that we would fly in typically for trans continental nights, that's roughly 9,000 pounds. the weight of the solar impulse 2 is only 2,300 kilograms, significantly less. so you can imagine what that means in terms of any kind of wind and how that would impact this particular plane. so it actually have to wait for any kind of cross winds to be less than 4 knots or about 7 kilometers an hour in order for this aircraft to actually fly. and by the way, for the cockpit, where the pilots actually sit, if their insulation was to fail, they could experience temperatures in the range from 40 degrees celsius above 0 to negative 40 degrees celsius. unbelievable stuff. okay, they are starting in abu dhabi. quite a check to eastern china. but they still have a long way go. as they travel across the pacific which is the next long duration travel, the true test of this particular lane, they