What makes us uniquely human? One of the most influential characteristics of modern humans is our sophisticated brains. Surprisingly, it is extremely difficult to study the human brain; it develops in utero and then is protected by the skull. What if we could re-create the brains of live people in the lab? Here, we will explore how scientists generate brain organoids from stem cells and use them to study diseases, consciousness, and brain evolution. Moreover, brain organoids at the International Space Station are teaching us about aging and will help with interplanetary exploration.