To facilitate identity exploration and career interest among underrepresented racial and gender minorities, a week-long Science, Technology, Engineering, and Mathematics (STEM) summer camp was designed in alignment with Projective Reflection's (PR) theory of identity exploration and Next Generation Science Standards (NGSS). The camp included the choice between three different space themed STEM tracks: astroengineering, astrophysics, and astrobiology which embedded project-based pedagogy with collaborative, hands-on experiences that immersed the students into STEM roles. Eighteen middle school students' data including surveys, focus group interviews, observation notes, student journals, and artifacts were collected and analyzed using a concurrent mixed-methods design. The data was organized and analyzed in three time points "starting self", "exploring possible selves" and "new self" using the four constructs of PR. The results showed no significant change in the survey due to the small sample size but meaningful mean changes in constructs of PR which were further supported by qualitative findings. The qualitative findings were also in line with previous research in which the interest is a mediator in developing identities toward STEM careers. The type of activities and the design features of the curriculum were also shown to be effective in developing integrated identity exploration.