In 2021, Crystan McLymore was a nuclear surface warfare officer in the U.S. Navy, in charge of more than 30 mechanics maintaining the systems and safety of a nuclear reactor aboard the USS Gerald R. Ford aircraft carrier. Two years later, she is excelling in a completely different world, if possibly in service to those working on a nuclear ship. McLymore has just completed a master’s degree in mechanical engineering at MIT, after participating in research on an ingestible device that can detect radiation in the gastrointestinal (GI) tract. In…