The concept of using harvested energy to power an unmanned aircraft is not new. In fact, the first completely solar powered flight took place on November 4, 1974 when the Sunrise I unmanned aircraft flew over Camp Irwin, California, powered only by the solar cells. Intelligent Systems Associate Laboratory (LASI), UNINOVA-Instituto de Desenvolvimento de Novas Tecnologias, CTS—Centro de Tecnologia e Sistemas, COPELABS from the Lusófona University, 1749-024 Lisbon, Portugal Solar-electric propulsion offers a practical way to lengthen the endurance of small. The Navy flew a drone nonstop for over three days to test new long-endurance solar-powered autonomous aircraft technology in maritime intelligence, surveillance, and reconnaissance missions. The Navy flew a solar-powered, unmanned drone for 73 hours straight, recharging the plane's. This paper details our investigation of a battery-free fixed-wing UAV, built from cost-efective of-the-shelf components, that takes of, remains airborne, and lands safely using only solar energy. The study concludes with prognostications on the possibility for solar-powered UAVs of greater autonomy and efficiency an alternatives in numerous sectors, such as the aviation sector. PV Technology Breaking Grou nd Since the mid-20th. Our advances in solar cell technology enable unmanned aerial vehicles to stay aloft in the stratosphere for extended periods, using only sunlight as energy.