Building miniature brains may sound like a page out of a science fiction novel, but fact is indeed stranger than fiction. Researchers around the world grow brain organoids—3D miniature brains—to better understand brain development, aging, injury, and other disorders, as well as to test new treatment strategies. Some scientists take brain building to the next level by launching their brain organoids into outer space. In this episode, Iris Kulbatski from The Scientist spoke with Alysson Muotri, a University of California, San Diego professor and Stem Cell Program director to learn more about how microgravity affects the cellular and molecular biology of brain organoids and how these discoveries can improve human health.  The Scientist Speaks is a podcast produced by The Scientist’s Creative Services Team. Our podcast is by scientists and for scientists. Once a month, we bring you the stories behind news-worthy molecular biology research. This month’s episode is sponsored by ACROBiosystems and Molecular Devices.