What's the key to satellite communication?
It's tracking.
Low Earth orbit satellites enter and exit quickly, circling the globe in just an hour or two, "whoosh—" they zip right over your head. The low Earth orbit Reconnaissance Star that old Zhao and his team sent to the future is only 300 kilometers high and circles the Earth in an hour. Such high-speed travel poses the same challenge to Ban Xia—the little thing is too fast to track. If it's hard to track, it's hard to aim. If you can't aim the antenna at it, then it's difficult to receive data.
"When you guys communicate with satellites, how do you track their orbits?" Bai Yang asked.
