NASA Solar Airplane Helios
Helios is a solar airplane by NASA, used for scientific research. Helios is a solar UAV with top speed of 27 mph and wingspan of 247 feet. Its wingspan is wider then Jumbo 747 jet. It has 62,000 solar cells and 14 brushless direct-current electric motors.
Prior to its loss in an in-flight mishap in June 2003, the Helios Prototype set a world altitude record for propeller-driven aircraft of almost 97,000 feet.