re: Helios built by Aerovironment Inc. also has altitude record
Helios (Aug.13, 2001) -- record peak altitude (96,863 feet), highest-flying non-rocket-powered unpiloted aircraft in the world. Like Proteus it was also built for NASA's ERAST Program. Helios was destroyed June 26,2003 when it suddenly disintegrated while flying over the Pacific Ocean.