Grand Challenges (GCs) are multi-faceted issues that are shaping the world such as climate change and pandemics. Evidence suggests that students are interested in GCs and motivated to contribute solutions; this project creates opportunities situate GCs in middle school science. Project goals include: 1) Develop four GC units. 2) Collaborate with science teachers to enact and study GC units. 3) Conduct research on student outcomes and factors affecting feasibility and quality of GC-oriented learning.