With a small blue crane, four researchers hoist a cylindrical fuel cell, which looks like a stack of flattened silver and gold soda cans bundled together, into the air and lower it into a rectangular cart on wheels. A tangle of tubes and wires spiral away from the system, where nearly 270 sensors and 1,000 components are nestled inside. “It’s a behemoth; it’s a researcher’s dream,” said Dr. Kerrigan Cain, lead engineer for the team at NASA’s Glenn Research Center in Cleveland preparing to test this technology, known as a regenerative fuel cell system, over the next few months. The system, about as long as a sedan and as tall as a person, operates like a rechargeable battery and could revolutionize the way NASA stores energy during future Moon missions through the Artemis program . When power is needed, it’s designed to combine hydrogen and oxygen gas into water, heat, and electricity, and then “recharge” by splitting the water back into hydrogen and oxygen — all on the lunar surface.…