuring outcome achievement in these nontraditional theatre settings is embedded assessment (i.e., unobtrusive instruments integrated into the experience being evaluated). This article presents a case study of using embedded assessment to measure the stability of audience understanding of three key concepts from a science show. During Lunch in Space, the project team developed a strategy where the audience took on the role of food scientists and completed a paper and pencil “menu” by selecting good foods to send into space. Results suggest that this is a stable strategy for measuring short-term learning from this type of program. Three key insights learned for embedded assessment with museum theatre include: 1) creating a role for the audience; 2) refining the assessment through rapid iteration; 3) and designing assessments with a universal design approach, simple, easy-to-understand instructions, limited text, and clear visuals.