Helios, a solar-powered aircraft developed by NASA's Dryden Flight Research Center in Edwards, Calif., and AeroVironment Inc. of Monrovia, Calif., has broken the world record for altitude of a nonrocket-powered aircraft, reaching more than 96,500 feet on Aug. 13. The previous record holder was a Lockheed SR-71 Blackbird strategic reconnaissance aircraft, which flew to an altitude of 85,069 feet in 1976.More than 62,000 bifacial solar cells from SunPower Corp. of Sunnyvale, Calif., cover Helios' 247-foot wingspan, providing approximately 35 kW for the plane's 14 propellers. The remote-controlled craft may find application as a low-cost replacement for communications satellites or as a flying probe to explore Mars.