The number of women and underrepresented individuals working in science, technology, engineering and mathematics (STEM) fields does not reflect the diversity of our societies. Even if children have an interest in STEM, they may not consider choosing a study or career in that direction if their perception is that they would not belong in science. This study examines the effects of a STEM lesson series aimed at inclusivity and diversity on children's perception and sense of belonging in space science. Before and after the lesson series, children filled out a questionnaire aimed at eliciting their perception of space science and space scientists. After the lessons, a subsample of children was interviewed about the effects of the lesson series on the children's perception and sense of belonging regarding space science. Six months after the last lesson took place, children from two classes filled out a short survey with open questions to measure retention. The results of this study showed that the lesson series had a significant impact on children's perception of space scientists, and that the implementation of the lessons facilitated thinking about (a future in) space science. This lesson series has succeeded in changing children's perception of space scientists as a diverse and international group of people.