BRUSSELS—Avoid typhoon in the Philippines. Check. Steer clear of massive California wildfires. Check. Keep away from test missiles in North Korea. What? Wait. As teenage pilot Zara Rutherford flew ever onward in a record-challenging global odyssey, she met little as strange or scary as when she tried to squeeze in between North Korean airspace and a massive cloud threatening to cut off passage for her ultralight plane. “Well, they test missiles once in a while without warning,” Rutherford said. More importantly, she was just 15 minutes from flying over one of the last places one should enter uninvited. So she radioed her control team to ask if she could cut the corner over the isolationist communist dictatorship to get to Seoul. “Straight away they said: ‘Whatever you do, do not go into North Korean airspace!’” Fortunately the clouds cooperated enough and she didn’t have to continue the crash course in …