In 2018, Qantas introduced the first nonstop link between Europe and Australia. Clocking in at 17 hours, an extended flight like this is possible only because airplane makers such as Boeing and Airbus have spent decades on innovations, including fuel-friendly wing shapes and stronger, lighter materials. But keeping a plane in the air all day is useless if you can't keep customers happy in cramped, sterile cabins for the duration. Plans include wider seats, lights that reprogram circadian rhythms, and cabin air that's more pleasant to breathe. Also, they might finally speed up the Wi-Fi. But they'd better hurry: Qantas plans to schedule 22-hour flights by 2022.