With the discovery of cosmic rays that constantly irradiate the earth, the protective role of the earth's atmosphere and magnetic field is now recognized as crucial preservation of biological life. If we move beyond the atmosphere to explore interstellar space, this protection is removed. In his talk, David Galbraith explores the sterilizing effects of cosmic radiation. We are left with the conclusion that preservation of our planet, Planet A, is the only recourse for the survival of humanity, and that "There is no Planet B". David Galbraith is a Ph.D Professor at the University of Arizona School of Plant Sciences, BIO5 Institute, Biomedical Engineering, and Institute of the Environment. Dr. Galbraith’s research and 2019 TEDxUofA talk focuses on the hazards and effects that an artificial space environment has on living bodies. Specifically, Dr.Galbraith’s interests include biological instrumentation, developmental and tissue-specific gene expression in eukaryotes, functional genomics and proteomics, and issues in biodiversity. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx