Solar powered aircraft. The Pathfinder solar- powered aircraft seen during a flight test in October 1993. Pathfinder is an unmanned all-wing aircraft, powered by eight electric motors driving propellers. The power comes from solar cells on the upper surface of the wing, and is supplemented by batteries. The wing span is 30 metres, and the aircraft weighs just 190 kg. It is hoped that Pathfinder will reach altitudes of up to 20 kilometres in future tests. With all power requirements being met by solar cells, a future version of the aircraft could loiter indefinitely performing surveillance missions.