This month, a collaboration between NASA and various research institutions pinpointed a “central biological hub” that controls health during space travel. The culprit is the cell’s energy factory, the mitochondria, which breaks down in function in a way eerily similar to aging. Like shutting down power and water in a city, disruptions to the mitochondria reverberate throughout the cells and organs, potentially leading to problems with sleeping, the immune system, and more in space. The results were [published in *Cell](https://www.cell.com/cell/fulltext/S0092-8674(20)31461-6).*