Earth is clearly discernible. The air is so thin–only 1.4 percent of the density at sea level–it is incapable of supporting life. It is also incapable of supporting sustained horizontal flight of an ...

The unmanned Helios solar-powered aircraft prototype reached the record-setting altitude of 96,500 feet in a 17-hour flight from the Hawaiian island of Kauai. The flight, according to backers of the ...

NASA’s unmanned Helios aircraft came down in the Pacific Ocean off Kaua’i, Hawaii during its second flight from Pacific Missile Range Facility (PMRF) today. No firm cause is yet known although a power ...

NASA's Helios prototype solar-electric remotely piloted aircraft crashed during a checkout flight from the Pacific Missile Range Facility (PMRF) on Kauai, Hawaii, on 26 June. The flying-wing aircraft ...