
Titusville, Florida—the ideal spot for launching spacecraft in the United States just happens to lie right in the middle of a region known as Lightning Alley. Even when the air over Florida’s Cape Canaveral—home to the Kennedy Space Center (KSC)—is free of storms, electrical conditions can cancel a liftoff. Flight controllers dare not send a rocket into a charged blue sky, where the craft might act as a giant, flying lightning rod. And before liftoff, an ill-timed bolt could easily scuttle a mission. “If lightning strikes near a vehicle being readied on the launchpad, we might have to retest every system to see if induced currents have caused damage,” says Frank Merceret, research director of the space center’s weather office. “We might even have to roll the space shuttle back into the Vehicle Assembly Building.”
For all these reasons, Merceret eagerly welcomes the visit of two veteran researchers from the University of Mississippi, Tom Marshall and Maribeth Stolzenburg, whose ongoing project here seeks to explore fundamental lightning physics. Marshall says, “There’s no lab analog for lightning.” This is why his team has packed two van-loads of equipment for deployment here at the peak of summer’s thunderstorm activity. Lightning is all too well-known for the way it conducts a potent rush of charge from agitated storm clouds down to ground level, but despite decades of research, the most important details of the dynamic still defy description. No one knows exactly how strokes begin—or “initiate” in lightning parlance—nor is it understood how they propagate within a cloud or from one cloud to another, or trace their jagged, stepped paths through the air from cloud to ground.
Marshall and Stolzenburg hope to capture the entire life cycle of a lightning flash by linking their custom-designed detectors to four other types of sensors, three of which are already permanent fixtures of KSC’s lightning-warning system. Each type of sensor detects a different electromagnetic frequency, tuning in to a specific phase of the lightning stroke. Combining the inputs from all the sensors on microsecond timescales—something that has never been done before—will allow the researchers to capture a stroke as it ignites, accelerates, and moves charge...
Image: Lightning makes a two-pronged touchdown from a cloud over Mobile, Alabama. The complex dynamics of such bolts are poorly understood.Sean Kauffman/Getty Images