ASFO 2021–07–10

Gold, copper, value added, and the economy of Chile (with a digression into trains) ; the SpaceShip Two concept of operations, and Tim Pickens’ hybrid rocket motor ; the Karmann Line and the definition of “Outer Space” ― no, “explosive decompression” is not a thing spacemen have to worry about, unlike deep–sea divers ; and intellectual blind spots.