I think contrails controlling the weather is not true myself, BUT I think a program that the pilots don't even realize is to put out chemical contrails not for weather but to help burn up stuff falling in groups from orbit. I was just reading about all the stuff out there in orbit and its a gigantic amount of tiny stuff. Well what if the stuff that is heat resistant like really high temps like ceramic or titanium pieces needed a bit of fuel to burn before striking the ground then maybe sprinkling the upper sky with magnesium dust or something similar would make them burn hot and super fast. Hell I'm wondering why there isn't a robot craft with the sole purpose of collecting this stuff and then releasing it toward the earth with a precision system so it lands in empty area's of land or sea for either collecting the rare earths or super rares and clearing up the orbital area. There must be some way like using static or magnitism to attract stuff and some super sensitive radar or even optics to find and collect and to also move the craft when a small part is head in at high speed. This could pay for itself and make it big enough to just push bigger pieces toward earth or out of orbit toward the sun.