Solar plane crashes on test flight

? An unmanned plane that set an altitude record two years ago broke apart during a test flight Thursday and crashed into the Pacific Ocean, NASA officials said.

The remotely piloted, one-of-a-kind Helios Prototype crashed off Kauai within the testing area of the Navy’s Pacific Missile Range Facility at Barking Sands, the National Aeronautics and Space Administration said in a news release.

The $15 million, solar-electric, propeller-driven Helios had a wingspan of 247 feet and looked more like a flying wing than a conventional plane.

It reached an altitude of 96,500 feet during a 2001 flight from Barking Sands. The altitude, about 18 miles, was considered by NASA to be a record for a nonrocket-powered winged aircraft.

Helios crashed about a half-hour into Thursday’s flight, which was intended to test its fuel cell system.