This study explored American high school students' perceptions of the benefits of a summer astronomy camp, emphasizing a full cycle of the research process and how the organization of the camp contributed to those perceptions. Semi-structured interviews with students and staff were used to elicit the specific benefits that campers perceived from their experiences and examine them in relation to the stated goals and strategies of camp staff. Among the perceived benefits that students described were peer relationships, personal autonomy, positive relationships with staff, and deepened science knowledge. These perceived benefits appear to influence the kinds of identities students constructed for themselves in relation to science. Gee's concept of "affinity space" is used to consider how features of the camp's design, especially those that promoted student autonomy, contributed to students' positive perceptions, and to draw implications for the design of informal science learning experiences that can link youth with larger communities of scientists. (Contains 3 tables.)