An experimental airplane powered solely by energy from the sun stored in batteries took off from Arizona early on Thursday on the 11th leg of a historic bid by its pilots and developers to fly around the globe without a drop of fuel.
The single-seat Solar Impulse 2 departed Phoenix Goodyear Airport before dawn on an 18-hour flight scheduled to arrive at Tulsa International Airport in Oklahoma, 1,000 miles (1,609 km) to the east, at 11 p.m. local time (0400GMT).
The long hours required for covering relatively short distances is a condition of how slowly the plane flies compared with conventional aircraft.