Many large-lecture introductory science courses for nonscience majors do not have a lab component and hence do not provide much opportunity for students to engage in the practice of science. I have developed a new instructional activity called Dorm Room Labs that enables students to conduct hands-on activities as homework (or dorm room work) to explore more deeply concepts covered in 100-level science courses. The labs focus on concepts relevant to many physical science courses and consist of no-cost or low-cost lab equipment or their smartphones, enabling their use in large-enrollment courses. Using qualitative research methods, I have found that these dorm room experiments have meaningful impact on the development of students' conceptual understanding of several important physics and space science topics. For example giving the students a magnet and compass (or using the student's own smartphone magnetometer) fosters the understanding of the structure of dipole magnetic fields. Dorm Room Labs help engage and motivate students to learn about the process and culture of science by having them "do" science.