Do You Know What's Going on in China?

Pentagon says China has a fleet of balloons that have been spotted over India, Japan, Taiwan, many countries, and five continents. What kind of scientific research can these balloons conduct that's useful for the PLA? Can they glean information from these platforms that they can't get from satellites? Well, as a former senior intelligence officer, I'm always leery about revealing sensitive sources and methods; we didn't know about this program when I retired in 2020.