We previously covered the Zephyr Solar Powered UAV on PyroElectro and it's back already. Just this sunday the UAV flew nonstop for 83 hours and 37 minutes. It used rechargeable batteries for flight during the night. Both articles are linked below.
PyroFactor:
September 20th, 2008 at 10:37 am
83 hours and 37 minutes….sounds amazing! Do you know the weight of the Zephy?