Battery safety is of paramount importance in space, where the risk of thermal runaway looms large. This dangerous reaction, characterized by a continuous escalation of temperatures within the battery, can potentially lead to a fire or explosion. For two decades, Judy Jeevarajan was the NASA engineer in charge of testing. Thanks to that experience, batteries for everything from industrial equipment to home appliances are tested using methods she originally developed for spaceflight. Jeevarajan began working at NASA’s Johnson Space Center in Houston in the 1990s, developing advanced battery test…