PAYERNE, Switzerland – An experimental solar-powered plane completed its first 24-hour test flight successfully Thursday, proving that the aircraft can collect enough energy from the sun during the day to stay aloft all night. The test brings the Swiss-led project one step closer to its goal of circling the globe using only energy from the sun. Pilot Andre Borschberg eased the Solar Impulse out of the clear blue morning sky onto the runway at Payerne airfield about 30 miles (50 kilometers) southwest of the Swiss capital Bern at exactly 9 a.m. (0700 GMT; 3 a.m. EDT). Helpers rushed to stabilize the pioneering plane as it touched down, ensuring that its massive 207-foot (63-meter) wingspan didn't scrape the ground and topple the craft.