A lighter-than-air aircraft includes a gas envelope for containing a buoyant gas, and a solar panel is carried by a predetermined portion of the gas envelope. A solar sensor is used for determining a direction of the sun. A propulsion system carried by the gas envelope orients the gas envelope so that the solar panel is oriented in the direction of the sun based upon the solar sensor. A navigation controller cooperates with the propulsion system to move the lighter-than-air aircraft along a desired flight path while the solar panel is oriented in the direction of the sun.