As the Summer Olympics in Beijing kicks off this week, the event is giving scientists a once-in-a-lifetime opportunity to observe how the atmosphere responds when a heavily populated region substantially curbs everyday industrial emissions. The National Science Foundation (NSF)-funded "Cheju ABC Plume-Monsoon Experiment" (CAPMEX) will include a series of flights by specially equipped unmanned aircraft known as autonomous unmanned aerial vehicles (AUAVs).