Longest Duration Unmanned Flight
UK defence firm Qinetiq, which built the Zephyr unmanned aerial vehicle, said it flew for 54 hours during tests. aircraft was flown using its solar electrical power system through two complete diurnal cycles. Some interesting facts about Zephyr is it verylight weight plane (31kg/68lb) is launched by hand, can climb more than18,000m, it uses solar energy at night and rechargeable lithium-sulphur batteries at night.