The NASA RealWorld-InWorld Engineering Design Challenge was a STEM competition that invited middle and high school students to tackle authentic NASA-inspired engineering problems. In the **RealWorld** phase, students worked individually or in teams with a teacher/mentor to research a current NASA mission-related challenge (such as lunar exploration, space habitats, or engineering systems) and develop proposed solutions. Successful teams advanced to the **InWorld** phase, where they collaborated in an online, virtual environment to refine and present their designs to experts. The program was primarily aimed at U.S. secondary students and their educators, emphasizing inquiry-based learning, problem-solving, and communication skills. Participants benefitted from exposure to real engineering practices, mentoring from STEM professionals, and experience presenting technical work to judges. The challenge has since been discontinued, but its materials and structure remain a useful model for project-based engineering and space science activities in the classroom.