Made history, Thursday after flying around the clock on the sun’s energy alone by solar powered aircraft bringing the dream of perpetual flight a step closer.
The Solar Impulse aircraft known as HB-SIA is in the middle of its first 24-hour flight including a complete day/night cycle. The aircraft took off from its home airfield in Payerne, Switzerland, shortly before 7 a.m. local time on Wednesday (1 a.m. Eastern time). It will spend the day climbing to an altitude to nearly 28,000 feet (8,500 meters) while charging its batteries.
Just before sunset, pilot André Borschberg will decide whether or not to continue the flight through the night. Once darkness falls over the Swiss countryside, the aircraft will fly on battery power. If the night flight is attempted, Borschberg will very slowly descend to around 5,000 feet (1,500 meters) before making a dawn landing back at the home airfield in Payerne.
HB-SIA (its Swiss aircraft identifier) is a prototype design powered by four, 10-horsepower electric motors with a cruise speed of roughly 40 miles per hour (70 km/h). A total of 11,628 solar cells power the motors and charge polymer lithium batteries. With a wingspan of 208 feet (63.40 meters), the delicate aircraft rivals a jumbo jet in width, but only weighs 3,520 pounds (1,600 kilograms).